Air France plane lost: 'no hope' of finding airliner ** UPDATE- Wreckage Found **

[BlackArcher101]

Should have just licked the ol finger and stuck it out the window at that point.

[ken0042]

Originally Posted by Ryan Coke

sa226 explains it well, Ken. Most modern aircraft use GPS (WJ's 737's have 2 on board, as well as other types of nav systems), however groundspeed from the GPS is really very different, though related, information. Airspeed is what is critical from an aerodynamic standpoint, hence the importance of the pitot/static system, which measure ram (dynamic) air pressure vs. static air pressure.

Yeah, I guess I was thinking this might be like an episode of Mayday that I watched where the pilots had a controlled flight into terrain; the ocean. Both pitot tubes were blocked by tape and gave conflicting readings. One showed a speed of 300 kts, and the other 400; when they were really only doing 170-180. (I forget the exact numbers; but both were false readings of "fast enough to gain altitude"; but in reality they were on a "final approach" speed range.)

I guess my thinking was that if they had GPS telling them they were flying at 140-210 ground speed; they would have known they were going too slow. Also the altitude could have told them they were not at 10,000 feet; but 200 feet.

And please, don't take my post as me thinking I am right and you are wrong; I just want to get a better understanding of this all.

I guess my other question; how do wind speeds at altitude compare to ground level? For example if the wind on the ground is 15 kts; would it likely be no more than 30 at altitude? Or can it vary so much, and maybe even be as high as 75 or 100? I know from a United flight they showed the outside temperature once, and I was surprised to see the temperature 45 C below the ground temperature.

[Ryan Coke]

And please, don't take my post as me thinking I am right and you are wrong; I just want to get a better understanding of this all.

No, not at all, you have a pretty good understanding and ask good questions.

First of all, winds can vary dramatically, but 100-150 kts at cruising altitude is not uncommon at all, regardless of what they are doing on the ground. I have also seen winds calm in cruise, though that is quite unusual. Temperatures are usually in the -55C range around 40000'.

So your thought is correct at lower altitudes, that without airspeed indications you could use groundspeed to give yourself an idea of what your airspeed should be, because they will be close, with the primary difference being head or tail wind. As you go up in altitude, the difference between the indicated airspeed and the true (corrected) airspeed becomes much greater. Ex. at sea level 250 kts indicated is basically 250 true, at 40000' 250 kts indicated is well over 400 kts true (due to pressure and temperature). However the airplane still flies as though it is doing 250 kts areodynamically, hence the importance of indicated airspeed. Then add winds into the equation, and you can see how groundspeed at altitude is of no real use when dealing with aircraft control.

The more appropriate way to deal with a loss of airspeed indications, whether at low or high altitude, is by looking at airplane attitude and power setting. Basically, with the proper power set in the engines, and the appropriate airplane pitch attitude (maybe 2.5 degrees nose up for cruise, or 10 degrees for enroute climb), you should be close to the desired airspeed. In the Mayday scenario you are talking about, if they looked at their pitch and power, they would have realized that the indicated airspeed they were getting was illogical, and could've attempted to correct it. Easier said than done of course, but that is how a crew can deal with erroneous airspeed indications.

I hope that makes some sense...

[Byrns]

Data is useable.

Investigators trying to determine why an Air France plane crashed mysteriously two years ago have recovered the complete contents of the flight data recorder and the last two hours of cockpit conversation, they announced Monday.

http://www.cnn.com/2011/WORLD/europe..._igoogle_world

[MelBridgeman]

pilot error

http://www.cbc.ca/news/world/story/2...sh-report.html

[atb]

Full pilot transcript and analysis:

http://www.popularmechanics.com/tech...ce-447-6611877


Pretty brutal timing as the captain was away from the deck when the pitot tubes froze.

[Coys1882]

Originally Posted by atb

Full pilot transcript and analysis:

http://www.popularmechanics.com/tech...ce-447-6611877


Pretty brutal timing as the captain was away from the deck when the pilot tubes froze.

That was a surreal read - I actually found my heart racing a little when I was finished.

[You Need a Thneed]

Originally Posted by atb

Full pilot transcript and analysis:

http://www.popularmechanics.com/tech...ce-447-6611877


Pretty brutal timing as the captain was away from the deck when the pilot tubes froze.

pitot tubes.

[Ducay]

Originally Posted by atb

Full pilot transcript and analysis:

http://www.popularmechanics.com/tech...ce-447-6611877


Pretty brutal timing as the captain was away from the deck when the pilot tubes froze.

PiTot tubes (not pilot).

They had things under control and the tubes started working again and then they screwed the pooch. Pretty sad ending, its almost easier to cope with for the families when its a technical fault and not pure human error.

[worth]

So, would any of the passengers have known what was going on? There was a point when the Co-Pilots didn't know if they were descending or climbing, but what would it have been like for the passengers? With no frame of reference to outside the plane, only g-forces to tell your body what is going on, I'm sure they would have known something is wrong, but would they be fully aware that something was really really wrong?

[Coys1882]

Yah that feeling of dropping altitude that fast must have been awful??

[KootenayFlamesFan]

Yeah, that was pretty sad to read, definitely could have been avoided.

[MarchHare]

That's a chilling read.

My thoughts regarding why the pilots ignored the stall warning: since the pitot tube was frozen, is there a chance they assumed the stall warning was a false indication because they lacked a functional airspeed indicator? Their ASI would be registering zero, which they could immediately conclude was a faulty reading, so would they also think the stall warning was similarly faulty?

This part floored me:

The men are utterly failing to engage in an important process known as crew resource management, or CRM. They are failing, essentially, to cooperate. It is not clear to either one of them who is responsible for what, and who is doing what. This is a natural result of having two co-pilots flying the plane. "When you have a captain and a first officer in the cockpit, it's clear who's in charge," Nutter explains. "The captain has command authority. He's legally responsible for the safety of the flight. When you put two first officers up front, it changes things. You don't have the sort of traditional discipline imposed on the flight deck when you have a captain."

How the hell does that happen? Even if there are two first officers at the controls, surely one must be the designated PIC when the captain isn't in the cockpit, right? I've logged time flying a 172 with a friend (also a pilot), and we always knew who was in command of the aircraft at any given time. This seems like such a rookie mistake, it's almost unbelievable. I know that's easy for me to say from the comfort and safety of my computer and not in the cockpit during an emergency situation, but still!

[kirant]

Originally Posted by worth

So, would any of the passengers have known what was going on? There was a point when the Co-Pilots didn't know if they were descending or climbing, but what would it have been like for the passengers? With no frame of reference to outside the plane, only g-forces to tell your body what is going on, I'm sure they would have known something is wrong, but would they be fully aware that something was really really wrong?

No plane will normally fly speeds of that fast or with that many Gs on your body. Because it sounds like they were decending for a minute, I think the automatic assumption is that something has gone horribly wrong.

[burn_this_city]

I fly enough that I get a sense when we're descending. I would think some if not the majority of the passengers knew they were going down.

[Bigtime]

Originally Posted by worth

So, would any of the passengers have known what was going on? There was a point when the Co-Pilots didn't know if they were descending or climbing, but what would it have been like for the passengers? With no frame of reference to outside the plane, only g-forces to tell your body what is going on, I'm sure they would have known something is wrong, but would they be fully aware that something was really really wrong?

I would say maybe, maybe not. In the dark of night and with the plane being bumped around from the storm the human body is pretty much useless at sensing ones true orientation. Accelerations feel like a pitch up, a decelerations like a pitch down, and rolls and other inputs the body can interpret in different ways.

I think the engines being at full 100% power would be the one thing that someone familiar with flying would get suspicious of. It would be noticeably louder in the cabin once they went to TOGA power.

I wonder if even the 10,000' descent would have given you that sinking feeling in your stomach? If the plane in a nose up stall built up towards that vertical sink rate you may not have been able to tell. Unlike nosing a plane over and dropping into that kind of descent (kind of like going over the top of a rollercoaster).

Such a damn shame to see that they did get all the pitot information back and still couldn't recognize the problem. But we can all take solace in the fact that this in now another lesson that all pilots around the world will read about and training will take into account the mistakes made that night.

The Transport Canada Aviation Safety Letter has a slogan that sums things up in regards to where we go from incidents like this:

"Learn from the mistakes of others. You'll not live long enough to make them all yourself."

[Leon]

Such a shame. They couldn't muster up CRM in that situation.

It's a little mind boggling as to why the FO had control for so long. In fact, a precarious situation like navigating around a storm at that altitude should really be administered by the acting Captain.

This solves the mystery though...Very very sad.