Input wanted on takeoff distance for 180hp, 170A with STOL

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learaviator
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Input wanted on takeoff distance for 180hp, 170A with STOL

Post by learaviator »

I purchased a cabin with 4o acres at 5400 msl. I have about 8 trees to cut down to get 1200 feet of runway. Temps would run around 60 - 75 at my intended takeoff time. Aircraft would weigh about 1790 at departure. Any ideas or experience on the takeoff roll distance? The runway would be hard packed. I have not had time to go to some equivalent runways to measure takeoff distance but plan to. The runway is level both ways. I also have an 80" prop.
"You can only tie the record for flying low"
1950 170A N9907A 180hp. STOL
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ghostflyer
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Re: Input wanted on takeoff distance for 180hp, 170A with ST

Post by ghostflyer »

It’s not easy to make an assessment on info given. We need the type of prop[variable pitch prop ?] is it a a fixed pitch what is the pitch of the prop and who made the prop and what is it made of . Then the engine ? Is it injected or carby and what brand of engine ? Continental ,Lycoming and superior , titan all make a 180 hp engine . Plus all 180hp engines are not created equal. Then we can ask about the size of wheels and pressures in the tires . Then it’s the pilot skill also. Plus not the end of of all variables is how much fuel and load you will have . Always check your density altitude .always be aware of wind direction and strength, and do you have wind shear in the area.
PS. I have a 170A with a Superior engine 180hp with a sensenich prop [aluminium] fixed pitch at 60 in pitch ,length of prop [i can’t remember] .
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GAHorn
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Re: Input wanted on takeoff distance for 180hp, 170A with ST

Post by GAHorn »

Well, Steven, as you know there's little info out there which can be relied upon. Your safest bet will be to find a place where conditions are similar to your query and see what YOUR airplane does (and then add a "fudge-factor" and POST YOUR RESULTS HERE.)

This is similar to questions asked about other conversions and the only info typically seen are the STC-holders statement to the effect that the converted airplane performance is "Similar or Meets/Exceeds original performance parameters".

If you could find the performance data of a C-175-C it would likely be similar. (175 HP w/Constant Speed) For example, the 172C and 175C were essentially the same airplane except* the former had an O300 and the latter had a GO300 w/constant speed which allowed fine-prop-pitch for takeoff. The 172C published performance of Ground Roll was 825' but the 175C Roll was 600'. The respective T.O. Distances over 50' was 1430 and 1205.
So a rough guess is about a 20% improvement. If I were in your situation that's where I'd begin my planning.

*The two examples had different gross wts the 172C being 2250 and the 175C being 2450.... but that difference could be ignored as it works in your favor in the example I'm suggesting.
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DaveF
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Re: Input wanted on takeoff distance for 180hp, 170A with ST

Post by DaveF »

learaviator wrote:I purchased a cabin with 4o acres at 5400 msl. I have about 8 trees to cut down to get 1200 feet of runway. Temps would run around 60 - 75 at my intended takeoff time. Aircraft would weigh about 1790 at departure. Any ideas or experience on the takeoff roll distance? The runway would be hard packed. I have not had time to go to some equivalent runways to measure takeoff distance but plan to. The runway is level both ways. I also have an 80" prop.
I have an O-360 with an MT CS prop, based at 5050msl. Depending on slope, wind, and obstructions, I'd say 1200 will work, but it'll keep you focused. Eventually your technique will improve enough that you'll wonder why anyone needs 1200'? :)
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learaviator
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Re: Input wanted on takeoff distance for 180hp, 170A with ST

Post by learaviator »

Thanks everyone for their input. I have a Hartzell constant speed prop, 80 inch. I've got 8.50's on it now at 15-20 PSI. I do have 29's for it. Cylinders have all had magic worked on them by Lycon so it breathes and runs good. Carbureted O-360 Lycoming. I got 7 trees cut down this weekend, about 5 more to go. I hopefully will be able to get to a comparable strip (elevation wise) and get some numbers which I will post for sure George!
"You can only tie the record for flying low"
1950 170A N9907A 180hp. STOL
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learaviator
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Re: Input wanted on takeoff distance for 180hp, 170A with ST

Post by learaviator »

ghostflyer wrote:It’s not easy to make an assessment on info given. We need the type of prop[variable pitch prop ?] is it a a fixed pitch what is the pitch of the prop and who made the prop and what is it made of . Then the engine ? Is it injected or carby and what brand of engine ? Continental ,Lycoming and superior , titan all make a 180 hp engine . Plus all 180hp engines are not created equal. Then we can ask about the size of wheels and pressures in the tires . Then it’s the pilot skill also. Plus not the end of of all variables is how much fuel and load you will have . Always check your density altitude .always be aware of wind direction and strength, and do you have wind shear in the area.
PS. I have a 170A with a Superior engine 180hp with a sensenich prop [aluminium] fixed pitch at 60 in pitch ,length of prop [i can’t remember] .

So with a comparable plane to mine what is your opinion on takeoff distance at that altitude?
"You can only tie the record for flying low"
1950 170A N9907A 180hp. STOL
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ghostflyer
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Re: Input wanted on takeoff distance for 180hp, 170A with ST

Post by ghostflyer »

I can’t really answer your question as australia is very flat and our highest mountain is only 7300ft. I normally take off at sea level and I think the highest area that I have taken off is 1500ft above sea level but saying that density altitude is another thing ,and I am normally full fuel and always around max weight and 90% of the runways are rough dirt/sand and I always look for 800 to 1000 ft for take off . I run 8in tires at 25psi . I can’t explain it but I have judged my take off on my landing roll when landing in a strange place. I normally add 1/3 extra for the take off roll. Yes, I have upset the birds on some of my take offs but it’s not my fault if they were sitting in the trees.
PS. Why the high pressure in the tires.. stops side wall damage .
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