Extended Flaps

Rebuild projects are a series of surprises. I just discovered the right rear wing spar of my PA-14 is bent. The web and caps are bent where the aileron bellcrank bracket mounts to the spar. Some substantial force came through the bracket. Also a number of the original ribs are in poor shape. As a result I am giving some thought to replacing the all the spars and ribs which gives me the opportunity to make some other changes. I am considering moving the ailerons out to the Crosswinds STOL Tips and extending the flaps based on several recommendations I have received here on this site. I have heard of two major benefits:
1. Additional lift
2. Lower nose on approach which is an issue on PA12/14?s.
What is people?s real experience with this setup on PA12/14?s? How much difference does it real make?
I talked at length with Ron Sullivan about his STC for this modification. I have several concerns.
1. Cost ? The STC calls for converting a set of PA-18 ailerons to flaps by squaring them off. This means buying a set and replacing the aileron hinges with flap hinges plus additional brackets, hardware etc.
2. Design ? The aileron bellcrank is moved outboard and is no longer supported by a compression brace putting more loads on the rear spar and the ribs. The aileron is shortened about 4-6?. The flap bellcrank is moved outboard and mybe in a stronger location but it will face much higher loads.
How well how does this all go together? Is there another STC for PA-14s that works better? It really seems to be a cost-benefit decision, and your experiences would be much appreciated. I currently have a 150hp ND engine, which may be relevant. I may swap for a 160hp at the next overhaul but I have no immediate plans for a 0-360 since I can?t get around the appearance of the Crosswinds cowling (just doesn?t look like a cub) which is the only STC for a PA-14.
Robert

PA 12/14

Robert,
I worked with Ron and Dave in the mid 70's when this stc. was approved. I held
hands with the FAA though the whole testing game. The flap hangers in the wing had
to hold 135 lbs. load, no problem. The weakest link in the system is the flap handle.
It will bend over in your hand before you can force the flaps down. We held the
flaps in the retracted mode and I pulled the handle until it bent. I have never had
any problems with the aileron bell crank loads and haven't heard of any. Yes they
do add to the performance, but it is up to you to deside if it is worth the money
and work. Good luck with your 12. Wayne

pa 14

Sorrry about that I ment your pa 14 Wayne

Flaps and Ailerons

Purcell: How's it going? I did just the opposit with my PA-14. It came with 8' flaps and 8' ailerons. I got a factory blueprint for the original flaps and ailerons from Cub Club and had Lee Buddi (Airframe Inc.) build a new set but used some of my original hinge brackets. Airframes still does this and will "rebuild" them to your specifications (any length, brackets where you want them) for $450.00 each for ailerons and $425.00 each for flaps. You could run them over with a dump truck and the price is the same. Airframes has all the jigs and uses all new parts except for maybe a hinge or two (they will even replace these if they don't pass for new) to call it a "rebuilt part". When finished you can't tell them from a new Dakota or Univair part. I flew my PA-18 with the long flaps and ailerons for 11 years and have taken it back to stock by way of a new set of Dakota wings. I am not a fan of "Butchered Up" wings. With all around bush flying in all kinds of crappy weather, stock wings work the best for me. The big wings were actually a pain in the ass at times. Crash

Are your Dakota wings stock? round tips, stock flap, ail., etc.

PS When the visibility is bad, slowing down gives you more time to see what the vis. allows.

Dave.

Excellent point Dave...........I learned that early on and have used it many times ( even, and more effective, in the Bonanza) when scud running is necesary. My old instructor used to say if you cut your speed in half you essentially double your visibility.

Yes.

Of course, Crash may have been talking about wind when he said "crappy weather".

Long wings can be a pain with a heavy x-wind. And also, who needs to land slow (airspeed) if you have a straight-in strong wind?? Also, long wings with droop tips tend to get the wing dropped by the droop tip shape when "side" slipped or otherwise yawed or flown uncoordinated with the top of that droop tip "seeing" the apparrent wind. It pushes the wing down.

PA-12 Driver Tim described Jerry Burr's Cub as a "KITE". It's light and will land and take-off really slow.......something you don't need if you spend alot of time on strong wind operations......although it broadens the operations envelope (landing and takeoff zone options).

Hey, how 'bout a Husky for strong winds? A guy I know that owns both Husky and SuperCub maintains the above viewpoint I described....."who needs slow-speed performance when there's wind to help?"

But if having to make one choice, I go for the long wing, slow take-off and landing, especially if used for floats, skis, big tires, or any extremely rough landing zones.......Oh, sounds like I'm talking about what we build Cubs for!!

Dave.

...........and BTW, another great article in NP Dave.........I never knew time on the ground doesn't count.

cubdrvr said:

...........and BTW, another great article in NP Dave.........I never knew time on the ground doesn't count.

Click to expand...

Chock to chock = Flight time...

Lift off to touchdown = aircraft, engine, prop (maintenance time...

Probably what Dave said in the article ...

Dave, the Dakota wings I got are stock and came with flaps, ailerons and 24 gallon tanks.

I do the one notch of flaps, 60-70 mph slow fly through crud all to often. Last Sunday I (and my dog) were coming back from Iliamna and in Lake Clask pass with 105 mph indicated airspeed, 50 mph ground speed on the GPS, 30' above the tree tops because that was the ceiling, heavy snow and fog, very rough air, less then 1/4 mile forward. Took almost an hour to get through that hell hole. I was doing a lot of praying and promised again never do it again. There is a God and he IS alive and well! Crash

We've all had our fun round Big River Lakes, coming outta Lake Clark Pass...my Garmin 295 saved my ass a couple years ago in the same place, while coming back from the hunting Season. God sure does look out for us low and sometimes "slow" pilots that push weather....Funny how a guy remembers to pray when he really needs it! Well, Greg, at least you and me didn't........Crash.
Andy

Has anybody considered installing wickerbill flaps (Gurney flaps) on the lower trailing edge of the regular flaps? Or on the lower trailing edge of the ailerons (they are sometimes used on control surfaces to reduce erratic pressure fluctuations). Wickerbills can sometimes increase lift by as much as 20% with minimal drag increase. Caution, there is also a possibility that they could cause catastrophic flutter on the ailerons.

How about on the upper trailing edge of the elevators to increase download authority at high aoa?

JimC

I was at Birchwood yesterday and spoke with a couple of "real" bush pilots who happened to be working on a Cub. The Cub had stock wings and I asked for their opinions about wings. They both said a stock wing with VG's was the best wing for their purposes. They also said they didn't need to go slower or land shorter than their stock wings were capable of. One of these guys had flown in 10 minutes prior. The AWOS reported the wind at 38. He said the flight wasn't bad. His GPS ground speed was 16-17 kts. all the way up the inlet. He said the scary part was taxiing through the tie-down area with a 38 mph crosswind. I'm not taking sides, just telling the story.
SB

Hey Stewart, great story. I used to do search & rescue flying in a J-3. I'm not as good as you guys are, but I don't think super slow flight is abut need; it is about technical challenge. I once watched my foster brother set our J-3 down while drifting slowly backwards. Fun on occasion, but not something you will be doing every day (I've never done it myself).
All the best,
JimC

Opinion from the other side:

A "real" bush pilot friend of mine with an extended wing and flap PA-12 built a set of extended PA-18 wing and flaps for a "real" bush pilot friend of his. The friend must have dinged a wing, Because he had to install a stock wing set for a time. He kept telling my friend that he would be really happy when the extended wings were ready to go back on. He loves them. Interesting to note that the guy operates on the AK. peninsula which is known for its high winds and sometimes crappy weather during hunting season.

Once again, personal preference rules. Go fly the configuration before you buy it. Even taking the advice of the guy you respect the most may leave you short of your intended goal. See if YOU like it before commiting to it.

Dave.