BR715-A1-30
Topic Author
Posts: 6525
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Why One Thrust Reverser On This Plane

Fri Mar 14, 2003 8:58 am


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If you look closely at this picture, the #2 Engine Thrust Reverser is open, but the #1 T.R. is closed. Why is this?
Puhdiddle
 
LMP737
Posts: 4943
Joined: Wed May 08, 2002 4:06 pm

RE: Why One Thrust Reverser On This Plane

Fri Mar 14, 2003 9:12 am

It's quite possible that the aircraft was having problems with the #1 T/R and it was placarded inop. In other words it was de-activated. Commercial aircraft can have one inop reverser as long as the other one is fully functional. Airports with short runways such as SNA it is required that both are operational.
Never take financial advice from co-workers.
 
ConcordeBoy
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RE: Why One Thrust Reverser On This Plane

Fri Mar 14, 2003 12:31 pm

Dont some regional jets not utilize R/T at all..... I've heard tell that BA's ERJs dont even come equipped with T/R-capable engines. How accurate is that?
Faire du ciel le plus bel endroit de la terre c'est impossible sans Concorde!
 
FDXmech
Posts: 3219
Joined: Sun Mar 19, 2000 9:48 pm

RE: Why One Thrust Reverser On This Plane

Fri Mar 14, 2003 2:14 pm

Could be. The F28 doesn't have any.
You're only as good as your last departure.
 
Guest

RE: Why One Thrust Reverser On This Plane

Fri Mar 14, 2003 3:28 pm

This question is for LMP737...

I was taught and am under the impression that thrust reversers were NEVER included in calculating the runway requirements for either takeoff or landing. Your comment about SNA was news to me. Can you clarify.
Jetguy
 
jwenting
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RE: Why One Thrust Reverser On This Plane

Fri Mar 14, 2003 5:15 pm

Another possibility is crosswind compensation.
If there's a bad crosswind, using only a single T/R would cause asymetric thrust which can help keep the aircraft on centerline.
I wish I were flying
 
T prop
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RE: Why One Thrust Reverser On This Plane

Fri Mar 14, 2003 5:22 pm

One possible reason for this is a lightly loaded airplane can get moving pretty quick. If you don't want to be on the brakes constantly, open a reverser and let one engine push the airplane.


T prop.
 
L-188
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RE: Why One Thrust Reverser On This Plane

Fri Mar 14, 2003 5:34 pm

We had a metro that had to taxi in with some beta on the upwind engine due to the winds we have been suffering up here.

But I have seen some G-V's taxi out and when in the run-up area pop one reverser and then close it and then do the same to the other side.

Some sort of preflight check???

[Edited 2003-03-14 09:35:04]
OBAMA-WORST PRESIDENT EVER....Even SKOORB would be better.
 
paulc
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Joined: Mon Mar 05, 2001 10:42 pm

RE: Why One Thrust Reverser On This Plane

Fri Mar 14, 2003 7:39 pm

BA regional EMB145's do not come equipped with reversers which had lead to some problems in the wet at my local airport ie insufficient runway length to stop when wet. They often divert to Bournemouth where the runway is longer.

As for the CRJ in the photo - T.prop is probably right - you do not want taxi speeds to get to high and it saves brake/tyre wear by not having to 'ride' them.
English First, British Second, european Never!
 
Guest

RE: Why One Thrust Reverser On This Plane

Fri Mar 14, 2003 11:08 pm

I'll buy the "taxi speed limiter" scenario. It's a quite common practice. The preflight check scenario is also a possibility, but the required checks are usually done on both engines simultaneously. However, I know of no reason why they must be done at the same time.

Thrust reversers are NEVER included in calculating the runway requirements for either takeoff or landing. Thrust reversers don't stop airplanes, brakes stop airplanes. That's the reason why they can be deactivated and the aircraft still dispatched - with no performance penalties. If I'm flying with a pilot who hasn't learned that basic lesson I won't let him touch the T/Rs at all. I've seen pilots nearly run off the runway while piddling around with the reversers. Many aircraft have minimum speeds at which the reversers can be deployed with anything more than idle reverse power. Get the airplane on the ground, get on the brakes while deploying the T/Rs. Under certain conditions, T/Rs can be very destabilizing and should not be deployed - they will only aggravate weather vaning tendencies. The braking effect of thrust reversers are never included in calculating the runway required for landing. Their effect is only used as a "pad" or "cushion".
Jetguy

 
m717
Posts: 540
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RE: Why One Thrust Reverser On This Plane

Fri Mar 14, 2003 11:41 pm

I will agree with the others who say that landing distances/runway required performance calculations are never predicated on the use of reverse thrust. Inoperative components that DO affect these calculations include brakes/anti-skid and spoilers. But not thrust reversers.

Also, the use of a single thrust reverser to compensate for crosswind is not a good idea or an accepted technique.
 
411A
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RE: Why One Thrust Reverser On This Plane

Sat Mar 15, 2003 2:10 am

'Never' applies to FAA certification, however those familiar with the United Kingdom certification requirements will recognise that 'never' does not apply to some aircraft on the UK register, ie: wet runway performance. Different strokes for different folks.
 
Guest

RE: Why One Thrust Reverser On This Plane

Sat Mar 15, 2003 4:06 am

Oops, my bad.

There are two words that you should use very cautiously when it comes to aviation - "Always" and "Never".

Jetguy

[Edited 2003-03-14 20:07:23]
 
sllevin
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Joined: Wed Jan 30, 2002 1:57 pm

RE: Why One Thrust Reverser On This Plane

Sat Mar 15, 2003 5:53 am

It's pretty common for CRJ's to taxi on a single engine, because, with both engines running, you're on the brakes quite a bit. So if you were already taxiing one one engine and still got a touch fast, you'd only have one T/R deployed. It certainly appears if the aircraft in this shot is on a taxiway and not a runway.

Steve
 
avioniker
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RE: Why One Thrust Reverser On This Plane

Sat Mar 15, 2003 6:25 am

Jetguy,
Don't feel too bad. Your choice of words wasn't that far off.
One more scenerio: A couple of my "buds" from Mesa told me that it has happened that maintenance has requested the engine be shut down with the T/R deployed (after landing) to prevent windmilling.
Any Mesa guys out there??
One may educate the ignorance from the unknowing but stupid is forever. Boswell; ca: 1533
 
LMP737
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RE: Why One Thrust Reverser On This Plane

Sun Mar 16, 2003 1:40 am

Jetguy:

The MEL for the 757 as an example states that one T/R maybe inop. However it stipulates that the aircraft not be flown into an airport with a runway less than 7100ft. Since SNA's runway is 5600 one would not be able, technically, to land a 757 there.

If I were a 757 pilot flying into SNA with a plane full of passengers I would want both T/R's functional.
Never take financial advice from co-workers.
 
fr8tdog
Posts: 120
Joined: Wed Feb 16, 2000 4:25 pm

RE: Why One Thrust Reverser On This Plane

Sat Mar 22, 2003 3:27 am

Most likely it is during taxi, that this event is occurring.
My airlines Ops specs specifically say that this is a "no-no" during normal taxiing, fearing Fod ingestion.
It also is common that a TR is MEL'd out due to a maintenance issue.

Under normal landing operations, TR reduction is started at 80kts then should be stowed at no less than 50kts, to reduce the chances of Fodding an engine.
Again this is the OPS procedures at my airline.
Fr8t.
 
Jan Mogren
Posts: 2014
Joined: Tue Dec 26, 2000 2:47 am

RE: Why One Thrust Reverser On This Plane

Sat Mar 22, 2003 11:28 pm

Most likely just Idle reverse, which I think should not be any greater risk of having FOD? You don't want any reverse so to speak, you just want the engine to stop pushing you faster.
/JM
AeroPresentation - Airline DVD's filmed in High Definition
 
Night_Flight
Posts: 183
Joined: Wed May 26, 1999 9:00 am

RE: Why One Thrust Reverser On This Plane

Mon Mar 24, 2003 11:14 am

I flew on a CRJ-200 our of ORD last night and I the #2 engine was not started until we had taxied closer to the runway. Is this a common practice on CRJ's , DC'9s, Citations????????

-Night_Flight-
Remember when sex was safe and flying was dangerous?
 
fallingeese
Posts: 2031
Joined: Sat Apr 28, 2001 2:33 pm

RE: Why One Thrust Reverser On This Plane

Mon Mar 24, 2003 11:38 am

Night_Flight - it is sometimes a common practice to save money, some carriers such as Westjet will taxi on one engine, fuel is money, and especially in these hard times, little measures save cash.
Mark McWhirter...Contrails Photography
 
BR715-A1-30
Topic Author
Posts: 6525
Joined: Thu May 30, 2002 9:30 am

RE: Why One Thrust Reverser On This Plane

Tue Mar 25, 2003 3:07 am

Of the 12 flights with AirTran I have taken, we only taxied on one engine once. The pilot started #1, and when we got to the runway we had to hold short because of incoming traffic, and that is when the pilot took the liberty to start #2.

IIRC, Valujet used to do Single-Engine Taxis all the time.

[Edited 2003-03-24 19:08:22]
Puhdiddle
 
fr8tdog
Posts: 120
Joined: Wed Feb 16, 2000 4:25 pm

RE: Why One Thrust Reverser On This Plane

Tue Mar 25, 2003 6:47 am

Night-flight,
Single engine taxi is dependent on several factors.
If I am faced with a long ground stop or if # 10 or 15 for departure, I may consider shutting an engine down for fuel conservation. Especially if I have a longer flight.

Weather has a huge effect on slowing departures down, some pilots may elect to shut an engine down to decrease fuel consumption, allowing them a greater chance of departing without having to refuel and start at the back of the taxi line again.
 
avt007
Posts: 1989
Joined: Mon Jul 10, 2000 4:51 am

RE: Why One Thrust Reverser On This Plane

Tue Mar 25, 2003 7:25 am

A certain Dash 7 operator was reputed to taxi on 2 engines, and on one occasion, attempted to takeoff the same way. As the tale goes, SOPs were changed after that. Another good aviation tale..........

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