46 T-craft COMPLETE!

[Milo Dyke]

Hey Guys,

Finally got the wings on my taylorcraft and got her in the air. I have a C-90 with a 71/42 pitch prop. I'm getting off the ground in about 400 ft. (1400 lbs gross) 2500 rpm on takeoff. 55 mph seems to be the earliest I can pull it off the ground with 8.50/6 tires. I have already adjusted the wings in and out on a couple of occasions, and are at factory specs. Stall seems to be in the range of 48-50 mph @ 2000 ft above sea level and 80 degree F. Cruise indicates 88-90 @ 2150.Are these numbers looking close to what they should be? Are these numbers realistic? Obviously when it gets down to 60 degrees its going to help, but it doesn't seem to be in the same ballpark as my PA-11 that I've flown for many years.(85 hp) I'm an A&P and have a few thousand hours in taildraggers (PA-11, Champ 7EC C-90, PA-16, and a hopped up PA-20) but only about 15 hours in this T-craft total. Any advice would help. The plane does seem to climb very well. It is a true joy to fly though and adding all the new glass to the airplane opened it up alot! On landing we are touching down around 55-57 indicated, 65 over the threshold. Thanks for all the help and I do appreciate it. Here are a few pics and one with a North Dakota sunset over the big lake.

Milo

[Milo Dyke]

Re: 46 T-craft COMPLETE!

The pictures wouldnt go on my last message, so hope you enjoy

[Guest]

Re: 46 T-craft COMPLETE!

nice plane!

[Dano"T"]

Re: 46 T-craft COMPLETE!

You should be closer to 100 on cruise with your set up....My 90HP BC12D with a 74-40 cruises at 97 on floats....and is airborn in about 400' also on floats at gross. On wheels I cruise at 102 and am airborn in 200' at gross....I also own a 85HP BC12D with a 72-42 McCauley....It gets airborn in 250-300' at gross and cruises at 107mph.....my stall on both ships is around 36-38mph.

[Milo Dyke]

Re: 46 T-craft COMPLETE!

We are gonna check with a gps one of these days, the air speed indicator may be off, but even if so, I know I am coming in hotter than 50 mph. On takeoff, at 50 indicated, it just seems to sit in ground effect and doesn't want to get off the ground or climb, but once at 60 it sure jumps (indicated). We have tried more wash "in" on the wings and all it seems to do is make the stall slightly more gentle. Any ideas would be appreciated. Thanks guys.

Milo
Hazen, North Dakota

[Guest]

Re: 46 T-craft COMPLETE!

try rigging the wings per the factory spec, I suspect the added washin does not help

maybe I misunderstood and they are at factory spec now??

[Guest]

Re: 46 T-craft COMPLETE!

where is your static line?

[Pearson]

Re: 46 T-craft COMPLETE!

Milo,

I would love to check my email and see a copy of whatever paperwork you have for installing a C-90 engine. My address is (neat1s @ yahoo . com) without the spaces.

It does sound like your airspeed indicator is a little low on the high end and high on the low end. Is your static line inside the wing, well away from any possible ram source?

I don't know much about props for a C-90, but it seems like your prop is pretty short for that flat pitch. I would think with a C-90 you would have a ground roll well under 400'.

[VictorBravo]

Re: 46 T-craft COMPLETE!

Wash-IN is moving in a dangerous (and not legal) direction. Wash-OUT is moving towards safety but costs a little bit of cruise speed.

(Dangerous from a stall/spin AND a divergent structural loads perspective.)

As strange as it seems coming from a rabid tinkerer and modifier like myself, I'd have to strongly agree with starting off at the factory spec (a tiny little bit of washout), and looking elsewhere for all that loss of speed.

Have you noticed that the landing gear without fabric on it is a huge drag producer? Take some plain old brown butcher paper and tape it on nice and taut over the gear to suimulate airplane fabric, and see what that does. Might be surprised. While you're busy with paper and tape, wrap it around the lower 12 inches of the wing struts (like the landing gear) and see what that does too.

Another speed loss on T-crafts is air leaking upward through the wing roots because of loose root strap fairings. These are notorious pains in the ass to get right. If air is blowing in and out of gaps in those fairings, you will get twoor three different types of drag at once. Beware, those fairings are a huge pain in thebutt and you will sooner or later HATE your airplane for a few minutes. One of my long-term projects is nice composite fairing molds for that area, but that's off in the distant future.

PARTIAL aileron gap seals (for the big square holes, not the "slot") is also an area where I believe I made some improvements. There is a little loss of lift because of those holes, but more so there is a "dip" in the "elliptical lift distribution" curve which affects the efficiency of the entire wing. This last concept is also one of the three drag types from loose wing root seals BTW.

[Robert Lees]

Re: 46 T-craft COMPLETE!

What a lovely aeroplane! Well done!

As for the static line question, just disconnect it from the back of the ASI (i.e. use cabin pressure) and see if that makes a difference.

[Milo Dyke]

Re: 46 T-craft COMPLETE!

The static is disconnected at the airspeed indicator. We are only about a turn and a half in from the factory specs right now. No tendancy to spin or anything like that. We will try a few more flights and check it out. Thanks for the advice guys.

Milo

[Guest]

Re: 46 T-craft COMPLETE!

Wash-IN is moving in a dangerous (and not legal) direction. Wash-OUT is moving towards safety but costs a little bit of cruise speed.

(Dangerous from a stall/spin AND a divergent structural loads perspective.)

As strange as it seems coming from a rabid tinkerer and modifier like myself, I'd have to strongly agree with starting off at the factory spec (a tiny little bit of washout), and looking elsewhere for all that loss of speed.

Have you noticed that the landing gear without fabric on it is a huge drag producer? Take some plain old brown butcher paper and tape it on nice and taut over the gear to suimulate airplane fabric, and see what that does. Might be surprised. While you're busy with paper and tape, wrap it around the lower 12 inches of the wing struts (like the landing gear) and see what that does too.

Another speed loss on T-crafts is air leaking upward through the wing roots because of loose root strap fairings. These are notorious pains in the ass to get right. If air is blowing in and out of gaps in those fairings, you will get twoor three different types of drag at once. Beware, those fairings are a huge pain in thebutt and you will sooner or later HATE your airplane for a few minutes. One of my long-term projects is nice composite fairing molds for that area, but that's off in the distant future.

PARTIAL aileron gap seals (for the big square holes, not the "slot") is also an area where I believe I made some improvements. There is a little loss of lift because of those holes, but more so there is a "dip" in the "elliptical lift distribution" curve which affects the efficiency of the entire wing. This last concept is also one of the three drag types from loose wing root seals BTW.

Hi Bill,

What makes it not legal?

Dave

[Dano"T"]

Re: 46 T-craft COMPLETE!

http://vb.taylorcraft.org/showthread.php?t=5901

I posted the paperwork you need for a C90 here