Have a 170 question

[airtractorflyer]

Hey guys have a performance question for ya. Looking for a 4 place airplane my wife and son can go places with me in and have a really nice citabria I wanted to keep. Had a 1957 172 and sold it few years ago and got a citabria and redone it. I fly ag planes for a living and prefer taildraggers. Ok I built a 1300 ft grass strip at my house. Live at about 250msl. Will a 170a haul me my wife and baby boy out of there? I weigh around 200lbs, wife around 110lbs and just had a baby boy. Been wanting a 180, but nice low time ones hard to come by and are really expensive. Nice 170a pretty resonable, and can keep my nice citabria. Thanks in advance for the info guys!!!

[Bruce Fenstermacher]

I'll say yes. But I will qualify that answer. What kind of approach departure do you have? If 1300ft flat with no obsticals of departure you will be fine. If you need to clear a 50 foot tree at the end of the 1300 ft there is going to be a lot of pucker facter going on and your likely not to like it. What kind of gas or flight duration do you want on departure is also a consideration.

My stock 170A was operated out of a 1300 ft grass strip at 500 msl for nearly 35 years including instructing students. They would routinely take two 200lb adults and half tanks of gas (20 gal) or a bit more. They, for the most part ran a 51" pitch climb prop. They new the runway and conditions. There was no extra built in safety margin meaning you could not screw up the departure or arrival. They throttled up and made a go no go decision 1/3 of the way down the runway. This field had 60 foot trees on the prevailing wind departure so we almost always took of downwind which had a fairly clear departure for at least another 2000 ft. Then your had to dog leg around some trees. But if you were that low you really screwed up. Yes there were times you just didn't go. And yes we departed under the right conditions with to 200 lb adults and nearly full fuel.

Arrivals were no problem but you didn't screw up and float down the runway either. If you didn't touch down on the first 1/6th of the runway you throttled up and went around over the 60 foot trees in front of you. If winds dictated arrival over the trees (we landed with a tail wind a lot) you could drop it in pretty easy but again there wasn't a lot of area to float and if necesary you went around and then probably landed down wind.

What I'm trying to say is if this is a tight 1300ft you probably won't like it much. If it has open approaches you'll be fine but you have to know the plane and know when to abort a departure or go around on landing.

[jrenwick]

This is a situation where a 170B with a STOL kit really shines.

[airtractorflyer]

Fly my citabria our of it all the time, with 2-200 lb adults and 26 gallons of fuel. It's a 115 hp and it will do it unless it really hot. Clear for half mile on departure end. Fly ag so I am very hard to spook! Lol

[airtractorflyer]

But have never flown a 170. A lot of 180 and maule time. Maule does it nice, but don't like them. Too cramped inside for me. I am pretty tall. 180 is first choice, but if can pickup something cheaper could keep my citabria too!

[Bruce Fenstermacher]

A 170 will fly exactly like the '57 172 your owned except of course the third wheel is on the correct end. You likely had a standard prop on the 172 so a climb prop on the 170 would be a bit better but if you had a climb prop on the 172 they'll be the same.

I'd be comfortable saying 170 will at least match your Citabria takeoff performance and a bit more like your new baby son.

I don't think there is a real difference between departure with a 170A or B and I don't think it would matter which model you added the STOL or VG kit to. The STOL or VGs will just make flying at a lower speed more comfortable, They won't necessarily get you off the ground appreciably shorter. It takes more power to do that.

[jrenwick]

I don't think there is a real difference between departure with a 170A or B and I don't think it would matter which model you added the STOL or VG kit to. The STOL or VGs will just make flying at a lower speed more comfortable, They won't necessarily get you off the ground appreciably shorter. It takes more power to do that.

A 170 with a STOL kit can climb at a steeper angle than stock, which makes clearing the trees at the end much easier.

[bagarre]

But, wouldn't it require more power to pull you up the higher angle of attack to prevent it from just mushing out?

[airtractorflyer]

Thanks a lot guys for the info. I really want to keep the citabria too! But would like to be able to go on a trip with a few bags in there also. Our airstrip is not too far from the house so could just go there and leave out. It's just the fun factor leaving from the house, and I don't mind rag wings. There are some out there that can be had fairly resonable from looking on trade a plane and barnstormers. I have always liked the looks of a 170. Want to convert 172 to tailwheel when has it, but ole boy kept bugging me about buying it so its his.lol

[jrenwick]

But, wouldn't it require more power to pull you up the higher angle of attack to prevent it from just mushing out?

If you're asking about my comment about the STOL kit giving a better angle of climb, this is what I have observed while I owned a 170B with the Horton kit. I think with the mod, the wing has a higher lift coefficient, so you get more lift for the same power. In any case, this is what I know from doing flight-of-two takeoffs with a stock 170B. I could always outclimb the stock airplane.

[GAHorn]

... I think with the mod, the wing has a higher lift coefficient, so you get more lift for the same power. In any case, this is what I know from doing flight-of-two takeoffs with a stock 170B. I could always outclimb the stock airplane.

What PROP did the "stock" 170-B have?

According to most performance claims I've seen, the "STOL" kits which incorporate vortex generators do not appreciably change angle-of-climb but DO shorten take-off roll slightly, and shorten landing roll considerably. Their claim is usually one of controllability.

To significantly change takeoff performance requires a significant horsepower change. That can be done with a re-pitched prop to a "climb" prop on a standard 170. The B-model airplane does outperform the A model on field length performance...below 4,000 ASL....but not cruise performance.

[airtractorflyer]

So is the 170A rag wing, or just has no dihedral? And the B has dihedral. Straight 170

[airtractorflyer]

Straight 170 ragwing?

[pdb]

What PROP did the "stock" 170-B have?
According to most performance claims I've seen, the "STOL" kits which incorporate vortex generators do not appreciably change angle-of-climb but DO shorten take-off roll slightly, and shorten landing roll considerably. Their claim is usually one of controllability.

George has the best description of the VG vs STOL kit debate. However, the biggest determinant of takeoff run will be the prop ( and pilot technique.)

Putting on an 8040 or 8042 prop will boost takeoff run performance more than any other single mod short of going to 180 hp and nothing's going to improve R/C except removing weight and/or adding hp.

[Bruce Fenstermacher]

I don't think there is a real difference between departure with a 170A or B and I don't think it would matter which model you added the STOL or VG kit to. The STOL or VGs will just make flying at a lower speed more comfortable, They won't necessarily get you off the ground appreciably shorter. It takes more power to do that.

A 170 with a STOL kit can climb at a steeper angle than stock, which makes clearing the trees at the end much easier.

I don't disagree but I was pointing out it doesn't matter whether an A or B model with STOL or VGs.