Dakar
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What Is This FO Doing?

Mon Nov 05, 2007 3:08 am

Pardon the ignorance, but what is the FO doing with the gear handle at 7:43 minutes? He says and points in the effect of "in the green" or "all green".

http://www.youtube.com/watch?v=gYuh1M71c0M

I am slowly trying to learn turbine CRM and procedures.

Thank you!
 
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jetmech
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RE: What Is This FO Doing?

Mon Nov 05, 2007 3:27 am

Quoting Dakar (Thread starter):

On the 747, the landing gear lever has three positions, DOWN, OFF and UP. You can hear the Captain request for gear up shortly after lift off. The FO will then move the lever from DOWN to UP. A short while later, when I assume they are doing after take off checks, the FO calls "all green". This means that all five landing gear are up and locked, and the gear doors closed. The FO then moves the lever from UP to OFF.

This depressurises the landing gear retraction actuators as they are not needed anymore. This saves #1 and #4 hydraulic systems from needlessly supply them with hydraulic fluid during cruise. IIRC, Airbus and the B777 only have UP and DOWN positions on their gear levers. The depressurisation is done automatically.

Regards, JetMech
JetMech split the back of his pants. He can feel the wind in his hair :shock: .
 
57AZ
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RE: What Is This FO Doing?

Mon Nov 05, 2007 3:28 am

He's returning the gear selector to it's OFF position. On large commercial transports, the procedure for retracting the gear on climb out requires the Pilot Not Flying to raise the gear once positive rate of climb is attained. Many transport type aircraft have a three position selector lever. The positions are Gear Extended, Gear Retract and Handle Off. Once the gear is retracted and uplocks confirmed, the PNF will return the gear selector to the Handle Off position.
"When a man runs on railroads over half of his lifetime he is fit for nothing else-and at times he don't know that."
 
Dakar
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RE: What Is This FO Doing?

Mon Nov 05, 2007 3:34 am

Thanks guys. Makes sense now, as in the Part 1 video, the Captain asks the ground crewman if it was ok to pressurize the landing gear hydraulics, which I am assuming the NFP (FO) did by switching the gear handle from "OFF" to "DOWN" before the pushback.

Nick
 
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jetmech
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RE: What Is This FO Doing?

Mon Nov 05, 2007 3:55 am

Quoting Dakar (Reply 3):

Before a pushback begins, the pilots will generally ask the ground crew for permission to pressurise hydraulics. This is to make sure nothing is in the way of the flight controls, which will move to neutral when hydraulics are applied. On a 747, the most important hydraulic systems needed for a tow or pushback are #1 and #4.

#4 is primary brakes, with #1 giving body gear steering. #1 system is also the first alternate brake system, which gives added safety in case #4 system fails. This pressurisation call is not really specifically for the landing gear, and usually, the gear handle will be in the down position whilst on the ground.

Regards, JetMech
JetMech split the back of his pants. He can feel the wind in his hair :shock: .
 
Dakar
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RE: What Is This FO Doing?

Mon Nov 05, 2007 4:27 am

Gotcha! Thanks a lot! I love learning about this stuff. Having a nice spring/summer yet? I wish it was spring here!
 
David L
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RE: What Is This FO Doing?

Mon Nov 05, 2007 10:29 am

Something I hadn't thought about before is that, given that the control movement checks are often performed during the taxi, I assume there would be a certain amount of weaving while the rudder movement is checked, due to limited nose-wheel steering via the rudder pedals... or is there something I've missed?
 
PhilSquares
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RE: What Is This FO Doing?

Mon Nov 05, 2007 11:03 am

Quoting David L (Reply 6):
I assume there would be a certain amount of weaving while the rudder movement is checked, due to limited nose-wheel steering via the rudder pedals... or is there something I've missed?

On the 744 (and all Boeings I've flown) if you hold the tiller while you move the rudder pedals the aircraft will track straight and won't follow the rudder pedal inputs. With rudder pedal inputs the nosewheel only moves +/- 7 degrees.
Fly fast, live slow
 
Tristarsteve
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RE: What Is This FO Doing?

Mon Nov 05, 2007 11:04 am

If you hold the tiller (steering wheel for the nose gear) while you move the rudder pedals, the nose wheels do not steer when you move the rudder pedals.
Also most airlines that I have met do control checks after engine start, and before taxying.
 
David L
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RE: What Is This FO Doing?

Mon Nov 05, 2007 12:22 pm

Quoting PhilSquares (Reply 7):
if you hold the tiller while you move the rudder pedals the aircraft will track straight



Quoting TristarSteve (Reply 8):
If you hold the tiller (steering wheel for the nose gear) while you move the rudder pedals, the nose wheels do not steer when you move the rudder pedals.

Ah! Cunning.  Smile

Thanks, guys.

Quoting TristarSteve (Reply 8):
Also most airlines that I have met do control checks after engine start, and before taxying.

That ties in with my observations.
 
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jetmech
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RE: What Is This FO Doing?

Mon Nov 05, 2007 10:10 pm

Quoting JetMech (Reply 4):
spring/summer

Officially it is the getting towards the end of Spring / beginning of Summer, but the weather seems determined to remain in Winter!

Regards, JetMech
JetMech split the back of his pants. He can feel the wind in his hair :shock: .
 
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Jetlagged
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RE: What Is This FO Doing?

Tue Nov 06, 2007 1:39 am

Quoting JetMech (Reply 1):
A short while later, when I assume they are doing after take off checks, the FO calls "all green".

I don't think he's saying the gear is "green" and they aren't running a checklist at that point. The gear indication is blank (not green) when up and locked. I believe he is waiting for the flaps to reach 5 degrees before selecting the L/Gear Lever to OFF. Maybe he says something about the gear so the captain knows he is going to move the lever. Or he may be saying the flap indication is green (i.e. in the selected position). Philsquares would know if it is typical SOP to wait for Flap 5, or whether they just wait a sufficient time with no gear disagreement indications.

The nosewheel steering only responds to tiller position. On the ground, i.e. with weight on the nosewheel, a pedal/tiller interconnect means rudder pedal movement also moves the tiller, which in turn moves the NWS. If the pilot holds the tiller still while the pedals are moved (a lost motion device in the interconnect allows this to happen), the nosewheel does not move. With no weight on the nosewheel leg, the pedal/tiller interconnect is disengaged so the nosewheel steering is not active as the gear retracts should the rudder pedals be moved. Once the L/Gear Lever is in the OFF position, NWS is depressurised anyway.
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