triscl
Posts: 138
Joined: Tue Jul 15, 2003 4:08 am

Question: Gear Left Down After T/o

Wed Oct 22, 2003 1:18 am

Flew a UA 762 LAX to JFK last Sunday, and the captain made a strange announcement before we left. He said that for those of us that fly frequently, the sounds after take-off might seem out of the ordinary. Reason: one of the breaks had been de-activated and they needed to let the wheels stop spinning for about 2 minutes after take-off before retracting the gear. He said it would be quite noisey for those 2 minutes. Sure enough, we took off and there was quite a bit of vibration, especially when they actually took them up. But then it was like, "aaaaahhhh".

Any insight into why they had "de-activated" the breaks or what that means exactly? Perhaps they needed to do it for the take-off roll? Landing seemed fine. They definitely breaked hard then, with more than just the reversed thrust.

Thanks!
 
levg79
Posts: 918
Joined: Sat Sep 27, 2003 10:59 am

RE: Question: Gear Left Down After T/o

Wed Oct 22, 2003 1:28 am

They definitely breaked hard then, with more than just the reversed thrust.


According to one pilot that I know, the reverse is only used when the brakes can't stop the aircraft in time, otherwise they only rely on brakes.

Another thing, according to the same pilot, why the reverse is used, is to taxi backwards, although it's not allowed in most airports.
A mile of runway takes you to the world. A mile of highway takes you a mile.
 
Rick767
Posts: 2613
Joined: Sun Jan 30, 2000 8:11 pm

RE: Question: Gear Left Down After T/o

Wed Oct 22, 2003 1:31 am

This happens quite regularly, when a brake is "capped off" meaning the wheel will continue to spin after take-off.

It is an MEL item and has an effect on MTOW (about 14 tonnes on the 757) to cover the single engine climb scenario.

I have only ever done this once in 4 years.

See my response to a Tech/Ops discussion on this topic some time ago:

http://www.airliners.net/discussions/tech_ops/read.main/64478/4/

Rick.
I used to love the smell of Jet-A in the morning...
 
LastBaron
Posts: 269
Joined: Tue Oct 21, 2003 9:55 am

RE: Question: Gear Left Down After T/o

Wed Oct 22, 2003 1:31 am

I was on an EI flight out of BWI to SNN a few years back on a leased MD-11 (named St. Brendan) and that thing had brakes so loud and noisy and full of shuddering, we all thought we should have detoured into Midas before taking off... they had to use the reverse-thrusters to get us to stop in SNN, which is unusual because SNN has a nice long runway.

Thanks Levq79 for your insight.
 
Rick767
Posts: 2613
Joined: Sun Jan 30, 2000 8:11 pm

RE: Question: Gear Left Down After T/o

Wed Oct 22, 2003 1:33 am

"According to one pilot that I know, the reverse is only used when the brakes can't stop the aircraft in time, otherwise they only rely on brakes."

This is very much dependent on company procedure, the brakes can always stop the aircraft in time by themselves (otherwise you are probably not operating legally).

In my company the procedure is full reverse on all landings, same at my previous company. Except of course, when r/t is locked out for maintenance (deferred defect).
I used to love the smell of Jet-A in the morning...
 
triscl
Posts: 138
Joined: Tue Jul 15, 2003 4:08 am

RE: Question: Gear Left Down After T/o

Wed Oct 22, 2003 1:41 am

thanks for the responses...makes a lot of sense.
 
jhooper
Posts: 5560
Joined: Thu Dec 13, 2001 8:27 pm

RE: Question: Gear Left Down After T/o

Wed Oct 22, 2003 1:47 am

Yea, they almost always use at least reverse-idle when I fly.
Last year 1,944 New Yorkers saw something and said something.
 
rb211
Posts: 413
Joined: Wed Oct 22, 2003 1:09 am

RE: Question: Gear Left Down After T/o

Wed Oct 22, 2003 1:58 am

Thanks for the information. Thank god there is a place where airliner junkies like ourselves can talk shop. By the way, I hate the landings of 767's. It usually feels like they are ripping the gear right out of the belly on touchdown.
Airline photography. Whether they're fully clothed, butt naked, having issues or confused I'm taking pictures!!
 
Rick767
Posts: 2613
Joined: Sun Jan 30, 2000 8:11 pm

RE: Question: Gear Left Down After T/o

Wed Oct 22, 2003 2:02 am

RB211,

I have been on (and indeed made) some awful landings in the 767, but also some very smooth ones too.

You probably had a pilot on his/her first flight after a fortnight of 757 trips  Big grin

Always caught me out...
I used to love the smell of Jet-A in the morning...
 
AWspicious
Posts: 2780
Joined: Fri Sep 14, 2001 7:47 am

RE: Question: Gear Left Down After T/o

Wed Oct 22, 2003 2:09 am

Rick767;
Am I to assume you alternate between the 767 and 757? If so - How often is your rotation?

a.w.
Nevermind political correctness - Envision using your turn signals!
 
Rick767
Posts: 2613
Joined: Sun Jan 30, 2000 8:11 pm

RE: Question: Gear Left Down After T/o

Wed Oct 22, 2003 2:26 am

AWspicious,

In my previous airline yes, we only had the 752, 762 and 763 in the fleet and so all pilots were qualified to fly all three "types".

The type rating is initially 757-only, with the cross-qualification for the 767 (making it a 757/767 rating) permitted by successfully completing a differences course.

There is no currency requirement for flying the different types, we keep the CAA happy by simply doing alternate sim checks (757 then 767, etc....)

In theory you could fly the 757 for say 5 or 6 years, then step into the 767 and be perfectly legal to fly it. In practice this is extremely unlikely to happen. Even BY pilots at 757-only bases will take a 767 roundtrip across the pond at least once every year to keep their ETOPS currency, for example.

In my present airline all pilots are 733 and 73G rated (differences course again permits the latter). The common type rating means exactly the same applies, alternate sim checks and we're good on both (despite the fact that some bases are practically all 733 and others 73G).

When the Airbus arrives it will all go to pot  Insane
I used to love the smell of Jet-A in the morning...
 
Guest

RE: Question: Gear Left Down After T/o

Wed Oct 22, 2003 2:40 am

Landing gear can be left down after takeoff for 2 reasons -
(1) Brake cooling... or
(2) Brake(s) deactivated - until wheel rotation as stopped...
In the 747, we can (like Rick 767 explained) operate with 1 or 2 brakes deactivated because of maintenance reasons.
xxx
Performance (takeoff and landing) is only predicated (for braking/stopping capability) on the use of wheel brakes and spoilers (speed brakes)... The thrust reversers, are NOT taken in account... they are just a "bonus"... An aircraft may be dispatched with one (or all) reversers inoperative, without reduction in braking performance considerations...
xxx
Happy contrails  Smile
(s) Skipper
 
AWspicious
Posts: 2780
Joined: Fri Sep 14, 2001 7:47 am

RE: Question: Gear Left Down After T/o

Wed Oct 22, 2003 6:46 am

Thanks Rick. Thanks Skip :-]

Question: Why would they deactivate the brakes? Should I assume when Skip says mx reasons he means there might be a fault with the system? (starting to delve into tech-ops forum territory, eh)

Also, Rick; I guess you wouldn't have flown a 762 one day then jump into a 752 two days later only to be flying a 763 the followng day on a layover to somewhere, eh?

I'll go back and read Rick's previous post in the tech-ops forum.


a.w.
Nevermind political correctness - Envision using your turn signals!
 
Cessna172RG
Posts: 642
Joined: Wed Aug 30, 2000 8:31 am

RE: Question: Gear Left Down After T/o

Wed Oct 22, 2003 8:14 am

On about every flight that I am on, the pilots always use reverse thrust. That's not only because I fly trans pacific a lot, but also within the United States. The only time I recalled reverse thrust not employed on a jet was on a Mesaba RJ85, as they don't have reversers!
Save the whales...for dinner!!!
 
high_flyr69
Posts: 497
Joined: Mon Apr 30, 2001 6:19 am

RE: Question: Gear Left Down After T/o

Wed Oct 22, 2003 8:35 am

Melbournes rwy 34/16 is sumthin like 3.6 kms long i think but EVERY aircraft that lands that has reverse thrust uses it. Even the dash 8's feather the props on landing.
Diplomacy is the art of saying 'Nice Doggy' until you find the shot gun
 
Okie
Posts: 3555
Joined: Wed Jul 16, 2003 11:30 am

RE: Question: Gear Left Down After T/o

Wed Oct 22, 2003 8:57 am

On my limited ERJ140/145 experience 10-12 flights I have yet to hear the T/R's used. I even looked up the specs on the ERJ to see if they even had them. Obviously very good brakes, I had always assumed the use of T/R was to decrease wear and tear on the brakes. Also since I am off subject I can tell you there was never any doubt about the pilot setting the squat switch on landing on any ERJ I have been on.
 
canuckpaxguy
Posts: 1482
Joined: Sat Sep 06, 2003 2:31 pm

RE: Question: Gear Left Down After T/o

Wed Oct 22, 2003 9:06 am

I don't think I can recall any Airbus or Boeing plane landing at YYZ and not using R/Ts. Is that unusual?

G

 
Guest

RE: Question: Gear Left Down After T/o

Wed Oct 22, 2003 9:14 am

Some ERJ operators have their pilots avoid using the reverse thrust to save on fuel. Sometimes the they kick the cans open though for the extra drag. I know American Eagle tries to avoid it on their ERJs and there are probably more than a few others. The few times i have been on a Continental Express ERJ they used reverse thrust though
 
donder10
Posts: 6944
Joined: Sun Oct 21, 2001 5:29 am

RE: Question: Gear Left Down After T/o

Wed Oct 22, 2003 9:16 am

I have seen this at LHR happen quite a few times,notably with an AC333 that kept them until it was over LCY or so.This can be explained by the long holding time some aircraft spend here.
 
SkydrolBoy
Posts: 334
Joined: Sun Sep 21, 2003 7:31 am

RE: Question: Gear Left Down After T/o

Thu Oct 23, 2003 2:53 am

High_flyr69,

The Dash-8's props go into reverse pitch on landing not feather, if the props went into feather you would get no stoping action at all.

Also Reverse thrust will not stop an aircraft completely it is only effective at certain speeds, that is why you will notice that the pilot will stow the reversers way before he has finished the landing roll. Also T/R's can be used to back up an aircraft but it is not normally done due to the reverse thrust blowing FOD forward and then being sucked into the intake of the engine, most airports do allow it but it is a company policy that prevents it from happening.