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-   -   a320 thrust reversers in-flight ??? (https://www.pprune.org/passengers-slf-self-loading-freight/156570-a320-thrust-reversers-flight.html)

j_davey 21st Dec 2004 20:06

a320 thrust reversers in-flight ???
 
Hello All! ,
i cast my mind back to 5th may 2004 when i flew from BHX to DUB on a MyTravel Airbus A320 flight No. VZ7043. When during our decent into dublin the aircraft began making a loud noise, much like the extra wind noise of having the gear in the down position. Soon after this started, a flight attendant came over the intercom and a told us that the noise was due to the use of reverse thrust to help slow the aircraft during descent and that it was a normal procedure for this type of aircraft. after ten minutes or so the noise stopped and everything was normal from then on in followed by a reasonably smooth landing.

when i heard what they said about using the reversers i instantly smelled bull :hmm: ... but was i right to be sceptical?

Can anyone shed some light on this?

John.

Wannabe Flyboy 21st Dec 2004 21:04

I'm not an A320 pilot, nor any sort of professional pilot for that matter, but I'm 99% sure you cannot engage the thrust reversers during flight. You'd drop like a stone!

My guess would be that they were using quite a lot of spoliers.

Thomas_Cook_757-300 21st Dec 2004 23:06

Hi,

It was probably the speed brake on the wings that you could hear.

Regards
Thomas_Cook_757-300

Carnage Matey! 22nd Dec 2004 00:27

No it is bull! A320 thrust reversers cannot be used in flight. The noise was almost certainly the speedbrakes. Perhaps the hostie had come from Britannia where they make a PA explaining what the reverser noise will be before landing so the shell suits don't panic.

126,7 22nd Dec 2004 02:40

I heard that a C-17 can engage reverse thrust on two engines when doing a tactical descent. Dont know if thats bull or not though.
Think back a few years ago when Lauda Air crashed in Asia when the one thrust reverser on a B767 opened at crusing level.

TightSlot 22nd Dec 2004 03:24

I seem to remember that the Trident was allowed to use reverse very shortly before touchdown (Hopefully somebody can confirm this?) - and that this is the only case of reverse being used in-flight!

IMHO, most likely speedbrakes or even early gear.

West Coast 22nd Dec 2004 05:06

I believe models of the DC8 have/had the capability.

Final 3 Greens 22nd Dec 2004 05:25

TS

My next door neighbour is an A320 driver, so I'll ask him about in flight reverse the next time our paths cross.

The Trident could use reverse and from altitude too - my info source is T3b sim time with an ex-Trident pilot.

It was impressive in the sim, fom BIG at FL150, it was no sweat to make 27L at LHR, but I guess it would have certainly got the attention of the pax ;)

Arthur Whitlock's book, behind the cockpit door, also relates an emergency descent into Palma, from FL30 odd, using reverse to hit the profile.

Wannabe Flyboy 22nd Dec 2004 10:25

I also think Concorde could engage two engines in idle reverse when a fast descent rate was required.

speedbird_heavy 22nd Dec 2004 10:35


I heard that a C-17 can engage reverse thrust on two engines when doing a tactical descent. Dont know if thats bull or not though
The C17 can indeed use reverse idle whilst in flight. It allows the aircraft to plumit at 15000fpm.

sywell-flyer 22nd Dec 2004 12:13

I seem to remember from my Software Engineering course that both main wheels had to be on the ground before the system would allow thrust reversers to be engaged...although I think this may have changed slightly after an A320 incident...although off the top of my head I can't remember how it has changed or what the incident was!

Cheers,

Sywell-Flyer

B Fraser 22nd Dec 2004 12:16

Quote
----------------
I seem to remember that the Trident was allowed to use reverse very shortly before touchdown
----------------

I recall from somewhere that the rate of descent was so rapid that the engineer had to increase cabin pressure prior to the descent otherwise the aircraft would over take the cabin :ok:

The main gear could also be used in isolation as a spreedbrake, however I recall that this was discontinued as it was considered an accident waiting to happen.

luvverly old beastie was the Trident :hmm:

sywell-flyer 22nd Dec 2004 12:23

Found some details in http://www.rvs.uni-bielefeld.de/publ...aw-report.html for the A320:

3. The aircraft automatics comprises, for basic landing configuration if the
aircraft (i.e. with flaps extended to FULL position), the programme which
subjects actuation of all braking devices to some specific conditions. Ground
spoilers, when selected, will extend provided that either shock absorbers are
compressed at both main landing gears (the minimum load to compress one
shock absorber being 6300 kgs), or wheel speed are above 72 kts at both main
landing gears. Engine reversers, when selected, will deploy provided that
shock absorbers are compressed at both main landing gears.
Such a logics result in the lack of possibility of immediate actuation of two
mentioned above aircraft's braking devices without meeting the conditions
described.

4 In emergency, the crew is unable to override the lock-out and to operate
ground spoilers and engine thrust reversers.

Cheers

Final 3 Greens 22nd Dec 2004 12:36

BF

My recollection from the sim briefing was that no 2 engine dealt with the pressurisation and thus would be kept around 11,000 - 11,500 rpm to avoid what you describe.

I also seem to recall that the ROD was about minus 15Kfpm.

SKYYACHT 22nd Dec 2004 16:32

As a Flight Crew Training Instructor on the Airbus, and the B777, I can assure you that it is NOT possible to deploy the thrust reversers whilst these types of aircraft are in flight.

There are numerous strain gauges, squat switches, proximity switches and microswitches mounted on the gear legs and oleos, the signals from which are normally sent to a ground/air sensing computer. Once the gear legs are compressed upon landing, the interlocks unlatch, and the reverse thrust buckets or translating sleeves are allowed to activate.


Hope that helps.
:ok:

alexban 23rd Dec 2004 10:37

I can assure you ,that also on the 737 you won't be able to deploy reversers inflight,only below 10' with thrust at idle.
I don't know why this is possible,because Boeing says is forbidden to do it.
Brgs Alex

j_davey 1st Jan 2005 20:53

hi all,

spoilers were deffo not deployed, my eyes are always glued to the wings.( besides this was much louder than the noise spoilers make)

it makes me wonder,

thanks for all the replys!


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