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Discussion in 'The light stuff area' started by Farfle, Jul 14, 2017.
Was the battery charge consumed about what was expected?
as the resident glider expert at this thread,....little off topic but you brought it up....do gliders ground loop?
Yes, even Cessna 172s can be made to ground loop. Took me a long time to figure out how pilots can do that. I finally found someone that could demonstrate it for me. Very interesting and informative with no damage. As they say, there is something to learn on every flight.
While I'm on my high horse. I disagree with VB in post # 98. He says "Farfle, I would like to suggest that doing extended high speed taxi is the wrong thing to do. It puts you in the most dangerous and accident-prone situation for the longest period of time, creating overwhelming odds that you will have a groundloop."
I generally agree with what VB says 98% of the time and I see that Farfle handled everything with test pilot precision so this comment is out of date but I refuse to let it go as I have heard the same comment too many times by too many pilots.
If doing extended high speed taxi creates overwhelming odds that you will have a groundloop you should do more low speed taxi or fix the airplane. Flying the plane is not an acceptable solution to the problem.
I’ve been keeping track, and VB is “almost always right 98 percent of the time.”
Cool video. Was that drone on "auto follow"?
Nice grass runway. Almost have to be an idiot to groundloop on grass.
Or loose a tail wheel spring. I see a lot of planes without the compression tail wheel spring.
Heya all! Tossing up an official flight report here for the zero powered Belite. It's a bit of a saga, so hold on.
After a day of slow taxi, a big teardown and inspection, a day of fast taxi and another inspection, finally yesterday 10-30-18 was the first flight at Madras airport from 16 in the grass.
Flight number one was straight down the runway, luckily madras (S33) has a 3k+ foot grass strip, so plenty of time to transition slowly from tail-up taxi to about 40mph and then let it transition into flight in a very smooth and controlled way, climb to about 30 feet, get it back on centerline and bring it back down for a wheel landing. Everything went flawlessly, and it was a piece of cake to keep it on centerline, although it needed a fair amount of stick forward pressure and stick left hold for level flight.
Flight two I removed the spring leveling the elevator, and adjusted the aileron heim joints to help center the stick a bit. Also adjusted the brakes to make them less easily triggered. Same flight down the runway and a greaser landing, It still needed some stick-left input for straight-and-level flight, but not bad.
Flight three's plan was to climb up into the pattern and then exit the downwind and climb above the pattern to determine what the thermal cutback behavior was, but after getting a few hundred feet up and in the downwind leg, I started catching some pretty serious thermal/turbulence action, and the stick was still heavily biased to the left. Fearing a lack-of left turn authority, and needing some knee-bumping stick travel I decided to stay in the pattern and bring it in for a landing. The landing was not good, i went for a three point, but while rounding out the approach pre-flare I had very little up elevator authority, and the landing was very firm. No bounce but at full elevator deflection it did not pitch-up quick enough and planted a little hard. No harm no foul, but the bumpy air and quickly increasing wind had us calling it for the day.
Day two, Gabe and I headed to Prineville airport (S39) as madras was windy and did some flights there taking off from rwy 33, and landing in the gravel bar to the left of rwy 33.
We adjusted the elevator control rod to buy us about 10 degrees more up elevator travel, and adjusted the strut heims to add some twist ti the wing and try and get the stick straightened out.
For flight one at prineville, The winds were very calm and I back-taxied down 33 to survey the gravel bar next to it for landing, then I took off on 15 and made right pattern out over the hill to the west of the airport. I left it firewalled while climbing out, and at the end of rwy 15 (3kft) I was at 480ft. Doing the math at a 55mph climbout says just under 800fpm climb rate from 3200ft to 3680ft. I continued to leave it firewalled as I circled up watching the temps climb. At about 4000ft it hit thermal cutback at 150C indicated and I watched the motor controller reduce power from ~360A to ~200A momentarily, then it recovered and stabilized at 280A a few seconds later where it climbed slower, but still around 2-300fpm climb in full thermal derating. I continued the climb to 4800 feet where I turned back and entered the left downwind for 33. I attempted another three point landing on the gravel bar, and it had more authority this go-round but not enough for a proper flare again, and it bounced pretty hard. It also still needed more right aileron trim, but not as badly.
Flight two, we adjusted the primary stick-to-bellcrank linkage to scoot the stick an inch or so to the right. I took off on the asphalt 33, and climbed into left closed pattern. The control stick was hands-free and centered, so making some progress there. On my landing I attempted another three point in the gravel carrying a bit more speed in the approach. It still did not have enough elevator to flare, and I had a good few bounces down the gravel (this plane bounces well!)
Flight three we made no adjustments, and were seeing some rain starting, so I quickly taxied out and did a more performance-takeoff with the brakes held and released at WOT, and it was off the ground in a four of five plane lengths. I ascended into left pattern for 33 again and brought it in for a flawless wheel landing in the gravel, with some beta thrown in at the end to get stopped faster. Electrics are pretty fun
We packed it up for the day, and called it. Gabe and Bob flew back down to SJC in Bob's awesome Lancair, and I stashed the cub at the shop.
There is a bit of a squawk list if things to sort out, but its flying and has transitioned from being terrifying and unknown to somewhat less terrifying and a LOT of fun.
Oh heavens, if I could only get my wife bamboozled like I got you guys in the bag...
The intention of my previous comment about being in the "Danger Zone" doing high speed taxi wasn't about the airplane being adjusted incorrectly. Obviously if there is any sort of control problem then you need to fix that instead of flying the airplane.
However, the transition between rolling and flying, tail coming up or going back down, and especially the gyroscopic propeller forces that turn that nose-up or nose-down movement into an uncommanded yawing movement, make the time during the takeoff and landing roll more prone to groundloop or straying off the runway. So extending that time, by keeping the airplane in that middle realm btween taxiing and flying for longer than it has to be... is in fact raising the chances of a problem because of that increased time.
Insurance companies charge more for the SAME driver and the SAME car when you drive the car more than X miles a year. Why? Because the car is in more danger of being crashed if only because it's spending more hours on the road, where the crashes occur.
Think of it this way. You're wearing a new pair of shoes. You aren't used to the shoes yet, they're not broken in. So UNTIL you're totally comfortable with the shoes, you are much better off spending as little time walking on ice-covered stairs as you can. Don't loiter on the icy steps, don't shuffle around for ten minutes on the ice steps while you're texting your girlfriend, don't walk on the icy steps with your hands full of packages unable to hold the handrail. It's simply not the time to spend hours on icy steps. Be careful and go up and down the steps, but for now just do it carefully and be done with it soon.
Later, after you're confident in the shoes and how they work, THEN you may find that you can walk up and down the steps for hours on end without falling on your ass. But the first day of your new shoes is a day to spend most of the time on dry grass (taxiing slowly) or even wet pavement (flying), and as little time as possible on those icy steps.
That is something that is messing with me. I have had EVs in my life forever, and am really good at estimating range. But aircraft are throwing me off.
On a moto, half battery at halfway there means you are on the right track, but in an aircraft you burn so much power getting off the ground that all my range estimation in my monkey brain is saying "HOLY **** YOU NEED TO BE ON THE GROUND NOW" because power is being burned so fast. But then you pull it back to cruise and its NBD. In that case you could be at 20% battery and halfway there and be just fine.
Flying the pattern @500ft used about 11Ah 7 of which is burned before the crosswind turn. (116AH total capacity).
Datalogging, that you can peruse on the ground, should be educational. I'd use a raspberry pi, but that's because I've used them for all sorts of projects already...
practice your power off landings, then run it dry (or not enough to stay level) over the airport with a stop watch
Doing "crow hops" on a new plane has been a point of discussion for a long time. As VB describes, crow hops are really an advanced maneuver that requires good pilot skills to accomplish safely. I've heard new pilots say that they would crow hop their plane because they weren't sure that they could fly it. This is backwards....if you aren't confident flying the plane then you probably aren't ready to fly it in a manner that puts you at higher risk for an incident.
how do you know it is rigged properly?
I am nobody's example of a test pilot or a professional pilot, but speaking only for myself, my personal method for a completely unknown aircraft is that I take off and fly down the runway at 10-15 feet, and do an immediate "full 3 axis control" verification.
I lift off and gain 15-20 MPH over liftoff speed (you wouldn't want to do this at or just above minimum flight speed). I rock the wings left and right using moderate aileron deflection. Once roll control is demonstrated then I pitch the aircraft nose up and nose down 10-15 degrees above/below the horizon. Once pitch control is demonstrated then yaw the aircraft left and right 10 degrees. These are not "full control" aerobatic control movements but moderate movements.
After all three axes of control have been demonstrated, then I feel that the odds of maintaining control of the aircraft for the rest of the flight are strong enough that I can climb away from the runway and start dealing with everything else, including stability, rigging, temperatures/cooling, etc. At any time before that go/no-go point, I can reduce power and try to wrestle it back on the ground before I'm "any higher than I'd want to fall".
Of course this demands a long enough runway to do the control verification on the initial takeoff run, but IMHO this is important enough on a first flight to go somewhere there is a long enough runway.
Again, this is only my personal way of thinking and I have zero formal education in stuff like this. If Dave Morss or Norm Howell or Jim Payne shows up here and says that my methods are stupid, take THEIR experience and skill over mine every time
Because you've checked and verified the wing/tail incidence, control surface deflections, etc. If the plane is as designed then it will fly as designed. If it's an original design that has never flown then it may be appropriate to ask a real test pilot to fly it first. I'm not saying that you should not do "crow hops", I'm saying it's an advanced maneuver that requires requisite skills.
I have seen pilots lift off the runway nose high on the verge of stalling and wallow along at 10-20 feet while hoping they get it back on the ground safely. I've read about pilots who wanted to just take off and fly at 10 feet and suddenly find themselves at a 100 feet and out of runway and not mentally prepared to fly the plane. In general I think it's better to plan to take off and climb normally to pattern altitude and then set up for a good stable approach to landing.
One technique that can make evaluating proper control operatiom, control power and acceptable rigging is to set power before the takeoff roll, and leave it there, rather than applying full power, climbing too high, then trying to land.
The first run shouls be with power setting well below rotation speed, and then, with favorable results, gradually increased for each run.
If the airplane has an engine that has not had the rings seated, the above procedure puts proper seating at risk.
Yeah, I would first barely get it light on the wheels then lift one wheel to test the controls and set it back down, all at low power.
I have less flying experience than most of you here.
My ultralight should takeoff in less than 100ft. For first tests, I will be looking for a loooong runway. Smith Reynolds is only a couple of miles from me. Too congested an area to fly a pattern in a 103, but it has a 6,600' runway that isn't very busy. That's plenty for short, low flights after slowly working through fast taxi. This is assuming they'll let me.
Some onboard video of the Electric Belite!
Not quite enough authority on the elevator to flare for a proper three-point landing.
I have a list of fixes to apply:
Move the CG rearwards by moving the rear pack to the rear of its tray.
Adding some oratex to the elevator to act as a gap seal there
Verifying that the elevator pushrod is not bending under flight loads, and that the travel is to spec.
How does the deck angle of your Belite compare to as-designed? It may be that your elevator has exactly enough authority as it's supposed to but because of longer gear legs/bigger tires your tail wheel doesn't reach the ground in the designed 'three point' attitude.
Separate names with a comma.