AVmail: June 6, 2011
Letter of the Week: Airbuses Fly "Like a Video Game"
I would like to offer my comments and perspective with regard to the Air France Flight 447 accident. I have been a A-330 captain since 2003 and have over 4500 hours in the aircraft. While many A-320 pilots undoubtedly have more series time, I believe this probably makes me one of the most experienced A330 pilots in the world.
When asked how I like the aircraft, I tell people that there is likely no easier airplane to take over an ocean, and that the systems design and presentation is superb. That said, the automation is more complex and less intuitive than necessary, and the pilot-aircraft interface is unlike that of a conventional aircraft. Most important with regard to this accident is the fly-by-wire sidestick control. The sidestick itself has a very limited range of motion, making inadvertent over-control very easy. Of even greater significance, the stick itself provides no "feel" feedback to the pilot. That is, unlike a conventional aircraft, the pilot does not get a sense through pressure of how much input is being sent to the control surfaces. The most important advice I give to pilots new to the Airbus is to treat the aircraft not as an airplane, but as a video game. If you wait for the sidestick to tell you what you are doing, you will never get an answer.
Taking into consideration that Air France 447 was at FL 350 (where the safe speed envelope is relatively narrow), that they were in the weather at night with no visible horizon, and that they were likely experiencing at least moderate turbulence, it does not surprise me in the least that the pilots lost control of the aircraft shortly after the autopilot and autothrust disconnected.
Let's keep in mind that these are not ideal conditions for maintaining controlled flight manually, especially when faced with a sudden onslaught of warning messages, loss of autofllght, confusing airspeed indications, and reversion to "alternate law" flight control, in which certain flight envelope protections are lost.
A very bad Airbus design feature is thrust levers that do not move while in autothrust. They are instead set in a detent which would equal climb trust in manual mode. If the pilots did not reset the thrust levers to equal the last cruise power setting, they likely eventually ended up in climb power, making it difficult to reset the proper cruise power setting and adding to what was likely already a great deal of confusion.
But the real problem probably occurred immediately after the pilot flying grabbed the sidestick and took over manually. Unfortunately, airline pilots rarely practice hand-flying at high altitude, and almost never do so without autothrust engaged. As a result, we forget that the aircraft is very sensitive to control inputs at high altitude, and overcontrol is the usual result. Because the Airbus sidestick provides no feedback "feel" to the pilot, this problem is dramatically compounded in this aircraft.
I believe the Air France pilot grabbed the sidestick, made an immediate input (because as pilots, that's what we tend to do), and quickly became quite confused as to what the aircraft was truly doing. This confusion likely was exacerbated by fixating on airspeed indications that made no sense while trying to find a power setting with no airspeed guidance.
When transitioning from autopilot to manual control at altitude in the Airbus, the most important thing to do at first is nothing. Don't move a thing, and then when you do, gently take hold of the sidestick and make very small inputs, concentrating on the flight director (which, in altitude hold, should still have been providing good guidance). Of course, this is much easier said than done with bells and whistles going off all over the place, moderate turbulence and a bunch of thunderstorms in the area. As I said before, treat it like a video game.
So why did the Air France pilot find himself at the limits of sidestick travel, and then just stay there, maintaining a control input that simply could not logically be correct? When things go really bad and we are under intense pressure, it is human nature to revert to what we know from previous experience. Remember, the Airbus flies like no other aircraft in that the sidestick provides no feedback to the pilot. It is a video game, not an airplane.
I believe the Air France pilot unintentionally fell back on all of his previous flying experience, in which aircraft controls "talkedF" to him when he moved them. Distracted by many confusing inputs, he instinctively expected to be able to control the aircraft by "feel" while dividing his attention to address other matters. I've seen it happen in the simulator, and in an Airbus this is a sure way to lose control of the aircraft and is possibly the most dangerous aspect of Airbus design philosophy.
One last note: Airbus pilots often claim that the aircraft "can not be stalled." When the flight controls are in "normal law" this is a reasonably true statement. However, in "alternate law," as was the case here, stall protection can be lost. If we ever practiced this in the simulator, I don't remember it.
Lest anyone think I am blaming the Air France pilots for this accident, let me be clear. Despite all of my experience in the aircraft, I am not the least bit certain that I would have been able to maintain control under the same circumstances. I do feel certain that were you to spring this scenario on pilots in a simulator without warning less than half of them would have a successful outcome. Safely flying the 320, 330 and 340-series Airbus requires something of a non-pilot mindset.
We have spoken with the writer of this letter to confirm his identity and honored his request for anonymity. For another analysis of the trials and challenges of flying an A330, be sure to listen to Friday's podcast with airline pilot Jason Goldberg.
We're Already There
Ed Hunt asks for a four-seat aircraft that will give 160 mph performance on less than 10 gph. That has been around for years. It's called the Mooney 201. It will carry 4 people at over 170 KTAS, using less than 10 gph. although you might not get 1,000 miles range with the seats full, you will get a great airplane for under $100K, typically.
Raising The Levels
Why does Class A airspace begin at FL180? Why not FL250, for example? Someone suggested that one could fly VFR if they do not wish to be tracked, which is a good idea and would be facilitated if you could fly VFR higher than FL180.
I always fly in the flight levels, but I fly a C-421C, so no one cares except my office, which always tracks me, and I am glad of it.
Shouldn't we raise the VFR limit to something higher than 18,000 feet? The commercial and business guys don't fly below FL250, so why not raise the ceiling? There is virtually no traffic in that area. There is not much to see, either, so it is nice to have a guy on the ground watching you in case there is some traffic, but is there a benefit to justify all of the associated cost? I am sure there must a good justification for this because the government would never do anything that makes no sense, would it?
Advice For Cessna's New CEO
You're going to get a million suggestions [in response to our "Question of the Week," "What's your advice for new Cessna CEO Scott Ernest?"], so here's just one more: General Aviation needs to be more affordable, or it will continue to shrink. LSAs seemed like a good idea, but $110,000 is still way out of reach of tens of thousands of would-be aircraft buyers. I don't have any specific suggestions, but making the ownership and operation of GA aircraft much more affordable seems critical for the future of GA.
I was extremely disappointed when Cessna went to China for the Skycatcher. No excuses, Cessna is an American company and if they do not want to build here, then simply sell out the entire company to foreigners.
Get Cessna manufacturing out of China and back to the USA.
Look at LSA as a major market in GA, not just something you need to be a part of. One of the greatest aircraft manufacturers, Cessna, offers the one of the least capable, most expensive, simple looking examples in the C-162 and can't figure how to produce it in the U.S.!
The LSA specs allow a very good airplane for private ownership, not just training! Put together an innovative design team including automotive manufacturing/process experts and produce an LSA we can be proud of!
Cessna needs to take the lead on training for people who want to be private pilots (as distingished from people who want to be professional pilots). The first step is to stop relying on [the current establishment] of the GA community. Those "training" operators are simply beyond repair.
Cessna should start over with company-owned and operated flight schools which make heavy use of flight simulators and all-new multi-media training materials. If you don't fix the training problem, GA will continue to die a slow death. Fixing training will not be sufficient to reverse GA's long-term decline (at least in the U.S.), but it is a necessary component of the reversal.
George Van Hoomissen
It appears that you do not have an airman license. If so, get one, and take a long cross-country trip in a Skycatcher. You need to understand this industry at its root levels, and not just at the level of marketing bizjets.
Shut down Cessna.
Pushing 60-year-old, 110 mph designs out the door at almost a half million a pop and a few dated business jets in today's world of advanced aerodynamics and structures is a disgrace. Until they (Cessna) can stand before the world with truly modern designs built by a competitive, non-union work force they can forget it.
Better Than Average
This was an especially good edition of AVweb. I would probably never have learned as much concerning flight 447 had you not published it. I'm 74 and too many hours to remember (dusterpilot and charter flights) and I enjoy all of them — but this one was especially well done.