William,
I used to experience this problem fairly frequently – not only on landing - but sometimes on takeoff.
After I had the occasionally problem of my gear not coming up after takeoff I added to my pre-takeoff checklist an item called “burp gear”. This means a quite turn of the hydraulic dump switch, hear the pump run, then turn it back. Since I have started “burping” my gear, I have never had it not come up after takeoff.
Similarly, at the end of a long flight I sometimes find that my gear does not come down. Again, another
“gear burp” seems to solve this problem.
D. Brunner
N 241DB 800 hours
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of William Ford
Sent: Wednesday, April 16, 2014 10:07 AM
To: lml@lancaironline.net
Subject: [LML] Gear Down...INOP
I believe that I recently experienced something in my Legacy that I remember reading about but can't remember all the details. I looked into the LML archives and was unsuccessful. Could someone out there please briefly summarize the situation, reason and any possible remedies for gear extension failure following high altitude cruise in cold air followed by a decent and landing in hot air. I seem to remember a discussion about boosted pressure in the hydraulics plumbing due to the rapid rise in temperature which in turn had an effect on the operation of the pressure switch In my recent experience...after opening the dump valve, the hydraulic pump did run, confirming continuity to the pump. After working the nose gear into the locked position, the landing was uneventful but I would like to avoid this uncomfortable situation in the future. Would a tweak on the pressure switch adjustment be called for here or just expect to momentarily crack open the dump valve to relieve excess pressure. Thanks for your thoughts.