short field question

[dgil]

Hello all, I'm starting to look around for an airplane, I have a grass field at my house here in Kansas that's 1650 ft long. It has a 3 ft high barbed wire fence at the S end and some 15 ft tall trees at the N end. Taking off to the S the field slopes up about 10-15 ft in the first 600 ft, then is level the rest of the way. Would a stock 170/170a/170b be able to get in and out of here ok? I know it would depend on temp, payload, etc. Out here we just about always have at least 5-20 kts of wind except in the early morning or late afternoon, in the summer it's usually out of the S. My field's a little bumpy so I'm looking for a taildragger, preferebly 4 place under 45K.

Thanks,
Dave

[tshort]

My '48 could do that no problem.
I have a climb prop, which skews things a bit, but I have taken 3 adults and full fuel in and out of similar strips on a hot day with no problem. Flew out of 7IN9 a couple of weekends ago (2100' long grass strip) and were off with 3 aboard in less than 1/2 the runway.
I think a 170 would do fine there... wish I had a strip like that here!

Thomas

[Bruce Fenstermacher]

You should have no problem operating a 170 out of that strip with some precautions. A full load on a hot day with tall grass might be a bit more exciting than you might want.

A friend and his students operated his stock 170A out of a 1300 foot runway with an open end and 60 ft trees at the other. Unless winds where greater than 10kts over the trees he always took off down wind over the open end. There where a lot of down wind departures.

For the most part he had a climp prop but not always and he liked to keep the tanks half full but would operate heavier under the right conditions.

[blueldr]

Any one of the stock C-170 series airplanes should have no problem on that strip.
However, I think I would be hesitant if it was equipped with a prop with more than fifty three inches of pitch. I think that could be very exciting.

[flat country pilot]

Dave,

Check out the link to our airstrip.

http://www.popularaviation.com/PhotoGallery/4308.JPG

Our yard is on the south end. The N S strip is 2200’, the trees are about 50’ high. Our 170B clears the yard very comfortably. I haven’t gone out and measured, but the 170 leaves the ground at about 700’, give or take, with two people and full fuel.

The N S strip has a hump in the middle. I definitely leave the ground well before the hump. Landing over the trees to the North, I can usually stop at the hump. Our 170 does have flap gap seals and aileron seals. I have not flown it without the stol kit so I can’t say what a stock 170 would do here. (There is a 170B within 4 miles of me, he and I should get together and compare.)

I would not consider your fence an issue. I believe all the 170s out there could clear your trees with ease.

There must be a C170 owner in KS that would go and take Dave for a ride on his strip, right? If I were closer it would be fun.

The best thing about a C170 is the cool factor. Of course, I am biased.

Bill

[Joe Moilanen]

I also have a climb prop but the strip at my house is only 650' long. There are a lot of conditions when I don't use it and I only do it VERY light.

Joe
4518C

[GAHorn]

Like myself, my airplane has gained weight over the years. I keep carrying around things that are almost never used. The result is that I've probably become accustomed to my airplane having lousy takeoff and climb capability. (We carried at least 50-60 lbs of stuff we never used all the way from TX to Brit. Columbia, Vacouver, Seattle, Salt Lake, N.M, and back to TX. Things like 15 lbs of steel tie-down stakes/hatchet/tools. 35 lbs of survival gear (water, spare parts, etc.)
Of course, it was a struggle getting all that, 120 lbs of bags, Jame, me and full fuel over Alamosa Pass, Colorado. (That snaking RR we were follwing thru the pass was OK but when we made the turn into the last bend, the tunnel was a bit narrow.)
The point of this is that I have no confidence my airplane would get out of 1600' and clear a fence at all, even with only two people and full fuel, if it's summertime down here at 1000' elevation. My 3500' grass strip has 25' power lines at the east end. I'm airborne, depending on weights, around 800-1400' OK but it doesn't want to get out of ground effect and those power lines frequently slide under the wheels only by about 10' or so. (It's very possible tho', that I've not been following my own best advice lately, as I sometimes sloppily raise flaps prematurely in an effort to increase the airspeed a bit, especially if it's bumpy crosswinds. The sage-pilots leave flaps down until the obstacle is cleared. If you use them for takeoff roll, raising flaps before the obstacle really hurts.)
The B-model* book says using 10 or 20 degrees of flaps, that at 2000' elevation, the airplane requires 2250' to clear a 50' obstacle at 80-degrees F. The ground roll is 850'. I'd expect those to be pretty typical Kansas numbers. Flaps Zero takeoffs are worse, they take another 100' to clear the obstacle and the ground roll is 940'.
If the temps are cooler, say 60-degrees, the same situation still requires 2050' to clear the obstacle with flaps, and almost 2200' without flaps. The ground rolls are still almost 800' and 900'.
These are all at gross weight. If you can fly at half fuel and two persons max,....then perhaps that short strip may be OK with you. But I'll bet you get scared a few times using it. And you'll be picking up your passengers at a nearby airport if you plan to take anybody anywhere.
When travelling to Brit. Columbia and back this summer, I made it a rule not to use airports less than 5,000' in length or more than 6500 in elevation. It required me to do some serious preflight planning. Some of our climb-outs were still pretty interesting. (Leaving Salmon, ID for Spokane was a close-up view of mountaintop flora/fauna for the next 50 miles.)

"I wecommend you be vewwy consofative with yooah estimates, and pwan to fwy light...vewwy, vewwy, lite." - Elmer Fudd


*B-models will slightly outperform earlier models in field-length performance.

[Bruce Fenstermacher]

George if I recall your are flying a cruise prop on your plane.

I routinely use 10 degrees of flaps for takeoff to obtain a slightly more positive rate of climb for noise abatement and usually do not retract them till I'm about 500ft agl well above any obstacles. Didn't know I was a "sage" pilot. Thanks George.

[doug8082a]

Before I sold 82A I used to operate on a 2200' grass strip routinely and only use half of it at best. Two people, full fuel, standard prop was no problem even in hot/humid August. Granted, field elevation is only 122', but DA in the summer got up there ways when it was 95-100 deg out. Never had a problem or even a concern.

[bradbrady]

Hey Everyone,
As always George's oritation is wonderfull! and insightfull! Many people brought good thoughts to this post, but were set on their opinion of a certin aircraft on a certin feild. I haven't flown that many 170's maby 10 to 15 diffrent 170's (and each fly differently! ) That is amazing to me but when you talk 50 years of people changing things, yea stuff can happen! The biggest differance is flap gap seals! aircraft without them have more lift, on landing, The ones with the seals are more like speed brakes. It takes a diffrent touch. My humble opinion would be take your aircraft out to a 5000 to 6000 foot strip and check out your own aircraft! Starting with what you are already comfortable with and increasing from there. Persenaly I would use sand bags not people (if you screw up real bad were only talking one fatility) (Just kidding, but just be on the safe side of anything you do!)
brad

[flyguy]

WAL OLE GAY HORNS "ORIETATION" MAY BE INSITEFUL FER SUM BUT I CAN TELL U I OPERATED OFF A 1200' GRASS STRIP JES CROSS FROM LEAVENWORTH KS! MAYBE THAT OLE FED PRISON MADE ME SUK UP INNA AIR FASSER AN BY THE WAY HIS OLE 46Y AINT GAIN AS MUCH WATE AS HIS B/A (big a---s)

ON HOT/HIGH DAYS WE DIDN'T DO ANY FLIGHTS WITH MORE THAN DEANA (AT HER PREVIOUS SVELTE 130#) AND OLE GAR (SKINNY 200#) AND AROUND 1/2 TANKS. POWER LINES - ABOUT 20' HI AT THE NORTH END USUALLY DICTATED A TAKE-OFF TO THE SOUTH - WHERE NOTHING BUT WHEAT OR SOY BEANS OFFERED COMFORT - AND SOMETIMES SOY BEANS WERE A HIGHER THAN PUCKER FACTOR ALLOWED!

COOL MORNINGS, COOLER AUTMN DAYS OR COLD SPRING / WINTER WERE THE DAYS WITH ZERO CONCERN. WIND OUT OF THE NORTH ABOVE 10 K MADE TAKEOFF IN THAT DIRECTION PREFERABLE BUT I DID OCCASIONALLY TAKE OFF WITH THE TAIL-WIND.

93D HAS THE CAL-TWIST PROP AND AT THAT TIME 8:00 TIRES. MY TECHNIQUE WAS TO ACCELERATE TO AROUND 50 INDICATED AND THEN POP IN THE FLAPS. WHILE STILL IN GROUND EFFECT AND BEGINING TO GAIN ALTITUDE - BLEED OFF FLAPS VERY GRADUALLY.

BTW I TRIED TO KEEP MY GRASS MOWED AT LEAST ONCE A MONTH AN - G A HORNY - I AINT A SAGE PILUT - IMA TOMATER OR POTATER- WITH SUM MUD BUGS SCATTERED IN - PILOT - MEANIN IMA ALLUS LOOKIN FER FREE GRUB! U GOT EENY?

[dgil]

Thanks guys for all the opinions, experiences, etc. A little more information about the field, the usgs map indicates it's at 1450 ft asl, give or take a few feet. I'm actually not going to be doing anything with it for a little while, I don't have a tractor yet so I had a neighbor cut the field for hay and he hasn't taken the bales back to his place yet. Also, he's going to bring over a box blade and level off a few bumpy areas. I do have a windsock up though! Gahorn mentioned weight, I'm good there, even though I've put on a few lbs as 40 rapidly approaches I'm still a good 25 under the faa's "average" person. There are a couple of 170's for sale here locally, a ragwing about an hour N of here and a B about an hour S, I'll be taking a look at them in the next few weeks and see if I can bum a ride in one or both.

Dave

[flat country pilot]

My numbers may not match Gahorn’s but he makes me think, think about what can go wrong. In my case, an engine failure taking of to the south over my yard could bend the airplane. I have thought about that and whether or not I could make a turn to avoid the yard? And I have used a local airport 4 miles away for giving rides.

I'll be taking a look at them in the next few weeks and see if I can bum a ride in one or both.

Good idea.

[GAHorn]

George if I recall your are flying a cruise prop on your plane.

I routinely use 10 degrees of flaps for takeoff to obtain a slightly more positive rate of climb for noise abatement and usually do not retract them till I'm about 500ft agl well above any obstacles. Didn't know I was a "sage" pilot. Thanks George.

Yes, that was my point.... my airplane, at my field, in TX summer weather...ain't a climber. But the figures I posted in blue are difficult to argue with. They are the factory performance figures for this airplane and I felt that if we wish to give truly useful information we must get away from purely anecdotal stories and offer the factory numbers.
When Jamie and I left Santa Fe for home, after the convention, we took off in the hot afternoon and deliberately measured our takeoff roll. According to the factory numbers, using Zero flaps we should have used about 3500' to clear 50' with ground roll of 1400'. (The temps were already 95F and the elev. of KSAF is 6300. We used the rwy edge lites as markers (they being 200' apart) and (brake-release/leaned method) we used only about 1300' to be airborne. We also met the 3500' at 50' of altitude. We were about 50# below gross wt, so my cruise prop apparently didn't hurt as much difference as I have previously imagined. The enroute climb was slow however, using 100 IAS for cruise-climb. It took many miles to reach 9500' ASL.

The B-model* book says using 10 or 20 degrees of flaps, that at 2000' elevation, the airplane requires 2250' to clear a 50' obstacle at 80-degrees F. The ground roll is 850'. By the way...that would be a new airplane using dry. level pavement. Grass would be worse.