The Tiny Diamond

Minimums

My head is beginning the switch to go-around mode. I glance up at 100 above, and see nothing. No difference from 1000 above. If I don't see something soon . . .

Minimums. No contact. My hand is on the throttle, my eyes on the PFD. My wife says, I see lights. On the ground.

I glance up again, just for a peek. Two red runway end lights, just where they should be.

“I'm going back in.”

Earlier

The METARS for Champaign, IL (KCMI), our destination, have been between 200 and 500 overcast most of the day. KCMI has been a red dot (low IFR) on my iPad (I'm using the ForeFlight app), but near KCMI, in Indiana and Ohio, are numerous blue (marginal VFR) and even a few green (VFR) dots. The air mass below 10,000 feet is warm. It is +8°C on the ground and  +5°C here at 8000 feet. But that warm air has been moving in over cold ground, a recipe for fog. All day we have been cruising in the clear over a solid undercast. Here is the scene as we approach Top Of Descent:IMG_0774-001The setting sun is not helping the weather: the new ATIS (Automatic Terminal Information Service) gives the wind as 160° at 11 knots and the ceiling/visibility as 200 feet and 3/4 mile. The RVR (Runway Visual Range) on runway 32R is 5000 varying to 6000 feet. The approaches in use (in theory) are 14L and 22.

For reference, here is the airport diagram:

IMG_0168During the last hour Terre Haute, IN (KHUF) has emerged as the new, practical alternate. Now it's time to finalize the approach and missed approach plans before things get busy.

At 8000 feet the wind is strong out of the south-southwest, backing around to 160/11 on the surface. My plan is to do the GPS LPV to runway 14L, and then if I can't see enough to land, do an ILS to the other end, 32R. That would have the advantage MALSR (approach lights) and PAPI (visual approach slope lights), which would make the transition to visual flight a lot easier.

Here we go. I check in with Champaign approach with the ATIS. She says cheerfully, what would you like? I request direct ORANJ for the LPV 14L approach. I pronounce it like the French word, with the accent on the second syllable. That's my take on the J. Sure, she says. Cleared direct orange and cleared for the RNAV 14L approach.

IMG_0166A digression is in order here. My first introduction to glass in the cockpit was the B-767, which I flew in the early 1980's as a First Officer. Boeing's philosophy was to make a track up display, which had the advantage of making an IFR approach easy. Fly the airplane so the track arrow on the HSI (Horizontal Situation Indicator) points up. But what about heading? In the Boeing, as I recall, there was a pointed tuque (triangle atop a square) which represented heading, and was of course, like the airplane, sitting off to one side in a crosswind.

It seemed wrong to me. Heading is where the airplane is pointing, which is where I am pointing if I'm sitting straight in my seat. So I was pleasantly surprised when I transitioned to my next glass airplane, the A-320, in 1995. The Airbus has heading up displays. And (I suppose just because that's the way my head is wired) I found it even easier to fly than the B-767. I remember, In my first year on the airplane, being cleared while on downwind for an ILS 18 at Val D'Or, Quebec. Instead of a full approach with procedure turn (there is no radar up there – or least there wasn't in 1995), I vectored myself onto an intercept like a controller with radar would have done.

Nothing is perfect. The Airbus is so highly automated, its fly-by-wire so distant from normal airplane feedback (no trim feel), that I was, I later realized, losing skills as I vectored myself for that approach using the heading bug.

Today I am going to need all the skills I can muster. True, I have been working hard for more than two years to regain what I once had. And I have had expert help: Andrew Boyd at Smiths Falls, Ontario. But I am seventy years old and tonight I am tired. This is the third leg today, and I have been airborne six and a half hours. The Bonanza does not have an autopilot, so all the flying, including an ILS at Albany, NY and an RNAV LNAV+V at Marion, OH, has been by hand. In deciding whether to even try the approach, the airplane and equipment and regulatory limitations fade in importance. My own limitations have moved into first place.

But I have good equipment and I am thoroughly used to it. Here is my Primary Flight Display, an Aspen 1000 Pro.

IMG_0919-001As soon as we pass the RRRED intersection (The Initial Approach Fix; head of the “T” on the chart) the localizer and glide slope scales will appear on the top half of the display. These are the green diamonds you see above. My tired eyes, doing their instrument scan ever more rapidly as we move down the narrowing cone of the approach toward the runway, won't have to move very far. The display is more or less the size you see above, so within and inch of the tip of the airplane symbol (attitude) I have localizer, glideslope, airspeed, and altitude. Just below the localizer scale is a data space with TAS (true airspeed) GS (groundspeed) and wind (148°/16 kt on the display above). But there is a more important piece of information, arguably one of the most important: track.

In the old days we flew a precision approach by guesswork: we flew a heading and a rate of descent and noted, over time, what happened. If the localizer and glideslope stayed centred, we had made good guesses. But if, for example, the loc indicator (needle or diamond) has moved right of center, it means we have drifted left off the centerline. What we do not do is turn right until the needle centres again. That was the technique Bill B. used in his Tri-Pacer down in New Jersey in 1969. I remember him saying, that loc needle was like a #$%# windshield wiper!

No. What we are doing in our heads is say, that 155° heading was not enough. We have a crosswind from the right. We'll turn right to 165° to re-intercept, then turn back to 160° and see what that does. Our heads are remembering the effect over time of various headings, and deducing what heading it will take to track the localizer. We do the same with the glideslope, deducing what rate of descent it will take to keep the needle centred. As we get close to minimums, down at the pointy end of the cone of the approach, those heading changes will be two degrees or less, and any deviation will have to be corrected more quickly. In effect our brains are doing Calculus: noting change over time and rate of change, differentiating. That is a lot of work. A lot of intense, hard, rapid work. I'm not sure I'm up to it tonight.

But wait: I don't have to. Move your eyes down another inch on the display. Just below the heading (163°) is the green tip of the track arrow, representing the on-course line of the approach.

If you look carefully, you can see a small aqua diamond superimposed on the arrowhead. That's where it is supposed to be, because the diamond is the aircraft's track, the track made good over the ground, even though the airplane is flying a heading through the air and being blown sideways by the wind.

Where does this information come from? The GPS. The GPS is computing position about once per second. Then it uses the Calculus, that great mathematical technique invented by Newton and Leibniz, to differentiate the series of positions (dS/dt) and calculate velocity, a vector, which has both speed and direction. These are displayed on the Aspen PFD as groundspeed (GS) and track (where the diamond is on the compass rose).

Having track was what made the B-767 and the A-320 easy to fly on instruments. A computer is doing the calculation you would otherwise have to do continuously in your head. And the Aspen has my favourite, the heading up display. So my scan now goes something like this:

  • Attitude? Correct if not on target. Now, bypass loc and glideslope, because they will still be where they were two seconds ago – centred.
  • Track Diamond? Is it on the tip of the track arrow? If not, turn immediately to put it back on.
  • Note heading on the way back up. That's the heading that works, at least for the moment.
  • Loc and Glideslope still centred? Whew. Caught that one in time.

What is the logic here? First you have to be on the localizer. Then, you have to steer so that the aircraft track made good (the diamond) is the same as the localizer track (the green arrow). That way what's good will stay good, because two seconds or ten seconds from now the aircraft will have moved along the localizer, not drifted off. The Track will be the same as the Desired Track.

That is the centre of the scan, the part repeated every cycle, a second or two apart as you get near minimums. With that diamond where it is supposed to be you can add another parameter or two to each cycle of the scan: airspeed, altitude, glideslope trend.

Now my talking to myself will perhaps make some sense. I have briefed the approach and the missed approach, speaking aloud both to keep myself focused and to keep my wife (not a pilot but a tremendous help) in the loop. We have passed ORANJ.

OK, we're slow here on base leg. A direct headwind and almost forty knots. Yeah, we're in cloud already. Hardly noticed. Get that landing light off. And the strobe, too. Go dark. Temp's good: +8°C. Diamond on the needle. Seventeen inches. Hold 3000 and intercept from there. Got gear speed. A little slower: sixteen inches. Wind's starting to back: 200/35. Diamond on the needle. (I don't know why I called it the needle instead of the arrow, but I did).

Bonanza Quebec Romeo Victor, contact tower one two zero dezimal four.

Quebec Romeo Victor, 120.4. See ya.

Switch freqs. Leave Approach in the standby for the miss. Diamond on the needle. Level three. Two from RRRED.

Champaign Tower,  Bonanza Charlie Foxtrot Quebec Romeo Victor on the RNAV 14L.

Quebec Romeo Victor, cleared to land runway one four left.

That's it. Now work. Should be under the slope at three at RRRED. Diamond on the needle. Watch for the turn alert on the Garmin. There it is: 8 seconds. Won't get the slope 'till we pass. Speed's slow enough: catch it. Eighteen inches. Diamond on the needle. 2 seconds. Turn left to 135° NOW. Not too fast. Diamond to 135°, not heading. Steady. OK, to waypoint now GRANJ. That's the FAF. And there's the loc and glideslope scales. Diamond on the needle. Heading 155°. Glideslope alive. Stand by for the gear. Diamond on the needle. Diamond keeps drifting left. More right rudder. Remember, 155° heading works.

OK, gear down. Trim. Fifteen inches should work. Diamond on the needle, 155°. Sagging under. Sixteen and a half inches. Want 90 knots and 300-400 feet per minute. Green light and down on the tape. Glideslope's good. Try sixteen inches. Diamond on the needle. GUMP check. Gas, right tank.  Diamond on the needle. Trim and power good. Holding the slope. Undercarriage: green and tape.  Diamond on the needle. Mixture rich. Prop fine. Here comes GRANJ. 2700. Missed Approach 2600, set. Diamond on the needle. Wind's backing some more. 180/34. Diamond on the needle. Still need 155° heading. Trim and speed good. Attitude's plus 2 1/2°. Not going to see much tonight at that attitude. Flap 10°. Trim. Diamond on the needle. That's better: attitude zero. One thousand to go.

I say that passing 2000 feet MSL. In the briefing I have rehearsed what minimums will look like on the old round altimeter as well as putting the number, 960, into the MIN window on the Aspen. 960 is 1000, the top of the dial, twelve o'clock. Here at 2000 we're a thousand above. My work now is to keep the airplane in the cone, to make this approach as accurate as possible, because there will be no room for any maneuvering at all at minimums. It will be right on or go around.

I am working really hard, and I almost feel physical pain when I look down and see that tiny diamond has moved. I haul it back quick with sharp, ten-degree bank turns that last for a second or two. I probably should be steering with my feet, but I haven't practiced that and now is not the time. I am sweating.

Diamond on the needle. Wind 180/30. Heading maybe 154°. Ground wind's 160/11. Watch for the change. Five hundred to go. Diamond on the needle. Changing now. Heading 152°. Speed's good. Gonna have to taper off the power a bit after we lose the wind. Diamond on the needle. Follow the change. Wind 180/25. Good, the change is not too abrupt. Diamond on the needle. Assess: loc and slope good. Speed's up a bit, fifteen inches and that'll be it. Diamond on the needle. A hundred above. Sneak a peek. Nothing. Just like a thousand above. Hand on the throttle. You'll have to pin 10° nose-up on the missed approach. That's gonna take a good push at full power. Diamond on the needle. Hang on. Heading 150°.

 I hear the tiny ping from the Aspen as we arrive at minimums. Insulated by the noise-cancelling headset, it seems like it is coming from another planet. In my peripheral vision, there is nothing. Not even a glow. My wife says,

“I see lights! On the ground!”

I look up. There are two fuzzy runway end lights, right where they should be.

“I'm going back in.”

What I mean is that my eyes are going back in, to the Primary Flight Display. When I glanced outside, I saw enough to know that the runway environment was where it should be, but also to know for sure that I would have no cues about height and very little about alignment if my eyes stayed outside. In my 500 millisecond glance the red lights were blurry. Sure, my wife had seen lights on the ground, but that is looking more or less straight down. My red runway end lights were ahead, farther away because of the slant range. And the runway itself, even further away and at a shallower angle,  was invisible. That means there is no ceiling as such, merely a vertical visibility.

But the METAR had been between 1/2 mile and 3/4 mile visibility all afternoon, and the ATIS and the tower were saying 3/4 mile. Best of all, the RVR (admittedly on the far end of the runway, near the touchdown zone for 32R) was 6000 feet. So at ground level, at the far end of the runway, the visibility is more than a mile.

I decide to fly it down to 100 feet, if I can keep it locked on the localizer and glideslope. I know these are not radio aids, locally transmitting on VHF and UHF like real, legacy localizers and glideslopes. Instead they are calculated from a series of positions relative to the runway in three dimensions. But the worst case accuracy for a WAAS GPS is a spherical error of 7.6 meters (25 feet), and the demonstrated accuracy (by the NTSB) is 1.3 meters (4 feet). So with this GPS localizer and glideslope nailed, I have no worries about not landing on the runway.

Diamond on the needle. Pull slightly to correct that sag. Wings level. Diamond on the needle. Heading 145°.

I look out again. Rows of runway lights. I don't remember how many. The visibility is better. Not much better, but better. The runway centreline paint is now visible. I hold attitude and wind off the power, using the vernier control. One of my better landings, God knows why.

Bonanza Quebec Romeo Victor, um, are you down? We can't see you.

Yeah, we're rolling out.

We are down to taxi speed and passing the C1. The visibility is better at ground level. I switch on the upper landing light.

Oh, now we have you, Quebec Romeo Victor. Cleared across 22 and into the ramp via Bravo. Stay with me.

History, Rules, and Politics (not to mention the Bottom Line)

The girl behind the desk at FlightStar, the FBO, tells my wife we are the only airplane that has landed at Champaign since she started her shift at 2PM. (We landed just before six.) Our son picks us up, and he also has to pick up a colleague flying in from Chicago. We hang around the main terminal for awhile. The flight winds up cancelling. I begin to wonder if I should feel bad for landing.

I recently read a brief history of low visibility approach techniques. It was by Jack Desmarais in Position Report, the journal of RAPCAN, the retired airline pilots of Canada. I don't have it here so I'll summarize as best I can.

The military developed techniques such as the PMA (Pilot-Monitored Approach), where one pilot flew the approach and go-around on instruments, and the other pilot stayed heads up and took control and landed the aircraft if he had sufficient visual references. This system had the advantage that neither pilot had to transition, to go from instrument to visual flight. Successful approaches were made even in zero-zero conditions, especially after the development of heads up systems, where flight path information was projected onto the windshield, so the pilots' eyes did not have to move.

But the airlines and the manufacturers moved in a different direction: to autoflight and autoland. Dual and triple-redundant autopilot systems and radar altimeters enabled a progression from CAT II (100 feet) to CAT III (autoland). Of course there were limitations: RVR (visibility), wind (not too strong) and equipment (everything had to be working.) There were approach bans (can't go beyond the outer marker if the visibility is below x or y) and procedures (go around if x or y fails before this point or that point). There were so many rules you almost forgot you were pulling off this amazing stunt. And it wasn't you anyway, it was you watching autopilots. So what equipment did the commuter airliners have tonight? Autopilots, for sure. (The Bonanza does not have one). But do they have WAAS GPS and glass PFD's like the Bonanza does? I'm not sure.

The bottom line is that 32R is not a CAT III runway, and the wind was 160/11, making it on (or just above) the tailwind limit for most airliners. So for one reason or another, autoland was probably not on.

Then there is the economics of it. The airline flight we were waiting for was a turn out of Chicago. Would it make economic sense to send the airplane down to try an approach? Probably not.

Why me?

Reflecting later on the approach, the first thing that came to mind was that the ATIS was reporting 200-foot ceiling and 3/4 mile visibility – exactly the limits for the LPV approach on 14L. What could they see from the tower? Were they helping me out? Luring me in?

Neither, of course. As Pilot in Command, the decision to land is mine. If they were calling the weather zero-zero and I landed, they would have to report me. That's paperwork, and if I had a compelling case for my decision, the paperwork wouldn't go anywhere. And anyway, in this business, if it is done right, there is no room for gotcha's. There is room only for teamwork.

And teamwork is what I got. The controllers cleared me for the approach as requested, and the tower cleared me to land on first contact, and then kept radio silence and watched on their radar. I could concentrate when I needed to. They broke the silence only when we had slowed almost to taxi speed, to confirm we were on the runway. ATC gets 100% on that one.

So I have made peace with it. I made my decisions as Pilot in Command, and our colleagues in Air Traffic Control supported us all the way. The airlines and aircraft manufacturers made their decisions, too, betting everything on autoland. Sometimes the little guy can do the job by hand when they can't.

Old and tired as I was, though, I couldn't have done it without the tiny diamond. For the next couple of days, the song keeps repeating in my head:

Diamond on the needle,

Diamond on the needle,

Diamonds on the soles of her shoes.

Pace, Paul Simon.

 

P.S. Oh, and here is Arcadia in Hangar 9 at FlightStar, after her work was done for the day.

IMG_0777-001

 

Open Net Letter to Sir Richard Branson

Condolences

Dear Sir Richard,

I offer you my heartfelt condolences on your loss: a life, a spacecraft, money, and momentum. The life and the aircraft will be missed. The money and momentum can be made up. But as in every disaster, there is also opportunity.

I have been a pilot for nearly fifty years, and in my trade accidents are fodder: nearly always, there is something vital to be learned. The accumulation of this knowledge is what allows us to hone our skills and make our missions safer.

Spaceship Two awakes powerful echoes from the past. We have been here before and moved on.

Disclaimer

The following is fiction. I look to the net for facts: what I find there may or may not be true. Using what I find I make up a story. My hope is to get everyone thinking about the way forward while we wait for the NTSB. Please accept my offering as help, and as hope for the future for this very special project.

Test Flying

One pilot friend has given up test flying. Another still does it and has flown an amazing number of types. His preparation method is simple: know and prioritize the systems. Knowing means finding everything you can and studying, asking questions in a practical way. Prioritizing means asking the question, what is going to kill me first?

Often it is the fuel system. But Spaceship Two's rocket motor was designed to be simple. Sure, it's new, and could kill us, but is it first in line?

Look instead at the flight envelope: subsonic atmospheric flight as an airplane or glider. High Q, high G, supersonic flight as a rocket plane. Ballistic flight as a near-spaceship. Re-entry as a badminton bird. Subsonic glide to landing.

Then look at configuration. Airplanes have flap and gear speeds. Maneuvering speeds. Spaceship Two is a chameleon: an airplane/spaceship/shuttlecock. Combine flight envelope and configuration and you have a whole world of limitations.

The Flight

Our pilots have trained in the fixed-base simulator. The clever helmet G sim has added realism to the profile. They are ready for the high G during the acceleration and pullup after rocket ignition. They are confident in their ability to glide to a landing at Mojave after re-entry.

But the real thing is frightening. It is more than training can prepare you for. It is like going over Niagara Falls in a barrel. The discipline required to stay exactly with the aircraft is huge. It is like learning to fly instruments in IMC and turbulence, believing what the panel says and ignoring what the body says. Only it is magnified by several factors of ten.

Pilots know that their IQ is cut in half the moment they strap in, and in half again under fear or stress. They prepare carefully, rehearsing in their heads so the real thing will not freak them out.

Our co-pilot was overwhelmed. Somewhere in his consciousness was a fear of forgetting his tasks. His mind left the present and moved ahead, rehearsing. He knew that at some point he would have to unlock the tail feathers.

The pilot was hanging on to his awareness for dear life. His field of vision had narrowed to a tiny cone centred on the Flight Director. He didn't see the co-pilot's hand reaching for the unlock lever. But he hung on to that thread of awareness and understood the ship was breaking up around him. He managed, though injured, to undo his harness and get free of his seat.

Crew Co-ordination

I am reminded strongly of Air Canada 621 in June 1970. Not in the pilots' behavior: our Spaceship Two pilots were not arguing. They had a good understanding of the ship and her systems.

No, the echo has more to do with the novelty and design of the systems and configuration. The DC-8-63's spoiler system was an early one, imperfect in its ergonomic design. The line between arming and deploying was not as sharp as, say, the later system on the DC-9, where up was arm (for landing), and up, back, and up was ground spoiler deployment (for a rejected takeoff).

Spaceship Two's feather system is an excellent mechanical and aerodynamic design. The lock can hold the feathers in the airplane position even at high Q in a high G powered pullup.

But crew co-ordination and Standard Operating Procedures are just as important. Our pilot did not see the co-pilot's hand reaching for the unlock lever. There was no communication:

Ready for Feather Unlock.”

Our pilot had no opportunity to say:

Negative. Standby.”

or

Get your $#%* hand off that f#%# lever!

He just saw the result: the breakup of the ship from aerodynamic forces.

Moving On

Let's go flying again as soon as we can. But designers, remember: it's not your ass strapped to the machine. It's the test pilots'. And they have to understand the implications of any action at any point in the flight envelope.

No, you don't have to design software to limit when the feathers can be deployed. You have to keep the pilots in the loop, not take them out of it.

But communication is all. And respect for each others' work. Bernard Zeigler designed the Airbus to be “pilot proof” and “un-stallable”. We know what happened there.

Aware of the past, analyzing accidents, we are wiser. We will respect everyone and expect the best from everyone. We will prioritize and rehearse. We will use all available means to communicate and to share information, hopes, and doubts. There will be Standard Operating Procedures. There will be verbal calls followed to the letter to eliminate misunderstanding. And there will be the joy of success.

 

Yours sincerely,

 

Former Captain

 

p.s.

Sir Richard, how about – every once in a while – offering a seat on Virgin Galactic to a prominent climate change denier?

Countdown

Routine Stuff

Arcadia and I take off  a week tomorrow to fly Mission 2014. Suddenly there is more to do.

I have already planned each leg and filed the route and altitude with FltPlan.com. All that’s left to do there is click the file this box the night before, and perhaps adjust the departure time or the fuel. I have mapped out a rough schedule, but of course nature is more powerful than I am, so there may be adjustments to make. That makes hotels and rental cars more problematic. What I'll do is research names and phone numbers and reserve 24 hours or so ahead.

I still have to write and print the Flight Logs.

Flight Logs? For each flight leg there is a new 8 1/2 x 11 sheet on my clipboard. It has all the information I will need to fly the leg: filed route, leg distances and bearings, frequencies, and airport elevations, with spaces to write operating times, ETA's, and clearances. I don't want to have to dig or turn pages for any of that while flying in cloud with my left hand.

Then there are the lists: before departure tasks, aircraft equipment checklist, things to buy. It feels good when I can draw a line through something and the list gets a little smaller.

New Stuff

Then there's the new stuff – particularly the kids. I am looking forward to going to schools or having the kids come to the airport. I just bought the parts to make a gadget they can hold in their hands and experience how a gyroscope works. I figure they will remember the gadget more than they remember me or what I say, and perhaps the memory will make them curious to learn more.t

And of course I will have to account for myself if (as I hope) the media are curious. This is a new skill for me to learn. Why am I doing this? What do I hope to accomplish?

I want to be able to answer briefly and clearly, without babbling or droning on. Will I be able to?

Over the Falls

Linda, my dear wife of 46 years, gave me the answer the other night. She said, Hey, your on your way. You're going over the falls. Enjoy it!

Mission Statement

Today we take an airline’s schedule for granted. We are surprised when a large snowstorm forces flight cancellations or when a line of thunderstorms causes delays. We regard the pilot’s job as routine, and that is the case much of the time.

It was not always so. In the early days airplanes could not vault over the Rockies as if the snow and granite weren't there. They could not shrug ice off their heated wings. They could not follow programmed profiles in four dimensions. Pilots had to fly these airplanes.

Seventy-five years ago Canada's national airline flew its first “transcontinental” mission: Montreal to Vancouver via Ottawa, North Bay, Kapuskasing, Winnipeg, Regina, and Lethbridge. The aircraft was a Lockheed 10A. I don't have a 10A or the resources to fly it, but I do have a Beech Bonanza, a single-engine aircraft of similar performance. Her name is Arcadia, after the fictional airline in my novel. Together we are going to fly that route this year. Our mission is to do again what the pioneers did: fly through Canadian weather at low altitude, evaluating the real risk and flying when we can, flying by hand.

Why?

To remember and celebrate that achievement of 1939, yes. To observe and celebrate how far airline flying has come since then – yes, that too. But there is more. Between then and now is a story, a story that includes rough weather and anxious moments. These advances and adventures are not always smooth sailing. There is risk, danger, and hard work. That is where the real story lies.

Although much remains in official records and memoirs, in news stories and film, much of the history of Canada's airlines has been lost. Many of the early pioneers have passed on, taking their stories with them. We could use their perspective now, as we face the coming shortage of fuel and pilots. Once again, there is rough weather ahead.

Flying is like living. Planning and good judgement are essential for survival. But once you're off the ground or out of the childhood home, it is no longer a rehearsal. The red light is on. You're live to air. Flying has been my trade now for forty-five years, and that live to air quality is still what gets my juices going.

Since young hotshot are not words which apply to me (I turn seventy this year), I have to make sure I am well prepared for this mission. I will be flying IFR (Instrument Flight Rules) and sometimes in IMC (Instrument Meteorological Conditions) without an autopilot (the Bonanza does not have one) and without a co-pilot. That can get pretty busy. But I do have WAAS GPS, an electronic PFD, and an iPad. The GPS lets us navigate anywhere and do an IFR approach at most airports. On the electronic PFD (Aspen 1000 Pro) I can set cleared altitudes and approach minima, just like I used to do on the Airbus. On the iPad I have the app ForeFlight, which acts as my electronic flight bag (charts and approach plates for all of North America) my moving-map display, and my weather briefing service, among other things. It is hooked up to a GPS and to a satellite weather link.

For the last three years I have been training for this mission. Written exams. Instrument rating renewal. Re-introduction to flying light aircraft. Aerobatic instruction. Working steadily toward regaining my Class II Instructor rating after forty-some years. And practical experience, of course. I have flown the Bonanza between Montreal and California. By this summer, God willing, it will have been two round trips.

Flying experience is measured in hours and in recent hours. These are handy because they are statistical, but they are not the whole story. Experience does not necessarily lead to competence. More important are real learning and practice. You can't perform a maneuver you don't know about, and you can't do it well until you have practiced it.

I know this from my own experience. I retired from airline flying at age sixty and didn't “touch a pole” for six and a half years. When I decided to come back to flying my performance was far from an acceptable standard, even with my 18,000 hours. With a valid instrument rating and my ATR, I was “qualified” to teach instrument and multi-engine flying, but lacked the recency, confidence, and knowledge to do it well. I had to go back to school.

Old dogs are reluctant to see the need for new tricks. Breaking through my crusty assumptions to teach me is not a job for the faint of heart. I have been fortunate to find teachers who will challenge me and move me along, almost against my will.

This burst of learning is a fragile thing. Old age is gaining on me. I know how the race ends. But Arcadia and I plan to fly the mission this summer of 2014, re-enacting the flight of 1939. Much of the detail of that flight has been lost, but we will re-create it by living it. It will be its own story, but it will have much in common with the lost story of 1939 – enough, I hope, to bring that story to life and bestow honour where honour is due.

The Lost Apprentice

Despite our words of concern for education and training, our workforce is racing toward the cliff of incompetence. Even though innovation and specialization have brought us marvelous new tools, basic skills are vanishing, collateral damage from a squeeze on labour. How? In a word, the apprentice has gone missing.

One company (BMW in South Carolina), experiencing first-hand the dearth of skilled labour, has set up an apprenticeship system. But there is resistance. After all, from skilled labour flows empowered labour and unions. From there a slippery slope leads to socialism and communism. Or so goes political thought.

Yes, we are on a slope, but the destination is not an 'ism'. It is incompetence.

My trade is flying airplanes, so I'll stick to what I know. But look around in your own trade or profession and you may see examples of what I'm talking about. Are you passing on your knowledge? Are there barriers to doing so? Will the young people taking up your mantle be able to learn from your mistakes and those of your teachers? Or will they repeat those mistakes? Will they master the new tools that arrive, it seems, every day? Or will they hide behind them, shirking responsibility simply because they are afraid, deep in their gut, that they can't do the job?

I was lucky. I joined the airline in the right seat of the DC-9 and learned fast. I flew with captains who took their teaching responsibilities seriously. I particularly remember Ike Jones, a great, generous, good-natured Newfoundlander. He was Master to my Apprentice. He taught me and I have never forgotten.

Learn By Doing

Lee Kang Kuk (the Asiana 214 Trainee Captain) was not so lucky. He was an “experienced” pilot, a captain on Airbus aircraft transitioning to the B-777. I put experienced in quotes because although he had thousands of hours of flying, he found the prospect of doing a visual approach “very stressful.” To me this seemed nonsensical until I began to think about it. I thought about the Asiana First Officer who told the investigation he had been flying the A320 for three years and had never landed the airplane manually.

I thought of myself. After retirement from the airline I didn't fly for 6½ years. I had to get training, pass exams and tests, and retrain myself. This year I have been working with Andrew Boyd, a Class I instructor, trying to get my skills up to where I can get my Class II instructor rating back. It has been a lot of joyful work. But I see even more than I did six months ago that we all learn by doing. Practice, practice, practice. Lee's airline recommends that its pilots fly their planes manually as little as possible.

Lee didn't have a chance. He said, “(it is) very difficult to perform a visual approach with a heavy airplane.” Horsefeathers. It is actually harder with a very light airplane. What is difficult (if not impossible) is to fly any maneuver without practice.

History Repeats Itself

Fifty years ago last month an Air Canada DC-8 crashed at Ste.Thérèse, Québec. Last month a Boeing 737 crashed at Kazan, Russia. The DC-8 hit the ground at 55° nose down. The B-737 hit the ground at 75° nose down.

It is unlikely that the young pilots in Russia knew of the DC-8 accident. After all, it happened before they were born. What possible relevance could it have for them?

Well, we know from the evidence so far that they were not prepared for the missed approach they tried to execute. They did make the decision to go around. They did select TOGA (Takeoff/Go Around) mode. The engines did spool up to takeoff thrust. They did retract flap from 30° to 15°.

Then comes the part that is difficult to explain. They disengaged the autopilot but did not fly the airplane.

On its own the B-737, trimmed for approach, will pitch nose-up with both takeoff power and flap retraction. The accident aircraft did just that, achieving 25° nose-up, about 10° higher than the target for this maneuver. Like the DC-8 fifty years before, it was accelerating, at least until it passed the 15° target attitude.

Instrument pilots know that acceleration can produce the sensation of pitching nose-up. That might explain the Ste. Thérèse accident. It surely played an important part at Kazan.

It would have helped if the Russian pilots had been trained to expect the missed approach. Pilots call it being spring-loaded for the Go-Around. It would have helped if they knew of and expected the illusions they were about to experience from the acceleration. But most important by far are the basics, and the foundation of any emergency, indeed of any maneuver, is fly the airplane. Somehow they omitted this crucial step.

How Did We Get Here?

It would be convenient if we could put the finger on one factor, one guilty party. But there are many: deregulation; lazy captains; automation; feeder airlines, merger, and bankruptcy as tools to reduce costs; regulatory impotence. Mark H. Goodrich explores all of these in depth on his website. His unique experience (engineer, pilot, teacher, lawyer, more airplane type ratings than anyone) give him an invaluable perspective. I will summarize from my own experience.

Lazy Captains

In my younger days there were captains who grumbled it was not their duty to teach flying. Their interpretation of the adage Learn, Earn, and Return stopped with the money.

Automation

I confess I am a technophile. I love new tools. Flying my Bonanza with its Aspen Primary Flight Display fed by the Garmin GTN650 is a delight. But there are changes. My instrument scan still covers the basic 'T', but there are new items in it, and the order is different. From the airplane symbol (attitude) my eye moves an inch to the right to see if there is any pink fuzz on the altitude tape (trend) and an inch and a half down to the aqua diamond (aircraft track). If there is no fuzz and the diamond is on the arrow (desired track), no further action is necessary for the moment. I can look further out, and think for a second or two about other issues.

And here, in front of the MacBook Pro, I can think about the wider implications. How I enjoyed teaching technology on the A320, and how much flying skill I lost in my nine years on the airplane. Yes, I would make sure each of us did an “everything off” visual approach at least once per cycle (trip, 2-4 day sequence of flights). But in the Airbus such an approach is a bit of a parlor trick, chiefly because there is no trim feel.

In the Bonanza I have the best of both worlds. There is no autopilot. You fly it every second you're airborne, and then some. And the tools I have at hand are better than I had on the Airbus. ForeFlight in my iPad, fed by a tiny GPS and a satellite weather receiver. New capability arrives every few months with a software change. Flying in IMC I no longer have to request permission to leave the ATC frequency, call the FSS, and copy weather with one hand while flying with the other. Instead, my right forefinger taps the iPad over the airport of interest, and the last METAR appears. Another tap brings the forecast or the winds aloft or the airport information. One more tap and the approach I have chosen is drawn over the map in scale. Using two fingers I zoom and pan as I brief for the approach. I am still flying with my left hand.

I love it all. But is it easier than the old way?

Yes and no. In the old days you started with heading and guessed at the track made good. You integrated (looked at change over time) the localizer or VOR needle to see how good your guess was. Now you just glance at the little diamond. That's a huge improvement. But you have to learn the system, to understand what is going on. The diamond is of no use whatever if you don't know what it is. And once you do you have to retrain your eye so it knows where to look. So I am solidly with Mark Goodrich when he says that automation requires more pilot training, not less.

Airline Management Strategies

Since deregulation (1978) airline management has focused on reducing costs. Robert Crandall (American Airlines) spoke out against deregulation, but once it was law he led the way, inventing one strategy after another for his airline's survival. The first of these was hub and spoke. As I young man I flew the DC-9 across Canada on many long, thin, multiple-stop routes. By the time I was captain on the same airplane (1987) hub and spoke had arrived and there were feeder airlines flying turboprops, bringing passengers from the smaller cities into the hubs where the jets flew. This not only made economic sense – it also provided the opportunity to set up a two-tier pay scale and reduce the power of the pilot unions. But there was a casualty: apprenticeship. Young pilots starting out at the feeder had no contact with the old guys (still mostly men, even then) nearing the end of their career. Instead, they flew with captains near their own age whose only concern was getting a job with the main line. Seniority and career trumped teaching and learning. The wisdom of the old farts retired with them.

Then, as Robert Crandall so accurately predicted (in the Senate hearings on Deregulation), the airlines started losing money. There was a frenzy of merger and acquisition, and then bankruptcy. Collateral damage to pilots came in training, salary, and pension.

When I joined the airline training on a new type included two hours at the controls of a real airplane, doing takeoffs and landings. Now a pilot's first landing on a new type is on a line flight with passengers. That can be interesting. I know because I spent my last eight years as a Line Indoctrination Training Captain. For more about reliance on simulators and airline training in general, see Mark Goodrich's Simulating Reality and The Training Paradox.

Regulatory Impotence

The FAA recently changed the regulations to require that First Officers on transport aircraft have 1500 hours total time and an Airline Transport Rating. This was largely a response to the Colgan Air crash at Buffalo, NY in February, 2009. There are not enough pilots with these qualifications, and airlines are beginning to cancel flights in the smaller markets such as Grand Forks, ND.

The FAA now requires some Asian airlines to fly GPS approaches instead of visual approaches if the ILS is unserviceable. Note that aircraft “land themselves” only if an ILS is available on the landing runway. Note also that GPS approaches with vertical guidance, although they allow an autopilot to fly the airplane down a glideslope, themselves require training.

So which is better? Apprenticeship, or regulations which say only masters can fly? Training pilots in the fundamentals so they have the confidence they can fly, or regulating the level of automation they must use?

Conclusion

We have come full circle. Laziness interacts with automation, cost cutting with simulator training, loss of apprenticeship with pilot confidence and competence. The emperor has no clothes. But again, why?

The answer, I'm afraid, is simple. We can't see that the emperor has no clothes because we don't want to look. Deregulation opened airline financial decisions to the market, which means you and I, the bargain-seeking traveler, push prices down to where flight operations can no longer be safely undertaken. It has taken a generation, but that is where we have arrived.

Losing Competence Part V: Asiana 214 and the Loss of Control Accidents

document.write(" serif">Automation and Hubris

Bernard Ziegler designed the Airbus to be pilot-proof. He is a good pilot, and he noticed that many pilots are less skilled than himself. In the interest of safety, he designed an airplane that could not be stalled. But it has been known for thousands of years that hubris is followed by nemesis, that Pride goeth before destruction, and an haughty spirit before a fall. (Proverbs, 16:18)

Hubris is arrogance before the gods. The goddess Nemesis alone can see the fine line between doing the best work you can and believing that your work is somehow superior. Cross the line and she is ruthless, finding your fatal flaw and using it to bring you down.

AF 447 was the fall of the hero. Pilot carelessness led the airplane into a line of thunderstorms. Supercooled water drops overwhelmed the pitot heaters, temporarily removing all three sources of airspeed information. The autopilot dropped off. The flight control computers switched from Normal to Alternate Law. The airplane can be stalled in Alternate Law.

Human or robot, there is always a fatal flaw.

How can we work with imperfection?

Don't Bow Down

Mankind, when confronted with the complicated or the divine, tends to bow down in worship. This can be hazardous in aviation.

The new automation – glass cockpit, fly by wire, IRS and GPS – together bring a change at least as momentous as going from props to jets in the 1960's. The aircraft is now such a capable pilot on her own that she almost seems real. We called the Airbus Fifi. Rather than bowing down, we found it was much better to treat her like a person. Dare to know her and maintain a relationship.

In her early days, frustrated pilots would exclaim, “What the #$%* is it doing now?” On a go-around at KLGA the map display would disappear, the airplane sailing off the edge of the world because it had passed the last waypoint in the flight plan. Or on a miss from a visual approach at KMIA the power would suddenly go to idle. Finger trouble with the Autothrust. She was trying to maintain go-around speed.

But the answers are right in front of you on the FMA. (Flight Mode Annunciator, at the top of the Primary Flight Display) We began speaking for her, calling out any change in the FMA, so we all knew what she was doing, or thought she was doing.

And yes, most of the time she was a damn good pilot. Just as we are. Exactly the same, including the occasional lapse. Which is why there is more than one pilot aboard. And which is why the human pilot should never bow down and never step aside. Know her (the automation, Fifi, the airplane) as well as you can. Always monitor her as you would a human pilot and call out anything unusual. And if she's not doing what she is supposed to, take over. For those interested in pursuing the subject, there is an excellent video, Children of Magenta, of a lecture by an American Airlines training captain. The take-away is the same: if she's not doing what you want, take over and fly by hand. You don't have time to figure out what you did wrong with the automation.

Crew Concept – and Not Just Humans

Moving from props to jets, pilots were introduced to many new concepts: mach tuck, dutch roll, deep stall, etc. Perhaps the most important were the long, shallow drag curve and the slow spool-up time of the engines.

Moving into the fly-by-wire era, we have to accept that the airplane (her automation) is part of the crew. Philosophically, it is perhaps a stretch, but in the real world of the cockpit it is a game changer and a life saver. As soon as you accept that the airplane is part of the crew – not a superior or inferior, but an equal – everything starts to make sense. She sounds the cricket as the autopilot drops off. In Alternate Law she says Stall, Stall as the panicked pilot pulls back on the sidestick.

But if you're on approach below 1000 feet (critical phase of flight) and the descent rate is 1300 feet per minute and the airspeed is below Vapp then someone isn't doing what needs to be done. (Without a glideslope the airplane will not understand that something is wrong.) The software doesn't care if the airplane crashes. She is a good pilot but she has absolutely no self-preservation instinct, no will to live. Human pilots have, or they have no place on the flight deck.

AF 447: Let’s Talk About Why – 2: Virtual Reality

How many times have you heard Airbus pilots say, “It's not an airplane, it's a video game.”?

In this blog I will explore the fact and fiction in this statement. My objective is not to praise a great airplane or run down a flawed one, but rather to find how to live with a perfectly good one.

For almost a decade I flew the A320 (and the A319 and A321) as Captain and Training Captain. I came to see her not as a video game but as a person with whom I had to deal. I came to appreciate her many sterling qualities and also her weaknesses. Both informed our work together.

Fundamentals

First, she is an airplane like any other. If you accelerate her to Vr and raise the nose, does she not fly? If you provoke her into an Angle of Attack above 16°, does she not stall? Do not the laws of aerodynamics still hold?

These fundamental things will always apply as we work through her many wonders: Fly-by-Wire, Envelope Protection, and Flight Guidance systems. These wonders are what software people call a “front end” to her conventional aircraft qualities. But the wonders can be a powerful distraction as well as a boon.

Another pilot comment heard (more frequently in the first decade of operation, roughly the 1990's) is “What the #*%# is it doing now?”. The question was being asked because the pilots didn't know where to look for the answer, and also because an airplane maneuvering on her own was a novelty. When things happen that we don't understand, we human beings tend to see them as acts of God. We substitute reverence for understanding. A320 software – partly because it is so good, most of the time – has been an object of such reverence.

But just as we are not perfect, neither is this marvellous software. As the history of the airplane in service demonstrates, it is only as good as its interface with the pilots.

The Crashes

The first three crashes – Mulhouse, Bangalore, and Strasbourg – are illustrative. In the first two the engines were at idle and the crew were unaware that the power was being commanded to idle by the Auto-thrust. This information is clearly presented at the left end of the Flight Mode Annunciator or FMA, which appears in a band across the top of the Primary Flight Display, or PFD. The Auto-thrust Mode is what the Auto-thrust thinks it is doing. The only acceptable modes for approach are Speed and Off. At Mulhouse and Bangalore the Auto-thrust Mode was reading Idle.

What was not clearly understood at the time of these crashes was how to change the Auto-thrust mode from Idle to Speed, which is to turn off both Flight Directors. Further, the annunciation of the Flight Director modes on the FMA was not as communicative as it is today. At Bangalore one pilot turned off his Flight Director and the other did not. As a result the Auto-thrust mode remained in Idle. Today in that situation the FMA would show 1FD- , meaning that FD 1 is operating on the left side and that FD2, on the right side, is off. (With both FD’s on the FMA would show 1FD2). Both pilots can see what is going on. This improvement was implemented after analysis of these crashes.

The Strasbourg crash resulted in another improvement in the airplane-pilot interface. The flight was performing a non-precision approach which specified a Flight Path Angle. The crew selected -3.3 into the Flight Control Unit but failed to switch it to Track/Flight Path Angle mode. The FCU remained in Heading/Vertical Speed mode and interpreted the command as -3300 feet per minute. (There is a big difference between the two. At normal approach speeds a Flight Path Angle of -3.3 would be 800-900 fpm.) The presentation has since been changed in two important ways: first, to change the HDG/VS mode on the FCU to show 3300 while leaving the TRK/FPA mode as 3.3. Second, the commanded rates are now repeated on the Flight Mode Annunciator.

In these accidents the crew were not aware of what the software was doing. In the following example, the loss of an A330 in flight test at Toulouse in 1994, the crew were not aware of a crucial software limitation.

In most autopilots there is an altitude capture mode. In Airbus aircraft this is known as ALT*, or “Alt Star.” The computer uses the selected altitude and the vertical speed to calculate how far ahead to begin the capture maneuver, which is an asymptotic curve. Higher vertical speeds require that the maneuver be begun earlier if “G” forces are to remain within limits. Crucially, because the software calculates the curve based vertical speed, it de facto assumes that the thrust available at the start of the capture maneuver will remain available. Thus the loss of an engine while in ALT* is a first-rate emergency requiring flight crew intervention within a few seconds.

Man/Machine Communication

I present these examples not as an exhaustive course on Airbus software, but as an illustration of how extra intelligence brings with it extra complication. First, the communication between man and machine is of paramount importance. The interface cannot be too well-designed and the pilot cannot take too much care in maintaining effective two-way communication. This is why at my airline any change in the FMA was verbalized by the Pilot Flying, in effect giving voice to the machine and keeping the three pilots (two human, one cybernetic) on the same page.

Second, each time a task is assigned to automation the process must remain transparent to the pilot. He must understand in general terms what the computers are doing, and even more importantly what they are not doing. Should the automation for any reason drop the task it must be immediately obvious to the pilot and he must have steps rehearsed which let him take control and do the task himself.

Engine failure in ALT* is a good example. With today's improved FCU interface the pilot can push the Vertical Speed knob, which simultaneously selects V/S as the vertical mode and sets the target V/S to zero. In less than a second he has intervened, taken control, and given himself time.

If altitude cannot be maintained on the remaining engine(s) he can twist the knob to set a modest descent. Then the drill calls for getting a clearance to a lower altitude, turning off the Auto-thrust and setting Maximum Continuous Thrust on the good engine(s), selecting the cleared altitude and Pulling the Altitude knob to select Open Descent. Speed and thrust can then be adjusted to suit the situation.

The above procedure is not difficult, is easily performed in the time available before losing control, and requires no particular skill. What it does require of the pilot is that he view the airplane (and her wonders of automation) as an equal: a skilled pilot who nevertheless can have a bad day, make a mistake, or be simply unavailable.

Anthropomorphism

I know I am not alone in assigning a personality to the Airbus. I have said elsewhere that I came to regard her as a friend, or more than a friend. I (ahem) even loved her. Perhaps I still do and that why I am writing this.

Wait, though. I know full well she is aluminum, carbon fibre, and Intel and Motorola Assembler. I also know she is a damn good pilot and that she can be trusted like a close friend. But – and this is the important part – she is my equal. I can fly too, but I sometimes make mistakes, have a bad day, or fail to communicate effectively. Ditto my software friend. I can be blinded by pride. Ditto my software friend. She is French and she has pride in her DNA.

In the Simulator we practice Pilot Incapacitation, recognizing that to err is human. What we have a harder time with is Automation Incapacitation. This is perhaps a symptom of our reverence for something that is beyond our understanding, for our unrecognized assumption that technology is perfect, or at least better than we are. This unrecognized and unwarranted assumption can be fatal.

It is much better to appreciate her as an equal and deal with her as a whole person, warts and all.

Feedback and Feel

Let's dig a step further. I believe what pilots are talking about, when they say Airbus aircraft are video games, is the lack of feedback and feel in the controls. The throttles, for example, do not move when the Auto-thrust is active. The pilot sees only Speed on the FMA and the engine indications on the ECAM. To take control smoothly (for example to do a manual approach) he must pull the thrust levers back until the little green donuts match the current thrust, and click the off button on the lever. The FMA says Off and he's on his own. But the approach is still a bit of a parlor trick because there is no feel in the sidestick. When a conventional aircraft gets slow increasing back pressure is necessary to keep the nose from dropping. Not so in an Airbus. Instead, the Autotrim will move the stabilizer nose-up to maintain 1G flight. The pilot's eye has to dart to the airspeed indicator to get what he might have sensed in the stick or control column. All of this contributes to the “video game” feel.

Perhaps a direct Angle of Attack readout in a Heads Up Display would compensate for the lack of feel. But this is ignoring an essential fact: the Airbus is a conventional airframe, with positive aerodynamic longitudinal stability. It is not like some fighter aircraft with neutral or negative longitudinal stability, where the aircraft is uncontrollable without fly-by-wire. The stability is there, but it is shielded from the pilot.

It must be pointed out that the Airbus is a beautiful airplane and a joy to fly and that it has hundreds of wonderful design features I would not like to see disappear. Just one example is “the hook” (the display on the airspeed tape of Vls (lowest selectable speed)) and its relationship to “the bug” (Vapp, or final approach speed). The bug speed is calculated by the FMCG (Flight Management and Guidance Computer) based on the Gross Weight (or Zero Fuel Weight) entered by the pilots. The hook is calculated from first principles by comparing Angle of Attack with dynamic pressure (airspeed). In a normal approach these are 0.5 cm (1/4 inch) apart. This is one of those comfort crosschecks for pilots. If the bug and the hook are too close together, the weight entered in the FMCD is likely wrong, and the calculated Vapp is too slow.

But even here an intelligence has been interposed between the pilot and his aircraft. Why not also display the Angle of Attack directly, and always fly the approach at the same angle of attack regardless of weight? (See my blog AF 447 – Let's Talk about Why – 1: Angle of Attack). It is this interposition of intelligence that contributes to what I see as the problem: the illusion of Virtual Reality.

Virtual Reality

Flying an airplane, any airplane, is a very real job. The airplane can be a bear or sweet to fly, it can be automated or not, it can “land itself.” But the bottom line of the captain's job does not change, and that is to be the arbiter of last resort: the man or woman who imagines, constructs, and sees the picture that determines the outcome. It is his or her job to maintain that picture. In the trade we call it situational awareness. If something goes wrong and that picture is wrong people die. And if the captain believes the glass display before him is superior to his own mental image, then he will be more likely to abdicate his responsibility to maintain situational awareness.

Today's glass cockpit is seductive. A wealth of information sits before the pilot: some of it is raw data; often it has been extensively processed into a colourful and sometimes beautiful picture. Like a video game, this is virtual reality. Software is doing the imagining for the pilot.

It can be argued that the picture in the pilot's head is also virtual reality, merely a representation of the external world. But this argument does not acknowledge the survival instinct that guides the pilot's doubt and questioning, his constant checking for consistency, his testing of the obvious.

Airbus aircraft are beautiful and a joy to fly. But they are not perfect. Like all of us, they have a fatal flaw. The Ancient Greeks knew this hamartia as an essential component of human character. Bernard Ziegler, the brilliant designer of the Airbus software, has been quoted as saying he wanted to make the airplane pilot-proof. Consequentially, as I have shown, there are areas where the pilots have been shielded from useful, even essential, information. The Airbus pilot must work hard to ensure he is not entirely removed from the loop.

Reality for an airline passenger is not virtual. This game cannot be started over. The next time you hear someone say, this airplane lands itself, will you be comforted? Or will you be hoping that the pilots are not just along for the ride?

 

AF 447: Let's Talk About Why – 1

Thanks to the work of David Learmount at Flight Global, and that of the Wood's Hole Oceanographic Institution and the Bureau d’Enquêtes et d’Analyses, enough is now known about this accident to start looking for useful lessons and to analyze the data along with the BEA. Flight safety and the future of the piloting profession depend on this becoming a wide and serious conversation.

Pilots obsess about accidents for good reason. There is always so much to learn. The AF447 tragedy is an epochal example.

There is a mind-boggling number of lessons to be learned here, in a host of areas and disciplines: Pilot Training, Standard Operating Procedures, Instrument Flight, and Aircraft Design are but a few of them.

I will commit today to joining the conversation. I begin with a consideration of Angle of Attack.

Angle of Attack

Wolfgang Langewiesche (father of William) emphasized Angle of Attack in his excellent Stick and Rudder, published in 1944. Advocacy of AoA was an uphill battle then and it still is today. Instead of talking about AoA, we prefer to use airspeed and explain why certain speeds we use change with aircraft weight and G loading. Many or even most aircraft flying today have no Angle of Attack indication. The accident aircraft had two AoA sensors. The flight recorders had access to the signals from these sensors but the pilots did not, at least not when they needed it most.

Lift is produced when the air flowing over the top of a wing has a longer distance to travel than the air flowing underneath. The air “stretching out” over the top produces a lower pressure, allowing the higher pressure underneath to push the wing up. There is a caveat, however. The airflow must remain attached to the upper surface of the wing.

Imagine a cross-section of wing, with a line drawn from the middle of the rounded leading edge to the pointed trailing edge. This is the chord line. Now imagine an arrow pointing at the leading edge. This is the airflow.

If the arrow meets a (symmetrical) wing head-on there will be no lift. But let the wing meet the air at a slight angle and the airflow around the wing will no longer be symmetrical: it will meet the rounded leading edge at an angle and it will divide lower on the curve of the leading edge. The air flowing over the wing will have a longer distance to travel. Lift will be produced.

The angle at which the airflow meets the chord line is called the Angle of Attack. Up to a point, increasing the Angle of Attack will increase lift. But beyond a certain point – usually about 16° – lift will instead decrease because the airflow is beginning to separate from the upper surface of the wing. This is called the aerodynamic stall, and it always happens at the same Angle of Attack.

Angle of Attack is controlled by the elevators, the control surfaces on the trailing edge of the horizontal tail. When the pilot pulls back on the stick, the elevators lift, causing a down-force on the tail and forcing the wing to meet the air at a higher Angle of Attack. Trim tabs (small surfaces at the trailing edge of the elevators) can be moved to change the neutral position of the stick. (Another way to think of it is the trim tabs change the Angle of Attack at which there is zero stick force.)

In a modern jet transport the entire horizontal tail is usually moveable. This is because of the very wide speed range of the jet and because flaps and leading edge slats also change the “trim.” The other side of the coin is that this horizontal tail, or stabilizer, is very powerful in modern jet transports. A runaway stabilizer is a true emergency. Traditionally there has been a STAB IN MOTION aural warning, and an emergency cutout switch close to hand. Most cases where the stabilizer ran all the way up or down in flight have resulted in the loss of all on board.

In most aircraft the pilot is used to trimming as he flies. A change of speed or configuration, be it in a Beech Bonanza or a DC-9, will require a trim change. With some experience on type the pilot knows (for example on a DC-9) that extending the leading edge slats will require two beeps (of the STAB IN MOTION aural warning) of nose-up trim. He can use the thumb switches on the yoke to move the stabilizer as the slats are extending and thus remain stick-neutral during the configuration change. This is part of anticipation, or staying ahead of the aircraft.

Airbus aircraft, from the A320 onwards, are different. They are fly by wire, where computers are interposed between the pilots' sidestick inputs and the control surfaces. This arrangement allows some elegant additions to aircraft design, such as envelope protection (which among other things makes it impossible for the pilot to stall the aircraft) and, relevant to our discussion today, stick force per G and autotrim.

In Normal Law, which is where the Airbus is most (and the pilot hopes, all) of the time, configuration changes can be made hands off, even flying by hand. Of course the pilot has the tips of his fingers on the sidestick, but he can make a configuration change with no pitch input because the control system, in Normal Law, will maintain 1G flight. When he calls for FLAP 1 and the leading edge slats extend, the nose-down pitch is sensed and countered by the system, maintaining 1G flight. (1G is what you experience sitting in a chair at home or in an aircraft at cruise in smooth air). In effect, the airplane is doing the anticipation for the pilot.

Like the transition in the late 1950's from props to jets, fly-by-wire has been a major change for pilots. In general we welcome it for the many advantages it offers.

Experience has shown that to do his job, which is to ensure the safe arrival of his aircraft, the pilot must fully understand a much more complex airplane. Chesley Sullenberger reached up and started the APU (the Auxiliary Power Unit, a small turbine in the tail which can supply electrical and hydraulic power on the ground or in flight) as soon as his engines lost power. Why? Because he knew his airplane and he knew he wanted to keep it in Normal Law until touchdown.

The transition from props to jets was all about speed range, speed brakes and spoilers, high Mach number, coffin corner, Dutch Roll and super-stall, but in everyday life it was more about high drag on approach, no propwash, slow spool-up times, and operating on the back side of the power curve. This change took some adjustment on the part of pilots: the more experienced pilots had more adjustments to make. The same is true with the transition to fly-by-wire.

In a traditional airplane the pilot controls Angle of Attack with the elevator and the trim tabs or stabilizer. (More often he will be thinking of Airspeed, which is the constant-weight, 1G manifestation of AofA). He is used to feel, which is essentially the change in elevator neutral point with AofA. Should the aircraft slow on approach, the nose will get “heavy”, prompting him to pull back or trim nose-up.

That feel is totally absent in Airbus aircraft. (Boeing, in the B777, have added artificial feel to their fly-by-wire system). The Airbus pilot points and shoots, so to speak. Flying by hand he can take the bird, turning on a symbol (like a bird or an aircraft seen from behind) on his Primary Flight Display. The bird shows where his velocity vector is pointed; in other words, where is airplane will be so many seconds from now if he makes no further adjustments. On approach he can pin the bird on his flare point on the runway and either let the autothrust take care of the speed or adjust the thrust levers manually. If he does the latter, he must remember that there is no feel or feedback in the sidestick.

Obviously there are quite different assumptions operating during an approach in a Bonanza, one one hand, and an Airbus, on the other. This is not necessarily a bad thing. Take for example driving a car versus riding a motorcycle. In a car you steer with the steering wheel. In a motorcycle you counter-steer, putting pressure on the inside foot-peg and forward pressure on the inside bar, in effect trying to steer the front wheel the opposite way.

But you know you're on a motorcycle and not in a car. You have learned how to ride a motorcycle.

Consider, however, flying an Airbus if something goes wrong with a sensor or a computer and you wind up in Alternate Law or Direct Law. You are in the same vehicle but suddenly the rules have changed; the assumptions have changed. It is, in effect, no longer the same machine. This is a recipe which messes with a pilot's head.

Unfortunately, experience has shown that Direct Law, where control displacement is proportional to stick force and the airplane handles like a wet fish, is actually the more benign of the two degraded modes. There is a big message in red on the ECAM saying USE MAN PITCH TRIM. The pilot moves the THS (Trimmable Horizontal Stabilizer) by moving a wheel almost a foot in diameter. This is old-style, normal airplane flying, commanding AofA with stick force and trim. There is still no feel in the sidestick, but the procedure is familiar.

Alas, in Alternate Law there is no such familiarity. It is still point-and-shoot, sort of, but autotrim is still working. As long as there is back pressure on the stick the THS trims nose-up, and vice-versa. There is NO Stabilizer in Motion warning except the movement of the trim wheels. That would seem to be an easy thing to detect, but I can testify from personal experience that it is not. On every landing (in Normal Law) the flight control computers memorize the attitude at 50 feet Radio Altitude and at 30 feet start rolling in nose-down trim, in effect trying to mimic the feel of a normal aircraft slowing in the flare. In almost a decade of flying as Captain and Training Captain, whether as Pilot Flying or Pilot Not Flying, I cannot remember ever seeing the trim wheels move.

In two recent accidents an Airbus has hit the ocean with the THS wound to full nose up. In both cases the aircraft was in Alternate Law.

I am not an engineer. There are likely many ramifications that have not crossed my mind. But sitting here this afternoon my personal recommendation would be as follows:

Disable Autotrim in Alternate Law

AF 447: Let’s Talk About Why – 1

Thanks to the work of David Learmount at Flight Global, and that of the Wood's Hole Oceanographic Institution and the Bureau d’Enquêtes et d’Analyses, enough is now known about this accident to start looking for useful lessons and to analyze the data along with the BEA. Flight safety and the future of the piloting profession depend on this becoming a wide and serious conversation.

Pilots obsess about accidents for good reason. There is always so much to learn. The AF447 tragedy is an epochal example.

There is a mind-boggling number of lessons to be learned here, in a host of areas and disciplines: Pilot Training, Standard Operating Procedures, Instrument Flight, and Aircraft Design are but a few of them.

I will commit today to joining the conversation. I begin with a consideration of Angle of Attack.

Angle of Attack

Wolfgang Langewiesche (father of William) emphasized Angle of Attack in his excellent Stick and Rudder, published in 1944. Advocacy of AoA was an uphill battle then and it still is today. Instead of talking about AoA, we prefer to use airspeed and explain why certain speeds we use change with aircraft weight and G loading. Many or even most aircraft flying today have no Angle of Attack indication. The accident aircraft had two AoA sensors. The flight recorders had access to the signals from these sensors but the pilots did not, at least not when they needed it most.

Lift is produced when the air flowing over the top of a wing has a longer distance to travel than the air flowing underneath. The air “stretching out” over the top produces a lower pressure, allowing the higher pressure underneath to push the wing up. There is a caveat, however. The airflow must remain attached to the upper surface of the wing.

Imagine a cross-section of wing, with a line drawn from the middle of the rounded leading edge to the pointed trailing edge. This is the chord line. Now imagine an arrow pointing at the leading edge. This is the airflow.

If the arrow meets a (symmetrical) wing head-on there will be no lift. But let the wing meet the air at a slight angle and the airflow around the wing will no longer be symmetrical: it will meet the rounded leading edge at an angle and it will divide lower on the curve of the leading edge. The air flowing over the wing will have a longer distance to travel. Lift will be produced.

The angle at which the airflow meets the chord line is called the Angle of Attack. Up to a point, increasing the Angle of Attack will increase lift. But beyond a certain point – usually about 16° – lift will instead decrease because the airflow is beginning to separate from the upper surface of the wing. This is called the aerodynamic stall, and it always happens at the same Angle of Attack.

Angle of Attack is controlled by the elevators, the control surfaces on the trailing edge of the horizontal tail. When the pilot pulls back on the stick, the elevators lift, causing a down-force on the tail and forcing the wing to meet the air at a higher Angle of Attack. Trim tabs (small surfaces at the trailing edge of the elevators) can be moved to change the neutral position of the stick. (Another way to think of it is the trim tabs change the Angle of Attack at which there is zero stick force.)

In a modern jet transport the entire horizontal tail is usually moveable. This is because of the very wide speed range of the jet and because flaps and leading edge slats also change the “trim.” The other side of the coin is that this horizontal tail, or stabilizer, is very powerful in modern jet transports. A runaway stabilizer is a true emergency. Traditionally there has been a STAB IN MOTION aural warning, and an emergency cutout switch close to hand. Most cases where the stabilizer ran all the way up or down in flight have resulted in the loss of all on board.

In most aircraft the pilot is used to trimming as he flies. A change of speed or configuration, be it in a Beech Bonanza or a DC-9, will require a trim change. With some experience on type the pilot knows (for example on a DC-9) that extending the leading edge slats will require two beeps (of the STAB IN MOTION aural warning) of nose-up trim. He can use the thumb switches on the yoke to move the stabilizer as the slats are extending and thus remain stick-neutral during the configuration change. This is part of anticipation, or staying ahead of the aircraft.

Airbus aircraft, from the A320 onwards, are different. They are fly by wire, where computers are interposed between the pilots' sidestick inputs and the control surfaces. This arrangement allows some elegant additions to aircraft design, such as envelope protection (which among other things makes it impossible for the pilot to stall the aircraft) and, relevant to our discussion today, stick force per G and autotrim.

In Normal Law, which is where the Airbus is most (and the pilot hopes, all) of the time, configuration changes can be made hands off, even flying by hand. Of course the pilot has the tips of his fingers on the sidestick, but he can make a configuration change with no pitch input because the control system, in Normal Law, will maintain 1G flight. When he calls for FLAP 1 and the leading edge slats extend, the nose-down pitch is sensed and countered by the system, maintaining 1G flight. (1G is what you experience sitting in a chair at home or in an aircraft at cruise in smooth air). In effect, the airplane is doing the anticipation for the pilot.

Like the transition in the late 1950's from props to jets, fly-by-wire has been a major change for pilots. In general we welcome it for the many advantages it offers.

Experience has shown that to do his job, which is to ensure the safe arrival of his aircraft, the pilot must fully understand a much more complex airplane. Chesley Sullenberger reached up and started the APU (the Auxiliary Power Unit, a small turbine in the tail which can supply electrical and hydraulic power on the ground or in flight) as soon as his engines lost power. Why? Because he knew his airplane and he knew he wanted to keep it in Normal Law until touchdown.

The transition from props to jets was all about speed range, speed brakes and spoilers, high Mach number, coffin corner, Dutch Roll and super-stall, but in everyday life it was more about high drag on approach, no propwash, slow spool-up times, and operating on the back side of the power curve. This change took some adjustment on the part of pilots: the more experienced pilots had more adjustments to make. The same is true with the transition to fly-by-wire.

In a traditional airplane the pilot controls Angle of Attack with the elevator and the trim tabs or stabilizer. (More often he will be thinking of Airspeed, which is the constant-weight, 1G manifestation of AofA). He is used to feel, which is essentially the change in elevator neutral point with AofA. Should the aircraft slow on approach, the nose will get “heavy”, prompting him to pull back or trim nose-up.

That feel is totally absent in Airbus aircraft. (Boeing, in the B777, have added artificial feel to their fly-by-wire system). The Airbus pilot points and shoots, so to speak. Flying by hand he can take the bird, turning on a symbol (like a bird or an aircraft seen from behind) on his Primary Flight Display. The bird shows where his velocity vector is pointed; in other words, where is airplane will be so many seconds from now if he makes no further adjustments. On approach he can pin the bird on his flare point on the runway and either let the autothrust take care of the speed or adjust the thrust levers manually. If he does the latter, he must remember that there is no feel or feedback in the sidestick.

Obviously there are quite different assumptions operating during an approach in a Bonanza, one one hand, and an Airbus, on the other. This is not necessarily a bad thing. Take for example driving a car versus riding a motorcycle. In a car you steer with the steering wheel. In a motorcycle you counter-steer, putting pressure on the inside foot-peg and forward pressure on the inside bar, in effect trying to steer the front wheel the opposite way.

But you know you're on a motorcycle and not in a car. You have learned how to ride a motorcycle.

Consider, however, flying an Airbus if something goes wrong with a sensor or a computer and you wind up in Alternate Law or Direct Law. You are in the same vehicle but suddenly the rules have changed; the assumptions have changed. It is, in effect, no longer the same machine. This is a recipe which messes with a pilot's head.

Unfortunately, experience has shown that Direct Law, where control displacement is proportional to stick force and the airplane handles like a wet fish, is actually the more benign of the two degraded modes. There is a big message in red on the ECAM saying USE MAN PITCH TRIM. The pilot moves the THS (Trimmable Horizontal Stabilizer) by moving a wheel almost a foot in diameter. This is old-style, normal airplane flying, commanding AofA with stick force and trim. There is still no feel in the sidestick, but the procedure is familiar.

Alas, in Alternate Law there is no such familiarity. It is still point-and-shoot, sort of, but autotrim is still working. As long as there is back pressure on the stick the THS trims nose-up, and vice-versa. There is NO Stabilizer in Motion warning except the movement of the trim wheels. That would seem to be an easy thing to detect, but I can testify from personal experience that it is not. On every landing (in Normal Law) the flight control computers memorize the attitude at 50 feet Radio Altitude and at 30 feet start rolling in nose-down trim, in effect trying to mimic the feel of a normal aircraft slowing in the flare. In almost a decade of flying as Captain and Training Captain, whether as Pilot Flying or Pilot Not Flying, I cannot remember ever seeing the trim wheels move.

In two recent accidents an Airbus has hit the ocean with the THS wound to full nose up. In both cases the aircraft was in Alternate Law.

I am not an engineer. There are likely many ramifications that have not crossed my mind. But sitting here this afternoon my personal recommendation would be as follows:

Disable Autotrim in Alternate Law

Instrument Flying: Behind the Basics – 3

INTEGRATING the ILS

We’ll start with a new image today – the megaphone. Put the small end at the touchdown point, line it up with the runway, and tilt it up three degrees. This is the ILS, or at least a useful image of it.

The picture helps because it gives an instinctive feeling for what we have to do to fly an ILS:

  • Maneuver into the big end of the cone
  • Fly down its axis
  • Make smaller corrections as we get closer to the runway

Last time we talked about how to stay on the localizer – maintain the published track – and how we were using integration. Looking closer, we can take the integration back several levels:

Bank --> Heading Change (and thus Track Change) --> Lateral Displacement

A shallow turn for a short time means a small heading change, changing the track. Imagine the new track drawing an arrow – this is your velocity vector. The longer you stay on the track, the longer the arrow. Visualize (I'll add diagrams when I learn the software) the arrow: if you are correcting back to the on-course you'll want to return to your tracking heading when the tip of the arrow gets there.

The same method – integrate and visualize – works for the vertical axis:

Power + Pitch --> Vertical Speed

Use V/S as you would track to manage vertical displacement – to track the glideslope, if you will. The same method works in both axes:

  • Before you start the approach, have targets in mind – the published track,  and a target vertical speed you calculate from your planned airspeed on approach: airspeed/2 X 10 = 600 fpm for 120 knots (if you have GPS, use your groundspeed).
  • Fly into the big end of the cone and center the localizer.
  • Fly the target heading and see what happens. Now you know something about the wind. Adjust your target. (If you have GPS, flying the published track will keep you on the localizer.)
  • Correct back on, then fly the new target. Repeat and get it nailed (at least for this altitude).
  • As the glideslope comes down to meet you, do what you need to get your target V/S. (It should be as little as possible and preferably only one thing: reduce RPM or MP a certain amount; put the gear down.)
  • See what happens. Adjust your target. (If you have GPS, glance at the groundspeed. If it's only 100 knots, your new target is 500 fpm.)
  • Correct back onto the glideslope by adjusting V/S, visualizing the arrow (your velocity vector in the vertical axis) intercepting the G/S. When you're back on, fly the new target.
  • Continue as above, visualizing the megaphone as it gets smaller, guiding you to that window 200 feet above the approach lights. (Your corrections are getting smaller and smaller.)
  • KEEP YOUR TARGETS IN YOUR HEAD RIGHT DOWN TO MINIMUMS. (They are now accurate to a degree or two of heading and 50-100 fpm.)

That's it! Simple, right?

Actually, it is, and it works, but it does take some thinking about. For example: if the needles are centered, are you flying down the axis of the megaphone?

We'll look at that next time.