PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   Spectators Balcony (Spotters Corner) (https://www.pprune.org/spectators-balcony-spotters-corner-52/)
-   -   The answer to all our secrets (https://www.pprune.org/spectators-balcony-spotters-corner/250597-answer-all-our-secrets.html)

ishe 4th November 2006 10:47

In the 747 There is one tiller per side for steering. Maximum deflection of the nose wheel is 70° either side of straight ahead. When 20° is reached, body gear steering is automatically engaged. With the rudder pedals, a maximum of 7° deflection can be reached.

It is a very strange feeling when looking out of the cockpit doing a tight turn, almost as though the aircraft is reversing or sliding sideways. (if that makes sense)

llanfairpg 6th December 2006 00:51

Hot brakes
 
Lots of rubbish above!

A320 carbon brakes noticably heat up virtually any time they are applied, if he was on a quick turnaround there may have been some residual heat left in them from previous landing and taxy in, although use of the brake fans should have cooled them. With a long taxy out you would need the fans on again.

There is a potential for dirt/crap and even debris to be thrown from the wheels on lift off which can go into the bay and rupture hydraulic lines or worse in the case where a tyre seperates so best to stop then spinning straight away, thats why they are braked, if you dont understand this say CONCORDE several times and you will!

There can be several reasons for leaving the gear down after take off, cooling has already been mentioned, or perhaps even a problem with the sequence, sometime if you think you have a problem that might be gear related and need a return you may not want to run the gear up in case you cant get it down again! Its not always a good idea to explain to ATC exactly what is going on because the reporter with the airband radio will write it up as an a dramatic emegency which isnt good for the companies reputation or image.

steviefartpants 6th December 2006 06:17

A/C on a quick turnround,brakes still hot as no brake fans are fitted,A/C takes off brakes still hot after taxi(but below take off limit),cool them down with airflow before putting them into the hole.

Its as simple as that!

Carbon brakes are meant to get hot as they work better when upto working temp .

Gary Lager 6th December 2006 13:32


Lots of rubbish above!
Certainly is isn't there, for instance:


Its not always a good idea to explain to ATC exactly what is going on because the reporter with the airband radio will write it up as an a dramatic emegency which isnt good for the companies reputation or image.
What are you, a professional pilot or the company's own version of Max Clifford? As pilots we are responsible for using all resources available to us to ensure the safety and security of our pax and crew, including talking to ATC about any non-standard/non-normal situations which may occur. You may even find them helpful from time to time.

FlightDetent 6th December 2006 14:31

I understand that 330 ECAM logic does have some differencies over 32x, (not rated on 330 do not know which), but on 320 HOT BRAKES is inhibited during takeoff for good reasons. Only comes up at liftoff to advise crew not to raise the gear as opposed to woefully suggest stopping with a brake problem.

Fatboy, can you advise what is the BRAKES HOT inhibit phase for 330, pls?

FD.
(the un-real)

fmgc 6th December 2006 14:49

Max Angle:

Quite why it's considered such a problem to have them rotating in the wheel well I don't know.
The other reason that you might want the wheels to stop turning before you retract them is to avoid the stress on the landing gear caused by gyroscipic presession.

magpienja 18th December 2006 17:58

Start number 1 Cross bleed number 2 ????
 
Something I here at my local airport, any kind sole tell me what it means, something to do with engines starts me thinks.

Nick.

BOAC 18th December 2006 18:17

Probably a 737, but may be other types too. When the APU is not able to suply air to start the engine, a ground-air unit is plugged in. On the 737 it plugs in on the right of the fuselage centreline. It is used to start No 1 (the left) and then disconnected (safely, away from the running engine - which is at idle only). Pushback takes place and number 1 is 'run up' to a medium power setting to provide enough air to start number 2 using 'crossbleed air'.

Other types may start number 2 on stand due to the location of the air connection.

A search will produce more. Here is one.

magpienja 18th December 2006 21:27

Many thanks BOAC.

Nick.

P.S. just wondering why my post was moved.

BOAC 18th December 2006 21:50

To the correct thread?:)
Have you read the announcement and this thread?

sniper9652 19th December 2006 09:53

Holding Patterns!
 
Hi all, just been observing a BMI Baby 737 in the hold at 'MIRSI' on my SBS-1. The pattern it creates is an absolute perfect race track shape pattern! I take it that it is auto pilot and instruments that maintain this shape and pattern during the hold? any feedback from aircrew would be appreciated!

Regards, Steve

Wodrick 19th December 2006 17:48

Post #21 A330 "HOT BRAKE" inhibit is from 80kts to lift off and again on touchdown to 80kts according to my FCOM which is not amended and quite old.

Tacitus 12th January 2007 16:42

Thrust reversers prior to touchdown
 
http://www.!!!!!!!!!!!!!!/search/photo.search?id=0348313
This is quite an old photo but i was amazed by this . Boeing and Airbus models can do this ? And why a pilot would do something like this ?

Maz11 12th January 2007 16:46

You can't do that on an Airbus. For the thrust reversers to deploy the ground squat switch needs to be depressed. In other words there needs to be weight on the wheels. You can go into the reverse position with the thrust levers but the thrust will remain at idle until the aircraft touches down.

i'm not sure about the Boeing but i would think they are the same.

Hope this helps. Maz

BOAC 12th January 2007 16:54

Modern Boeing no, and I assume Airbus no also. There are 'switches' that need to be made before reversers can normally be deployed, such as weight on wheels, radio altitude and others. Maybe there was no protection on this Russian model.

Problems of doing it would be that if you could not retract the buckets and needed power...................................

I've no doubt some old Trident puke:D will be along soon to tell you that they used to use reverse on number 2 engine (yawn:) ). It may be that the B727 used it as well - in both cases to expedite descent.

Just beaten to the post by Maz:ok:

Tacitus 12th January 2007 17:26

Thanks a lot for your replies . I've searched for western airplanes but i did not find a similar photo . I've never experianced something like this as a passenger but i assume it must be quite scaring . But i still don't understand why a pilot would do something like this instead of raising the speadbrakes for example

stanley 12th January 2007 21:02

I seem to remember the DC8 had this reverse in flight for decent and short landing

Jet2 14th January 2007 22:04

Thrust reversers on 737-3/4/500 will deploy below 10ft Rad Alt. Usually achieves a rather firm touchdown :eek:

TURIN 16th January 2007 09:29


Originally Posted by llanfairpg (Post 3004527)
Lots of rubbish above!
There is a potential for dirt/crap and even debris to be thrown from the wheels on lift off which can go into the bay and rupture hydraulic lines or worse in the case where a tyre seperates so best to stop then spinning straight away, thats why they are braked, if you dont understand this say CONCORDE several times and you will!.

Yes there is isn't there?:rolleyes:
Most a/c I know only brake the wheels when gear selected up. They will spin away quite happily until hydraulic fluid is ported through the landing gear selector valve to the brakes.
As has been mentioned, the A320 MEL allows for a u/s brake, and SOPs state that the gear is left down for 2 mins after t/o to allow the wheel to spin down. (Gyroscopic forces and all that malarky apparently).:ok:

con-pilot 16th January 2007 16:31


I've no doubt some old Trident puke will be along soon to tell you that they used to use reverse on number 2 engine (yawn ). It may be that the B727 used it as well - in both cases to expedite descent.
Yes you can reverse any or all engines on the 72 anytime one desires, as long of course you are at idle power. Now I do not believe that there were any procurers on reversing in flight published by Boeing, at least I never saw any. Personally I never reversed the number 2 in-flight to expedite a descent. I did reverse all 3 engines during a sim ride once when we wasting time at the end of a recurrency ride.

Instructor placed us over the outer marker of 26L at Lax, 250 Kts IAS, 10,000 feet, clean and said "Land it, straight ahead, no turns." I did, it was not easy and in no way would I ever try it in real life, unless I had no other option. Was kind of fun.


All times are GMT. The time now is 16:48.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.