[kcameron]

I've heard it said that many (all?) pilots of RVs w/ CS props execute landing approaches with greater than idle power selected. The reason for this is said to be that the descent rate is too great with the power lever full back and the prop lever full forward. I guess the prop needs to be full forward to allow a quick power-up for go-around if need be?

So how about it? Do any of you CS RV pilots execute gliding approaches?

I've never flown an approach in an RV or with a CS prop. When I got my tailwheel training, I was taught to alway do gliding approaches (in Citabrias). This meshes well with the instincts I developed in 14 years of flying hanggliders. I'm mainly just wondering what to expect in that bright, distant future when I finally get my plane finished.

 

[Bob Axsom]

No set routine

I usually make a short approach and the power is way back but not to the stop until I'm sure I have it made with kinetic energy to burn which is usually just off the end of the runway. I do not have a set and forget procedure and even with the throttle all the way back I'm ready to dial the vernier if my instincts were a little off or the winds force a power adjustment. I try to make every approach so I can glide in with margin if I loose power but I do not "test it".

Bob Axsom

 

[dan]

I guess the prop needs to be full forward to allow a quick power-up for go-around if need be?

That's how I was taught, but in an RV the power to weight ratio is kinda ridiculous. I did a takeoff a few weeks ago with 14". It felt like flying the old Cherokee or whatever, but the thing still climbed out respectably.

My point is that even if you didn't put the prop in full fine pitch on final approach, and let's say you left it where it was set for 2300 RPM in cruise...and then you go around with full throttle...the thing is still gonna climb out like a bat out of jello.

That said, I do push my prop control full forward as soon as I'm at an airspeed where doing that wouldn't surge the RPM. In my airplane, it's when I've pulled the power back to about 10" MAP or lower, and the airspeed decays below about 120 mph. Prop goes full forward at that point.

I make my approaches with as little power as possible, relatively steep approaches, but I do leave a little manifold pressure in. Power off, with full flaps, my -7 glides like a set of car keys tied to a cinder block (so to speak). A little manifold pressure (like 2-3" up from closed throttle, say 9" MAP) goes a long way to flatten out the approach and retain energy into the flare. Just my 2 cents.

 

[DeltaRomeo]

...what Dan said above applies to my landings almost identically.

Most of my arrivals back at 52F involve an 'initial' over the field with a 2g 180degree turn to bleed speed down to what you want in the pattern. Once on downwind abeam the numbers (hi key) I'm a little high on purpose, because when the prop goes in and flaps go down the plane SINKS. At this point I am usually still in gliding range of the field (tight pattern).

Now I zero in on the AOA and start playing with power. I always have to add some to maintain the proper AOA as I initiate the final 180 base to final turn. With the prop in and the flaps down you need to add power - and add in just a little more for a second there about 2' above the runway to stop the sink as you begin your flare.

With the prop in, flaps down, AOA at the proper angle and a little power burp there at the end I consistantly land (and stop) in the first 1,000' of our 3,000' runway with no headwind. The Bravo turn off on runway 17 at our field is right at the hanger I'm in, so if I did it right I'm home. If I did it wrong I turn at Charlie and taxi back for another minute and a half.

You can see the Bravo turnoff halfway down the runway in this Airnav photo (notice the displaced threshold):

It's amazing the difference that proper technique makes. We routinely see pilots touching down at the Bravo turnoff and squealing their tires to keep from going into the fence at the south end.

The FP prop I had on the plane a year ago made the landing approach/result much differerent. It had a MUCH bigger pattern with time spent waiting for the plane to slow down. That configuration called for a 'gliding in' approach most definitely.

Geez, all this makes me want to go take a '2 hour lunch' if you know what I mean... .

I'm doing it - don't tell anyone.

B,
D

 

[kcameron]

Thanks for the input, guys. That helps me visualize what it will be like.

 

[jonbakerok]

I practice P/O landings regulary

My normal landings are pretty much what Doug described, except for the 2G turn to downwind . The beauty of the C/S prop is that you can cross the field at 150 mph and still enter the pattern at 100 while descending without any radical manuvers.

But I enjoy practicing power off landings regularly. I fly out to a less-used field (usually Navasota) and pull the power at various places in the pattern and try to make the field without touching the throttle. With no wind, I can usually make it even from the upwind if I start from pattern altitude.

It takes a little practice to control the descent right at the end before touchdown without adding a little power. But when you do it right, it feels really cool. You're coming down like a rock at about 1000 fpm; you pull back just about the moment you hit ground effect and it feels like you've hit a cushion -- suddenly you've got plenty of time to just ease it down.

It helps to carry a little more speed on short final. I usually make the first one at half flaps and 85-90 mph, to get use to the higher than usual AOA at touch down. Then I start doing them at full flaps and 80. You don't want to be much below 80 when you round out or it will drop out from under you. That's why Doug (and the rest of us) normally add a little blast of power right about then during a normal approach -- you're usually much slower (more like 65-70) because you're trying to make that first turn-off.

It's true that most guys with C/S props use power-on landings normally. But that's not because it's not possible to land power-off. It just takes a different technique and a little more concentration.

 

[L.Adamson]

It helps to carry a little more speed on short final. I usually make the first one at half flaps and 85-90 mph, to get use to the higher than usual AOA at touch down. Then I start doing them at full flaps and 80. You don't want to be much below 80 when you round out or it will drop out from under you. That's why Doug (and the rest of us) normally add a little blast of power right about then during a normal approach -- you're usually much slower (more like 65-70) because you're trying to make that first turn-off.

It's true that most guys with C/S props use power-on landings normally. But that's not because it's not possible to land power-off. It just takes a different technique and a little more concentration.

Since there are definately two techniques as just described, I get a kick out of reading articles, where an instructor, or who ever is writing the article, attempts to tell us to treat every landing as though the engine is out.

The choice with a C/S prop is to carry some power and perhaps add a bit at the flare if needed to arrest the descent, or just carry a "higher" airspeed through the landing process.

Many backcountry pilots landing on short airstrips will routeinly carry some power through the landing for a steep approach on the front side of the power curve, that allows a lower airspeed that they know works. Since the runway might only allow for a one way in and the opposite way out, with no go-arounds, the slowest possible airspeed technique fits the bill, in these cases.