Landing patterns and reverse thrust!

I don't know how long of a distance it takes for most of you to land, but when diving in below the treeline from 200 feet I pick up tremendousspeed on my EasyStar to the point of hitting 50 mph and overshootingthe runway, ending up in the trees.

Of course I can land in 500 feet easy, but making my autopilot do it wasnot. I was curious if anyone wanted to chime in on how they solvedtheir landing issues and minimizing the length of space required.

I was able to get mine down to 500 feet diving in from 200 feet and leveling off. The attached photo is my landing pattern.

1) Circle the landing zone, sample the winds
2) Go downwind
3) Turn for final approach
4) DIVE! with a feedback loop on airspeed able to do reverse thrust
5) flare and land.

My reverse thrust is done with a car speed controller. I can get +1 lbthrust as well as -1 lb of thrust. (Wasn't expecting that either.) Thisis just by running a typical 5x5 prop backwards!

The end result is that I slow down from 50 mph to 20 mph in a few seconds after the dive.

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  • I would like to point out that at the very last stage - actual landing and touch-down you need your airplane be very stable.
    My suggestion is this:
    Make your reverse-thrust stage even more agressive but start at mid-descent. I should end at the beginning of your runway.
    Follow it with a normal landing throttle setting. This way you will decelerate at safe altitude and have a safe margin to a stall speed. Ideally your approach speed at the end of the reverse-thrust stage will be same as you would have at the end of a longer "normal" landing procedure.
  • Great idea! That sounds like a good solution. I had thought of:

    1) Limiting the reverse thrust to 50% of what it is now
    2) Just cutting out the reverse thrust when I get within 50 feet of the ground

    but yours sounds the best...

    3) Scale maximum reverse thrust with elevator command.

    I hope I can encourage others to try reverse thrust as a valid way to slow down in a hurry. It works reasonably well.
  • Sounds like a lot of fun doing these combat approaches! Maybe you could program the autopilot to reduce the reverse in proportion to the elevator command or maybe use less reverse for a longer time to keep control?
  • One thing to point out again. I am trying to be VERY AGGRESSIVE here. That's why I'm diving and using reverse thrust.

    I can land my plane in the same space because I circle in and avoid the trees. I am trying to program the AP to do it in one step. Dive in and land.
  • Thanks everyone. Actually @mike-- You are spot on. With full reverse thrust, I can't hold the nose up on the plane beyond -15 pitch. Which when I'm trying to lose altitude isn't a problem, but during the last 30 feet I have to cut reverse thrust to regain my pitch authority. I think the negative is definitely the disturbed airflow situation. My landings have been perfect until this weekend when my reverse thrust had to stay on longer and closer to the ground. In both cases I had HARD landings.. .but my elevator was FULL UP going 25+ mph (plenty of airspeed) but couldn't hold the nose up.

    All and all I think this technique works but has it's drawbacks.

    Also, I purposefully descending too late. I am getting ready to land in my backyard, where I only have a few hundred feet and tall trees all around. I'm trying to practice :)

    You are also right in controlling descent with throttle, but that requires more space. This was an experiment to see if I could do better by breaking all the rules.
  • Looking at your landing diagram again, it is looks to me that you are starting your landing descent too late. Try starting a decent when you are abeam the end of the runway on the downwind leg (pretty much where the road is in the picture). Turn your base leg when the plane is about 45 degrees from the end of the runway, then turn final when you line up with the runway.

    Standard descent angle for most real real runways is about 3 degrees, which is 300ft/mile. So if you are 1 mile out from the touchdown point when turning final, you should be at 300ft, 1/2 mile final is 150ft, 1/4 mile final is 75 ft etc. Hope this helps.
  • I think it's fine to use reverse thrust if you have to, but I can tell you from my experience flying the full scale Piaggio Avanti (which is a pusher prop like the easy star), reverse thrust significantly decreases stability due to the disturbed airflow over the horizontal and vertical stabilizers. Just something to think about.
  • Totally off topic, but that is a sweet ride :)
  • Interesting discussion. I take it you can't just do tight circles on the way down. I can't imagine actually reversing the motor. Sure it can be done but props are not effecient running backwards. Heck, whatever works for you I suppose. Just doesn't sound very graceful :)
  • 1) I wonder why they ALWAYS turn the carrier into the wind for landing ops? Optimize LZ approach fix select.
    2) Landing is not a 1-step process. Initial Approach Fix - set up appropriate clean config prelanding A/S-ALT
    3) Final Approach Fix - set up landing config devices - Conventional FLAPS (anyone?), whatever else you want to try XCEPT rev. thrust in the air (great for stunt flying but no pilot/autopilot in their right mind/subroutine would do it while landing).

    There is actually an already deployed SUAS that has a polyhedral wing and uses kick-up horizontal stabilizer DT to float down to a landing (of sorts).
    Forget 'chutes, I had to use one back in the day to land Lear 23's w/out thrust reversers (either one for use AFTER touchdown only!) for charters into Lathrop Wells/Mustang Dude Ranch. Way too much xtra maintenance/pack-repack or they don't open when you want them to!
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