Robert M
Well Known Member
I installed the gear leg fairings on my RV-9, following the instructions. They seem to be straight and in line with a level flight configuration. All 3 wheels were off the ground, the fuselage was leveled and the alignment process as follows......
Cut the fairings per the RV-9 template, set the trailing edge straight on the bench using tape marks on the aft edge as alignment points. Installed the hinge pieces with tape spots lined up. They were trimmed and realigned.
Three alignment points were measured on both gear legs at 11 1/2" off the floor, the next up was 21 1/2" and the top location was 31 1/2".
The center line of the fuselage was determined with plum bobs. One hanging off the tail spring where it exits the fuselage and the other at a marked, center point on the firewall.
On the pilot side....
A plum bob was aligned with the 11 1/2", 21 1/2", 31 1/2" marks on the gear leg and those plum bob spots were marked on the floor as extended fuselage center line marks.
A measurement was taken to each new extended mark from the fuselage center line mark and these measurements were transferred to the aft of the aircraft at the HS.
I used tool cabinet drawers and clamps to mimic the height locations, (11 1/2", 21 1/2", 31 1/2"), on drawers of the cabinet. I opened the drawers to line up plum bobs with the extended fuselage center line measurements.
Put on the fairing, wrapped kite string around the fairing at the 3 height locations and then back to the corresponding clamp. Then wrapped the string tightly around the clamp.
Centered the fairing (top to bottom) between the two strings and clamped it into position with the hose clamps.
Repeated the procedure for the passenger side.
Took off to test the new gain in airspeed and I saw absolutely no gain in airspeed and there was absolutely no extra yaw during flight. The plane flew as if I had done nothing. Shouldn't I be seeing SOME increase in airspeed?
Any ideas?
Thanks for any and all help,
Robert
P.S. I have intersection fairings coming but if I don't see significant increase with airspeed from the fairings alone, I will have to think long and hard before going to all that work of prep and installation for zero return.
Cut the fairings per the RV-9 template, set the trailing edge straight on the bench using tape marks on the aft edge as alignment points. Installed the hinge pieces with tape spots lined up. They were trimmed and realigned.
Three alignment points were measured on both gear legs at 11 1/2" off the floor, the next up was 21 1/2" and the top location was 31 1/2".
The center line of the fuselage was determined with plum bobs. One hanging off the tail spring where it exits the fuselage and the other at a marked, center point on the firewall.
On the pilot side....
A plum bob was aligned with the 11 1/2", 21 1/2", 31 1/2" marks on the gear leg and those plum bob spots were marked on the floor as extended fuselage center line marks.
A measurement was taken to each new extended mark from the fuselage center line mark and these measurements were transferred to the aft of the aircraft at the HS.
I used tool cabinet drawers and clamps to mimic the height locations, (11 1/2", 21 1/2", 31 1/2"), on drawers of the cabinet. I opened the drawers to line up plum bobs with the extended fuselage center line measurements.
Put on the fairing, wrapped kite string around the fairing at the 3 height locations and then back to the corresponding clamp. Then wrapped the string tightly around the clamp.
Centered the fairing (top to bottom) between the two strings and clamped it into position with the hose clamps.
Repeated the procedure for the passenger side.
Took off to test the new gain in airspeed and I saw absolutely no gain in airspeed and there was absolutely no extra yaw during flight. The plane flew as if I had done nothing. Shouldn't I be seeing SOME increase in airspeed?
Any ideas?
Thanks for any and all help,
Robert
P.S. I have intersection fairings coming but if I don't see significant increase with airspeed from the fairings alone, I will have to think long and hard before going to all that work of prep and installation for zero return.
Last edited: