Cruise Speeds

[flyguy]

Re: Cruise Speeds

Thanks Terry. I looked and only found one reference and it had a dead end NASA link that no longer has that page. No ref under A&M or NASA.
Anyway I'm finished with my testing but if you ever run across that report or a online link let me know. Should make interesting reading.
DC

[Forrest Barber]

Re: Cruise Speeds

Thank you Terry , it is good to read all history before exerting a lot of effort on things that have already been done. The 23012 is an interesting air foil; have you ever seen anything on the inverted numbers, we looked way back and found nothing, then did the tests here at 2D1 , good climb rate , higher stall speed , etc...
If I recall the 23012 on the BC12D with 65 HP was a great match , the AOI was 3 degrees 49 mins by measurement; for the 180HP we brought the angle down a bit by raising the forward attach point of the hor. stab by a little over 3/4 in. . I have all the figures some where. Working on taxes, IRS, snow , no freeze yet. Soon! .
One problem out in the field is the variations of the aircraft. I recall testing a new F-19 toward the end that was extremely fast in cruise, the rear of the wing was lined up directly with the top longerons. Min trim speed was right in middle of range ( 60-70) at 64 mph . We found that a new employee had built the wing upside down on the initial wing fixture and had the ribs as high as they would go on the rear spars. I always felt Dorothy should have kept her as a factory demo ship.... Our prototype 41T had a wind rool over accident around 1976-77 and the "new" wing put on her never was the same as the opther side, I had to adjust the barrels clear out on one side and clear in on the other. We even used an aileron fixed tab too!
have fun out there, the airspeed calibration is real easy with GPS , i ahd to use the old airspeed course ont he next road back from Barber Airport and the OLD factory. had to let her slide with the drift and use a slide rule. YES a slide rule...... The whole ship was measured with a micrometer and cut off with a dull axe. Remember she was built to +/- 1/8th inch......

[barnstmr]

Re: Cruise Speeds

Here is the report #... NACA-TN-2948. But, I was wrong... this report is about low-speed tests (not cruise performance). But it is interesting nonetheless. Try this link to see if it will get you there for download (almost 5M).

http://ntrs.nasa.gov/search.jsp?Ns=A...t=naca-tn-2948

[flyguy]

Re: Cruise Speeds

Thank you Terry Sir. I finally got back here again. Very interesting reading.

As for what difference I observed on my plane; not very much.

The most noticeable characteristic was that with full wash out adjustment getting the normal climb speed for best rate, 80 indicated for me, required raising the nose noticeably higher on the horizon than at my "normal" adjustment.

Only other thing I noticed was that I managed to get the plane to fly sideways straight and level. Considering the wings have different "rest" twist it is obvious that the same adjustment positions on the adjust screws did not produce the same twist. Optimum trim adjustment tracks with that.

As for speed; no difference that I could measure.

All back to "normal" now, and tweaked a little better with the final adjustment. The last 1/2 turn really balanced it out at 2300 through 2100 rpm. Nice.

[WigetAMT]

Re: Cruise Speeds

Flyguy, my static port is on the side of the boot cowl(flush) just in front of the left door. On a no wind day my IAS and GPS are dead on no matter what Alt.(I never rarely go above 5k). I have a c85 clipped wing and see about 90mph at 2350 in the summer and about 100mph in the winter at the same settings.(solo). The more weight the slower I go, no matter where I put it. Craig

[flyguy]

Re: Cruise Speeds

I have a static port in about the same position. As I remember I tried it when I first got the plane and it gave some pretty strange readings. Maybe I need to check that again. I think I came to the conclusion that it was in a higher pressure area.
Thanks for the reminder
Darryl