gravityrules

I graduated from an aerobird challenger to the GWS P-51 (big mistake). After smashing the holy heck out of it, I got an E-Starter and actually learned how to fly a bit. With the miracle of Minwax Polycrilic and fiberglass cloth, I've resurrected the P-51 from what I thought was an early death (it's now called Lazarus). Anyway the thing's been flying great and am having lots of fun, but when I bring it in to land, about two feet off the ground it tip stalls, veers to one side and cartwheels in the grass. I have no landing gear and am trying to get a nice soft belly landing. What's the trick to bringing one of these home? Do you have to skid it in at high speed? I'm getting a little tired of re-gluing the wing mount gear.

Thanks in advance.

BuzzBomber

My Feedback: (4)

Keep some power on in the final approach, slowly feed in a little up elevator to bleed airspeed and control altitude, and cut the throttle just before final flare. Basically, you don't want it to stall until the moment of touchdown.

gravityrules

Thank, Matt. I think you're right that I'm cutting power and flaring too soon. I also might be giving too much up elevator on the final, causing the stall. If weather permits I'll try your advice this evening (epoxy should be nice and solid by then).

BuzzBomber

My Feedback: (4)

With my spitfire, I find that as I flare, I seem to enter ground effect at the same time, so a little up elev. makes it want to climb and stall. With a little experimentation, though, you'll find the right balance.

gravityrules

Yeah, it did seem like ground effect was a factor as it kind of floated about 18" from terra firma. I don't get that on my E-starter probably due to the high wing.

I'm considering the Spitfire for my next plane as I hear it's fun and a bit less quirky than the stang. How do you like yours? What do you use for a powerplant?

BuzzBomber

My Feedback: (4)

I've had good luck with the spitfire, and mine really impresses the other pilots at the field (I know that sounds arrogant, but I get a lot of positive comments on its performance). I am using an AXI 2212/26 with an APC 8x6 slowfly prop, a Jeti 18-3P ESC, and 8-cell CBP 650 batteries. I haven't timed the flights yet, but I'm ready to land by the time the power is waning. Performance exceeds scale--steep climbs, quick rolls, big loops, and seemingly blistering fly-bys are all part of the program with this setup. I don't even have it propped for max. efficiency--I picked a compromise that would allow me to use either 8-cell nimh or 3S li-po without overheating the motor.

On the other hand, my father also flies a spit--his is bone-stock, and he has not had good experience with it. I think part of this is due to the fact that he is still on the steep part of the electric flight learning curve and unwilling to accept the fact that a supposed ARF won't always fly well out of the box. That, and acute epoxy-itis. His definitely has a far nastier stall characteristic than mine--using the recommended throws, I can loop from full throttle level flight using *almost* full back stick without stalling out of the loop; his will spin out if he tries this. So, basically, it needs to be kept light and balanced conservatively to avoid flying like a lead sled. I think it can be successful on the stock powerplant and something like Kan 650 8-cell packs, but if you do go brushless, I can heartily recommend the AXI line--making a full throttle strafing run sounds SOOOO cool with this plane; all you can hear is prop noise and the 'whoosh' of airframe drag on the downlines!

SBR_RV

well alot of people tip stall the mustang including me, but when i get it on the ground the weak landing gear just give way anyway, so what does it matter lol.
about a month ago i was flying inverted and well, the wing poped out (screw holding the wing on came of, dang) and i was fairly high so the fuse picked a extreme speeds for a fomie, while the wing just floated down which was hand, didnt have to do any repairs for that. but the fuse brock in half, stuffed the motor some how (it was the stock 350 motor luckly). Then came the challenge of getting the battery out, it forced its way about 3cm further into the fuse, so i stuck a ruler through the motor area where i could reach the battery. So i pushed as hard as i could, hard enough to crease the fuse paint, but eventuly it came out. just thought id metion that the spinner was buried in the ground, it left a perfect mold of it.
so its glued together, i even gluded the wing to the fuse lol, wont come of know hehe.

if ur thinking of going brushless, and have the money to spare, its a good idea. friend of mine did it, capable of big inverted flight, big loops and everything else.
oh and he glued the wings on also for outside loops.
just to mention, i would suggest cutting away the center part in the fuse and mount the servos on the side of the fuse, so u can get to the speed controller, but thats if u want to glue the wings on.

gravityrules

Well, I took it out last night and forgot to check CG before launch and it was flying pretty squirrelly. As I was bringing it back in, it stalled, veered left and became a high speed lawn dart [&o]. It's pretty smashed up, so it might be time for retirement (with all the fiberglass and epoxy, the thing weighs a ton). Matt, I think the AXI motors look very interesting. How do you mount them on a GWS? It doesn't look like they adapt to the stick mount. Do you glue a piece of wood to the foam as a firewall? I assume these are direct drive and don't use a gearbox.

I have a Himax 2015 with a GWS-like gearbox on my E-starter, but am not totally thrilled with performance. My E-Starter is a bit heavy though, as I glassed the wing and fuse for strength. Still debating whether to put that motor in my next warbird.

BuzzBomber

My Feedback: (4)

The Himax can be tuned for optimum performance in the GWS warbirds; it's the matter of selecting prop, gearing, and battery to match that makes it a little difficult. What sort of batteries and gear ratio do you use in the e-starter? As for mounting the AXI, Stevens Aeromodel offers a stick mount adapter, of you could "roll your own" like I did. Basically, I cut the motor stick in half, determined how far out the motor needed to be for prop clearance, and used a plywood plate between the two sticks to locate the motor. I cribbed the idea from LenBFP on the e-zone forum, and here's the thread where the idea was discussed: [link=http://www.rcgroups.com/forums/showthread.php?t=182058&highlight=axi+spitfire]Axi in Spitfire thread[/link]

gravityrules

Very cool AXI mounting idea!

As for the E-starter the current config is Himax 2015-5400, Gear ratio 6.6:1, prop GWS 9070, battery 8 AAA cell 9.6v 730mA NiMH. I've been meaning to experiment with different ratios and props. Now that the Stang is out of commission, I'll get to it. The Himax gear box came with 5.3:1 and 4.4:1 spurs and pinions. Do you have an idea on what props you'd use with the different gears? My instinct tells me - lower gear ratios, higher rpm, smaller prop with less pitch. Right? If I use small ratio with same 9070 prop, I'll get more current draw - yes? By the way, I live at about 6000 ft elevation in Colorado.

BuzzBomber

My Feedback: (4)

I think you're on the right track as far as the gearing/prop relationship. On that note, I only come up with 3.6 amps in and 29.6 watts out for your e-starter setup, with 10 oz. thrust and pitchspeed of 30 mph. I think this could be optimized. The AAA batteries are probably going to dictate your final power limit, as they seem to crap out above 5 amps (in my admittedly limited experience with them--I could be wrong). Given your elevation, you may want to prop up one size to compensate for the less dense air. I think a GWS 10x8 slowfly prop would be better for you on that gearing and battery. I generally run power setups through P-calc ([link=http://brantuas.com/ezcalc/dma1.asp]link[/link]) before I try them out in the air. It seems to give a fair approximation of power. As a side note, if you plug in "custom" prop type and use a prop constant of about 1.7, it seems to fairly approximate a GWS slowflyer prop. Hope all this helps you out.

Hepdog

Never - ever - ever had my Mustang "tip stall". Tried a bunch of combinations of turn-stall tonight but it just mushes out. As for landing, on grass with no gear you don't need to go that slow. Its pretty tough. I landed way too fast last night cause a mosquito (the bug not the plane) was sucking on my right knuckle causing a loss of concentration and next to no flare!! No biggie.
BTW I run BL on my GWS stang and it rocks. E flite 400 - 4200kv in GWS C box, GP 1500mah 3s Lipos, CC 25 ESC, GWS 9060 or 1080 props, RTFW 15.8 ozs, ATE. Unlimited vertical.

Airbourne in Japan

My Feedback: (3)

what c of g are you guys using for your p51 ?