Back ] Next ]

Cozy MKIV - Seventeenth Flight Test

Date: September 21, 2002

Friday after work I headed out to the airport to install the oil cooler accoutrements that I had fabricated - i.e., the plenum chamber and small scoop, with a SCAT tube connecting them. This I did.

Saturday morning I preflighted the plane and installed the original pitch trim system springs - I had the thought that maybe I wouldn't have to move the pitch trim system, or make any other adjustments, if the system had the added spring tension from the original springs. I verified that I still had full range of motion without undue force levels. I won't be able to verify the utility of this addition until I get to the higher weight, forward CG, low speed testing.

This flight was intended to be a cross-country at 8500 ft., with stability and flutter tests performed along the way. Due to cloud cover, with only a few holes, this was not to be. Also, the oil cooling got WORSE with my wonderful new scoop system - the oil temperatures reached unreasonable levels even faster in the climb than they had before.

So I climbed up through a hole to 6500 ft. - as high as I could get while keeping oil temperatures reasonable. I performed the longitudinal (pitch) static stability tests. These consist of trimming for a given speed (140 mph in this case) and ensuring that going faster requires a "push" on the stick to maintain (both to 155 mph and 170 mph), and that going slower requires a "pull" on the stick to maintain (both to 125 mph and 110 mph). In all cases, the trim is left at the 140 mph level. My aircraft is statically stable.

At this point, the oil temps had climbed too high, so I descended back down through the hole and did the stall tests at the 1900 lb., 102" CG position. No surprises, and I'm getting used to sitting in the clothes dryer at the 60 degree bank angle -).

After the flight, I added the turbulators that Eric Westland recommended, as well as cutting some access holes to the fuel level senders so that I could calibrate them at both the full and empty levels.

I also measured the canard incidence angle with respect to the top longeron - it seems as though (depending upon the exact placement of the canard template - an inexact science) the canard incidence is somewhere between 0.6 degrees and 1.1 degrees low - this is out of the tolerance range. Now, as I've demonstrated for MY plane, stalling behavior is still completely acceptable even at the most rearward CG position (so far, with only the 2150 lb. run left at the rear CG position), so modification of this incidence angle may or may not occur, depending upon final stability/pitch trim authority tests.

End Date: September 21, 2002

Back ] Next ]

[Zeitlin's Cozy MKIV Information] [Zeitlin's Cozy MKIV Logbook]
[Cozy MKIV Information]

Copyright 2002, All Rights Reserved, Marc J. Zeitlin