Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: Vermillion on January 25, 2000, 08:10:00 AM
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Last night I spent 8 consecutive sorties in the C-Hog, and noticed what seemed to be a Trim or possibly a CG problem in the F4U. This is really my first time I flew dedicated Hog time, so it may be nothing new.
My impression was that this aircraft, is exceptionally "nose heavy", in all fuel states from 75% + Centerline Drop Tank, down to pure empty.
It also seemed to be very sensitive to trim settings in the pitch vector. With the nose constantly wanting to "hunt or bob" with very little to no change in speed. Then if you tried to trim it out, one click in either direction would overcorrect the problem. FYI this is not the typical nose bounce, and its not control movement related.
Another strange effect is that in every other aircraft, if I am making a high speed BnZ pass, I have to input at least 2-3 clicks of nose down trim, or the increased dive speed will give me increased lift and bring the nose up. In the Hog, I had to do the opposite. I had to put in a couple of "nose up" trim adjustments.
One indicator I also noticed is that the elevator trim, even after using auto trim settings, is almost always in the top 1/3 or higher of the vertical gauge.
This is another test. Take it up, and put it into auto-level trim. Take your hands off the controls, and then turn off the autotrim. On my machine at least, the nose of the Hog will immediately drop down. This doesn't happen to any other planes I fly.
Now I admitt I am not a full time F4U driver, most of my time is in the P51,N1K2, and the La5 in that order. But its seems unstable to me in the pitch vector, especially when compared to the other aircraft I fly.
I talked to quite a few other pilots about this last night on private, all extremely experienced pilots in WB's who are familiar with trim and its effects, and they seemed to have the same impression I did.
I am going to be outta town for the next 4 days, so I won't be here to comment on this thread.
But I was wondering if anyone else here has experienced this?
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Vermillion
**MOL**, Men of Leisure,
Dicta Verm: "Never give the suckers an even break!" or translated "Never engage without an advantage"
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Yeah, I see the nose drop when you turn off auto trim. Also, see the vator trim near the top limit of its range in auto.
Hog doesn't seem unstable in pitch, though. Although I don't fly many other planes, so maybe I'm just used to the way the Hog handles.
popeye
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Maybe it's those enormous guns. (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
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True VERM when auto trimmed to best speed climb (initial alt x setting) around 155 knots and then auto trimm off the nose will go down ... also you are not able to attain that speed just with manual trim (full nose up trim)
i usually have the trim centered only when going faster than 300-350 KIAS and then the nose still does not come up on it's own ..
(-> dedicated HOG driver)
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Phillip "Duckwing6" Artweger
Flight Officer "E" Flight
Skeleton Crew (http://www.picknowl.com.au/homepages/oneshot/main.htm)
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IF you use ONE DTank and nothing in the other spot, THAT will thoss yer CG off by a large margin. I don't recall ever seeing ONE Dtank on any F4U vrsion that was "centerline". But then I have been wrong in the past...
Actually best climb rate for F4UC is 165, or so I found. Very little nose drop at that speed and at alt you can maintain control thru 23K after that, switch to 175 - 225 CR.