B739ER, Speedbrake Lever in Flaps Up Landing

[mmrassi]

Hello Everyone,

In our FCOM there is a note for 739ER which says:
"Following an all flaps up landing, the SPEED BRAKE lever will not move beyond the FLIGHT DETENT and the spoilers will not fully deploy"

Now my question is can we move the speedbrake lever manualy and fully deploy it?
There is no notice in the QRH PI for considering the half deployment of the speedbrakes and put penalties on landing distance.

I was thinking to try this in Sim but all the Sims we use here are 800s.

Looking for your useful ideas.

Thanks

[AerocatS2A]

Thinking logically here based on the information given.

1. It says the speed brake lever won't move beyond the flight detent. Surely that answers your question main question.

2. There is no note in the QRH because the flaps up checklist would have penalties for landing flaps up and those penalties would necessarily include the loss of full spoiler deployment. In other words, the loss of spoilers is an inevitable consequence of a flaps up landing so there is no need to make specific mention of the spoiler penalty.

I don't fly any Mk of 737 so could be way off base.

[NSEU]

Strange... I had a quick look through some old NG maintenance and training manuals and couldn't find any inputs from the flaps into the autospeedbrake system.

Are there any other aircraft configuration changes involved in a flaps up landing?
Is there anything on your aircraft which stops you moving the speedbrake lever to UP in flight? (I thought the NG had no electromechanical lock, just a notch to let you know you'd reached the flight detent)

[mmrassi]

Strange... I had a quick look through some old NG maintenance and training manuals and couldn't find any inputs from the flaps into the autospeedbrake system.

Are there any other aircraft configuration changes involved in a flaps up landing?
Is there anything on your aircraft which stops you moving the speedbrake lever to UP in flight? (I thought the NG had no electromechanical lock, just a notch to let you know you'd reached the flight detent)

This only applies to 739ERs for their flaps up landing. There is no note for 800s in our FCOM.
Although ERs has a lock as protection which prevents moving the lever beyond flight detent in flight.

[TopSwiss 737]

mmrassi,

Do you have an FCOM reference where exactly this note is?
Could not find anything on this note you mention. Could be a thing specific to the -ER though; I have the -900 non -ER manuals in front of me. No difference with the -800 in these books for the all flaps up landing.

Rgds, TS737

[mmrassi]

https://i.imgsafe.org/7b41019.jpg

[mmrassi]

TS737,
Here is the part mentioned about my question. YH951,952 are 900ERs. FCOM 9.20.20

[NSEU]

his only applies to 739ERs for their flaps up landing. There's no note for 800s in our FCOM.
Although ERs have a lock as protection which prevents moving the lever beyond flight detent in flight.

Thanks, Mmrassi.
It's interesting to see how other Boeings handle "flight detent". The Boeing 767 uses air/ground signals into the Spoiler Control Modules. The lever still moves through the same range. The 777 uses a similar system (with air/ground input). The 747-400 uses an electromechanical lock in the lever assembly (activation logic is also based on air/ground logic) so you get a restriction in lever movement. I don't see why flaps should be involved in the logic on a 737-900ER. Is there also an input from the landing gear?

Is there a similar note for a gear up landing on the 737-900ER? Hopefully there is not an error in the FCOM.

[Yeelep]

Now my question is can we move the speedbrake lever manualy and fully deploy it? No.

This is not a 900ER specific thing, it's part of the short field performance package. The speedbrake lock is controlled by the trailing edge flaps up switch S245. So, if the flaps are up, you cannot move the speedbrake lever to the up position regardless if you are in the air or on the ground.

[mmrassi]

NSEU,
Thanks for your reply.
In NG, the flight and ground spoilers get signal from Landing gear strut compressions. Flight spoilers from any of them, Ground spoilers from right landing gear strut.

Yeelep
Thanks for participating in this topic.
I was thinking that SFP is found only in 800s. Do you mean we have a ER with SFP performance characteristics or they are only similar in some sub systems? Do you have a ref from Boeing stating this to share with us? I do appreciate.

[Denti]

The 900ER (unlike the 900) has the SFP as standard equipment. On the 800 it is an option, and one you can configure, not all SFP users use the two position tail skid for example.

See for example here the press release on certification (http://boeing.mediaroom.com/2006-07-27-Boeing-737-Design-Enhancements-Earn-FAA-Certification).

[767200ER]

Previous poster was correct.. it's the switch that signals trailing edge flaps not in "up" wimhich controls the solenoid lock in the speed brake lever itself. Even in ground mode with flaps out, if you don't move lever past flight detent, you don't get ground spoilers. regardless of air ground sensing.

[Yeelep]

You will get ground spoilers even with the handle only in flight detent. Ground spoilers will deploy with the spoiler handle at or greater than 29° from stowed position. Flight detent is 35.5°, up is 48°.
What you won't have is full flight spoiler deflection. Flight spoilers 2, 3, 10, and 11 will be at 19.5° and flight spoilers 4, 5, 8, and 9 will be at 24.5°. When the speedbrake lever is full up, flight spoilers 2, 3, 10, and 11 will be at 56° and flight spoilers 4, 5, 8, and 9 will be at 65°.