PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   The Pacific: General Aviation & Questions (https://www.pprune.org/pacific-general-aviation-questions-91/)
-   -   Check Flights and Pulling Circuit Breakers (https://www.pprune.org/pacific-general-aviation-questions/638374-check-flights-pulling-circuit-breakers.html)

deja vu 31st Jan 2021 07:35


Originally Posted by Capt Chambo (Post 10979295)
Take a moment to Giggle “National Airlines Flight 27” in November 1973 before doing anything like this in flight!

Interesting read. Reminds me of the guys on the B727 pulling flap CBs and then partially extending slats during cruise.

Seriously though, if you can't do it in a simulator, don't do it at all.

exfocx 31st Jan 2021 07:39


Originally Posted by blind pew (Post 10979801)
Wasn't there a new big one having a pre acceptance engine run up at Toulouse that ended up broken over the blast deflectors after some bright spark pulled a CB to silence the take off warning?

From memory (if I've got it right) that was a M.E. airline crew doing a 4 engine full power engine run on an A340, it jumped the chocks and .........

compressor stall 31st Jan 2021 07:59


Originally Posted by exfocx (Post 10980130)
From memory (if I've got it right) that was a M.E. airline crew doing a 4 engine full power engine run on an A340, it jumped the chocks and .........

Possibly you're mixing up the Etihad A340 and the Saudi 747?

A340 in TLS was doing high power with no chocks. No untoward CB playing. There was a customer rep on board, but the Airbus test guy was in charge.

The Saudi 747 in KL was being taxied with 1 and 4 started but the brakes run off 2&3's hydraulics.

srjumbo747 31st Jan 2021 09:21


Originally Posted by Lookleft (Post 10980008)
I would be interested to know why the question about C/Bs and check flights is being asked in the first place.

Indeed. The initial poster, Flying Taxi, is a new member therefore why have you,
Flying Taxi, asked the question?
Also, why are the rest of you even commenting and indulging this character?
Beggars belief!

mustafagander 31st Jan 2021 09:36

Ah Stallie,
B747 brakes. Primary brakes #4, secondary brakes #1, reserve brakes #3. There is an auto select of secondary brakes if primary hydraulics low pressure. No problem in your case, a world of pain if using only #2 & #3 engines.
As I recall it they were taxiing on inboard engines, #2 & #3. That's a huge cock up - no body or nose gear steering. Simply selecting #1 & #4 ADPs to auto solves it all.

compressor stall 31st Jan 2021 12:11


Originally Posted by mustafagander (Post 10980188)
Ah Stallie,
B747 brakes. Primary brakes #4, secondary brakes #1, reserve brakes #3. There is an auto select of secondary brakes if primary hydraulics low pressure. No problem in your case, a world of pain if using only #2 & #3 engines.
As I recall it they were taxiing on inboard engines, #2 & #3. That's a huge cock up - no body or nose gear steering. Simply selecting #1 & #4 ADPs to auto solves it all.

thanks for clarification. Not type rated sadly!

Ex FSO GRIFFO 31st Jan 2021 13:22

Thankx 'LL',.......sounded good at the time.....
Cheers

Teddy Robinson 31st Jan 2021 13:59

Safer and perhaps cheaper option
 

Originally Posted by Lazyload (Post 10979922)
How else can you practice a manual gear extension? Pull gear motor cb, select gear down, nothing happens, pump gear down manually. Not that you need to do this every check flight but it’s nice to know that it works.

Perhaps ask the engineers to put the aircraft on jacks while you play with an emergency system ?
Some of these do not permit retraction after the emergency system is used.


armchairpilot94116 31st Jan 2021 14:36

https://www.nytimes.com/2015/12/02/w...indonesia.html


Checkboard 31st Jan 2021 15:03


Interesting read. Reminds me of the guys on the B727 pulling flap CBs and then partially extending slats during cruise.
Also not true, It was an accusation from the investigation - but later criticized (and corrrectly, imho).

https://en.wikipedia.org/wiki/TWA_Fl..._investigation

MissChief 31st Jan 2021 16:41

Interesting thread. I recall on a few occasions leaving the 2-person Flight Deck of an A330, trotting to the rear of the aircraft (QRH in hand) and pulling a whole raft of c-b's. Then re-setting the pesky things after a suitable time. OK, it was a procedure for when the lavs stopped flushing, not a good event with 5 hours over-water remaining and 320 pax.

I wonder how that approved procedure would have been defensible if the single pilot then had to deal with a major problem, with no easy way of the other pilot being informed and returning to his/her post.

Consol 31st Jan 2021 16:44

Don't! John T's comments earlier on in this thread are quite correct. Often several systems on a cb, some electrical systems are picky about how they are powered up or down, cbs get mixed up....I could go back on.

I remember a trainer in a previous airline who thought he was far smarter than he ever really was. His command training trick was to reach up to the overhead panel and switch something off/on that shouldn't be whilst the command cadet was looking elsewhere 'to make sure he was constantly checking things'. Think he hit the ram air one once. Stupid behavior from a 'trainer' who would have had a limited understanding of systems anyway.
Always have a healthy suspicion of your ability to cock something up.

neilki 31st Jan 2021 19:17

Approved!
 

Originally Posted by FlyingTaxi (Post 10979252)
Check Flights and Pulling Circuit Breakers

Industry thoughts/rulings/legislation on pulling circuit breakers to fail systems on high performance aircraft during check flights in aircraft (not simulator flights)?

I think it's a great idea. Please see the following:

1) Ensure you have no children. The gene pool will thank you.
2) Proceed to an overwater location
3) Have at it

Honestly; there I was thinking 'there's no such thing as a stupid question...'

CargoOne 31st Jan 2021 20:30


Originally Posted by Lookleft (Post 10980008)
I would be interested to know why the question about C/Bs and check flights is being asked in the first place.

I smell the question comes from bizjet practices. There are large number of bizjet operators who do the sim only once a year and one in between is replaced by the training on a real aircraft - sounds it might have happened there. I have a hard time to believe any airlines (at least first and second world) are doing anything like pulling cbs on a real aircraft check rides.

Squawk7700 31st Jan 2021 23:16

Pull the breaker, sure... on the instructors intercom!


KRviator 1st Feb 2021 00:10

That LOT 767 gear up a few years back was the result of an open CB labelled BUS BAT DIST (in combination with no hyd. fluid for normal extension, mind you).

Who would have thought a CB labelled BUS BAT DIST would also be critical to the alternate gear extension system? The point being, just because the CB says X, doesn't always mean it also powers Y.

jimtx 1st Feb 2021 00:33


Originally Posted by Checkboard (Post 10980416)
Also not true, It was an accusation from the investigation - but later criticized (and corrrectly, imho).

https://en.wikipedia.org/wiki/TWA_Fl..._investigation

There were rumors and possibly some that admitted to knowing the technique to pulling a certain CB, name escapes me, which allowed some flap extension without leading edge devices to allow high altitude cruise. But there were two CBs associated with the leading edge devices. LEFUS rings a bell and I don't remember the other one but if you believe the rumors the FE was told to pull one and it was the wrong one. There is no doubt that if you pull the right one you will get flaps without LEDs.

Eclan 1st Feb 2021 01:46


Interesting read. Reminds me of the guys on the B727 pulling flap CBs and then partially extending slats during cruise.

Originally Posted by Checkboard (Post 10980416)
Also not true, It was an accusation from the investigation - but later criticized (and corrrectly, imho).

https://en.wikipedia.org/wiki/TWA_Fl..._investigation

Apparently it was quite common practice on the 3 holer back then, Checkboard.
They'd pull the CB to prevent slat deployment, then move the flap lever to extend the flaps to about 2° and enjoy the ride. The investigation didn't prove anything untoward but I think they were concerned there were a few porky pies being told when they realised the CVR had allegedly been erased after landing.

deja vu 1st Feb 2021 02:25


Originally Posted by Checkboard (Post 10980416)
Also not true, It was an accusation from the investigation - but later criticized (and corrrectly, imho).

https://en.wikipedia.org/wiki/TWA_Fl..._investigation

Lets say unsubstantiated rather than not true. IMHO.

MENELAUS 1st Feb 2021 03:26

Many moons ago my then excellent employer had a tech wash up every year; combined with the cabin crew on the second day ( refresher AEP and again an attempt at harmonising relations with the cabin crew, although from memory they didn’t really need harmonising ). And a few drinks laid on afterwards as an extra incentive. Win win.
Anyhoo. In the spirit of educating the rest of us two recently joined DEC’s ( from a recently defunct airline with the initials A*) fessed up to being rostered together on a LGW BGR run in the 757. Both were experienced training captains at that time. Rostered together for reasons that were never explained.
Just prior to reaching the ETOPS segment they had an issue with the analogue displays on both sides and therefore elected ( unbidden ) to trip both ADC cb’s. Problem solved. However, shortly thereafter a brief phone call from the L3 vicinity to say that there was a strange “whirring” noise from beneath the floor. Further investigation suggested that the boys had inadvertently deployed the RAT. Which was being driven both by Bernoulli’s and the C hyd system. ! Cue Portishead radio call to company and eventually Boeing whose suggestion was to continue, and turn off C hyd sys until on approach. Which they did.
Lord knows what the pax thought with the racket for 7 hours. Nor was there much questioning of the wisdom of flying past several perfectly useable ERA’s where they could have restored the RAT under eng guidance. From memory using the C system to stow it via a switch in the bay. And then be on their way.
Suffice to say, when they landed in Maine, the boss and hub of the RAT were glowing cherry red.
So the moral of the story. ? DFWI unless under OEB/FCOM/ Eng guidance. And even then think about it.
And if it’s got dust on it...don’t touch it.


All times are GMT. The time now is 19:01.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.