I use thrust reversers after touchdown in the 737NGX, and then apply the (manual) brakes after stowing them when I get down to about 70 knots. This is simply because I want a decent rollout (without stopping too quickly or stopping too late), and because I love the sound of those reversers. Landing without activating the thrust reversers is not an option for me......unless I am flying the BAe 146 :smile:

Hey Kevin,

 

I think it is a PMDG issue purely to do with the time it takes for the engines to spool down to idle & reach the criteria for rev thrust to deploy. Pretty sure it has nothing to do with the nose wheel being in the air, just people have different de-rotation techniques.

 

Not 100% sure of the above

I agree. I don't have problems with ground idle switching affecting reverser deployment but others clearly do. It does appear to be related to how throttle hardware is set up. PMDG say it's been improved in SP1 which is promising.

 

 

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You're not supposed to let the brakes take the brunt of all the breaking.

I've never seen a commercial flight not use reverse thrusters after touchdown, primarily for safety reasons.

 

Many airlines do this. Can be noise abatement rules of the airport or on some runways pilots can let the plane roll to the end of the runway before they can vacate.

 

For instance in many occasions planes landing on 18R at EHAM, in the early morning dont use any thrust reverse and let the planes roll for vacating.

 

 

It is definitely possible for the reversers to open en reverse before the nosewheel is on the ground. as said before it has to do with the idling. 

 

i alwys cut the AT when doing a manual landing in time to make sure that when i hit about 10 feet the engines go to idle and then i can reverse my baby when the mains touch down.

 

I dont always use reversers because in comibation with Autobrake 1 I get an absurdly short runway ussage for landing. thus the braking is way to heavy, even for a fully loaded 777

 

 

Something I found is the (apparent) inability to select reverse thrust whilst the nose gear is still in the air. Does anyone else see this?

 

I can activate the reversers before the nosewheel touches down.

 

Iain Smith

 

 

I dont always use reversers because in comibation with Autobrake 1 I get an absurdly short runway ussage for landing.

Autobrake 1 is very light.

 

@FLEX1978: I wondered if it is the time to spool down that is the issue. My throttle can NOT override the AT during IDLE phase (in fact, it can't override it at any time unless it is in HOLD mode or AT is disengaged). I press and hold F2 for reverse, and the instant the nose wheel is down, then I get reverse thrust.

 

As for derotation - it's autoland, so I have no say in the matter.

 

When manually flying (which at the moment is extremely rare given the FBW issues) I cut the thrust at about 30 ft, which works really nicely.

 

@Kevin: It's not my hardware. First of all, it is entirely digital. Second, any supposed "noise" that some systems make doesn't exist because of the first point. Third, any noise that other systems make that can override the fully engaged AT system will exhibit the exact same behavior if you manually move the thrust levers. I can not do this - it is 100% disabled except in HOLD or fully manually mode for thrust.

 

For many years, I have suspected that digital inputs are handled differently inside FS than analogue, with analogue inputs being able to override the systems, for reasons I don't understand. I haven't had an analogue throttle or stick for nearly 14 years, and never ever had controller input issues.

 

My current setup is a Warthog HOTAS.

 

Best regards,

Robin.

@Kevin: It's not my hardware. First of all, it is entirely digital. Second, any supposed "noise" that some systems make doesn't exist because of the first point. Third, any noise that other systems make that can override the fully engaged AT system will exhibit the exact same behavior if you manually move the thrust levers. I can not do this - it is 100% disabled except in HOLD or fully manually mode for thrust.

 

 

 

For many years, I have suspected that digital inputs are handled differently inside FS than analogue, with analogue inputs being able to override the systems, for reasons I don't understand. I haven't had an analogue throttle or stick for nearly 14 years, and never ever had controller input issues.

 

 

 

My current setup is a Warthog HOTAS.

 

We seem to be talking at cross purposes. I'm not saying your hardware itself is the problem, but maybe the way you have it set up. Do you use FSUIPC to calibrate the throttle in reverse, or do you idle the throttle and then use F2? I do the latter and have no problems whatsoever with thrust reverse on any PMDG sim.

 

I strongly suggest you try a manual landing and hold the nose up until rpm drops to ground idle (should be about 5-6 seconds after touchdown IIRC). Ensure the wheel brakes off to help hold the nose up. If you can now get reverse with the nosewheel in the air then that shows it is not part of the problem. The problem you are seeing is more likely to do with the flight/ground idle problem which affects reverser operation for some users.

 

Think about it logically. Why would PMDG incorrectly add nosewheel on ground to the reverser logic when there is no reason to? Also had they done so it would be a problem for all users, not just some of them.

Hi,

 

I never suggested that PMDG tied anything to a nose ground switch, however it just appears that way (the timing is impeccable).

 

Don't be under any illusions - I understand aircraft systems and software very well.

 

As you said, it seems that it is to do with the flight/ground idle, and the timing of it is just that it coincides with nose gear touchdown.

 

I have hand-flown the aircraft and I don't see the problem there.

 

Best regards,

Robin.

Here's a screenshot showing my 777 with reverser operating after I held the nose up deliberately on landing.

 

I do not have any idea how it happens maybe it depends on the airport, because at LROP( romania) i have my reversers on a button and i press it a million times, only after the nose wheel touches down.I can only make such a picture using a replay. other than that i got no idea.

I do not have any idea how it happens maybe it depends on the airport, because at LROP( romania) i have my reversers on a button and i press it a million times, only after the nose wheel touches down.I can only make such a picture using a replay. other than that i got no idea.

I assure you that was not a replay. I took that screenshot by switching to an external camera after touching down. The reversers deployed correctly with the nose wheel still in the air.

 

It has absolutely nothing to do with which airport you are using. FSX does not need nose gear on ground for reverse thrust activation and there's absolutely no reason why PMDG would add such logic  I understand you have a problem with this but please believe me when I say that I don't.

I assure you that was not a replay. I took that screenshot by switching to an external camera after touching down. The reversers deployed correctly with the nose wheel still in the air.

 

It has absolutely nothing to do with which airport you are using. FSX does not need nose gear on ground for reverse thrust activation and there's absolutely no reason why PMDG would add such logic  I understand you have a problem with this but please believe me when I say that I don't.

I have no problem. When some people are better than me I admit it. I recognized it wasn't a replay because it didn't have the red label. And as much as I know from the REAL T7 manual, "Reverse thrusters during flight is strictly prohibited". But once you've touched down that's no longer flight. Right?

Hi,

 

Something I found is the (apparent) inability to select reverse thrust whilst the nose gear is still in the air. Does anyone else see this?

 

I'm going to do some test flights.

 

Best regards,

Robin.

On the real B777 there is a "Weight on Wheels" switch to prevent inadvertent thrust reverser deployment in flight. The switch activates an unlock valve to allow deployment. I am not sure where the switch is located (Mains or nose wheel). This is an FAA requirement after the thrust reversers were inadvertently deployed on a Lauda Flight 004 B767-400ER causing a crash.

The "weight on wheels" is on the mains.

Hi Stefan. OK Thanks! Regards, Bob.

 

 

This is an FAA requirement after the thrust reversers were inadvertently deployed on a Lauda Flight 004 B767-400ER causing a crash.

Off topic but this isn't strictly true. The 767 already had an interlock to prevent reverser deployment in flight, as did all airliners with few exceptions (e.g. DC-8, Trident, 727, Il-62, Concorde). However, inadvertent reverse thrust in flight remained a remote possibility, due to system failure. That was what happened to the Lauda Air 767. After that accident an additional mechanical locking system had to be installed on the reverser to prevent this. A positive lock that system failure could not unlock. But from an operational point of view this is transparent to the pilot.

To be exact, they implemented an over-center cam, so if the reverser did attempt to unlock, the aerodynamic forces would actually be in the lock direction.

 

Best regards,

Robin.