Microlighters

Need some tech info, currently flying a Windlass 503 with a cutback wing. P prop 72/46 currently straight and level in PTA is at 5300rpm full throttle and bar in neutral position she gets about 450-500 sometimes 550f/min. (early morning) What more could be done to increase the climb rate. Any advise or suggestions?

Hi Superman

Looks like your prop is to aggresive. For cruiseing its fine , if you want climb rate you need more engine revs for thrust thus a finer pitch.
Cruise prop (72'/46) =low revs=fuel consumpt. low=less thrust=need more runway.
Finer pitched prop=Higher eng. revs (6200)=more thrust=climb rate incr.

Wing = speed.
Eng+prop = Thrust.

Can't have both of 2 worlds,thats why Blik aeries invented variable pitch props, for thrust and for cruiseing. Us small flys or "erdwurms" must fit according to our spesified needs.

Cheers

Would be nice to have a variable pitch prop if thats the case.

Don't over fill your fuel tank-less fuel=less weight.

Hi Superman,

what is the maximum RPM your prop gives you on takeoff? If it is anywhere in the 5300 then you have the wrong prop on your plane.

If I remember correctly the correct P-prop for a 503 is 42deg pitch and for a 582 is 44 deg pitch. You have a 46deg pitch. (phone Pieter De Necker at P-Prop tell him what engine, gearbox and prop length you need and he will give you the right info)

Your static rpm on the ground, plane tied to something must be about 6250. You max rpm is 6800 and being a two stroke they love to run at high revs, in fact if you watch your EGT's you will notice that the plane runs cooler at 6500 than it does with a heavily loaded prop at 5300

Your peak power is at 6500 and your peak torque for cruising is at 5500

running at full throttle at 5300 the engine is only giving you about 38hp

The solution. Sell your prop (here on Microlighters), buy a ground adjustable or get the proper P-Prop from Pieter. (or look here on microlighters for a second hand prop). In fact there is a second had ground adjustable 3-blade WARP drive prop for sale in the Classified - Aircraft Parts and Accessories section.

Morning Morph. At the current moment static is 6100rpm and in the air it is 6300, as mentioned cruise straight and level is about 5300rpm my egt sit at about 540-560 cruise, full throttle 580-600.

Hmmmm,

When I bought my short wing Challenger (503) is was getting 6100 static. She would give me a solo climb at sea level of 500 and 300ftpm dual. I cranked it up to 6250 and that gave me 700 solo and 400 to 450 dual.

Maybe somebody here has a ground adjustable prop to lend you so you can experiment

Apart from that the other ways of increasing rate of climb is lower weight or bigger wing (lower wing loading - This is expensive and will reduce your cruise speed.)

Now for something I know very little of but I have seen the others at my field do,

what about the shape of your battens? maybe they have become flat and need to be re-profiled? Trike guys

Else you could go this route for R6k:

viewtopic.php?t=4809&highlight=powerfin

Henni

I went through this kind of stuff with my mainair alpha, thought I was getting full revs static 6200, only to find out my tach was way out, prob only getting 5700-5800 giving the effect of making the engine run rich,

Always had a prob with the engine surging at cruise revs till I re-pitched the prop which I found out to be a sign of rich mixture, with the aid of a laser optical tach set the RPM to 6200 static, now run smooth at cruise RPM,

And it goes like @hit off a shovel now.

Nick.