If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Flight test update - endpoints and elbows
A few more hours in the past few days.
I took the Bud Dake news as a wakeup call and pulled the airplane apart and inspected everything on Monday. Nothing scared me, so it went back together. Oil is still dark, so I figured I'm getting blowby somewhere (more on that in a sec). More than one A&P has suggested this is due to the engine not being fully broken in, so I'm still running it hard. EGTs and CHTs have come down nicely across the board, with EGT around 1350 and CHT ~360-380 in cruise. 150 deg split in EGTs, 80 deg split in CHTs. I figured things were working out OK. Did a post maintenance flight yesterday with speed runs and a little maneuvering to make sure I got all the greasy bits back in the right spots, and everything was fine. Came back into the pattern, high and hot as usual, and worked like a dog to slow down. I ended up high and tight abeam when I finally got the flaps down, and rather than stretch final over a housing development I turned in early and ended up way high on final. Slipping didn't work (that's how high I was) so at about midfield and several hundred feet AGL I started to go around. I made a call, cobbed the power, and the engine went "chugga...chugga...chugga..." Heck with this. I made a call something along the lines of "everybody get outta my way!" and started a turn to downwind when the engine caught and started running normally. Made a circling approach and landed on-speed, amazingly enough, but tailwheel-first, then chirpchirpchirpchirp. Off the runway everything ran fine. Runups, mag check, jam accels, no hesitation or rough running. Checked it over closely, and found oil on the #2 plugs. Cleaned and reinstalled, and everything checked fine on the ground. Couple of flights today and everything was good until the last landing, when I bumped the throttle to clear the engine and it hesitated again. On the ground this time CHT showed the #2 bottom plug wasn't firing well or not at all. Pulled the plugs again and could see a little oil in the #2 cylinder. It's hard down until I get this worked out. I'll swap plugs tomorrow and do the 25 hour checks and see if that works. If not, the cylinder probably needs work. Dang. Other than that flights are progressing well. Got a 6g endpoint today, so envelope expansion is complete for g's, zero to six. I don't have inverted oil or fuel injection, so while -3 is the negative limit 0 will suffice for my purposes. Altitude and speed to go. Been to 8.5K and 170 KIAS. I plan on going to 11K (maybe) and Vne (183 KIAS), but getting there gradually. Everything everyone says about RV's being slick is true, and getting under the Class B tier from 10 miles out and while trying to keep the engine running hard is sometimes challenging. Always fun, though. Also cruising up the river this afternoon it was a little bumpy. Best I can tell, I bumped the canopy lever with my left elbow. I don't remember doing it, all I know is that I was zipping along and all of a sudden the CANOPY UNLOCK light came on. I just read an article in Van's newsletter about someone who did something similar, but his first clue was a face full of canopy and a lot of wind, noise, and blood. I looked at the handle AND CONFIRMED THE RIGHT WAY TO MOVE IT (aft is lock, opposite of the normal sense), and moved it. I expected that the contact switch had shifted, but sure enough, the lever moved back about 1/2" and the light went out. I'm glad I put that little light in. I have no idea how much more travel would've been required to fully unlock the canopy, nor do I want to find out. (I also have a personal story about loose canopies and supersonic flight, but that's for another time). So the bottom line is: down for engine work after 24 flight hours. I'll know tomorrow whether or not I have to pull the cylinder. Dave 'Daddy Lowbucks' Hyde RV-4 in flight test, EAA tech counselor |
Thread Tools | |
Display Modes | |
|
|