Pitot tubes air disaster... Aero Peru 603

I absolutely LOVE the "Air Crash Investigation" show on NatGEO (aka, Mayday).
Almost 10 years running, with the best flight disaster recreations out there.

Just found this episode (link below).... about the insanity that can result
from plugged pitot tubes - this time on a Boeing 757. Just struck me about
the Airbus Atlantic crash and the claims about pitot tubes....

If you're NOT familiar with this series, let this be your introduction - virtually
every episode is on YouTube. They are all in 5 or 6 parts, but very easy to
select the next part and immediately resume the episode.

This particular episode is quite chilling....

Jedi

[ame]http://www.youtube.com/watch?v=pXTbseOEFdQ[/ame]

 

wow, thanks for sharing.

 

Total morons.

Apparently they were not familiar with the memory item "Unreliable Airspeed" nor the QRH.
that gives a power setting in pitch for such situations.

Tragic and avoidable with a properly trained crew.

Paul

 

As for pitot tubes, it was not the pitot tubes in the two 757 accidents... one in Peru and the other a German charter I think out of the DR. Both were caused by taped over static ports not pitot tubes as has been implicated in the A330 Air France crash.

Just wanted to clarify. Also I am unfamiliar if the 757 has an unreliable airspeed memory item as does the Airbus.

 

wow. Thanks Paul. So are you saying that all the expert conclusions and the
criminal charge for the guy with the tape were wrong? Not questioning you....
But sounds like an utter disaster of confusion in a pitch black night with no
external altitude / speed / attitude references.... can you expand on your comments?
(You did watch all parts of the episode, right??)

Thanks for the clarification of pitot vs. pitot static.

Jedi

 

Maybe so, but the poor crew training is simply one element of the cascade that ended in the fatalities. I do not think that the crew is nearly as much at fault as you do.

The whole cascade was kicked off by the maintenance personnel taping over the static ports without (I VERY strongly suspect) the use of flagging tape.

Jedi: The static system provides the pilots with altitude reference data, and crucially provides a reference for the pitot system. The pitot system provides the pilots with airspeed data. The static system utilizes static port vents that are flush with the skin to sense the ambient air pressure around the airplane. These ports are designed in such a way to minimize the turbulent air around the port. These ports are about the size of a looney. On a 757 there should be 4 or 5 of these on each side of the aircraft (I'm not 100% familiar with the 57) for various aircraft static systems (pilots and copilots altimeter/air data computers, an alternate static, and potentially an autopilot). the ambient air pressure around the aircraft is then presented to the pilots as altitude data.

The pitot system is a ram air sensor that senses air pressure created by the aircraft moving forward through the air. There are usually two of these on either side of the aircraft one for the captain and one for the first officer. The pitot system utilizes the static system as a reference for the air speed output.

The problem that occurred here, is that the maintenance personnel not only failed to remove the tape, but crucially they failed to apply the tape in a manner in which it is instantly visible. What SHOULD have occurred is that the tape should have been applied with a length of safety orange flagging tape. I personally like to use a length long enough that it is visible from both sides of the airplane, I also do not apply the tape flush such that god forbid if I miss it and everyone else misses the BRIGHT ORANGE static covering that is 20' long the airflow may remove the tape itself.

this operation happens thousands of times a day in maintenance shops (not just to wash the airplane), as it is required to comply with several government and manufacturer mandated maintenance tests. The vast majority of the time the checks and balances in the system work. Unfortunately in this case the maintenance personnel taping over the ports were careless, and 70 people lost their lives because of his actions

 

They had attitude and heading data, they just didn't have altitude or airspeed.

They actually did have radar altitude available, but they didn't use it.

While it is very disconcerting when you have all manner of erroneous alarms and lights going off, the crew should have been able to handle the issue. Pitch, power, and radar altitude should have been plenty of information. In just about any aircraft today, you could also get GPS altitude, if you had the presence of mind to look for it, but I don't know that they had it in that airplane.

The proper procedure would have been to get the airplane stabilized at a safe altitude (whatever that is), and then come back and do the ILS. Anyone with enough experience should be able to fly an ILS with no airspeed indication, by using the proper power setting and tracking the glideslope.

 

Obviously maintenance was at fault as well. However, the crew should have looked at the static ports on the preflight. I don't know where they are on the 757-- maybe they aren't visible. However, in any aircraft I've flown (and ESPECIALLY now with RVSM), a physical inspection of the static ports is always a part of the preflight.

They didn't, and they didn't handle the subsequent inflight problems correctly either.