Boeing Landing Gear Lever: UP & OFF
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Boeing Landing Gear Lever: UP & OFF
Hi there,
A question regarding the "Landing Gear" lever on Boeing aircraft.
What is the difference between the "UP" and "OFF" positions?
As well as this, do you not have to pass the lever through the "OFF" position to get to the "UP" position? Why can you not just move the lever from "DOWN" to "OFF" upon reaching positive climb?
Thanks for any insight offered!
A question regarding the "Landing Gear" lever on Boeing aircraft.
What is the difference between the "UP" and "OFF" positions?
As well as this, do you not have to pass the lever through the "OFF" position to get to the "UP" position? Why can you not just move the lever from "DOWN" to "OFF" upon reaching positive climb?
Thanks for any insight offered!
If you did then nothing would happen. The gear would stay down. You need to select them up to get them up. Selecting them to off isolates the hydraulics from the gear selection system.
The B777 does not have the "OFF" position.
The B777 does not have the "OFF" position.
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"What is the difference between the "UP" and "OFF" positions?"
Up - the gear is hydraulically powered up
Off - as 'Billyt" says; the gear is held up by the mechanical uplocks because the gear hydraulics are shut off. In the event of turbulence the gear handle is selected back to UP to provide hydraulic up pressure to reduce structural loads on the mechanical uplocks.
Up - the gear is hydraulically powered up
Off - as 'Billyt" says; the gear is held up by the mechanical uplocks because the gear hydraulics are shut off. In the event of turbulence the gear handle is selected back to UP to provide hydraulic up pressure to reduce structural loads on the mechanical uplocks.
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The general principle (not aircraft specific, I'm sure there are exceptions) is that with the gear selector up or down, the gear hydraulics are pressurised in the appropriate direction, and move the gear appropriately.
Once it is up, and the (generally mechanical) uplocks are engaged, you go to off, which relieves the pressure in the gear hydraulics. Passing through off makes sense as you need to reverse the direction of actuation.
As billyt points out, if you simply selected off after leaving the ground, the gear would go nowhere - it's off, not 'up and off'.
Once it is up, and the (generally mechanical) uplocks are engaged, you go to off, which relieves the pressure in the gear hydraulics. Passing through off makes sense as you need to reverse the direction of actuation.
As billyt points out, if you simply selected off after leaving the ground, the gear would go nowhere - it's off, not 'up and off'.
"In the event of turbulence the gear handle is selected back to UP to provide hydraulic up pressure to reduce structural loads on the mechanical uplocks."
Never heard of selecting "UP" in turbulence. It's new one on me.
Never heard of selecting "UP" in turbulence. It's new one on me.
In the event of turbulence the gear handle is selected back to UP to provide hydraulic up pressure to reduce structural loads on the mechanical uplocks.
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Plus it was during turbulence on a departure one day that while the PM was moving the handle from UP to OFF that we got a bump and slipped back towards DOWN we heard the rumble of the doors opening again.
I wouldn't go anywhere near the gear handle during turbulence.
On the 777 with the landing gear retracted and all doors closed, the landing gear hydraulic system is automatically depressurized.
I wouldn't go anywhere near the gear handle during turbulence.
On the 777 with the landing gear retracted and all doors closed, the landing gear hydraulic system is automatically depressurized.
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Let's say an update toward the current modern technology !
The Boeing 75/76 ldg gear lever looks like old fashion car
The Boeing 75/76 ldg gear lever looks like old fashion car
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"In the event of turbulence the gear handle is selected back to UP to provide hydraulic up pressure to reduce structural loads on the mechanical uplocks."
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I say, steady on chaps............
All I can say is that I seem to recall this procedure back in the early 70's as a flying spanner on 747 Classics - or perhaps DC8's. I thought it was a safety precaution related to the weight of the bogie gear, so perhaps N/A on 737's and such like.
And yes, part of the "uplock check" when you went from UP to OFF was to ensure that none of the gear door lights (front or back) came on indicating something amiss; if so the handle went back to UP and stayed up.
And yes it went back to OFF when out of the turbulence.
And yes a lot of Ruddles County has gone under the bridge since then, so I'm always ready to stand corrected if I'm remembering it wrong.
All I can say is that I seem to recall this procedure back in the early 70's as a flying spanner on 747 Classics - or perhaps DC8's. I thought it was a safety precaution related to the weight of the bogie gear, so perhaps N/A on 737's and such like.
And yes, part of the "uplock check" when you went from UP to OFF was to ensure that none of the gear door lights (front or back) came on indicating something amiss; if so the handle went back to UP and stayed up.
And yes it went back to OFF when out of the turbulence.
And yes a lot of Ruddles County has gone under the bridge since then, so I'm always ready to stand corrected if I'm remembering it wrong.
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All I can say is that I seem to recall this procedure back in the early 70's as a flying spanner on 747 Classics - or perhaps DC8's. I thought it was a safety precaution related to the weight of the bogie gear, so perhaps N/A on 737's and such like.
DC 8 no clue, but you might be right.
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Can't say for the 747, but I remember on the 727, the gear went up and then off after clean and climbing to check the uplocks. I do remember putting the gear back to up when at high speed the gear doors would rumble. I flew the 8 also, but I can't remember an off position with the gear handle. I think that was a Boeing thing. Mind you, it's been a long time for both aircraft, so I could be wrong.
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little old red light
737- 500, in cruise over bay of biscay, noticed RED gear light for nose wheel. No sounds or other indications.I dont recall there was an actual checklist for this, but anyway, i selected the lever to up position and the light went out, i left it there for a while and then very gingerly selected the off position.It worked. Obviously wrote it up and they found a microswitch out of kilter.
Dont want a big discussion about VLE's and such like but it was my solution on the day.
Dont want a big discussion about VLE's and such like but it was my solution on the day.
DC8 normally flew with the gear lever in the UP position but after retraction it was selected to UPLATCH CHECK to isolate the hydraulics to ensure everything was mechanically locked up, then returned to UP for the rest of the flight (until DOWN was required).
DC10, as far as I can remember, only had UP and DOWN positions and also flew in UP all the time with hyd pressure ON as there was no system for isolating hydraulic pressure.
DC10, as far as I can remember, only had UP and DOWN positions and also flew in UP all the time with hyd pressure ON as there was no system for isolating hydraulic pressure.
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Probably due to inadvertant lowering of the gear, there is a memo that has just come out from our company on how to 'hold' the landing gear lever when positioning it from UP to OFF (including a do and don't illustration!!).
Memo on how to wipe our a
e next week no doubt.
MB
Memo on how to wipe our a
e next week no doubt.MB
Per Ardua ad Astraeus
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Originally Posted by MB
Memo on how to wipe our a
e next week no doubt
e next week no doubt