737NG Landing Gear Changes?
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Joined: Feb 2013
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From: Wherever LNAV Goes...
737NG Landing Gear Changes?
I've noticed that our new 737Ng's delivered over the last 6 months or so are much smoother to land than the older aircraft. It feels like the main gear oleos have a bit more give than before and there is definitely less of an impact when we land, even when I'm expecting a controlled crash
Does anyone know if changes have already incorporated in preparation for the MAX, just like the landing lights, start levers etc.
Does anyone know if changes have already incorporated in preparation for the MAX, just like the landing lights, start levers etc.
Joined: Jan 1999
Posts: 6,209
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From: north of barlu
B737900er
Low nitrogen pressure is likely to result in less resistance to movement and a softer ride ( untill you hit the stops ) as is low fluid quantity.
Both correct nitrogen pressure and fluid quantity are critical to maintaining tail skid clearance.
Both correct nitrogen pressure and fluid quantity are critical to maintaining tail skid clearance.
Joined: Apr 2008
Posts: 525
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From: Nearer home than before!
SFP? it's standard now isn't it (well free so everyone takes it as an option?)
Otherwise Dunno? Oleo is oil/Air (Nitrogen) so the air is the spring and the oil is both the damping and quantity determines rising rate to the spring. During line servicing, they can't really account for oil level as this is a shop thing, so will measure extension and pressurize accordingly.
Thus as the legs "age" (or get towards shop overhaul point) the oil level lowers. Thus at any given extension, the correct pressure "adjusted" by line crew will give less of a rising rate than a new leg. Thus it will sink in a bit softer and feel better. Most types I have flown show a tendency to land smoother as the legs get towards the end of their time... my last type must have been a 5,000hr limit, as anything just over a 5,000hr total landed like a brick..
Not noticed as much on a 737 except for the new ones are screwed together a bit tighter so rattle less on impact.
Otherwise Dunno? Oleo is oil/Air (Nitrogen) so the air is the spring and the oil is both the damping and quantity determines rising rate to the spring. During line servicing, they can't really account for oil level as this is a shop thing, so will measure extension and pressurize accordingly.
Thus as the legs "age" (or get towards shop overhaul point) the oil level lowers. Thus at any given extension, the correct pressure "adjusted" by line crew will give less of a rising rate than a new leg. Thus it will sink in a bit softer and feel better. Most types I have flown show a tendency to land smoother as the legs get towards the end of their time... my last type must have been a 5,000hr limit, as anything just over a 5,000hr total landed like a brick..
Not noticed as much on a 737 except for the new ones are screwed together a bit tighter so rattle less on impact.
Joined: Apr 2012
Posts: 84
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From: Seattle, WA
During line servicing, they can't really account for oil level as this is a shop thing, so will measure extension and pressurize accordingly.
I checked the IPC for two 900ER's, one two weeks old, the other four years old. Both have the same strut assy. part numbers.
Joined: Jan 1999
Posts: 6,209
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From: north of barlu
RVF750
There is a procedure that Boeing published for the B737-200 for line maintenance to check the PX/EX of the landing gear and then put a measured weight of fuel on the aircraft then re-check the PX/EX.
The result would tell you if the oil level in the leg was correct, I assume they publish the same sort of procedure for the -800.
The result would tell you if the oil level in the leg was correct, I assume they publish the same sort of procedure for the -800.
