SonexFlight Episode 75 - Pattern Precision

[sonex1374]

SonexFlight Episode 75 "Pattern Precision" is available for download!

The Sonex is a great handling, easy flying sport plane with absolutely no bad habits. We cover the techniques used on a typical pattern flight, discuss the speeds and performance a pilot will commonly see, and lay down the foundation for flying a Sonex pattern with precision.

http://sonexflight.com/75

Jeff

[WesRagle]

Thanks a lot Jeff, John, and Mike,

This is a very timely topic for me. Right now I'm basically grounded for an "Excessive Heat Warning" but it looks like we'll get a break in the heat next week so I can continue with Phase 1.

Jeff, near the end of the podcast you said "I think we've checked all the boxes." One thing I didn't hear discussed was power settings. I've always been taught to pull power to idle abeam the touchdown point and not to touch it again before landing. I only have about 30 landings in the airplane but ... I'm not sure I'll be able to do that with the Onex. I think the Onex glide is steeper than the other aircraft I've flown. I end up having to add power on final to make my touchdown point.

Next time out I think I'll try a different technique. I'm going to determine the RPM needed for level flight at 80, setup that RPM on down wind, add flaps and trim for 80 abeam the touchdown point and see what kind of decent rate I get. Hopefully that will give me a reasonable sized pattern and I can pull to idle once I have the runway made and with enough altitude left to stabilize the approach.

The goal is safety. What I'm looking for is repeatability and not having power at idle until I'm sure I have the runway made. Also, if trimmed for 80 it will leave me in a slightly nose down trim condition during final, round out and flare.

Thoughts anyone?

Thanks Again,

Wes

[GraemeSmith]

For VFR landings where I'm not trying to come down the instrument glideslope. I basically fly a power off 180 like the Commercial Rating landing.

My SONEX numbers are:

Power to idle when abeam the numbers. Start a continuous semicircular curved approach. I don't fly the three sides of a box with right angle turns at downwind to base and base to final.

Pitch to hold altitude till 80KIAS, flaps 10 and start to curve in.
At about the base position (half way around the curve), I'm at 70KIAS and flaps 20. Project the runway outwards and have a really good look along final for anyone sneaking in on me.
As I turn short final I like to be a touch high and decaying to 60KIAS. Now a mixture of slips to decay the excess energy and as I come down to about 50KIAS I can go flaps 30 as needed to go with slips to get set up.

This is a tiny nimble plane. I stabilize my approach - usually at about 100ft AGL and just prior to touch down and put in any X-Wind correction at that point.

Touch down at about 40 KIAS and flaps zero as I touch down. Kill the lift, stick the plane.

--

With LOTS of practice it is a continuous smooth blend of changing airspeed, pitch and flaps from abeam the numbers to touch down. No drama.

YMMV

[WesRagle]

Hey Graeme,

Pitch to hold altitude till 80KIAS

How fast are you abeam the numbers?

Wes

[GraemeSmith]

Hey Graeme,

Pitch to hold altitude till 80KIAS

How fast are you abeam the numbers?

Wes

Ummm..... About 90KIAS.

As you chop power and hold altitude - you very quickly decay to 80 and then it's flaps in and nose over and roll into the curve to start down. It's not like I hurtle down the downwind and blow by the numbers.

The wind is more of a factor and how hard I roll into the curve to stay close to the runway. And that's always the variable that makes this fun. If we could always practice in no wind - we would have this down pretty quickly.

[sonex1374]

One thing I didn't hear discussed was power settings. I've always been taught to pull power to idle abeam the touchdown point and not to touch it again before landing.

Wes,

I do landings both ways - power-off style, and using a low-rpm power setting. I like the power-off landings for the practice, and they're fun to keep your energy management skills tuned up. However, the Sonex flies a fairly close pattern when doing power-off approaches. If you're mixing with the local GA traffic, sometimes it's easier to fly a larger pattern, and for this you'll need a bit of power throughout the approach.

For a typical low-rpm approach, I'll fly downwind at 2500 rpm and 120mph, pull power to about 1700 rpm abeam the numbers while slowing to 100 mph, then turn base (either dropping flaps just before the base turn of on base). I'll commonly fly a continuous turn from downwind to final, but if you're doing a large pattern it's really just a rounded-corner pattern rather than a semi-circle. I'll hold 1700 rpm thru to final while descending about 400 fpm on the glide slope, and then as I slow up to 65 or so on short final I'll start to reduce power as needed to control the touchdown spot. 60 mph over the threshold works well (under 55 and the rate of descent can start to get high, over 65 and you're too fast).

For a power-off approach, I tend to try to fly downwind a bit tighter than the typical GA traffic will, pull the power off to idle abeam the touchdown point, and make sure I don't get too far out before turning base. My aim point is about 100 ft in front of my desired touchdown point, and I shoot for the same 60 mph over the aimpoint as before.

Flying power-off approaches is fun and helps keep you sharp, but just like in gliders you won't fly the approach without a way to extend your glide. In a glider you start the approach with partial spoilers so that you can clean up as needed to extend. You'll never fly the pattern without keeping options in the bank. In the Sonex you'll want to keep the same mentality. You can always turn base a little sooner, keep a little high or close on downwind, and get your flaps in earlier rather than later (so you can assess your glide path and make adjustments before you fall hopelessly below the glide path).

Jeff

[GraemeSmith]

Flying power-off approaches is fun and helps keep you sharp, but just like in gliders you won't fly the approach without a way to extend your glide. ..... can always turn base a little sooner, keep a little high or close on downwind, and get your flaps in earlier rather than later (so you can assess your glide path and make adjustments before you fall hopelessly below the glide path).

Jeff

Jeff makes a really important point here. This is why I always stay a little high and slip it off when I know I have it made. Running out of energy on a power off 180 is not fun.

On an old 172RG I used to fly - if you were low - you could milk an extra 2-300ft by slamming in flaps 40 and floating on in ground effect! Doesn't work in the Sonex. Slam flaps 30 and it's an airbrake and drop in!

[Rofomoto]

Nice podcast came just at the right time for me. Thanx billy

[WesRagle]

Hi Guys,

Thanks.

Graeme,

Ummm..... About 90KIAS

That's one thing I haven't been doing. I'm down to 80 MPH when I come abeam the numbers.

Memories can get foggy after over a decade, but I swear I used to come abeam the numbers in the Sonex, pull power and 2/3 flaps, trim for 70 and fly that all the way to round out. I don't fly a rectangular patter either. Just a smooth circle to land. I would have enough "straight" on downwind and final to get a good picture on final. I don't remember my speed as I came abeam the numbers but I'm sure I was below the 100 Vfe. I do remember slipping it at times if I was too high. I would touch down, dump flaps, pin the tail, verify I was on a stable roll out, apply half power, lift the tail, apply full power and takeoff. That was the routine. The goal was to be airborne again before the first turnoff which is at about 1900 ft. I could do that consistently.

Jeff,

Flying power-off approaches is fun and helps keep you sharp, but just like in gliders you won't fly the approach without a way to extend your glide. In a glider you start the approach with partial spoilers so that you can clean up as needed to extend. You'll never fly the pattern without keeping options in the bank. In the Sonex you'll want to keep the same mentality. You can always turn base a little sooner, keep a little high or close on downwind, and get your flaps in earlier rather than later (so you can assess your glide path and make adjustments before you fall hopelessly below the glide path).

Yep, I like power off landings. That is the way I was taught. I did have the engine on the Sonex quit on final one time and it was a non event because I was used to not having power after pulling it abeam the numbers.

The winds around Olney, where the airplane is, are pretty awful this time of year. Just hot, windy, and gusty. The only time I can get any flight time is early morning. During the night, when the sun's energy is taken away, the gusts go away and the surface winds die down but just above the surface the winds are still blowing. Last time out surface winds were about 5 kts right down the runway but at pattern altitude the winds were about 20 kts. That makes for a strange landing. You have to get close and ride the elevator down. But, be careful not to get too slow because the elevator ride ends before touchdown.

I'll keep practicing and trying things until I find the combination that is right/safe for 90% of my landings and work at perfecting that. I do think the Onex is considerably different compared to the Sonex.

Anyway, thanks for all the comments. Your experience helps me build mine. I do appreciate it.

Wes

[caveman371]

Wes,
I’m in that excessive heat area. Must be near each other

Mike


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