Idle in the pattern - gear box wear?

[rvbuilder2002]

Originally Posted by NinerBikes

We have obstacles on both ends of the runway, in the form of tall trees, electrical power lines, and buildings, that are quite close to the runway.

The owner has his RV-12 with 2 people in it set up for 1550 rpm, on the ground. Still requires a lot of forward slip to clear the obstacles, make the fence, and attempt to drop on the numbers. He uses a 65 kt approach with both of us in the plane, and 58 or 59 kts solo.

Says the plane still wants to float a long ways down the runway, and that managing your approach speed is what's most important. Especially with the occasional wind shear at this airport, being located right next to a good sized hill in the foothills.

Still floating a long ways down the runway is a good indicator that the speeds being used are too high.

[DaleB]

Originally Posted by rvbuilder2002

The way to get an RV-12 to descend at a steeper angle is to have the idle speed set properly, and raise the nose to lower the speed.

50-55 Kts IAS (depending on weight)and it comes down pretty good.

^^^^^^^^^^^^^ This. Especially with me in the plane, slowing down much below 55-60 knots with full flaps, it will come down like an elevator.

[Piper J3]

So, with all the talk here about idle speed and angle of decent, I took better note of RPM on this morning?s flight. Idle RPM on the ground is 1550 and at 65mph (56kph) IAS I shows 2100 RPM with prop being back-driven and providing aerodynamic drag.

I am in total agreement that flaps don?t do very much for angle of decent. Flaps on the 12 primarily reduce stall speed but don?t add very much drag. Forward slip, even with full flaps, doesn?t do a whole lot either. Airplane gets slightly sideways, and even with full rudder, doesn?t scrub off much speed or altitude.

I have over a 1000 hours in a Cub and I can tell you that forward slip is very effective at steeping the approach without gaining speed. I miss those days. I also have 100 hours in a Cessna C170B which has 40 degrees of flaps ? it?s an elevator ride with full flaps. Many times you need at add power with full flap deployment to make your aiming point and then when you pull power back the flap drag is enormous.

[Tacco]

Sorry everyone. My question was not intended to generate a landing technique discussion. I was wondering about gear box wear with a windmilling prop.

[newt]

Originally Posted by rvbuilder2002

Because of that, crossing the threshold and transitioning in to the round out for flare at more than about 50 Kts will result in either a long landing or flat/fast touch down (or both depending on how excessive the speed is).

How would approaching at any speed whatsoever make any difference to the touch down speed or attitude?

A properly held-off landing should result in the aircraft touching down at the same speed/attitude every time, when it's ready to land. The only variable should be the amount of runway required to wash-off the difference between Vref and touchdown speed.

If someone is touching down fast/flat, they need to work on their landing technique. That's unrelated to their approach speed, which only determines whether they're landing short or long.

If you only fly from very long runways and/or don't care about rapid tire wear, I guess it doesn't matter

Quite!

- mark

[newt]

Originally Posted by Tacco

Sorry everyone. My question was not intended to generate a landing technique discussion. I was wondering about gear box wear with a windmilling prop.

That was answered ages ago.

- mark

[NinerBikes]

Originally Posted by rvbuilder2002

Still floating a long ways down the runway is a good indicator that the speeds being used are too high.

I would not call it a long ways, the runway is 4120 ft to work with. Sometimes, like with a 7 to 10kt head wind, the plane settles easily, you almost feel nothing except hearing the main tires squeal ever so lightly. Other times, you wait for the plane to lose energy, and keep the stick back, and it seems like 4 to 6 seconds to get it from 50 to a landing speed that the mains finally touch.

I am not the PIC, these are my perceived observations. The nicest landings seem to occur when there's a headwind of from 5 to 15 or so knots, 30 degrees or less from either side.

[rvbuilder2002]

Originally Posted by newt

How would approaching at any speed whatsoever make any difference to the touch down speed or attitude?

A properly held-off landing should result in the aircraft touching down at the same speed/attitude every time, when it's ready to land. The only variable should be the amount of runway required to wash-off the difference between Vref and touchdown speed.

If someone is touching down fast/flat, they need to work on their landing technique. That's unrelated to their approach speed, which only determines whether they're landing short or long.

The "when it is ready" is the key....

I was speaking in the context of a normal landing with minimal float. I guess I was incorrect to assume that was how it would be taken.

I personally don't consider a landing of an RV-12, that may have been a perfect squeaker but used 2500 ft of runway, to be a normal landing.


BTW, I am not here for the purpose of judging anyone, but there is a lot of people that use the forums as a source of trust worthy info. When that info is not correct, I think it is totally appropriate to comment. From that point on, it is up to the reader to decide.

[RFSchaller]

I love my trusty Cherokee 180 that I?ve owned 34 years, and it has much more drag than my 12. It was a real adjustment for me to realize that applying full flaps in the 12 did not act like speed brakes as it does in the Cherokee. I tell other pilots that the 12 flaps drop the stall speed, but don?t add significant drag. I use the forward slip or a steep turn to final to shed energy if I need to, and I apply the former in preference to the latter.

[GatorsR1]

I was at an Oshkosh forum this summer, a guy was "complaining" about the long landing float on an RV12. Well that seemed to raise Van's dander, he was in the audience and got up to address the issue.
His advice was to go to altitude, practice slow flight and not come in so fast.
Can't wait to finish my 12 and do as he says