Air France jet vanishes

www.pprune.org has the best write ups on the AF447 incident on their forums. There is a locked thread with over 50 pages, and a second one has just been started. IMHO it is the best pilot oriented website out there.......and, if you're a pilot, you'll be able to follow the conversation about this accident, otherwise, it's pretty technical and full of industry lingo, but still very, very, interesting for the uneducated.

 

That's what I'm wondering.

It's very sad to hear this.

 

That's what I was thinking

 

just read this:

Transmissions from the aircraft in the final moments before it vanished over the Atlantic Ocean show there was an "inconsistency" in measured airspeeds, Airbus said.

"If [airspeed indicators] are malfunctioning, it can give a false read into the cockpit that can be misinterpreted," said Peter Goeltz, former managing director of the National Transportation Safety Board.

The jet flew into a storm before going down and may have been flying at the wrong speed for those weather conditions, officials have said.

Air France Memo:

The memo sent by Air France Friday says that a series of actions to reduce the risks of loss of airspeed information are being reinforced by "notably, the improvement of pitot models on Airbus' fleet of medium- and long-haul flights."

"On this topic, a program of replacing pitots with new models is under way," the memo reads. "It should be completed in coming weeks."

A blocked or malfunctioning Pitot tube could cause an airspeed sensor to work incorrectly and cause the computer controlling the plane to accelerate or decelerate in a potentially dangerous fashion.

Airbus said the French agency investigating the crash found that the doomed flight had faced turbulent weather and inconsistency in the speed readings by different instruments.

That meant "the measured air speed of the aircraft was unclear," Justin Dubon said.

In such circumstances, flight crews should maintain thrust and pitch and _ if necessary _ level off the plane and start troubleshooting, Dubon said.

Meteorologists said the Air France jet entered an unusual storm with 100 mph (160 kph) updrafts that acted as a vacuum, sucking water up from the ocean. The moist air rushed up to the plane's high altitude, where it quickly froze in minus-40 degree temperatures. The updrafts also would have created dangerous turbulence.

The jetliner's computer systems ultimately failed, and the plane likely broke apart in midair.

* * * * * *
Best rough air penetration speed is most important - slowest possible speed, so if too slow then it stalls and down it comes admist the 100 mph updraft possibly with the -40 deg temps causing havoc with the heated pitot tube and thunderstorm conditions that existed that night culminating in a recipe for disaster. (just my thoughts)


Here's a link to a review of the book on Weather Flying by Robert N. Buck (I remember this book!) go to page 197
http://books.google.com/books?id=Lou7f1tpERoC&pg=PA182&lpg=PA182&dq=what+happens+when+flying+too+fast+into+thunderstorms&source=bl&ots=64Ak_EH4Ph&sig=cDlWyaxPMtvFgdAJ-_DdbHQFcGw&hl=en&ei=5nYpSqjzL47DtweBioDBCA&sa=X&oi=book_result&ct=result&resnum=6#PPA197,M1


Carol

 

There seems to be some question about the RAT and the A330.

It has one. A few years back an A330 crew doing a transatlantic flight misdiagnosed a fuel leak and transfered fuel from the full tank to the leaking tank and basically pumped all the fuel out of the plane. Lost both engines and all electrics save the batteries. The RAT deployed and they dead sticked it into the Canary Islands (amazing job btw... makes Sully's impressive deed look like a walk in the park)

The RAT on the Airbus has two fuctions... it is an electric generator and it also pressurized the "Green" hydraulic system is it is needed.

The RAT generates enough power to power the computers signal the hydraulic actuators for the flight controls.

 

Pretty much the same for the 777. Also provides power for basic flight instruments.

 

I think that would pretty much make me wrong on RATs. Not possible on something as small as an F-16, but easily possible, apparently, on aircraft with a lot of real estate.

Taz
Terry Phillips

 

You ARE correct in that the abilities of the RAT are severely limited. In no way do these provide anything close to full controls and instruments, more like minimal 3-axis abilities with minimal instruments and NOTHING ELSE.

 

Al- The F-16 has a hydrazine (rocket monopropellant) powered turbine for its emergency power unit to provide electrical power and limited hydraulic power in case of a flame-out and allowed a rapid descent and landing. The hydrazine provided about 10-15 minutes of power and hydraulics under flame-out conditions. Hydrazine is the reason the Navy would never sign up to use the aircraft on carriers, because it was considered too dangerous for use in the confined, below decks environment of carrier. Hydrazine is highly corrosive and carcinogenic.

The F-4 had a RAT, extended by a nitrogen air bottle and usable between 90 and 515 KCAS, which powered the emergency generator and could provide electrical power in case the the engine driven generators gave up the ghost. It provided no hydraulic pressure, however, so if you lost both engines, you had no flight controls and stepped over the side.

Taz
Terry Phillips

 

2 bodies found according to CNN.

 

"RECIFE, Brazil — A Brazilian military official says searchers found two male bodies in the Atlantic Ocean near the area where an Air France jet is believed to have crashed.

Air force spokesman Col. Jorge Amaral says the bodies were recovered Saturday morning.

They were picked up roughly 400 miles (640 kilometers) northeast of the Fernando de Noronha islands off Brazil's northern coast.

Amaral says a suitcase also was found containing a plane ticket for the flight."

AP News

 

God rest their souls.

Taz
Terry Phillips

 

This accident has now denigrated to Air France blaming Airbus and Airbus blaming Air France. I have a feeling this accident is going to be expensive for both of them.

Did I mention the part about me not liking Airbuses?

Taz
Terry Phillips

 

There is talk about the A330 pitot freezing up and the static ports being plugged by "mud wasps" causing faulty readings. Has anyone heard of heated pitot masts and pitot covers? I have never heard of this problem with any Boeing or any other airplane with which I have had experience. If that is thought to be the cause, then let's get it fixed and continue to investigate this accident and determine the sequence of events if possible and then give a hard and long look at who is responsible.
I'm with you, Terry, on Airbus.
Switches

 

I recall two 757 crashes, one off the Dominican Republic and one off of Peru, where pitot problems were implicated. A report on the Dominican crash that I read indicated the possibility of a mud wasp nest blocking the pitot/static ports; in the case of the Peru crash a mechanic apparently left masking tape on the ports. Of course, Boeing was not implicated at all. Can anyone supply any additional details?

 

Okay, Jim, I'm wrong and I do remember those incidents now . Sounds like a lack of pre-flight checks. As far as I know , there aren't any new reports on causes but they have found more bodies and debris. I have a strong feeling that they flew into turbulence inside a cell and just broke up.
Switches

 

A couple years ago a friend had to make a quick landing after airspeed indication went wacky. Upon inspection maintenance found a bee had made a perfect impact into the pitot tube, it was really a one in a million situation and kinda funny in retrospect.

 

I imagine that all of us are guilty of missing some pre-flight or post-flight procedures and I am guilty of one of not covering the pitot after a summer flight. The next time up I found that I had no airspeed. After landing I decided to clear the system if it was plugged. I disconnected the line at the instrument fitting and back-blew the line. The pitot tube turned into a mini machine gun firing out all sorts of green and brown bugs and eggs ( I think). It never happened again.
Switches

 

I remember the Peru crash. Take off at night, out over the ocean. They soon found that they had no way of knowing up from down because the instruments were giving incorrect readings or were non-functional. This was in IFR conditions.
Eventually flew straight into the ocean under power. Tragic. You are correct in that the static ports were covered with masking tape left over from maintenance/washing etc...............

 

Here I go again. I happened to be walking down a transportation aisle in the old 707 final assembly building when there was a tremendous explosion behind me. No smoke or flames but a lot dust or mist. People were staring at the first 707-320 in the line where its wing center section was being leak tested. Even though a test bench was hooked up to it to control the pressure, the center section had blown up. The employee assigned to monitor the pressures had gone to lunch and nobody was present to see that the pressure had gone sky high. Upon inspection it was found that the pressure sensing port was still covered by masking tape from a recent overhaul and repainting of the bench. Unbelievably, the center section was repaired INSIDE the airplane.
Switches

 

Spasso- The standby instruments were determined to be in perfect working order on that 757. Anyone who flies a glass or TV based cockpit aircraft knows, or should know, to cross-check the standbys, and fly off them if the glass screens look squirrelly. The pilot and co-pilot on that aircraft killed everyone on board because they were lax, ill-trained, or incompetent. On simulator checks, they should have seen the identical malfunction dozens of times. They flew a perfectly capable aircraft with minor instrument malfunctions into the water.

Taz
Terry Phillips

 

Learned more than I thought I could about the subject off of FChat, one hell of a resource.

I'm still curious if the plane made any navigation changes prior to getting into the weather or if the crew just decided to ride out the storm.

 

Just amazing that a .02 cent piece of masking tape can bring down a $50MM+ airliner.

When I started my pilot's training (which I regrettably never completed), the pre-flight wasn't stressed enough. However, even an eagle-eyed pilot doing a walk around might not have picked up on something so mundane.

And, in this instance, it would be highly unlikely to be able to recover those specific bits (unless they're still attached to a bigger piece of recoverable debris). So, we may really never know. Just educated guesses. Would data from the FDR or CVR clarify? Why would they be operational for the first several hours of flight and then fail? Iced over? So many questions...

CW

 

Now that you mention it I do remember something about the flight crew failing to cross check off of other systems and because of that the errors stacked up. I read an abbreviated transcript of the communications and these guys were totally paniced and turned upside down, literally.
Thanks for clarifying that Terry