BA Airbus over Ealing,13.07 today - landing gear down

[Phoenix1969]

Hi all

Ealing, 13.07 today heard a louder than usual jet engine noise and looked up to see a BA A319/320/321 heading northeast as planes out of LHR do, but with its landing gear still down.

Anyone know what was going on?

Phoenix

[DaveReidUK]

BA1342 LHR-LBA, landed at Leeds 20 minutes ago, so no cause for alarm.

[SpringHeeledJack]

I saw a BA 787 coming out of LHR yesterday around 4pm and it too had it's wheels down for the first few miles, unusual, but i put it down to hot brakes needing to be cooled before retraction. Was there a lot of stop/start for the departures yesterday afternoon ?


SHJ

[Wirbelsturm]

It's standard practice on the Mini Bus to leave the gear down if you have 'hot' brakes during the taxi.

It's been a while since I was on it but the limits used to be 150 degrees with brake fans on and 300 degrees with brake fans off for take off. You would then leave the gear down in the airflow for a minute or two to drop the temps prior to tucking them up into the wells.

Hope that helps.

[Phoenix1969]

It's standard practice on the Mini Bus to leave the gear down if you have 'hot' brakes during the taxi.

It does help, makes perfect sense now. Thanks.

And it probably wasn't a 'louder than usual jet engine noise' I heard either, was it? More likely the sound of the gear in the airflow

[Evanelpus]

a louder than usual jet engine noise

Possibly a total myth. Wind speed and wind direction can make an engine sound 'noisier'

[AndoniP]

I assume having gear extended would mean having to restrict your departure speed, does this do anything to the departure rates of the subsequent aircraft? or is there a departure speed limit of sorts until aircraft are up to cruising altitude?

thanks

[DaveReidUK]

Originally Posted by AndoniP

I assume having gear extended would mean having to restrict your departure speed, does this do anything to the departure rates of the subsequent aircraft? or is there a departure speed limit of sorts until aircraft are up to cruising altitude?

Departing traffic is limited to 250 KIAS in the London TMA below FL100.

The A320's gear retraction limit speed is 220 KIAS, so it will have had little, if any, effect on other traffic.

[Flying Fred]

I saw a BA 787 coming out of LHR yesterday around 4pm and it too had it's wheels down for the first few miles, unusual, but i put it down to hot brakes needing to be cooled before retraction.

It's because the aircraft had a wheel brake deactivated, which is an allowable defect in the 787 Minimum Equipment List (MEL). In the event of departure with a brake deactivated, there is a requirement to leave the gear down for two minutes after liftoff so the affected wheel stops spinning before it is retracted into the gear bay. Normally, without a brake deactivated, the brakes are applied automatically to all braked wheels as part of the retraction sequence.

I suspect the A320 mentioned above was for the same reason.

FF

[AndoniP]

Departing traffic is limited to 250 KIAS in the London TMA below FL100.

The A320's gear retraction limit speed is 220 KIAS, so it will have had little, if any, effect on other traffic.

Thank you Dave.

[tdracer]

Possibly a total myth. Wind speed and wind direction can make an engine sound 'noisier'

Not a myth - everything else being equal a 'dirty' aircraft (flaps and gear down) is ~3db noisier than a 'clean' aircraft - some are even worse than that.