Saturday Jan. 28th, 2012 shown bright, clear and calm in the afternoon, making it a perfect day for flying.
Finally weather and peoples schedules came together to make the first flight on Don London’s RV-8A at Scappoose, OR. Dan Forney (RV-12 builder) flew with me in my -9A from Troutdale and Ray Peabody flew over in his -9A from Mulino. Don & his wife Dixie met us at KSPB at 1:30.
This is Don’s 3rd RV build, starting with one of the early RV-4’s; RV-6A and this, his RV-8A. Unfortunately for Don, he lost his FAA medical during the build period. When a friend suggested I do the flight testing, I worked out the details with Don, which brought us to today.
First flight is about establishing power train stability, instrumentation operation, aircraft rigging and indicated stall speed. I wanted the loaded CG to be at about the forward 1/3rd of the envelop, which required 80 lbs of ballast in the baggage area.
The one unusual aspect of Don’s -8A is a Swiss muffler system. The effectiveness of this will be evaluated as part of test program. Ground observers thought the airplane sounded noticeably quieter than other RV’s, but we will be taking actual decibel readings at some point.
With all preflight and briefing matters taken care of, I taxied out to Runway 15 and waited my turn. Traffic was actually pretty busy, it seems EVERYONE was out flying today. Lined up on the runway and slowly fed in the throttle, rudder authority was immediately available for steering. Within about 8 seconds I had in full throttle and compared to my -9A, the acceleration was breath taking. The nose easily lifted off the runway with normal aft stick pressure, held it off and within a few more seconds we were airborne. There was no adverse roll force or yaw and max RPM was stable at 2660. Oil & fuel pressures were stable, EGT & CHT values were “normal”, Fuel flow transmitter indicated 6.4 GPH, clearly that was wrong, but because EGT’s were all less than 1300 deg F at this power level, I knew there was good fuel flow.
Within 1 orbit of the airport I leveled off at 3500 ft; full throttle MP was 27” so I slowly pulled the prop back to 2500 RPM. At 3500 ft I clearly knew I had a well trained Stallion in my hands!! By the second orbit, I knew I really want one of these!! Well…at least I can dream.
The next 50 minutes was a matter of maintaining this power level for engine break-in and monitoring the engine. Average CHT at the start was 371 and at 50 min it was down to 358, a good sign of rings breaking in. Oil temperature was stable at 180 Deg F. With no wheel pants, indicated airspeed was 175 mph! I called Portland Approach for transponder Mode C check and they matched exactly my indicated altitude.
The engine/prop is extremely smooth. I also noticed a distinct lack of cockpit floor vibration, which has been noticeable in other RV’s I’ve flown in. It would clearly seem related to the exhaust system mufflers, which in this installation doesn’t permit the pressure pulses under the cockpit floor.
The airplane is in perfect rig, no tendency to roll with neutral trim and the ball is perfectly centered.
At 50 minutes into the flight I swapped fuel tanks and verified stable fuel pressure. The throttle was pulled back to 20” MP then returned to full throttle to check prop governor stability, which was rock solid. Over the next 5 min I slowed to 100 mph to begin stall tests. With the sun positioned to my back I pulled the throttle back to 1500 RPM and slowed into a flap up stall, which occurred at 70 mph IAS. There was some stick force change just before stall and the actual stall was a brisk nose drop. Stall was repeated at ½ flap (65 mph IAS) and full flaps (still 65 mph IAS). Using the 1.5 times stall, gives a traffic pattern speed of 100 mph, which is also the max flap extension speed.
Now was time to thread myself back into the busy traffic pattern (with at least 5 others) and land. I flew downwind at 100 mph, and final at 85 mph with full flaps (1.3 times stall), maintained about 1500 RPM to flair, pulled throttle back a little more and let her settle to the runway with a kiss of the wheels. It was PERFECT!!
There are a few squawks, but mostly instrumentation calibration related items.
Observations on handling qualities of the RV-8A; in two words, LIGHT & NIMBLE. Stick forces are low and well balanced, much like the RV-6A. I see why spam-can ally pilots can have a tendency to over control these airplanes. This airplane just takes thought control, think it, point it and away you go! Wow, I LOVE IT!!! Clearly it makes a great aerobatic airplane, but because the control pressure is so neutral, you have to fly this guy all the time. My RV-9A also has well balance control pressure, but stick pressure is significant compared to the -8A. That of course, makes the -9A much more stable and lower work load, which is great for cross country. But then, you don’t want a stable airplane for aerobatics, thus the -8A is perfect for that.
Which airplane a person prefers really does depend on your mission, and the handling differences between the -8/A (I assume also the -7/A), are quite dramatic when compared to the -9A.
Which do I prefer? I LOVE THEM BOTH!!
First flight video from Saturday. http://www.youtube.com/watch?v=UoaUtbl9qSA
Pictures here: https://picasaweb.google.com/mikerv9a/RV8AN468DL