This morning I noticed the post concerning Reverse Thrust but I decided to put this info into a separate post since the first post was mainly concerned with hardware calibration settings.

 

If any of you have had issues with a delay in activation of reversers as I have on many occasions, I have found a solution. I do not use hardware only mouse and keyboard but the solution should work for hardware users as well.

 

After back and forths with Paul at Support over the issue of NGX not responding fast enough to reverse thrust command, I finally was about to give up. I have had the problem with other sophisticated add-ons and, in each case, developed a unique technique that would produce the quick response as in the RW. Pressing F1 first and then F2 seemed to be required for the PMDG B744 but this only delayed action on the NGX. ConcordeX required two presses of F2, the first to set the actuators and then when "blue steady" pressing and holding F2 to accelerate into full reverse. This also did not work with FSX.

 

Paul relayed that he was having success by waiting 2 seconds after touchdown and then holding down F2 key. That seemed to work some of the time but it was unreliable and inconsistent. Youtube videos show reversers activating at the point of touchdown on landings where they are used but I was unable to duplicate that in the sim until I went back to the FCOM.

 

According to FCOM, the NGX reversers can be deployed any time the aircraft is below 10 AGL without waiting until main touchdown. By beginning to press and HOLDING the F2 key as soon as I hear the 10 AGL announcement, the actuators respond immediately regardless of the N1 speed with full deflection (detente 1, reverse idle) by main wheel touchdown. Continuing to hold without releasing will accelerate into full reverse right away. This has worked consistently in 8 test flights. I would think that applying this technique with hardware would yield similar success.

 

Again, as mentioned in previous posts, most airports restrict unnecessary reverse thrust beyond idle due to noise factors but nice to know that it is immediately available and responsive if needed.

_{Great find, will give it a try tonight!}

Afaik all gear must be touching the ground before you deploy reversers.

If one of the engines is faulty it can provide unbalanced thrust and cause the airplane to yaw before the nose gear is on the ground.

...and holding down the F2 key at 10ft AGL in the flare is not really a solution IMHO, it is a good work around however.

 

If some coding could be done to get the engines from FLT idle to GND idle *triggered when the main gear touches down (compresses)*, that would be a solution, not a work around.

 

There have been several posts on this, I have also opened a ticket many moons ago shortly after initial release. I don't recall the answer I got, if this was an FSX limitation or some other issue. I recall someone quoted the Boeing manual to me as well in regards to a 2-5 second delay from main gear touchdown to GND idle being achieved. I did not verify that statement, but I can tell you IRL that GND idle power is commanded and achieved almost immediately after the main gear is down, you should be able to get the reversers (doors) active by the time you gently get the nose gear down....all other things equal and all that :-) A look at any youtube or FL350 video of 737NG landings will verify this to be true.

 

Rob.

I agree Rob. This is the only issue that bugs me with this plane. I use PFC hardware and after the mains touch down the reverse will not work at all with the wheel still up. As well if I plant the nosewheel quicker in order to activate the reversers quicker it takes a a little longer than it should. I also notice sometimes the reversers will engage then stop causing me to cycle them again. I miss many a high speed turn off because of this. Fwiw, my hardware is calibrated through fsuipc.

Afaik all gear must be touching the ground before you deploy reversers.

 

Not so, according to the FCOM for the NG!!!!!

 

...and holding down the F2 key at 10ft AGL in the flare is not really a solution IMHO, it is a good work around however.

Rob.

 

It is not a just a work-around. It is an acceptable procedure for the NG according to the FCOM:

 

"The thrust reverser can be deployed when either radio altimeter senses less than 10 feet altitude, or when the air/ground safety sensor is in the ground mode." FCOM2 P.369

 

 

There is no need to have N1 reach "ground" idle first, as long as throttles are brought to idle stop position and plane is below 10 ft RA! This is a mechanical operation not dependent on N1 rotation speed!

 

A good test of this is to accelerate N1 while taxiing and immediately press and hold F2 and you will see the deflectors move into position with N1 still rotating rapidly. All this power is immediately deflected forward instead of rearward causing rapid deceleration. This is modeled correctly. Pressing the F1 key repositions the deflectors out of the flow stream and aircraft immediately begins forward acceleration again regardless of N1 speed! This is RW. Why the unrealistic delay when pressing F2 AFTER touchdown must be an FSX issue because this is definitely not RW performance.

"or when the air/ground safety sensor is in the ground mode." - I thought that sensor was in the main gear when it compresses, the sensor is closed?

 

Regardless, holding down the F2 key really should not be required to speed up achieving GND Idle power / activating reversers - my hardware has throttles # 3 and # 4 mapped to reversers via FSUIPC which works great with non-PMDG aircraft...don't have this problem with the PMDG B744 either using the lower tab of all 4 throttles mapped to reverse thrust, I understand it's a different aircraft...still.

Every flight I've ever taken in a real 737 NG did not deploy reversers until the plane's main gear plus nose gear were firmly on the ground....they were all with United though.

Some other airlines may do it differently.

All 737NG are able to deploy the thrust reversers with RA less than 10 feet from the ground or when the airplane is on the ground, only there is a time delay of 0.1 seconds to unlock the sync-lock of each thrust reverser half.

"or when the air/ground safety sensor is in the ground mode." - I thought that sensor was in the main gear when it compresses, the sensor is closed?

 

Robert, note the operative word there is "or". And the holding of the F2 key (set to the right for "repeat") is simulating the moving of the reverse levers thru detente 1, detente 2, and (if desired) on to accelerated (or full) reverse thrust. You don't just press a button to deploy reversers, you physically move the levers as necessary to achieve the desired results. This rightly simulates that. The problem with FSX different from reality is that once you release the F2 key and then re-press it, nothing happens. In real world I can begin with reverse idle (detente 1) and if I am not slowing fast enough I can push the levers farther to increase N1 reverse. Can't seem to duplicate that in FSX.

 

Every flight I've ever taken in a real 737 NG did not deploy reversers until the plane's main gear plus nose gear were firmly on the ground....

 

A.J., were "driving" or just riding as a passenger? Watch YouTube and you will see NG using reverse thrust simultaneous with wheels on ground. The reverse levers had to be activated a split second before (as Mark stated above to unlock the deflector sync-locks). This can be done in the last stage of the flair so that you as a passenger would begin to hear the thrusters revving by the time all wheels were down.

As a passenger. Which video? Interested to see which airline does that.

Hi A.J.!

 

No particular one. But there are countless NG landing videos and many of them use reverse thrust. Just put "737 landing" in the search and you will find many. And as I mentioned in real life the reversers can be delayed to any point in the runway roll but FSX will not respond in timely manner if you try to vary the procedure. Fortunately there exists the procedure that we are discussing as an option in the Boeing FCOM. Instead of debating the issue read it for yourself and then try it. It is a real world procedure or it wouldn't be mentioned in the FCOM. If it works for you then at least you have one method of deploying the reverse thrust in a timely manner. If you find another way let us know, but a long delay after activating the reverse levers is definitely NOT REAL WORLD.

Regardless, this procedure worked for me. When I hear "10", I deploy the reversers (calibrated through FSUIPC), and they will deploy immediately when the wheels touch down. This solved a very annoying reverser delay that usually required me to do a lot of excess taxiing. Great discovery, very much appreciated. Now if only we could a work-around for the equally annoying SID/STAR/FMC problem.

Anyone tried hitting F1 on the ground, and then holding F2?

Ive seen countless in cockpit videos, and you can find them to, but I have failed to see the activation of reversers before main wheel touchdown.

If you can point me to one I will gladly take a look and subsequently change my previous statement.

If it is in the FCOM, maybe it is pointed towards the NGs operating in shorter runways?

If you can point me to one I will gladly take a look and subsequently change my previous statement.

 

737 FCOM doesn't suggests when you can use reverse in flight, it just tells that it's possible.

 

On Tu-154 pilots use it for short and/or slippery runways (0:39). But I haven't seen any airborne 737 with activated reversers.