Cessna 170A grass field performance

[Biscuit]

I'm thinking of purchasing a 170 A model. Just want to make sure I will be safe with this setup. 3200' grass strip with trees on both ends, 120' elavation and in Fl. so we have been having 100 degree days here lately. The aircraft has a stock 145hp and a 49 pitch prop. What do you guys think?

[Bruce Fenstermacher]

Not a problem at all unless you do something dumb like over load the airplane. The 49 pitch prop is a seaplane prop.

[edbooth]

We took off from a 2600 ft grass strip in our 53 "B" model sporting a 55 pitch prop with full fuel, four people and overnight bags....and....we made it. whew !

[4-Shipp]

Flew our 53 B off of 1800' grass, 1000' msl, power lines on the south end. big hill going south towards power lines. Stock engine with mid range prop. Never took off at gross over about 90 degrees but with 2 adults, full gas and a few bags I never felt like I was cutting it close. 3200' at sea level is great!

[3958v]

You should be all right. But still approach the gross weight limit with some care and aways be on the look out for soft sod and long grass as either one can lengthen the take off quite a bit. In spite of what any one tells you be careful. Bill K

[Bruce Fenstermacher]

Now for something a little more official. From the A model owners manual is the performance charts.

The chart is for a McCauley prop with 53 pitch. A 49 pitch prop will accelerate the aircraft to flying speed faster but cruise will suffer.

Not included with this chart is the asterisk info which says that for each 6 mph of wind velocity the takeoff and landing distance would be 10% shorter. Also note this chart is for no flaps. The manual says using 20° flaps would shorten the distance required but doesn't say how much. I also could not find it in the manual but generally a 10% longer distance is applied for operating of grass, this chart is for pavement.

So as you can see at gross with no wind on a 100° day at sea level on pavement with a standard prop you would use 2050 ft to clear the 50ft obstacle. Adding 10% for grass brings that to 2255 ft. You would actually use less because you could use 20° of flaps and you have a 49 pitch prop.

BTW I operate my stock 170A out of a 1800 ft grass strip one way in and out with a 3 degree slope to the departure end. Winds are usually a crosswind. We have a two story house to clear or fly around at the departure end. We limit fuel or passengers and have no problems but every operation requires attention. You do what you have to do.

[W.J.Langholz]

We took off from a 2600 ft grass strip in our 53 "B" model sporting a 55 pitch prop with full fuel, four people and overnight bags....and....we made it. whew !

When we had our 57 we would take off from the grass at home (2100') and it was fine. .......but I'm 2 of Ed and my son is 1 1/2 of Ed so we were about the same....

[Biscuit]

Thanks Guys, I appreciate all the responses.

[flat country pilot]

We have a 54 B model, stock engine, 54 pitch prop, 1280 lbs empty weight. 2200' grass strip with large trees on the south end, 1900' msl. No problems taking off over the trees with one passenger and very little wind. Don't take off in hot air, keep the grass mowed, and decide before it ever happens what you will do if the engine quits before you have cleared the trees.

[GAHorn]

... and decide before it ever happens what you will do if the engine quits before you have cleared the trees.

There's been a heated discussion on some websites lately regarding the 180-degree turn back to the field. It's all based upon imaginary concepts... so it's unlikely to produce any concrete/sound advice.... But I cannot help but feel it's got to be better to run off the end of a runway, decelerating with the brakes applied.... than it is to strike them while airborne with the stall warning blaring. For that reason, when flying small recips I always plan on rejecting any takeoff until insufficient runway remains ahead of me for landing... then I plan on landing straight ahead until I get to pattern altitude... unless there's a crossing runway/clearing which allows a simulated base-leg.

If one flys off of the same airfield regularly, then it's a good idea to make a few low-level observation-flights to develop your plan-of-action ahead of time, and to determine where/at what altitude your options (if any) exist. Don't wait until the fateful event to make your plan.