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-   -   self test for pitot static system? (https://www.pprune.org/engineers-technicians/637982-self-test-pitot-static-system.html)

BRE 11th Jan 2021 18:41

self test for pitot static system?
 
A LH Cargo 772 recently took off with the two main static port lines not connected after maintenance. Clogged, capped or frozen Pitot tubes have caused air plain crashes.

Is there no self testing system commercially available or has been proposed that would detect major leaks, unconnected lines or closed ports to the outside world?

https://www.bfu-web.de/EN/Publicatio...ublicationFile

Basset hound 13th Jan 2021 16:52

That’s pretty sad. Some engineers signed off the work as completed, when it obviously was not. Could have cost lives, as it was it did cost the price of all that fuel they dumped.

Non Linear Gear 14th Jan 2021 23:20


Originally Posted by BRE (Post 10965840)
A LH Cargo 772 recently took off with the two main static port lines not connected after maintenance. Clogged, capped or frozen Pitot tubes have caused air plain crashes.

Is there no self testing system commercially available or has been proposed that would detect major leaks, unconnected lines or closed ports to the outside world?

B2 should have carried out a complete test with a test set. If the system was incomplete, it would have showed a massive fail. The stamper should be prosucuted in a legal court if they signed it off. Too many gash people with stamps. Actually both stampers should be done as they stamped and never checked.


BRE 15th Jan 2021 14:03

Yes, all that has been discussed ad nauseam in the Rumours & News forum. Does anyone know if a self test has been proposed or commercialised?

Non Linear Gear 15th Jan 2021 22:53


Originally Posted by BRE (Post 10968430)
Yes, all that has been discussed ad nauseam in the Rumours & News forum. Does anyone know if a self test has been proposed or commercialised?

A pitot static system is a physcial thing. It needs an external test device to prove it. That needs a competent person to do the test. I would never operate a Drunk test set without the training. B1.1 . Not passed the levels of knowledge to be proved as competent.

Sokol 18th Jan 2021 11:31

They avoid that issue nowadays by placing a sensor directly into the Port. Wether it is Pitot or Static. This eliminiates long lines of Pressurehose which could be a problem. And yes, one could do really high damage to costly Equipment. So this Problem will "phase itself out" and become an electrical problem. But at least one easier diagnosable. Avionics guy here.


BDAttitude 18th Jan 2021 13:15

For my part I was more astonished that the indepenent check of work being done to System L and R would not involve any tests to System L and R but to the backup System C. But I have to concede - it did the job, they had one set of working clocks.

cod liver oil 18th Jan 2021 16:41

Per AMM, leak test of the pitot-static system is not required after flushing the system if quick disconnects are removed and reinstalled.
Having said that, does not exonerate.
cod

mnttech 24th Jan 2021 18:49


Originally Posted by BRE (Post 10968430)
Yes, all that has been discussed ad nauseam in the Rumours & News forum. Does anyone know if a self test has been proposed or commercialised?

Hum.... To "self test" the system, I would think you would have to close off the pitot and static system (by automatically controlled valves) at the pitot/static ports, and then apply a known pressure and vacuum for x minute(s) and see if the system responded correctly. That would take care of testing the inside of the aircraft. I guess at that point you could apply bleed air to the "outside" part to blow off any tape on the pitot/static ports.
Now, how are we going to verify that the system has returned to normal? E.G. all the valves that were installed have returned to normal state?
And it would have to be certified/configurated/tested that the system would not operate in flight.
What about a short taxi and the test is not complete, a take off warning horn when power is applied?
And even if the pressure would blow off the tape/obstruction, there is no easy why to verify it is all gone, which means errors that are unknown.
I'm pretty sure no operator wants to add this complexity to a "simple" system.

Non Linear Gear 25th Jan 2021 15:52


Originally Posted by cod liver oil (Post 10970576)
Per AMM, leak test of the pitot-static system is not required after flushing the system if quick disconnects are removed and reinstalled.
Having said that, does not exonerate.
cod

No it doesn't. Some one also fitted a panel over those ADMs and didn't do a proper clear to fit.


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