pitot tube failure ?

[ghostrider]

Hi
I am curious if the pilots have training about pitot tube failure,in this
air crashes probably not?


Birgenair Flight 301

Northwest Airlines Flight 6231

Austral Lineas Aereas Flight 2553

Aero Peru Flight 603

Air France Flight 447

[Highkeas]

Originally Posted by ghostrider

...................
Aero Peru Flight 603
.............

My recolection is that this flight crashed because its static pressure ports were blocked by tape thus giving a faulty altitude reading.

[Evan]

Originally Posted by Highkeas

My recolection is that this flight crashed because its static pressure ports were blocked by tape thus giving a faulty altitude reading.

Aero Peru Flight 603 crashed because the crew were not monitoring the radar altitude. If they had been, an escort plane would have reached them and helped them back to the airport. Contributing was the ATC not realizing that the transponder altitude was inaccurate because it was coming from the plane and not the air search radar as they somehow imagined. And then of course Boeing neglected to provide hi-visibility flags for the static ports, and specified using tape instead...

[Gabriel]

Originally Posted by Highkeas

My recolection is that this flight crashed because its static pressure ports were blocked by tape thus giving a faulty altitude reading.

Aeroperú had ALL its static ports blocked with sticky-tape rendering ALL its altimeters AND ALL its vertical speed indicators AND ALL its airspeed indicators faulty.
That included the encoding altimeter that sent the altitude information with the transponder and that the radar operator relied to the pilots.

Neither the radar operator nor the pilots realized that the altitude shown in the ATC's radar screen would be as faulty as the on-board one because it WAS an on-board one.

The pilots never fully understood that they had a total static-pitot system failure, they sometimes believed that the airspeed was right and the VSI wrong, then that the altitude was right but the attitude wrong, they had simultaneous overspeed and stall warning and didn't know which to believe (the stall warning was not affected by the failure but the overspeed warning was). It was a hell of a nightmare and of a workload in that cockpit. Two times they descended below the radio-altimeter threshold (its readings become "alive" at 2500 ft) but they didn't follow it, maybe because they didn't think of that or maybe because they didn't believe them either. And to make things worst, all the flight was in the clouds.

All in all, they managed to keep the plane upside down and within the envelope for quite a long time and when they crashed, they did so with the plane in-control (the plane skimmed the water, bounced and crashed a second time). A contrast with Air France where only the airspeed indicators were unreliable for about just one minute and they lost control of the plane and crashed totally out of control.

Had they realized that they had a total static failure, they could have applied the UAS procedure, climbing above the clouds based on attitude and power settings, and navigated to a airport with visual conditions for landing.

[AVION1]

Originally Posted by ghostrider

Hi
I am curious if the pilots have training about pitot tube failure,in this
air crashes probably not?


Birgenair Flight 301

Northwest Airlines Flight 6231

Austral Lineas Aereas Flight 2553

Aero Peru Flight 603

Air France Flight 447

Not sure about training, probably is about common sense.
On most of the flights you mention above, the crew failed to perform a 360 around the aircraft and visually check the pitot tube and static ports for obstructions.
One day I took off on my PA-28-161 with the pitot tube clogged with dirt. I realized something was wrong when I was on the runway taking off, I didn't have any airspeed indication and the airplane was almost airborne, you could feel it, the yoke pushing against you and the aircraft lifting from the runway, so I decided to take off and go around, and land again.
At least it was better than aborting the take off and crashing at the end of the runway.

[ghostrider]

I think the visible pitot-test on the ground it´s not enough ?

[guamainiac]

The "book" called for a bright silver tape and really, as former line crew fellow, that tape should have been removed by maintenance after cleaning.

It is hardly Boeing's fault.

Silver shiny speed tape stands out so the line crew doesn't miss it or, if they do, it is easier to spot during a preflight .... but they used dull grey duct tape which is not exactly eye catching is it? I was an airframes mech in the military and by default ... did hydraulics too so I had done my share of washing and painting.

Evan, Boeing or not, still you have a good idea. They should use orange tape of sufficient quality to withstand the cleaning/washing of the aircraft. That (orange tape), or a color that is "oppositional" (that is), easy to spot and different from the color of the aircraft.

Avion, we all know that mud "wasps" and bird nests are common blockages, but imagine doing a "360" walk around on something that is large and high. Heck, I remember boarding a 747 TWA bird bound for Hawaii and almost offered to stop drill the cracks that were visible from the gangway. I almost wanted to say ... "It'll only take a minute". The bigger the plane the more places there are for cracks and leaks to hide and quite frankly, I was a nervous wreck with all of the "what if's" not even mentioning the "accepted (but non sanctioned), short cuts", now toss in a bit of rain and such?

I am simply amazed that fewer aircraft go down than those that actually do. I think the proper way to state it is that .... more planes stay aloft despite us, not because of us.

[Evan]

Originally Posted by guamainiac

The "book" called for a bright silver tape and really, as former line crew fellow, that tape should have been removed by maintenance after cleaning.

It is hardly Boeing's fault.

Silver shiny speed tape stands out so the line crew doesn't miss it or, if they do, it is easier to spot during a preflight .... but they used dull grey duct tape which is not exactly eye catching is it? I was an airframes mech in the military and by default ... did hydraulics too so I had done my share of washing and painting.

Evan, Boeing or not, still you have a good idea. They should use orange tape of sufficient quality to withstand the cleaning/washing of the aircraft. That (orange tape), or a color that is "oppositional" (that is), easy to spot and different from the color of the aircraft.

Avion, we all know that mud "wasps" and bird nests are common blockages, but imagine doing a "360" walk around on something that is large and high. Heck, I remember boarding a 747 TWA bird bound for Hawaii and almost offered to stop drill the cracks that were visible from the gangway. I almost wanted to say ... "It'll only take a minute". The bigger the plane the more places there are for cracks and leaks to hide and quite frankly, I was a nervous wreck with all of the "what if's" not even mentioning the "accepted (but non sanctioned), short cuts", now toss in a bit of rain and such?

I am simply amazed that fewer aircraft go down than those that actually do. I think the proper way to state it is that .... more planes stay aloft despite us, not because of us.

I would think they would have proper plugs with "remove before flight" flags on them. It would also be pretty simple to put photocell sensors in the ports that would detect a light blockage and deliver a "check static ports" warning on engine start (sensitive enough to work on an apron at night). I think pitot blockage would be pretty obvious before V1, as Avion had experienced.

Silver shiny speed tape stands out so the line crew doesn't miss it

Not on American...

[Evan]

http://zaviation.ca/products/sesame/...t%20covers.htm

A400:

[guamainiac]

True indeed. That is why I "caged" your follow through with an oppositional color. They must use pressure washers and such and that would knock out or dislodge any pop-in or press fit devices.

However, if you take it one step farther, having a numbered system of devices to keep water or solvents out may be more real world and not expensive. Having a line crew member whose job it is to prep it out with 25 seals/panels or whatever combo, better come back to the shop with 25 or whatever that variant calls for?

Pretty "KISS" isn't it?

BTW, pressure washers are one of the worst tools ever to come around. I have seen a lot of perfectly good components ruined by those things blasting out grease or oiled parts. That pressure forces water where it was never intended to be. We had one fellow bring one out to our flying club (when washers first came on the general market), he did a lot of damage to a WWII Jeep, a farm tractor and a few other devices before we banned him and that damned thing from the field.