Dom,

 

Assuming you have not detecting any unusual binding and that you have lubricated all moving parts (including the rat trap springs), you may not have a serious problem.  Remember that when the dump valve is opened, that allows the fluid in the up-side of each actuator to transfer and fill the down side.  Restriction in flow and/or resistance in seals could affect the free fall.  If it takes no more than 2-4 lbs of outward hand pressure on the wheel to get the over centers to lock, then things are good.  The nose gear gas spring must be able to exert 100 lbs of pressure to get it down and locked in flight and, if I remember correctly, 25 lbs pushed against the nose wheel when it is about half way down would translate to about 100 pounds of gas spring pressure because of the geometry.

 

However, after satisfying yourself of proper gear operation on jacks, the only real test is that made in the air.  Carefully slow to 87 Kts (100 mph), flaps optional (I use 10 or so degrees to keep the nose down a bit), motor breaker open, gear switch down, dump valve open and check for green lights.  Skid the plane appropriately to add air load to any main until it locks.  If the nose gear doesn't lock, the gas spring is not strong enough - you may want to carefully try a G adding maneuver (without nibbling at a stall).  If some gear doesn't lock, close the dump valve and the motor breaker.  If all lock, land and kiss the ground - fix the sticky problem. If it still doesn't lock, oooops.  Any further activity is left as an exercise for the student.

 

Blue skies,

 

Grayhawk

 

PS I often have to enter a mild skid to get my right main to lock.  One can wonder if the middle door provides an anti-load in some cases.

 

PPS If you go below 87 KIAS, you have failed the test.

 

I’d like to draw on the opinion of listers regarding LNC2 gear free fall problem.

The main gear is slow to free fall, and on the jacks (most likely in the air) the RMG won’t lock in.

Slight pressure on the wheel locks it in, which is handy if one wing walks upside down.

Disconnected the actuator strut and it drops like a beauty and snaps into position.

I doubt the actuator struts are the problem because both main gear have exhibited the same problem at the same time. The LMG does eventually lock down on the jacks.

One thing I’ve noticed is the NG is slower to lock down under normal extension than it usually does. Until recently, it was always the first, and quick to lock down. Under free fall the gas strut dives the NG down and locks as it should quite quickly.

Wondered if anyone might have a trouble shooting sequence I can draw upon.

Thanks

Dom Crain

VH-CZJ