787 ground test enable switch
Thread Starter
Joined: Apr 2003
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From: Sutton
787 ground test enable switch
Had a pilot today (unaware of whether engineers were working on the aircraft) move it from enable back to normal.
There were engineers working on it but his response afterwards was that there would have been no problem anyway as the flying controls would have been locked out to prevent any unwanted control surface movement.
What tests is that switch used for, is he right that there is no chance of someone potentially getting hurt?
There were engineers working on it but his response afterwards was that there would have been no problem anyway as the flying controls would have been locked out to prevent any unwanted control surface movement.
What tests is that switch used for, is he right that there is no chance of someone potentially getting hurt?
Joined: Sep 2001
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From: Blighty
Silly pilot.
Not much chance of someone getting hurt but a good chance the trouble shooting results from the test will be compromised.
That switch is selected prior to almost all BITE System tests. It allows systems to operate during tests that would normally be inhibited. EG CAC/Pack with only two Ground Electrical Power sources.
If the engineers are working on the aircraft please ask before touching anything. We're just trying to do our job as quickly as possible, the aircraft will be ready when it's ready, not before.
Not much chance of someone getting hurt but a good chance the trouble shooting results from the test will be compromised.
That switch is selected prior to almost all BITE System tests. It allows systems to operate during tests that would normally be inhibited. EG CAC/Pack with only two Ground Electrical Power sources.
If the engineers are working on the aircraft please ask before touching anything. We're just trying to do our job as quickly as possible, the aircraft will be ready when it's ready, not before.
Thread Starter
Joined: Apr 2003
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From: Sutton
Thanks Hovis, I only ask as I want to emphasise to this guy that moving the switch is a big no no,One of our engineers said that if there were any tests that were likely to cause an unpleasant surprise then there would be an engineer in the cockpit and pilots wouldn’t be allowed in. Is there any test which the enable postition would be used that falls into this category. Or there are no tests that would move say thrust reverser trim, spoiler or primary Control surface.
Joined: Dec 1998
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From: .
An interactive tests that involves T/R or flying control movement then there should be someone in the flt deck, also some tests can be quite lengthy but don't require any interaction, 60 minutes or more, so could potentially compromise this, having to start again, with a possible delay. I always try to be there, to advise crew please don't touch.... That said it would be courteous to check before moving grnd test enable etc, as we can not always be in 2 places at once. A lot of tests on the 350 for instance require ADIRU alignment, first thing crew do on arrival, start a realignment, so if I know the crew are imminent I will endeavour to tell them, and to be fair a lot of our crews do ask first.
Thread Starter
Joined: Apr 2003
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From: Sutton
Thanks SS so are there tests which involve T/R or flying control movement which would require the switch to be moved to the ground test position. I know what you are saying about someone should always be in the flight deck, but am concerned commercial pressures mean we may not always have as many engineers available as we would like.
Joined: Sep 2001
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From: Blighty
There are definitely flt control tests that would need the ground test switch enabled. But as has been said, if hydraulics are supplied then I would expect a big 'DO NOT TOUCH ANYTHING' Placard on the pedestal at the very least.
Joined: Jul 2008
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From: Australia
Had a pilot today (unaware of whether engineers were working on the aircraft) move it from enable back to normal.
There were engineers working on it but his response afterwards was that there would have been no problem anyway as the flying controls would have been locked out to prevent any unwanted control surface movement.
What tests is that switch used for, is he right that there is no chance of someone potentially getting hurt?
There were engineers working on it but his response afterwards was that there would have been no problem anyway as the flying controls would have been locked out to prevent any unwanted control surface movement.
What tests is that switch used for, is he right that there is no chance of someone potentially getting hurt?
Some B787 have a wireless setup where the engineer can access system tests from a maintenance laptop from outside the cockpit. So even if there isn’t an engineer in the cockpit he/she might be elsewhere doing a test. stopping a test on a B787 mid way can cause a lot of headaches for everyone involved. Best is to leave it alone and call maintenance just to double check if they are done.
Joined: Feb 2002
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From: UK
Joined: Apr 2004
Aviation Qualifications: LAME
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From: Dorset UK
I used to carry a couple of circuit breaker clips with a red flag attached. Very useful safety device that could easily be attached to any CB, switch, lever, etc that you don't want moved.
