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Old May 06, 2011, 11:03 PM
MaladroitFL is offline
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Flyin' low & slow T-28s!
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United States, FL, Vero Beach
Joined Feb 2011
3,326 Posts
Quote:
Originally Posted by turboparker View Post
Picked my B&F up at the LHS yesterday, and flew it in the parking lot. Problem was - shortly after takeoff, the wind picked up to 15+ MPH. That was one of the most hairy flights I can remember in my 27+ years of flying RC. The F4U does not like the wind! At least not as compared to the Sukhoi XP.

I checked everything over & decided that it needed more elevator & rudder, so I moved the elevator to the third hole from the top, and I moved the rudder to the second hole from the inside. I then centered the surfaces mechanically. Popped in a freshly-charged Hyp 160 cell & headed to the parking lot. She sat on the tarmac just fine, despite the wind. I rolled into the throttle & fed in right-rudder. The P-factor is significant on this one. If you're not good with the rudder, this plane will teach you to be. She was airborne within 10 feet.

At about 20 feet AGL, things went awry. The wind had picked up significantly at ground level. Up there, the F4U struggled. The wind made her balloon straight up & back over my head. I fought the sticks & got her under control. She didn't have enough speed to make headway, and I fought to bring her back to the parking lot. I found myself really wishing I had increased the aileron throws. In a dive @ WOT, she was just barely moving forward, and then backwards she went. She was heading tail-first towards a garden shop's tent that was set up in the adjacent lot. In a last-ditch effort to save her, I dove for the windward side of the tables & attempted a hover-landing. I lost sight of the plane during the last 10 feet of descent, but I managed to get her down without a scratch. Needless to say, I didn't fly her again.

As I was driving home from the LHS, I noticed that the flags were motionless. Since I had everything I needed with me, I went directly to the club's asphalt runway. I maxed the rudder throw & moved the ailerons to the second hole from the top of the horns.

I flew a bunch of Hyp 160s in the calm, and had a chance to really wring her out. I assessed the CG placement, and ended up with the Hyp 160 at the front of the slot. Even so, she acted like she may be just a slight bit tail-heavy for a warbird. See below:

Flight conditions:
920' AMSL
73 F, calm

Takeoff & climbout

The P-factor is quite noticeable on this plane, so takeoffs require a fair amount of rudder. Rolling into the throttle gives best results. Those who use some finesse on the throttle & know how to use the rudder will be rewarded with great-looking scale takeoffs. Climbout is leisurely as compared to the UM P-51.

General flight

The F4U tracks well. In the calm, low passes look great, and it's easy to fly circuits @ WOT just inches off the deck. Coordinated rudder rewards the pilot with scale-looking turns. She's rock-solid - even at slower speeds, but she'll drop a wing suddenly when slowed to a stall. Recovery is quick, however.

Aerobatics

Even with the Hyp 160 cells, my F4U can just barely loop from level flight. Speed bleeds of quickly during climbs. Even short vertical climbs are a challenge.

With the increased aileron throw, rolls are about right for a warbird. Maintaining altitude throughout the roll requires quite a bit of top-rudder & a fair amount of down-elevator, however.

Inverted flight is possible, but she doesn't really enjoy it. Later into the flight, it is difficult to climb when inverted.

Landing

Keep some power on, and she's a pussycat on approach. Use throttle to manage sink-rate, and use elevator to manage speed. When she's in ground-effect, relax the elevator a bit & let her down on the mains as you cut the power. She'll do a great-looking two-wheel landing, and the tail will still be flying during the rollout. If you'd rather do a 'carrier landing' - just bring her down as above, but flare for a 3-point landing & plant her solidly on the deck.

Conclusion

The 4FU is a relaxing plane to fly. She's rock-solid on the sticks, which makes it fun to do really low passes @ WOT. Shooting touch & goes is a blast, and she looks great in the air and on the runway. However, she is sorely lacking the speed & climb performance one expects from one the top-performing warbirds of the era. She should be capable of performing large, round loops. She should be able to execute a decent Immelmann. She should be able to execute a zoom-climb. However, the above maneuvers are not possible with my particular aircraft. In general, she seems to be flying too slow - even at WOT. The UM P-51 is a more capable performer. I suspect that the 3-blade prop is the culprit, and will be trying a 5043.

Joel
Excellent review!
Thanks, Joel.
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