Backcountry Pilot • Air France Flight 447

Air France Flight 447

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Re: Air France Flight 447

Exactly nmflyguy,

Northwest Airlines had identical pitot system failures on two of their A-330s. The captains flew "Pitch and Power." Worked their way out of the crisis and landed safely.

I would not have wanted to be in the cockpit of AF-447 that night.....but it seems clear that "experience" was a factor. Remember.... these foreign airlines often hire kids right out of college with zero time and teach them to fly. Next thing you know some youngster with 500 flt. hours is sitting in for the captain during his rest break....then the s***t hits the fan.

At Osh Kosh about 15 years ago I had a Lufthansa A-340 captain trying to buy my Pitts from me. He was 35 years old had a bit less than 5,000 hours total time and was in command of a 4 engined, international airliner. Most new copilots at the major U.S. air carriers have close to that much flight time the day they are hired.

Different world.

Bob
Last edited by z3skybolt on Thu Jun 02, 2011 9:16 am, edited 1 time in total.
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Re: Air France Flight 447

When a swept wing plane is fully stalled it's different than in a small straight wing GA plane. It can drift straight down with no air flow over the wing or elevator.

Had these ding dongs pushed over then who knows, they might have broke the stall. Many times you have to take more action, like drop the gear or raise the boards to change the flight characteristics enough to break the stall and get the nose going into the wind. Heck, even going into reverse thrust inflight might have saved the day. That would have caused one heck of a pitch down with wing mounted engines!

As to Mach tuck. When the shock wave forms it causes separation, thats true. But it also moves the center of lift sharply aft, further exasperating the problem by putting the nose even more down. Many pilots have been heard on the radio stating they are over sped and can't control the situation only to break up in flight and never be heard from again. Not that this happened here, but that's how Mach tuck works.
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Re: Air France Flight 447

I'm another one glad he wasn't in the cockpit of AF447 that night.

This was a deep stall in a swept wing aircraft at night over a boiling cauldron of Inter Tropical Convergence Zone thunderstorms when the flight computers threw up their hands and said "I don't know WTF is going on, so, YOUR AIRPLANE". Yeah, a few minutes later they were all in the drink, but I can't judge any of their actions or experience. I don't think very many A330's have ended up in alternate law flight mode, let alone over the middle of the Atlantic in such scary conditions.

Maybe they did violate the first law of inflight emergencies: DO NOTHING until you hear more. There may have been a short period of inertia when a light bulb could have gone on in the mind of the pilot flying, but, once the airspeed (that they didn't know) started to decay, the handwriting was getting plastered on the wall. Why didn't they just nose over??? Well, this was not like any stall we ever practiced with our CFI. First, the A330 has no aerodynamic feedback to that wimpy side stick and no stick shaker to let you know you are on thin ice. Second, in Alternate Law mode, the fly by wire system that just cut the autopilot and autothrottle has also removed the stall protection, ie, it will let you stall without intervening by limiting the control deflections. Alternate law mode removes high AoA protection as well as low energy protection so you can place yourself in a situation with high drag, low airspeed and high AoA pretty quickly. There was an aural stall warning buried in the 20 other alarms that were going off.

Swept wings start to experience a lot of spanwise flow at high angles of attack. The tips stall, leaving you with compromised roll control and a center of lift that shifts forward holding the nose UP. AoA increases while your deck angle is seemingly normal, i.e. your attitude indicator looks like everything's OK. Meanwhile, your elevators are becoming useless as you start to plummet almost vertically while sitting dead level. This happened to a BAC 1-11 way back when. It had test pilots aboard. They stalled at 30,000 feet. They tried everything: full stick forward, full stick aft, full roll right and left, full throttle, idle throttle, full throttle on one side, thrust reversers, every tool on their belt. They came down flat at over 9,000 ft/min (sound familiar?). They all perished. Now, imagine trying to pull it off IFR...at night...in turbulence...with little or no information to Google a solution with.

My bed is gonna feel extra snug, safe and comfortable tonight. God rest their souls, all of them.

YB
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Re: Air France Flight 447

The Airbus aircraft are "designed" to be flown by the Flight Management System and the autopilot. Airbus Industries STRONGLY encourages airlines to adopt their "get the autopilot ON and keep in ON to avoid human error" attitude. A lot of airlines try to get the crews to be on autopilot ASAP after takeoff and only disconnect it on final, and a lot of captains want their F/Os to do just that (I don't but I'm just a misplaced bush pilot :wink: ). When I went through training on the A320 family the oft heard response to my "Boeing" type systems/procedures questions were either a) you can't affect that so you don't need to know, or b) the odds of that happening are so low that you don't need to worry about it. [-X I was fortunate to have a couple check airmen who were as old-school as I about the aircraft that we fly so I was able to go beyond the standard training package. I had done high altitude stalls in a B737 simulator previously, and had the opportunity to get the A320 simulator into Direct Law (Airbus logic: Normal ops-Normal Law, loss of some of the computer protections-Alternate Law [where AF447 was] and loss of all computer protection-Direct Law) and then perform a high altitude stall. A swept wing fully stalled at high altitude requires a lot of altitude and a smooth hand to recover. The ability to hand-fly a jet in the narrow part of coffin corner is a stick-and-rudder skill that is not trained by many carriers (our training department does). Most foreign carriers use an "Ab Initio" training program where their pilots are trained from hour 1.0 to fly the airline's way. Very structured, very insulated, very controlled and very little breadth of experiences. Most US/Canadian airline pilots have extensive military and/or general aviation experience and thus have a fairly big bag of knowledge and experiences to draw from. Take a First Officer and an IRO from an Ab Initio background, fail the pitot system (which they probably have never seen), at night, at high altitude, around thunderstorms, loose the autopilot due to the loss of airspeed indications, have multiple alerts/warnings/ECAM messages of various multiple failures related to the loss of the pitots going off and you have just overwhelmed that crew. The autopilot fails, the Pilot Flying grabs the stick and intentionally or inadvertently adds a little back pressure, the aircraft begins a slow climb, the indicated airspeed begins to rise due to the iced over pitots, the PF increases the pitch a bit more to "slow" the aircraft which increases the altitude resulting in more indicated airspeed. Added to all of the other commotion the "mystery" of the increasing airspeed is really beginning to play with the PF's mind. "Why won't this thing slow down?" More pitch up, more speed. :? I think that this is how they ended up in that extremely high deck angle and angle of attack and thus the deep stall. Once you get a swept wing aircraft into a deep stall you are in trouble. Corrective action must be aggressive and immediate or you will return to earth just as AF447. I agree that one should, in this kind of a situation, ignore the Mach/Airspeed indicator and fly pitch and power. But if you have never experienced that kind of failure or have been trained to fly that way it may not occur to you, especially if there are multiple other distractions going off at the same time. "You do not rise to the occasion, you default to your level of training" - Barrett Tillman. One of my favorite quotes because it is so true. Train hard.
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Re: Air France Flight 447

Cowboy wrote: "You do not rise to the occasion, you default to your level of training" - Barrett Tillman. One of my favorite quotes because it is so true. Train hard.


Thank you Cowboy. I better understand now. When I was in the Fire Dept we trained, hour after hour. For stuff we would probably never see for the reason you Barrett Tillman said. The more I think about that the more I realize how true it is.

I always assumed that these jet pilots were trained for every conceivable emergency. I sure know better now. I get to fly to South Africa in September on Virgin Atlantic. Glad it is a Boeing 747.

Good day
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Re: Air France Flight 447

Great insight, guys. Thanks. Reading the stuff about deep stalls in a delta wing really gives me the chills.
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Re: Air France Flight 447

As every other post says, this whole episode points right back to numerous threads regarding training over the last 20 or 30 years and the lack of the basic building blocks that are now sadly lacking. Not very many of today's airline pilots have gotten out there and scared themselves for 1000 hours before getting a job in a light twin. Unfortunately that is not likely to change anytime soon. I look at the follow up to the Colgan crash and the call for new hires to have 1500 hours. The regionals are still advertising for sub 1000 hour pilots and won't talk to you if you have over 2000.
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Re: Air France Flight 447

Here's something I've been wondering about for a while, since I've never flown anything with hydraulic or fly-by-wire controls:

Is there really much aerodynamic feedback in the yoke of a big Boeing? Since the control system is all hydraulic, it seems to me that you wouldn't get much feedback there either. I realize that the fly by wire in an airbus/most fighters completely takes control feel out of the equation.

Do some of the big jets or fly-by-wire fighters try to simulate control forces back to the pilot?
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Re: Air France Flight 447

There is a long discussion of this on

airliners.net

in the forums. Of course there you have to figure out who knows what they're talking about-and who is just 'talking'..... :) Here, we are all 'experts' :lol: .....

lc
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Re: Air France Flight 447

From my own experience I've flown a B727 and a CRJ. It's been awhile but here's how I recall it.

The 727 used cables, pulleys and push rods. Control surfaces are flown by tabs you turn the yoke and a tab on each aileron moves. With this movement of the tab airflow flies the whole surface to a position that then moves the plane as the pilot wanted. Feedback was normal as there weren't any hydraulics or wires involved.

The CRJ was different though. It used cables, pulleys and pushrods as well, but they all terminated at a hydraulic actuator at each surface. Obviously there is redundancy built in. There are 3 separate hydraulic systems with a minimum of two pumps each (1 has 4 pumps) and primary control surfaces have inputs from all 3 systems. Any 1 hydraulic system can run the whole show, still, a COMPLETE loss of hydraulics turns the plane into a lawn dart.

As to feel in the CRJ, how do you provide feedback to the pilot when his yoke and the actual control surface are separated by a hydraulic actuator? Easy...you hook a servo up to the cable to give the pilot the feel the computer thinks he should feel.

Sounds crazy, but it did work very well. Never had a problem and it was accurate too. It "felt" like a real plane and you move through various phases of flight.



...sorry this got wordy.
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Air France Flight 447

Artificial feel system...
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Re: Air France Flight 447

Rooster Cogburn wrote:Artificial feel system...



Lol. Well, that would be the much shorter answer...
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Air France Flight 447

GlassPilot wrote:
Rooster Cogburn wrote:Artificial feel system...



Lol. Well, that would be the much shorter answer...


Roger that Glass, actually an artificial feel device to enable the pilot to receive feedback...
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Re: Air France Flight 447

Rooster Cogburn wrote:Roger that Glass, actually an artificial feel device to enable the pilot to receive feedback...


First our airplanes, and now this...



Gump
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Air France Flight 447

GumpAir wrote:
Rooster Cogburn wrote:Roger that Glass, actually an artificial feel device to enable the pilot to receive feedback...


First our airplanes, and now this...



Gump


I hope they don't short out and electrocute big daddy when he unloads at end of vid in menage a trois...
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Re: Air France Flight 447

GumpAir wrote:
Rooster Cogburn wrote:Roger that Glass, actually an artificial feel device to enable the pilot to receive feedback...


First our airplanes, and now this...


I have spewed Newcastle all over my keyboard, and my Hot Air annunciator is screaming red alert.
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Re: Air France Flight 447

porterjet wrote:As every other post says, this whole episode points right back to numerous threads regarding training over the last 20 or 30 years and the lack of the basic building blocks that are now sadly lacking. Not very many of today's airline pilots have gotten out there and scared themselves for 1000 hours before getting a job in a light twin. Unfortunately that is not likely to change anytime soon. I look at the follow up to the Colgan crash and the call for new hires to have 1500 hours. The regionals are still advertising for sub 1000 hour pilots and won't talk to you if you have over 2000.



Porterjet,

The regionals are scooping up all the low time pilots that they can....prior to the 1,500 hour rule going into effect. They won't talk to the 2,000 hr. guys as they are saving them as a hiring pool "after' the 1500 hr. rule takes effect. What a upside down situation in which the more experienced pilot loses out to the less experienced.

It is an absolute crime that the regionals could care less about experience and safety. All they want to do is hire the cheapest kid they can....so as to maximize the profit which they recieve in their contract flying for the majors. The regionals depend upon technology to provide the safety net; not unlike the Air France/Airbus disaster. Once the 1,500 hour rule takes effect it would seem that supply and demand will cause the starting salary to creep up as more experienced pilots become harder to find and thus more expensive.

All this is why our bright, youngest son who soloed at 16,had a private and instrument rating at 18....gave up on the idea of following in dad's footsteps and is one year from finishing Law School. As recommended by Zane and others in a different thread.....our son will use his profession to fund....."flying for fun." Sad that he and others will not have the opportunity that some of us did .....having a vocation and avocation that were one and the same, while enjoying outstanding benefits and compensation.

Bob
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Re: Air France Flight 447

Well said Bob, I have a younger friend who is in the Regional business. He says they only hire low time pilots because the 4500 hour Chief Pilot doesn't want a highly experienced pilot telling him what he thinks of the airlines policies.
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Re: Air France Flight 447

If flying a modern large transport airplane is a lot like getting your stick wiggled by a Japanese sex bot, then this scene from Airplane! is amazingly prescient:

Image
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Re: Air France Flight 447

Once they entered the deep stall they were probably cooked. Air France has put some of their experienced pilots through this situation in the sim and the results weren't good. It is possible to recover from a deep stall in some t-tail sweptwing jets, but it is fairly difficult even for test pilots who are expecting the situation. A third officer, with alarm systems going crazy, in a severe thunder storm, at night....

Rest in peace for all souls aboard.

D
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