MD80 NLG Vibrations
MD80 NLG Vibrations
(OP)
As some of you know, the MD80 has the generic problem of NLG vibrations during T/O. This sometimes translates into aborted T/O. From my experience, this generic problem could be due to many factors....wheel balancing,type of tyre (new or rethread), difference in wear between both wheels, defective bearings, nlg excessive play(between links).
What do you guys think according to your experience?
Any new suggestions?
Thanks and take care you all.
What do you guys think according to your experience?
Any new suggestions?
Thanks and take care you all.





RE: MD80 NLG Vibrations
RE: MD80 NLG Vibrations
RE: MD80 NLG Vibrations
RE: MD80 NLG Vibrations
RE: MD80 NLG Vibrations
Experience on F28, BAE146, and B737 has led me to believe that the limits set by the OEM are often initially a stab in the dark based upon history upon other programs (it is certainly the case with the 737).
As a NLG becomes worn, the trigger threshold for shimmy initiation lowers but the damping of the tyres and the shimmy damper will mask this somewhat until a tyre imbalance occurs.
Consider the NLG to have a tyre imbalance margin that is eroded by an increase in NLG torsional free-play and a reduction in shimmy damper condition.
Rectifying any of the factors will have a beneficial effect. The trick for an airline is to select the best overall strategy that will minimize overall cost and pilot reports.
At one airline I worked with, I implemented a strategy of scheduled mid-life torque-link changes (a relatively quick job ) to get new bushings installed and reduce the torsional free-play. It was effective, and cheaper for them than playing clever tricks with tyres (and suffering delays on-line ).
Best of luck.