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B737/B757 Shock Struts Extension Variation

Posted: Fri Jun 17, 2005 6:29 pm
by HAWK21M
Its Supposed to be common for Oleo Shock Struts of the B737 & B757 when serviced in Warm Climates.The Extension will reduce when it lands at a cooler climate Airfield,thus the Extension will be lower.
Due to volume of shock strut fluid/nitrogen is reduced at extreme cold conditions.
Out here Apart from the North the Difference is not very Significant temperaturewise.
Anyone Experienced such Variation in Strut Extension at Work.
regds
MEL

RE: B737/B757 Shock Struts Extension Variation

Posted: Sun Jun 19, 2005 6:43 am
by miles_mechanic
Hi Hawk21M
I used to work on Beech 1900's and Jetstream 31's, and we had a hangar that was just big enough for the tails to get in the doors when the oleos were serviced just right up here in canada where it can be very cold outside, the airplanes if they were heavily loaded would end up getting the oleo gas pressures inflated out on route so they could carry the extra weight, we put the cold airplane in the hangar and it looks a bit higher, well as the night goes on, the airplane gets taller and so by morning we have to drop the oleos again to get the plane out of the hangar, and then repeat the same procedure during the day if they had big loads
It was a big pain in the butt, but hey I didn't buy the hangar, just had to make things work around it.

Miles

RE: B737/B757 Shock Struts Extension Variation

Posted: Sun Jun 19, 2005 8:50 am
by FDXmech
I don't recall Boeing or Douglas strut extensions having a temperature variation chart when servicing. Though Airbus does.

RE: B737/B757 Shock Struts Extension Variation

Posted: Sun Jun 19, 2005 10:20 am
by lorm
Quoting FDXMECH (Reply 2):
I don't recall Boeing or Douglas strut extensions having a temperature variation chart when servicing. Though Airbus does.

Doesn't the 747 have a chart on a placard attached to the nosegear?

RE: B737/B757 Shock Struts Extension Variation

Posted: Sun Jun 19, 2005 1:59 pm
by FDXmech
Quoting LorM (Reply 3):
Doesn't the 747 have a chart on a placard attached to the nosegear?

Yes. As do all the other gears (wing and body on the 747) and all landing gear on any type aircraft. But the placard has; Pressure vs Extension, not Temperature. The only aircraft maker that I'm aware using Temp as well is Airbus.

RE: B737/B757 Shock Struts Extension Variation

Posted: Sun Jun 19, 2005 2:26 pm
by HAWK21M
Quoting Miles_mechanic (Reply 1):
It was a big pain in the butt, but hey I didn't buy the hangar, just had to make things work around it

Wasn't there any attempt to raise the Hangar door cutout if this problem was being frequently occuring.
regds
MEL

RE: B737/B757 Shock Struts Extension Variation

Posted: Mon Jun 20, 2005 9:27 pm
by miles_mechanic
Hawk21m
well the the hangar doors could have been raised, but we were just a small regional airline and only had the 6 airplanes that it would affect at the time. They have since sold 3 of the planes and bought a Saab 340, so had to make a tail cut out in the hangar to allow it to fit inside. The hangar is really too small for the operation we had at the time, but we made it work. Some nights we had the planes parked very tightly in the hangar.

Miles

RE: B737/B757 Shock Struts Extension Variation

Posted: Thu Jun 23, 2005 7:18 pm
by troubleshooter
On ERJ´s there are different servicing curves (pressure vs. extension) for some temperatures. You always use the nearest one in relation to the actual temperature.
On the 737NG (don´t know the classics) there is one wide servicing band with no specific temperature correction. You always have to put the strut within the servicing band and it´s fine.

RE: B737/B757 Shock Struts Extension Variation

Posted: Thu Jan 11, 2007 9:17 pm
by HAWK21M
Quoting Troubleshooter (Reply 7):
On the 737NG (don´t know the classics) there is one wide servicing band with no specific temperature correction. You always have to put the strut within the servicing band and it´s fine

The MLG has both Operational & Service Bands.
The NLG has only Service band.
regds
MEL

RE: B737/B757 Shock Struts Extension Variation

Posted: Fri Jan 12, 2007 5:51 am
by Valcory
Quoting FDXMECH (Reply 2):
I don't recall Boeing or Douglas strut extensions having a temperature variation chart when servicing. Though Airbus does.

It depends on what is in the mm i have seen one airline use temperature when serving the struts in winter time you had to an an extra inch to the x-demision when serving the struts and i have also see other airlines that did not use temperature.