Takeoff distance issues

[8451]

Try higher tire pressure. I went back to 32 PSI after playing with the lower pressures. If I pushed mine out of the hangar with the lower pressures it rolled about 8 feet.. with 32 it rolls out about 20 feet. I would think it would also effect you takeoff run.

I was under the impression that the low book pressure was designed to help cushion out the spring gear, especially on pavement. Have you experienced anything adverse in that regard, or seen signs of over inflation wear at 32 psi?

[6298]

The wear is very even and they last a long time. At the lower pressures they didn’t feel right and wore a lot more on the outer edges, and didn’t roll as well. I’ve had this 140 for over 30 years.

[2356]

Flying Fiddler has a YouTube video of him doing touch and goes atLeadville in a 120.

[a64pilot]

Flying Fiddler has a YouTube video of him doing touch and goes atLeadville in a 120.

Why not a stop and go?

[2356]

He did that as well.

[6863]

Daniel, re-addressing your original concerns about takeoff performance, I would echo what has been said here about not depending on the airspeed indicator to tell you when your airplane is ready to fly. On grass, shortly after beginning the takeoff roll, relieving tailwheel surface drag by slightly lifting it, then tickling it into the air when its body language tells me it is ready to fly works for me on a normal takeoff.

That being said, I respectfully disagree with the notion that these airplanes are "dogs".

In the "tire pressure for 800-6 tires" thread, Jody you make the statement, "In my opinion a 140 isn’t a good bush plane". Compared to what? A $70,000 Super Cub? A $150,000 Husky? If those are your benchmark, you may have a point. But for our $30,000 or less airplanes producing less than 100 HP on takeoff, my experience in my C-90 powered 120 with cruise prop is that it makes a great little bush airplane and I'll gladly do a flyoff against a standard Super Cub. No it won't outdo a miracle Cub or Husky on steroids. But does this disqualify it from being a good bush airplane? Not my 120, flapless as she is.

Lastly, Leadville, elevation 9934 ft. A stop and go there says lots. Hopefully though we're not establishing Leadville as a new benchmark against which our airplanes are now going to be judged.

[7896]

I'm just guessing, but it sounds like she is heavier than you think. When I was searching for an airplane to buy, quite a few sellers quoted the original Cessna certification value for gross weights (which I suspect is unrealistic for most of the still flying fleet).

On the weekends I tow gliders with a Piper Pawnee. During the summer, when the temps are over 90F, the time/distance required to accelerate to take-off speed and the initial climb when pulling a heavy two-pilot glider with average sized people, a is MUCH longer than when pulling a light single seat glider. This seems to mimic what you are describing.

I fly around at +1400 lbs. quite a bit, and still get 400-600 fpm climb behind an 0-200 powered 120. I'd love to know what your actual weight is.

Cheers,

[6183]

Great points thus far, but I curious about the health of your engine. How many hours on and how many years ago was the engine in your airplane overhauled? Is the engine producing the power? Also how old and how many hours on the magnetos? Are you operating early during the coolest part of the day? Your airplane should be able to take off much sooner during cooler parts of the day than what you’re describing.

On a similar note a very good friend of mine and former VP of this organization once had a 140A with a tired C-85 (his daughter now owns it). Some of us who flew it always commented that it was slow to accelerate, takeoff, and climb. One of Mac Forbes outstanding A&P IA’s convinced him that an overhaul was desperately needed. Not trying to spend your money here, but how’s the health of the engine?

[8451]

I'm just guessing, but it sounds like she is heavier than you think. When I was searching for an airplane to buy, quite a few sellers quoted the original Cessna certification value for gross weights (which I suspect is unrealistic for most of the still flying fleet).

On the weekends I tow gliders with a Piper Pawnee. During the summer, when the temps are over 90F, the time/distance required to accelerate to take-off speed and the initial climb when pulling a heavy two-pilot glider with average sized people, a is MUCH longer than when pulling a light single seat glider. This seems to mimic what you are describing.

I fly around at +1400 lbs. quite a bit, and still get 400-600 fpm climb behind an 0-200 powered 120. I'd love to know what your actual weight is.

Cheers,

I think this is likely a culprit in addition to pilot technique. 12 years, some STCs, and a coat of paint since the plane was properly put on the scales.

Great points thus far, but I curious about the health of your engine. How many hours on and how many years ago was the engine in your airplane overhauled? Is the engine producing the power? Also how old and how many hours on the magnetos? Are you operating early during the coolest part of the day? Your airplane should be able to take off much sooner during cooler parts of the day than what you’re describing.

On a similar note a very good friend of mine and former VP of this organization once had a 140A with a tired C-85 (his daughter now owns it). Some of us who flew it always commented that it slow to accelerate, takeoff, and climb. One of Mac Forbes outstanding A&P IA’s convinced him that an overhaul was desperately needed. Not trying to spend your money here, but how’s the health of the engine?

Its approximately a 750 hour engine on a 2004 overhaul. There was a top overhaul by a previous owner about 200 hours ago. Since then compressions are mid to high 70s each cylinder, and oil consumption is about a quart every 10 hours, and oil analysis has been coming back clean. As I stated in the OP static RPM is within limits for my prop pitch. Magnetos are about 350 hours I believe.

I think temperature effects from flying in the afternoon are having a greater effect than anything mechanical. At the very least I can say I'm not able to detect any signs of the engine just being tired.

[8233]

Have you confirmed your tach is accurate?