Go Back  PPRuNe Forums > Misc. Forums > Spectators Balcony (Spotters Corner)
Reload this Page >

Retracting landing gear (China)?

Spectators Balcony (Spotters Corner) If you're not a professional pilot but want to discuss issues about the job, this is the best place to loiter. You won't be moved on by 'security' and there'll be plenty of experts to answer any questions.

Retracting landing gear (China)?

Old 20th Jan 2021, 13:55
  #1 (permalink)  
Thread Starter
 
Join Date: Oct 2000
Posts: 19
Likes: 0
Received 1 Like on 1 Post
Retracting landing gear (China)?

So I'm standing with a bunch of other non-pilot plane-spotters watching AC depart runway 18L at ZSSS (Hongqiao Shanghai). A local carrier Airbus A330-200 takes off normally and disappears into cloud a little while later... with its landing gear still down! Question for professsional types; don't you want to retract the landing gear ASAP after clearing the runway? On this day Aviation Weather said broken cloud 2600 feet, ceiling 2600 feet. PS Actually I was the only plane spotter, the other folk were concentrating on catching fish in the canal.
Ab Initio is offline  
Old 20th Jan 2021, 14:18
  #2 (permalink)  
 
Join Date: Jan 2021
Location: HKG
Posts: 26
Likes: 0
Received 0 Likes on 0 Posts
Non-pilot avgeek here. My HK$0.2 is that the flight crew forgot to retract the gear since I can't find any info regarding when not to retract the gear shortly after takeoff. Waiting for actual pilots to comment here; this case is interesting.
Sleepsleep is offline  
Old 20th Jan 2021, 16:10
  #3 (permalink)  
 
Join Date: Dec 2008
Location: UK
Age: 62
Posts: 277
Likes: 0
Received 0 Likes on 0 Posts
It's quite normal and is caused by hot brakes, they'll leave the gear down until the brake temperatures drop to a safe level.
Big Eric is offline  
Old 20th Jan 2021, 17:19
  #4 (permalink)  
UV
 
Join Date: Oct 2001
Location: Essex
Posts: 649
Received 3 Likes on 2 Posts
If the runway was wet and the temperature near freezing it is common to leave it down for a bit to dry everything out before retraction.
UV is offline  
Old 20th Jan 2021, 17:31
  #5 (permalink)  
 
Join Date: Aug 2015
Location: Sunnydale
Posts: 251
Received 38 Likes on 23 Posts
What??? Actually what what. A330 Will not have hot brakes issue at least not on a normal turnaround and drying the breaks. I beg this is just sarcasm.

unless you account for it in the perf calcs you completely invalidate your second segment

wet brakes. Really!!!
back to Boeing is online now  
Old 20th Jan 2021, 18:27
  #6 (permalink)  
 
Join Date: Mar 2001
Location: Either the back of a sim, or wherever Crewing send me.
Posts: 1,031
Likes: 0
Received 1 Like on 1 Post
If the runway was wet and the temperature near freezing it is common to leave it down for a bit to dry everything out before retraction.
What a crock, I’ve read some garbage on here over the years but this is up there with the best of them.

Whilst it is not common, the explanation about hot brakes will be the most likely reason.
Johnny F@rt Pants is offline  
Old 20th Jan 2021, 18:30
  #7 (permalink)  
 
Join Date: Nov 2007
Location: amsterdam
Posts: 2
Likes: 0
Received 0 Likes on 0 Posts
Good observation, and reasonable question. The A330s I flew had no brake cooling fans and on short turn arounds, or taxi routes that required multiple brake applications, brake temperatures could become a concern. It was standard practice to keep the gear down for a while to cool the brakes. We only did this when factors such as fuel, wx, ATC and terrain/climb gradients weren't a factor. In the event of anything out of the ordinary occurring you could always raise the gear and sort the problem out, realising that you might later on get a warning of hot brake temperatures later. It was always pre briefed as it is a potential threat and a deviation from standard practices. I hope this answers your question.
dange is offline  
Old 20th Jan 2021, 18:31
  #8 (permalink)  
 
Join Date: May 1999
Location: london
Posts: 53
Likes: 0
Received 0 Likes on 0 Posts
Could well have been that they forgot. It also could have been an allowable dispatch with a single brake unit deactivated?
That would mean leaving the gear down for one minute after lift off to allow the main gear wheels to stop spinning. Normal retraction applies pressure to the brake units during the retraction sequence, but with a brake unit deactivated that won't happen.
But it was China....... Who knows.
bigbird is offline  
Old 20th Jan 2021, 18:45
  #9 (permalink)  
 
Join Date: Mar 2006
Location: Western Europe
Posts: 294
Received 2 Likes on 2 Posts
Okay flight simmers it's simple. The MEL allows departure with a brake (there are eight) u/s. This needs the gear to be left down for some time after lift off. Nothing to do with forgetting or wet runways.
Consol is offline  
Old 20th Jan 2021, 19:03
  #10 (permalink)  
 
Join Date: Jan 2008
Location: Reading, UK
Posts: 15,788
Received 196 Likes on 90 Posts
Good to get lots of varied opinions.
DaveReidUK is offline  
Old 20th Jan 2021, 19:45
  #11 (permalink)  
 
Join Date: Jun 2001
Location: Fragrant Harbour
Posts: 4,787
Received 7 Likes on 3 Posts
Hot brakes, a brake unit unserviceable and departure from a contaminated runway are reasons to leave the gear down after take off on Airbus types. In the case of an engine failure in these circumstances, the gear should be raised. In the brake unit failure case, the time for retraction after rotation is one minute (A320) and two minutes (A330).
Dan Winterland is offline  
Old 21st Jan 2021, 00:36
  #12 (permalink)  
 
Join Date: Jan 2021
Location: HKG
Posts: 26
Likes: 0
Received 0 Likes on 0 Posts
Oh I see now. The gears can be left down for a while for it to dry or cool down.
Sleepsleep is offline  
Old 21st Jan 2021, 01:43
  #13 (permalink)  
Thread Starter
 
Join Date: Oct 2000
Posts: 19
Likes: 0
Received 1 Like on 1 Post
Thanks all for taking the time to reply. So likely reasons: forgot, hot brakes or a brake/s deactivated.

Dange, thanks for your recollections on dealing with hot brakes. The model you flew had no brake cooling fans. Would that still be the case today?

bigbird, interesting to hear about the deactivated brake thing. Question; if a brake were deactivated, how long would it take for a wheel to stop spinning? Surely 5 or 10 minutes... no?
Ab Initio is offline  
Old 21st Jan 2021, 07:16
  #14 (permalink)  
 
Join Date: Sep 2018
Location: Seattle
Posts: 221
Likes: 0
Received 1 Like on 1 Post
Don’t they normally use 18R for departures out of Hongqiao?
BoeingDriver99 is online now  
Old 21st Jan 2021, 09:28
  #15 (permalink)  
 
Join Date: Jan 2002
Location: Europe
Posts: 1,199
Received 0 Likes on 0 Posts
Originally Posted by dange
Good observation, and reasonable question. The A330s I flew had no brake cooling fans and on short turn arounds, or taxi routes that required multiple brake applications, brake temperatures could become a concern. It was standard practice to keep the gear down for a while to cool the brakes. We only did this when factors such as fuel, wx, ATC and terrain/climb gradients weren't a factor. In the event of anything out of the ordinary occurring you could always raise the gear and sort the problem out, realising that you might later on get a warning of hot brake temperatures later. It was always pre briefed as it is a potential threat and a deviation from standard practices. I hope this answers your question.
Two small questions if I may:
If you do raise the gear in " In the event of anything out of the ordinary occurring" do you lower the gear later or need to take any other action? And how do you protect from actually forgetting the gear down for good?
Rwy in Sight is offline  
Old 21st Jan 2021, 10:27
  #16 (permalink)  
Thread Starter
 
Join Date: Oct 2000
Posts: 19
Likes: 0
Received 1 Like on 1 Post
left..right!

Originally Posted by BoeingDriver99
Don’t they normally use 18R for departures out of Hongqiao?
Ah yes, you're no doubt correct. Looking at the map again, and where I was standing on the side of the G318 highway, it probably did depart on 18R not 18L. You can't get away with anything on this forum. Ha ha
Ab Initio is offline  
Old 21st Jan 2021, 12:11
  #17 (permalink)  
 
Join Date: Jan 2008
Location: Reading, UK
Posts: 15,788
Received 196 Likes on 90 Posts
Originally Posted by Ab Initio
Question; if a brake were deactivated, how long would it take for a wheel to stop spinning? Surely 5 or 10 minutes... no?
A previous post quoted the time delays applied for two typical narrow- and wide-body types.

I'd be amazed if any wheel could carry on spinning for 5, let alone 10, minutes.
DaveReidUK is offline  
Old 21st Jan 2021, 13:47
  #18 (permalink)  
 
Join Date: Aug 2007
Location: 4DME
Posts: 2,908
Likes: 0
Received 12 Likes on 10 Posts
Originally Posted by bigbird
But it was China....... Who knows.
You should have asked him.
N707ZS is offline  
Old 21st Jan 2021, 22:42
  #19 (permalink)  
 
Join Date: Apr 2002
Location: UK
Posts: 1,221
Received 9 Likes on 7 Posts
Thread drift.....
Pre 9/11 I was lucky to get a cockpit ride on a 757 into Heathrow. On approach a combination of circumstances ended up with us being a bit too close to the aircraft in front. The captain reduced speed to minimum, announced that over the radio and the plane behind us replied "I can't fly that slow". We got landing clearance just before we crossed the perimiter track for 27R. Full braking caused the brake overheat warnings to go off as we taxied towards 28L and T5. Having consulted the manual they decided that the plane would have to take extra time on the stand to let the brakes cool.
Hartington is offline  
Old 22nd Jan 2021, 01:23
  #20 (permalink)  
 
Join Date: Sep 2018
Location: Seattle
Posts: 221
Likes: 0
Received 1 Like on 1 Post
Ha! I'll wave next time I depart!
BoeingDriver99 is online now  

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

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