Question About Reverse Thrust / Ground Spoilers

[adamant365 28]

Hello Experts,

 

Can someone explain to me the logic behind the ground sensing mechanism and the reverse/ground spoiler lockouts? The reason I ask is that I am unable to unlock and engage reverse thrust until the nosewheel is on the ground. In addition, the ground spoilers only deploy when the nose wheel is on the ground. I get all of the flight spoilers, but I do not get the ground spoilers until NWG touchdown. I don't think this is correct because I've seen many a 777 video where reverse and all spoiler panels come in before the NWG is on the ground. Here's how I perform the landing:

 

1. Flare

2. Land

3. As SOON as the Main Gear are on ground, I hold F2 until the reversers unlock.

4. I then proceed to use my hardware throttle assigned to reverse to set the amount of reverse I desire.

 

But no matter what I do or how long I hold F2, the reversers don't unlock and those last two panels of spoilers that make the "Ground Spoilers" don't deploy until the nose wheel is down.

Can someone else give this a try and see what happens? I have read about this in the manual (FCTM and FCOM) but there is some vagueness about when these two systems are available.

[lekijiji 15]

Hi Adam, what happens to you IS NOT supposed to happen.

 

Speedbrakes.

As per the FCOM: "In the ARMED position, the speedbrake lever is driven aft to the UP position when the landing gear is fully on the ground (not tilted) and the thrust levers are at idle..."

(check, and make sure your thrust levers are at idle before nose gear touches down)

 

Reversers.

As per the FCOM: "The reverse thrust levers can be raised only when the forward thrust levers are in the idle position..."

(check, and make sure your thrust levers are at idle before nose gear touches down)

[Azapata87 173]

I am having the same issue and I have the hardware throttle at idle on all landings. No reverse until nose wheel is on the ground. I thought it was a little odd. The same thing happens even if I disable the auto throttle on final approach. I do not use fsuipc for hardware controller calibration.

[adamant365 28]

I have always left the A/T engaged until touchdown with the T7 and I have gotten into the habit of pulling my hardware throttle to idle at TOD (hardware throttle override is set to Never, BTW) just to eliminate potential issues later on. Therefore my hardware throttle and the A/T throttle should be at idle at main gear touchdown or very shortly after. Either way, I HOLD down F2 as soon as the mains are down which would certainly bring the thrust levers to idle in FSX. Even when I hold the nose off for a bit, I still don't get REV in yellow on the EICAS telling me the reverses are unlocked until the moment the nose gear is down.

 

Should I have to disconnect the AT when the mains touch? Or is it possible the AT isn't really commanding full idle and also isn't disengaging until after the NWG touches therefore preventing my F2 press and hold from having any effect? It's a minor inconvenience and I have yet to run off the runway...of course I'll only put more wear on my brakes with REV not coming available in a timely fashion. As for the spoilers, like I said, 8 out of 10 panels are deploying on MLG touchdown which should be plenty to put weight on wheels for braking effectiveness. It's just the last 2 panels for the ground spoilers that aren't coming up until NWG touchdown.

[ger 2]

Hi Adam  ,

 

if you land with auto thrust off ( I switch auto thrust off a few miles before touchdown  after autopilot off ) you can deploy the reversers when the main wheels are on the ground and the mose gear is still from the ground , like in real .

If i land with autothrust on ,  the reversers deploy only when the nose gear is on the ground

 

Gérard

[adamant365 28]

So can someone confirm for me if this is an issue with the PMDG sim or not? It seems odd that using the AT (per Boeing recommendation) would prevent reverser operation until after NWG touchdown.

[adamant365 28]

Can anyone confirm if AT being on at touchdown prevents reverser deployment until nose wheel touchdown in the real aircraft?

[Aamir 2,907]

I think the real aircraft can only deploy reversers after NWG touchdown, that's what I can gleam from watching YT videos of the T7 landing.

[PinkPony 171]

I think the real aircraft can only deploy reversers after NWG touchdown, that's what I can gleam from watching YT videos of the T7 landing.

 

Wrong. 

 

See here 

 

I have submitted a ticket to PMDG. Im sure they will get it fixed quickly.

 

There is nothing in the FCOM that says the 777 can only unlock reversers after NLG touchdown.

 

Furthermore a close friend is a 777 F/O at Emirates. He confirmed that this is 100% a bug.

[Aamir 2,907]

:rolleyes:

[adamant365 28]

I have submitted a ticket to PMDG. Im sure they will get it fixed quickly.

 

There is nothing in the FCOM that says the 777 can only unlock reversers after NLG touchdown.

 

Furthermore a close friend is a 777 F/O at Emirates. He confirmed that this is 100% a bug.

Did you ever get a response from PMDG?? I don't see that this item has been added to the Issue Tracking Thread as of yet.

[PinkPony 171]

Yup. Here the email reply I received

 

This issue has actually been identified and corrected for the SP1 update. The issue was caused by the A/T not reaching full idle thrust and actually had nothing to do with Nose Gear touchdown. We have also added a mode to allow the users to manually retard the throttle as well during flare to ensure they deploy as designed.

 

 

Did you ever get a response from PMDG?? I don't see that this item has been added to the Issue Tracking Thread as of yet.

[adamant365 28]

Yup. Here the email reply I received

 

This issue has actually been identified and corrected for the SP1 update. The issue was caused by the A/T not reaching full idle thrust and actually had nothing to do with Nose Gear touchdown. We have also added a mode to allow the users to manually retard the throttle as well during flare to ensure they deploy as designed.

 

 

Excellent, thanks!