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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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.
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.
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.
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.
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.
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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