I once flew on a United Airlines DC-10 from Denver International to Los Angeles International Airport. As I was sitting behind the wing, upon landing I saw the speed brakes deploy and felt the brakes bite but did not seem to hear a change in sound that would indicate that reverse thrust had been selected by the pilots. Was it possible that the plane landed without reverse thrust or perhaps was it used but my hearing could not detect it? On another flight from DEN into LAX on the UA DC-10 I felt a very brief application of reverse thrust and then just felt the sense of braking deceleration.

Does anyone know if the DC-10 in revenue passenger service could land without reverse thrust? Thanks to any DC-10 pilots out there with information!

We often just use idle reverse, meaning the doors are opened but thrust is not increased. In this case there is no increase in whooshing.

I don't know the DC-10 specifically AFAIK no airliner requires the reversers to be operative for dispatch. They can be MELed. This may affect landing distance, but in most cases, reverse doesn't "count" in the calculation anyway.

3 installed, 2 required. One can be put on MEL.

But, as Starlionblue indicated, the aircraft are certified to stop without their use.

fr8mech wrote:

3 installed, 2 required. One can be put on MEL.

But, as Starlionblue indicated, the aircraft are certified to stop without their use.

Can the AC be dispatched with either #1 or #3 inop?

How many airliners have thrust reverse on MEL for dispatch? Or does this vary by the conditions for a given flight? (Better way of asking: What aircraft can be dispatched on a 121 with all T/R inop?)

Landing distance is calculated without the use of thrust reverser. So if the landing distance allows, all airliners can land without using thrust reversers.

rjsampson wrote:

? (Better way of asking: What aircraft can be dispatched on a 121 with all T/R inop?)

Emb-145 can dispatch with no thrust reversers operative. Actually the carrier I worked for has it in their manual that thrust reverser usage is prohibited if you have working thrust reversers and the runway is over 7000ft long. So basically can’t use them even if I have them. The only time I’m allowed to use them is if I’m about to go off the end of the runway where they are the least effective and brakes are more appropriate.

How much thrust are we actually talking about with idle reverse? I always wondered if there was something to be gained simply by the doors opening and adding a bit more drag to the slowiing-down-the-beast equation, particularly in the case of the flower-petal style reversers and maybe the clamshells. Or is idle reverse a means of simply killing off ANY forward thrust (like coasting with the clutch disengaged approaching a traffic signal.)?

rjsampson wrote:

fr8mech wrote:

Can the AC be dispatched with either #1 or #3 inop?

How many airliners have thrust reverse on MEL for dispatch? Or does this vary by the conditions for a given flight? (Better way of asking: What aircraft can be dispatched on a 121 with all T/R inop?)

Any of the 3 can be deferred.

Every type I’ve worked on allowed a reverser to be deferred. None allowed all the reverser to be deferred. I seem to recall the DC8 allowed one per wing, but I’m fuzzy on that.

Types I’ve worked:

B727-100/200, B747-100/200/400/8, B757, B767, A300/310, DC8, L1011, MD11

I don’t list the DC10 because I only worked it once as a contract mechanic, but that once was to MEL a reverser…wing thank God.

IFlyVeryLittle wrote:

How much thrust are we actually talking about with idle reverse? I always wondered if there was something to be gained simply by the doors opening and adding a bit more drag to the slowiing-down-the-beast equation, particularly in the case of the flower-petal style reversers and maybe the clamshells. Or is idle reverse a means of simply killing off ANY forward thrust (like coasting with the clutch disengaged approaching a traffic signal.)?

Idle reverse is drag, as you said, but you do get some reverse thrust, a percentage of forward idle and, once moving, at landing weights most planes will maintain some taxi speed.

Woodreau wrote:

Actually the carrier I worked for has it in their manual that thrust reverser usage is prohibited if you have working thrust reversers and the runway is over 7000ft long. So basically can’t use them even if I have them. The only time I’m allowed to use them is if I’m about to go off the end of the runway where they are the least effective and brakes are more appropriate.

Prohibited, even on a contaminated runway?

rjsampson wrote:

fr8mech wrote:

3 installed, 2 required. One can be put on MEL.

But, as Starlionblue indicated, the aircraft are certified to stop without their use.

Can the AC be dispatched with either #1 or #3 inop?

How many airliners have thrust reverse on MEL for dispatch? Or does this vary by the conditions for a given flight? (Better way of asking: What aircraft can be dispatched on a 121 with all T/R inop?)

A320 can have both reversers on MEL without big restrictions (obviously you have to consider the inoperative reversers when dispatching from/to a wet/contaminated runway and there are a couple of checks that have to be done be maintenance, but nothing major)

As I understand it reverse thrust is not included in the stopping calculations for aircraft certification so the answer to your question is yes. Quite often at airports with longer runways or where noise is an issue, aircraft use idle reverse which does aid in slowing the plane down but makes no noise.

Modern aircraft such as the A320 use reverse to take the pressure off the brakes when auto-braking is used but this does not shorten the stopping distance. This reduces wear and tear and also enables quicker turnarounds because the brakes are cooler.

IFlyVeryLittle wrote:

How much thrust are we actually talking about with idle reverse? I always wondered if there was something to be gained simply by the doors opening and adding a bit more drag to the slowiing-down-the-beast equation, particularly in the case of the flower-petal style reversers and maybe the clamshells. Or is idle reverse a means of simply killing off ANY forward thrust (like coasting with the clutch disengaged approaching a traffic signal.)?

As I see it, the main purpose of idle reverse is to have the reversers deployed already in case you need full reverse. Otherwise, you have to wait for the doors to open.

Say you plan for idle reverse, but there's more tailwind than you anticipated and you've floated a bit. You go to reverse idle thanks to muscle memory. As you assess that you're going a bit fast and have rolled a bit far, all you have to do is pull the reverse levers out of the idle detent and to the stops.

fr8mech wrote:

Every type I’ve worked on allowed a reverser to be deferred. None allowed all the reverser to be deferred. I seem to recall the DC8 allowed one per wing, but I’m fuzzy on that.

A quick correction, the B747 (all models) 2 reversers may be MEL’d so long as the inoperative reversers are on symmetrical engines. This is a 3 day item.

fr8mech wrote:

rjsampson wrote:

fr8mech wrote:

Can the AC be dispatched with either #1 or #3 inop?

How many airliners have thrust reverse on MEL for dispatch? Or does this vary by the conditions for a given flight? (Better way of asking: What aircraft can be dispatched on a 121 with all T/R inop?)

Any of the 3 can be deferred.

Every type I’ve worked on allowed a reverser to be deferred. None allowed all the reverser to be deferred. I seem to recall the DC8 allowed one per wing, but I’m fuzzy on that.

Types I’ve worked:

B727-100/200, B747-100/200/400/8, B757, B767, A300/310, DC8, L1011, MD11

I don’t list the DC10 because I only worked it once as a contract mechanic, but that once was to MEL a reverser…wing thank God.

All types have their own quirks I suppose. The A330 and A350 allow both reversers to be deferred.

tjwgrr wrote:

Prohibited, even on a contaminated runway?

The only thing I remember the last time I flew the plane 13 years ago is that thrust reverse use is prohibited on runways longer than 7000ft. Reversers may be used on runways less than 7000ft and reverser use is mandatory to prevent runway excursion is how I remember the limitation. There was nothing that I specifically remember about condition of the runway. I’d have to refer to the flight manual that I no longer have access to. So you didn’t consider using it except right before you go off the end of the runway.

It would be a bad day if you use the reversers at an airport where you landed on a runway that was 7000ft and longer and you needed to call maintenance for a reverser fault afterwards. while you wouldn’t be in any trouble with the FAA (although you demonstrated intentional disregard of a limitation in a FAA approved manual) You’d still have to do a coach and counseling session with the chief pilot afterwards for using the thrust reversers when their use is prohibited.

EMB-145 reversers are pretty nominal from a effectiveness standpoint, sort of some in extremis conditions (and I've stopped a -145 entirely with T/Rs.) I believe some European operators elected to take delivery without them (Swiss/CrossAir?) and the biggest issue was that EMB had determined most W&B planning with T/Rs and without the aft weight of the T/Rs, the non-T/R aircraft had a weird loading schedule, to the point the operator just put in aft ballast to make life easier.

Woodreau wrote:

tjwgrr wrote:

Prohibited, even on a contaminated runway?

The only thing I remember the last time I flew the plane 13 years ago is that thrust reverse use is prohibited on runways longer than 7000ft. Reversers may be used on runways less than 7000ft and reverser use is mandatory to prevent runway excursion is how I remember the limitation. There was nothing that I specifically remember about condition of the runway. I’d have to refer to the flight manual that I no longer have access to. So you didn’t consider using it except right before you go off the end of the runway.

It would be a bad day if you use the reversers at an airport where you landed on a runway that was 7000ft and longer and you needed to call maintenance for a reverser fault afterwards. while you wouldn’t be in any trouble with the FAA (although you demonstrated intentional disregard of a limitation in a FAA approved manual) You’d still have to do a coach and counseling session with the chief pilot afterwards for using the thrust reversers when their use is prohibited.

Don’t really understand that mindset


‘Prohibiting reverse thrust’ on runways greater than 7000 feet ?


Its never a good thing to take options away and you never know when you might need every deceleration device you have, a wet or contaminated runway and / or a tailwind at the limits plus other unexpected circumstances like system failures may require pilots use everything they have to stop the aircraft



Problem with reverse is you need to use it as soon as possible after touchdown, it loses effectiveness as you slow, pilots overeagerness to stay within such a mandate can produce an unintended consequence when they realize stopping may be a problem but the opportunity to use reverse most effectively is gone

FlapOperator wrote:

EMB-145 reversers are pretty nominal from a effectiveness standpoint, sort of some in extremis conditions (and I've stopped a -145 entirely with T/Rs.) I believe some European operators elected to take delivery without them (Swiss/CrossAir?) and the biggest issue was that EMB had determined most W&B planning with T/Rs and without the aft weight of the T/Rs, the non-T/R aircraft had a weird loading schedule, to the point the operator just put in aft ballast to make life easier.

BE had them without reversers, which suprised me when I read about this (minor) runway overrun. http://avherald.com/h?article=412df767/0001&opt=0

Max Q wrote:

Don’t really understand that mindset

Me neither. Not my rules. It was the airlines rule approved by the FAA.

I agree with everything you’ve posted.

The limitation looks like it was written by lawyers.

pilots would get counseled by the chief pilot for using thrust reversers.

Don’t work there anymore.

But the airline recently had lots of planes go off the end of the runway and has been under FAA scrutiny

They fly grey regional airplanes with red white and blue tails.

Woodreau wrote:

Max Q wrote:

Don’t really understand that mindset

Me neither. Not my rules. It was the airlines rule approved by the FAA.

I agree with everything you’ve posted.

The limitation looks like it was written by lawyers.

pilots would get counseled by the chief pilot for using thrust reversers.

Don’t work there anymore.

But the airline recently had lots of planes go off the end of the runway and has been under FAA scrutiny

They fly grey regional airplanes with red white and blue tails.

Seems like it wasn’t a great idea, understood


Best wishes

Woodreau wrote:

Max Q wrote:

Don’t really understand that mindset

Me neither. Not my rules. It was the airlines rule approved by the FAA.

I agree with everything you’ve posted.

The limitation looks like it was written by lawyers.

pilots would get counseled by the chief pilot for using thrust reversers.

Don’t work there anymore.

But the airline recently had lots of planes go off the end of the runway and has been under FAA scrutiny

They fly grey regional airplanes with red white and blue tails.

Any airline that has management "counsel/coach" a reasonable safety decision is A) unsurprising in the US regional world and B) completely at odds with any idea of a just safety culture.

The only thing regarding T/Rs to manage in my estimation is that most aircraft (including the -145, IIRC) are precluded from a go-around once T/Rs are deployed. In my view, go-around ability should be preserved as long as possible, in the opinion of the crew at the obvious command of the captain.

mxaxai wrote:

FlapOperator wrote:

EMB-145 reversers are pretty nominal from a effectiveness standpoint, sort of some in extremis conditions (and I've stopped a -145 entirely with T/Rs.) I believe some European operators elected to take delivery without them (Swiss/CrossAir?) and the biggest issue was that EMB had determined most W&B planning with T/Rs and without the aft weight of the T/Rs, the non-T/R aircraft had a weird loading schedule, to the point the operator just put in aft ballast to make life easier.

BE had them without reversers, which suprised me when I read about this (minor) runway overrun. http://avherald.com/h?article=412df767/0001&opt=0

Trans States also had E145's with no T/R's. They experienced 4 runway overruns, 3 in YOW. Lack of T/R's was listed as a contributing factor for at least one of them.

shamrock137 wrote:

mxaxai wrote:

FlapOperator wrote:

EMB-145 reversers are pretty nominal from a effectiveness standpoint, sort of some in extremis conditions (and I've stopped a -145 entirely with T/Rs.) I believe some European operators elected to take delivery without them (Swiss/CrossAir?) and the biggest issue was that EMB had determined most W&B planning with T/Rs and without the aft weight of the T/Rs, the non-T/R aircraft had a weird loading schedule, to the point the operator just put in aft ballast to make life easier.

BE had them without reversers, which suprised me when I read about this (minor) runway overrun. http://avherald.com/h?article=412df767/0001&opt=0

Trans States also had E145's with no T/R's. They experienced 4 runway overruns, 3 in YOW. Lack of T/R's was listed as a contributing factor for at least one of them.

Those were originally European delivered aircraft, IIRC. Uncle Hulas bought them used.

In many ways, operations in North America appear to be more climatically challenging than Europe.