PA28-140 Cherokee - Flaps for Takeoff with Hershey Bar Wing

flycoopfly

The owner's manual states no flaps for a regular takeoff and 25 degrees (2 notches) for short field takeoffs and short field over a 50' obstacle. It does not mention 1 notch of flaps for takeoff at all.

I have been experimenting a bit, especially since the airport elevation here is 5000'. It is a nice, long runway.

Would anyone else like to share their experiences with 1-notch and 2-notches of flaps for takeoff? Thanks in advance.

Jmcmanna

I played around with using a notch of flaps on takeoff in my Hershey bar Arrow. The plane really pops off the ground. In the end, I went back to no-flap takeoffs because I didn’t want to add another thing to do to clean the plane up after takeoff (along with gear, throttle, prop, etc....). I rotate 5 knots faster and have about the same effect.

flycoopfly

Thanks for your reply Jim. I appreciate hearing your experience.

Harley Kleemann

I have the tapered wing on my Arrow. One notch of flaps does help it get off the runway a bit faster. But, just as Jim has shared his experience, I also went back to no flap takeoffs. Just one less thing to have to juggle.

flycoopfly

Thanks for your reply Harley. I guess I was a bit surprised to read in the POH that 25 degrees of flaps is recommended for short field takeoffs. It seems a bit much, but I will do some more testing the next time I am solo.

Harley Kleemann

Piper flaps are different than Cessna flaps. Cessnas with those huge barn door Fowler flaps create drag, but they also create lots of lift. Piper flaps create a little lift, but mainly create drag.

jimcurns

Part of the time my Cherokee 180 is kept at my home grass airstrip and part at the local airport. On grass or short fields I always use the 25 degree setting. It does help it pop up quite nicely, and I just ease the flaps back to 10 degrees once up far enough to be appropriate. At my weights and power setting, it climbs very well with 25 degrees out until safe to retract them. I do sometimes use a one notch setting on paved runways.

A friend taught me a trick I have not used for soft field take offs. Use no flap as you accelerate, then at near flying speed pull all three notches. The plane will leap out of the soft stuff, then slowly retract a notch and fly to greater altitude before retracting the rest. I am not recommending this, but I have seen it work. It's a bit like watching someone who fly's a lot of back country STOL and has learned his or her airplane very well. They sometimes have a hand on the flap during the flair to land to aid in ultimate control of the wing. Pretty advanced stuff which is why I am not condoning it, but I have been around long enough to know there is often more than one good way to do something. Art Mattson, of Cherokee mod fame was one of those guys who learned to do this type of thing to increase the planes ability.

When I owned my Cessna 150 we experienced the same debate. There were those who would strenuously preach we would all die if we didn't do everything exactly according to the book. The book was mostly right and not to be ignored. There are however a few things the book doesn't mention. For example, greater degree of flaps at a much lower takeoff weight than gross in cooler weather. It would have been too complicated for them to graph every possible scenario so they didn't mention it, and I can't blame them.

Disclaimer, a 140 may not have the ponies to do this, where a 180 does.

Jim

griff390

Asked one of my CFII's the 10 degree flap question years ago on a BFR checkride. His response was "It will definitely work, but it's not in the POH. So let's say you have a problem during takeoff and go down. When the investigators find the flap handle was in a non standard 10 degree position, what questions do you think they're going to ask you?" I realize for liability he's obligated to answer by the book, but his point was well taken.

Years later I tried it (PA28-161), and my results were just as good as others have mentioned. Did it spur of the moment and ran into the exact problem others are concerned about. Shortly after takeoff the airspace got busy and I focused on flying. On my way to cruise altitude, the plane was a bit sluggish and wouldn't come up to speed. You guessed it, the flaps were still at 10 degrees. At 10 degrees, the handle is only a couple inches off the floor, so its easy to miss during a flow check, and since I tried it on a whim, it was never put on my mental checklist. These days if I'm in an environment where flaps are required, I use 25 degrees. Works great, and you won't forget it because the handle position and difference in performance are obvious.

flycoopfly

Thank you Jim and Griff for your comments. I really appreciate your input. I look forward to testing a few different things on my next solo flight. I'll report my experience back on this forum.

Scott Sherer

I can't wait to here.

KuemmFly

I have a ‘73 180 Challenger (pre-Archer with Hershey wings) and occasionally I use 10 degrees for hot and heavy operations with good result. I already have a flap climb check list item because also it can be easy to miss retracting the POH 25 used for short/soft.

RayMadron

I had an old instructor show me the way Jim was doing accelerate and than right before rotation add 10 degrees of flaps. I was flying out of a 1600' grass strip in my 140. Moved to a 2000' paved and don't use it anymore.

Jmcmanna

1600’ grass strip!! I don’t think I’ve made a turnoff in the first 1600’ of any runway in the last year and a half

krelsey

I own a 67 Arrow and previously owned another 67 Arrow and 69 Cherokee 140. I use 10 deg. of flaps for takeoff and a minimum of 25 deg. for landings. I do this mainly for habitual practice as the auto gear extension system on my current Arrow has been removed and the modification includes a sensor/switch on the flap tube that actuates the gear warning horn when the throttle is retarded with the gear up and flap settings below 25 deg. The habitual practice of using flaps for both takeoff and landings helps to insure that I do not land with the gear up. Just my practice.

bearair70

Back in a former life, I was flying a PA28-140 and landed at a state park in western Kansas that had a 3,000' grass strip. On takeoff, I elected to "drive" uphill (about 1 1/2% grade) since the wind was from that direction and taking off downhill involved a 40' HAM radio beam antenna on centerline. I used the "pop 10 deg of flaps" at rotation, along with bouncing my nosewheel into a prarie dog hole and by doing so, lowered my flyable airspeed and remained in ground affect until I had reached about 5 kts above rotation speed. I then retracted my flaps slowly. The density altitude was about 4,000' and I was about 200# under gross with camping gear and one pax. I fly a PA-28-235B and have noticed that if I take off with 10 deg of flaps, the center of lift moves aft and the plane has a tendency to want to "wheelbarrow" before rotation. I have found that a slick wing on takeoff at a density altitude of 7,000' results in a ground roll of maybe 1000'.

P47Lucky

I have flown the 140 and the 235. I always use a notch of flaps. It seems to help my birds get into the air a little quicker

MikeJJ

In the interest of preserving the wisdom of our ancestors, I will relate this tidbit revealed to me by an instructor who had been flying before Eve was a bone: “If you are ever not sure of what flap setting to use on takeoff (should you need flaps), take a look at the aileron max deflection and match that with the flaps.” Not unreasonable, if no other info is available at the moment.

Regards,

Mike

Scott Sherer

I've been reading the messages that our members have been posting and I have a slightly different take on it. Everyone is entitled to do it their way but here's the way I do it. About four years ago I got my Commercial license (multi, instrument). My instructor told me that the biggest difference between being a private and commercial pilot is attitude and organization. So for me, having been trained as a Commercial pilot, I try and do my flying very precisely and "by the book". I'm not a test pilot and if it's not in the POH I'm not doing it. No experimentation, just safe, predictable flying. But that's just me. You do it your way!

arrow76r

"precision" was what my flight instructor drilled into me when I got my commercial license in 1972. Granted, I took the practical test in my C-150 BUT nevertheless, precision flying even in that "kite" is possible! That meant "by the book", just as Scott said.

MikeJJ

I have a general comment about always doing what the POH says, not strictly flaps related. Some aspects of the POH are age sensitive. Case in point - published take off distance, obstacle climb, fuel burn, etc., all heavily influenced by engine condition, airframe rigging, aircraft weight, and pilot technique. The numbers in the POH were computed with a very proficient test pilot when the airframe and engine and prop were brand new. Not a good idea to operate right at the POH published limits in older aircraft unless your airframe, engine, and prop are in like new condition, your empty weight is right on, and you are as sharp as you were the day you passed your check ride 😬. While the pilot in me says the manufacturer knows best so follow the POH, the commercial pilot in me knows the devil is in the details and not everything in the POH is applicable "forever."

arrow76r

True! For example at my home-drome (6880 MSL) a full flap landing with just me in my straight wing, "short stabilator" Arrow simply begs for an "arrival" rather than a "landing". So 2 notches is much better. Take-off with 1 is ok but 2? Don't think so. And due to removing the "auto-extend" gear retract system, 2 notches with full throttle blows the gear horn if I retract before reducing down to one notch (or zero). Not sure why that was done.

kzadora

Jim, presumably as means to warn you if you forget to lower the gear down. For my silly brain another reminder is a good thing.

My POH says 0-25 degrees are “approved” for takeoff. 25 degrees is prescribed for short-field takeoff. Normal takeoff checklist says “flaps set”. Not zero, or any other number, just “set”. My interpretation is, the PIC is to decide which setting in the 0-25 range is best given takeoff conditions: runway, wind, aircraft loading etc. I usually use first notch for normal takeoff.

CherokeeCF-BLG

Thanks for all the interesting opinions. I am currently flying a 1972 PA28-140 with a zero time 150 hp engine out of a 2,000 ft grass strip with 50 ft Pine trees on the runway ends. I have the Art Mattson VG kit installed & Horner wingtips. My prop is also 1 inch finer pitch. I am using 2 notches of flap for take-off.