BA 787 Nosewheel collapse @ LHR
Easy Street
"Just out of interest, what exactly is tested by cycling the gear handle if the intent is for the legs not to move?"
According to the AAIB report (see earlier link), cycling the gear handle was the approved procedure to clear a number of maintenance messages related to a snag that the aircraft was carrying.
Why that was being done on the ramp just prior to departure, some 36+ hours after the aircraft had arrived at LHR, is a mystery.
"Just out of interest, what exactly is tested by cycling the gear handle if the intent is for the legs not to move?"
According to the AAIB report (see earlier link), cycling the gear handle was the approved procedure to clear a number of maintenance messages related to a snag that the aircraft was carrying.
Why that was being done on the ramp just prior to departure, some 36+ hours after the aircraft had arrived at LHR, is a mystery.
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Dave... To a pilot or engineer you are of course stating the blindingly obvious!
However, as you are aware, the ramp is an open area that is notoriously difficult to control. There are many workers carrying out many different roles from different departments and companies. The only thing they know is that.... 'When the beacon is on you do not approach the aircraft'. You appear to presume that the engineers conducting the check were sufficiently numerous as to prevent others approaching - In this day & age that is pretty unlikely!
However, as you are aware, the ramp is an open area that is notoriously difficult to control. There are many workers carrying out many different roles from different departments and companies. The only thing they know is that.... 'When the beacon is on you do not approach the aircraft'. You appear to presume that the engineers conducting the check were sufficiently numerous as to prevent others approaching - In this day & age that is pretty unlikely!
Hi Magplug, (responding to your post #156), Quite so. Here we have one of the two leading aircraft manufacturers, and one of the leading operators - in terms of high standards, supposedly.
A manufacturer with years of skill and experience of aircraft design and construction behind it. A very experienced operator who would have us believe they are the best and who is not a LoCo, so charges high prices for tickets.
They are both supposed to be setting an example of quality and safety, with no need to cut corners and de-skill its workforce. Absolutely shameful.
A manufacturer with years of skill and experience of aircraft design and construction behind it. A very experienced operator who would have us believe they are the best and who is not a LoCo, so charges high prices for tickets.
They are both supposed to be setting an example of quality and safety, with no need to cut corners and de-skill its workforce. Absolutely shameful.
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DaveReidUK
If the aircraft was being prepped for dep, then there's every chance the messages reappear on power up or even power changeover from gpu to apu. The 787 is renowned for this. Hence why they need clearing before departure and not on arrival.
If the aircraft was being prepped for dep, then there's every chance the messages reappear on power up or even power changeover from gpu to apu. The 787 is renowned for this. Hence why they need clearing before departure and not on arrival.
Yeehaw22
"If the aircraft was being prepped for dep, then there's every chance the messages reappear on power up or even power changeover from gpu to apu. The 787 is renowned for this. Hence why they need clearing before departure and not on arrival."
Except that the AAIB report makes it clear the snag was already in the Tech Log as an ADD from a previous sector. If it wasn't considered acceptable to dispatch the aircraft from LHR carrying the ADD (which is understandable), then WTF had BA been doing since the aircraft's arrival a day-and-a-half previously ?
"If the aircraft was being prepped for dep, then there's every chance the messages reappear on power up or even power changeover from gpu to apu. The 787 is renowned for this. Hence why they need clearing before departure and not on arrival."
Except that the AAIB report makes it clear the snag was already in the Tech Log as an ADD from a previous sector. If it wasn't considered acceptable to dispatch the aircraft from LHR carrying the ADD (which is understandable), then WTF had BA been doing since the aircraft's arrival a day-and-a-half previously ?
Usual disclaimers apply!
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"Except that the AAIB report makes it clear the snag was already in the Tech Log as an ADD from a previous sector. If it wasn't considered acceptable to dispatch the aircraft from LHR carrying the ADD (which is understandable), then WTF had BA been doing since the aircraft's arrival a day-and-a-half previously?".....
You might just find waiting for the spare pressure switch for a drop dead ADD is the answer!
AND 3 previous incidents. It is a shame though that they hadn't carried out the mod to plug the apex pin. Incidentally the 777 has the similar design but it hasn't happened to one of those.
You might just find waiting for the spare pressure switch for a drop dead ADD is the answer!
AND 3 previous incidents. It is a shame though that they hadn't carried out the mod to plug the apex pin. Incidentally the 777 has the similar design but it hasn't happened to one of those.
Yeehaw22
That would make sense, so every flight since the ADD was raised would involve cycling the gear handle prior to pushback.
As the saying goes, what could possibly go wrong ... ?
The account of the aircraft's maintenance history in the final report will be interesting reading.
That would make sense, so every flight since the ADD was raised would involve cycling the gear handle prior to pushback.
As the saying goes, what could possibly go wrong ... ?
The account of the aircraft's maintenance history in the final report will be interesting reading.
Magplug
Actually, having performed this procedure quite recently, we waited until all ground equipment and personnel were clear of the aircraft before selecting gear up. Even the crew were kept in the terminal building. It caused a delay but we considered it prudent to do so. It can be difficult sometimes trying to explain to operators that this is the correct way to behave and it can mean the LAE in charge has to be quite firm with airline station managers, MOCs and airport duty managers that need the stand ASAP. Pressure for an on time departure should never trump safety.
Actually, having performed this procedure quite recently, we waited until all ground equipment and personnel were clear of the aircraft before selecting gear up. Even the crew were kept in the terminal building. It caused a delay but we considered it prudent to do so. It can be difficult sometimes trying to explain to operators that this is the correct way to behave and it can mean the LAE in charge has to be quite firm with airline station managers, MOCs and airport duty managers that need the stand ASAP. Pressure for an on time departure should never trump safety.
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A lot of the tests we run via the CMC do actually do this by configuring the system "electronically" to simulate the required condition. In some cases however a physical change is required. In this case maybe there is a mechanical switch or prox sensor in LG lever module that needs to be physically made to get a suitable response? The other issue of course is how far do you go with maintenance switches? How many would be required to simulate every potential test mode? What is the risk if a switch is left in the incorrect position prior to flight, or fails? Remember the A320 that had spoiler problems on take off (at LGW?) because the ground maintenance safety selector on the spoiler actuator had been left in the wrong position? Putting it in another context, this kind of incident has happened maybe 3-4 times now on B787s, how many times has the test been carried out successfully in the same period? Putting more complexity into the system when there is a known simple preventative fix available is not the solution.
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The airframe is currently being repaired by Boeing. After strip out and assessment they make up a surrogate repair and bond it in. This is then subject to NDT. If all is good it is removed and the final repair made up and bonded. It will be totally invisible and will not need any further inspections later in the life of the aircraft..
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The airframe is currently being repaired by Boeing. After strip out and assessment they make up a surrogate repair and bond it in. This is then subject to NDT. If all is good it is removed and the final repair made up and bonded. It will be totally invisible and will not need any further inspections later in the life of the aircraft..
