Posted on 07/29/2011 10:38:19 AM PDT by magellan
My instructor put my plane into a power off stall first lesson I ever had. Almost caused me to quit taking flying lessons altogether, I was so scared.
Every lesson afterwards we practiced stalls, and later on he added power on stalls and those I hated even more. I have done more stalls than I care to remember, but I learned to keep flying the plane. This may sound ignorant but doesn’t Airbus have a stall warning blare?
“Dave’s not here.”
Awesome.
The French produce as quality a pilot as anyone - so what went wrong here?
It appears it's not so easy when your airspeed indicator goes away and you have to guess at the proper throttle setting and angle of attack.
Here's a little story about a Northwest Airlines crew who dealt with a similar situation and lived to tell about it. Posted by Orval Fairbairn
not long after the crash:
I just got this email from a retired airline pilot:
From a retired NWA buddy of mine
This from Brent Stratton, a friend and NWA pilot I flew the B-757 with
out of our Tokyo base.........Now obviously on the A-330
Well, I'm sure you have all heard of the Air France accident. I fly the
same plane, the A330.
Yesterday while coming up from Hong Kong to Tokyo, a 1700nm 4hr.
flight, we experienced the same problems Air France had while flying
thru bad weather.
I have a link to the failures that occurred on AF 447. My list is almost
the same.
http://www.eurocockpit.com/images/acars447.php
The problem I suspect is the pitot tubes ice over and you loose
your airspeed indication along with the auto pilot, auto throttles and
rudder limit protection. The rudder limit protection keeps you from over
stressing the rudder at high speed.
Synopsis;
Tuesday 23, 2009 10am enroute HKG to NRT. Entering Nara Japan airspace.
FL390 mostly clear with occasional isolated areas of rain, clouds
tops about FL410.
Outside air temperature was -50C TAT -21C (your not supposed to get
liquid water at these temps). We did.
As we were following other aircraft along our route. We approached
a large area of rain below us. Tilting the weather radar down we could
see the heavy rain below, displayed in red. At our altitude the radar
indicated green or light precipitation, most likely ice crystals we
thought.
Entering the cloud tops we experienced just light to moderate
turbulence. (The winds were around 30kts at altitude.) After about 15
sec. we encountered moderate rain. We thought it odd to have rain
streaming up the windshield at this altitude and the sound of the plane
getting pelted like an aluminum garage door. It got very warm and humid
in the cockpit all of a sudden.
Five seconds later the Captains, First Officers, and standby airspeed
indicators rolled back to 60kts. The auto pilot and auto throttles
disengaged. The Master Warning and Master Caution flashed, and the
sounds of chirps and clicks letting us know these things were happening.
Jerry Staab, the Capt. hand flew the plane on the shortest vector
out of the rain. The airspeed indicators briefly came back but failed
again. The failure lasted for THREE minutes. We flew the recommended
83%N1 power setting. When the airspeed indicators came back. we were
within 5 knots of our desired speed. Everything returned to normal
except for the computer logic controlling the plane. (We were in
alternate law for the rest of the flight.)
We had good conditions for the failure; daylight, we were rested,
relatively small area, and light turbulence. I think it could have been
much worse. Jerry did a great job fly and staying cool. We did our
procedures called dispatch and maintenance on the SAT COM and landed in
Narita. That's it.
They had a backup airspeed indicator and altimeter that were working. The bottom line is that nobody in the cockpit knew how to fly the airplane without a computer. When the transcripts came out, it was obvious.
The French produce as quality a pilot as anyone - so what went wrong here?
From what I've read, European airlines have no reservations about hiring a pilot with no experience, and the pilot who flew the aircraft into the ocean was one of those people.
HF
“were there no visual cues? Did the storm block the flight crew from seeing the plane was falling?”
Most likely there was nothing to see outside, however, there were plenty of instruments inside to tell them they were descending, had a nose up attitude, and needed to pitch down and power up. There are backup instruments plus several sets of redundant primary instruments.
And they were flying 200 passengers trans-Atlantic?
That's nuts!
SPLASH!
Was there no sensation of ‘falling’ during those 4+ minutes? Even a fast controlled descent feels a bit like falling and also the ears ‘pop.’
Do these aircraft have mechnical guages,even as a backup? I’m thinking They may have had elect issues and the digital went down
Ya, been reading about that crash the past two years. I get updates through Airbus and other threads but thanks for thinking about me.
“Even a fast controlled descent feels a bit like falling “
You’d be surprised. A continued freefall would equalize in the senses fairly quickly and can actually become a sense of climbing. Flying by the seat of the pants is dangerous without a visual reference to the horizon.
Yep. They fell like a leaf, but that nose was way up. I believe the data recorders put it at an average of 16 degrees and as much as 65.
Coming up through the ranks as I have you HAVE to manually learn hands on control. Did these so-called pilots learn in a full motion simulator that was all electronic and then set loose on the public? Air France should be sued back to the Wright brothers. Didn’t recognize a stall???? Good Grief! A Turkish airline pilot pulled the same stunt years ago leaving some island in the Caribbean. A Boeing 757 - rammed the power levers full on and still was going down.
I don’t know, the passengers must have felt they were just in rough storm turbulents if they were never notified of pending doom.
At 16 degrees, they must have had a fear of hitting the water because they weren’t sure of their altitude. I wonder how far into the four minutes it was when fear struck or did they think they were still high in the sky?
I recall speculation about rudder loss shortly after the crash. However, the black boxes have been found, and there is no evidence the vertical stabilizer broke off.
As for AA587, I have seen speculation that the composite material out of which the A-300 vertical stabilizer was constructed may be subject to fatal flaws. But, I believe the NTSB concluded it was stressed well beyond its design limits. So, that would indicate it was the rudder limit protection that failed.
I had not thought of it being night. If the accident happened at night you would be right.
There is a line in the main article that said whenever the crew would take proper corrective action the alarm bells would sound telling them they were wrong. In short, there was a tremendous instrument failure with mis-direction. The crew apparently could not overcome “the double whammy.”
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 "talked" 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.
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