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This morning, I took flight VS156 from LAS to LHR, aboard a 787, tail number G-VSPY according to flightradar24. The pilot made a strange announcement before takeoff - specifically, that due to a recent maintenance procedure, the pilots would not be able to raise the gear for the first 10 minutes of flight. The rest of the flight continued normally. What was the procedure likely to be, and why would leaving the gear down be safer?

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  • $\begingroup$ I have not heard of that situation occurring for maintenance reasons, but I know that it is done occasionally when the brakes are too warm due to a previous flight being on the heavier side and a really quick turnaround time. Leaving the gear down in that situation would be giving it the cooling that it did not get at the gate. $\endgroup$ Mar 13, 2023 at 23:26
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    $\begingroup$ That would be quite surprising here, considering that the turnaround was around four hours (and the weather was fairly cool)? $\endgroup$ Mar 13, 2023 at 23:35
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    $\begingroup$ @RalphJ If the gear cannot be retracted after takeoff because of a gear/brake issue (re: required quick turn around limitation, excessive brake temp indication on the EICAS or similar, known wheel brake issue, etc.) then a departure should not occur until the issue is resolved. Or, compliance with an MEL requirement like shown on the MMEL in the answer below. Meeting the takeoff performance climb gradient needs to be considered in the event of an engine failure. $\endgroup$
    – user22445
    Mar 14, 2023 at 0:46
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    $\begingroup$ What's weird to me is why would they tell you about this? I'm sure random stuff like that happens all the time, but the passengers really don't have any need to know about it, and telling them can only lead to confusion or possibly even panic, which is the last thing you want. $\endgroup$ Mar 14, 2023 at 13:55
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    $\begingroup$ This was to reassure us that any additional noise/buffeting in the cabin was normal. $\endgroup$ Mar 14, 2023 at 15:41

1 Answer 1

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It could be that the Wheel Well Fire Detection System was inoperative.

According to the B-787 "Master Minimum Equipment List" (as shown from this website, in pertinent part) the Wheel Well Fire Detection System:

"May be inoperative provided landing gear remain extended for ten minutes after takeoff."


enter image description here

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    $\begingroup$ This is the most probable reason for leaving the gear down for 10 minutes. $\endgroup$ Mar 14, 2023 at 0:55
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    $\begingroup$ Yeah that was it. "Maintenance procedure". Imagine the freakout if the pax knew you were able to depart with all sorts of systems not working lol. $\endgroup$
    – John K
    Mar 14, 2023 at 1:49
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    $\begingroup$ @fraxinus If the wheel is on fire, (for example, because a brake did not release) you do not want to retract the wheels, because that mean you are putting fire into an closed box near hydraulic lines $\endgroup$
    – Ferrybig
    Mar 14, 2023 at 9:10
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    $\begingroup$ @RonJohn The curious part to me is the wording "may", since I initially read it as "may become inoperative if..." which was like...why would you want that?? (Vs. upon re-reading, it is "allowed to be inoperative if"...) $\endgroup$ Mar 14, 2023 at 18:56
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    $\begingroup$ @Ferrybig The issue isn't the wheels on fire, the issue is if there's leaking hydraulic fluid in the wheel well, the hot wheels and brakes can ignite it. Leaving the wheels out allows hot surfaces to cool below the ignition point of hydraulic fluid. $\endgroup$
    – user71659
    Mar 15, 2023 at 3:00

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