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Sportsman vs Robertson STOL Kit

Ive heard the gap seals for the flaps reduce effectiveness from a few people now. Any experience out there with adding or removing the flap gap seals?
My 53 180 had flap gap seals when I bought it.
Not sure whose-- the only documentation was a 1980 entry in the airframe logbook: "installed flap gap plates".
Having heard not very many good things (and some bad) about flap gap seals,
I decided to remove them from my otherwise stock wing about 6 months after I bought the airplane.
FWIW I didn't check the before-and-after stall speeds,
but I didn't notice much if any change in cruise speed, climb rate, or handling.
 
They were/are STC'd but never placed in production. I bought the plans and permission to install from the STC holder/designer. The droop system was electrically operated using a Cessna 172 flap motor. There is a micro switch on the flaps which sends a signal to the droop controls which tells the ailerons to be up when the flaps are up. They are activated by a toggle switch on the yoke. STC # SA1148SW They are approved on the A185E, I installed them on an A185F.

I looked up the STC on the FAA DRS (library) website, it's applicable only to the A185E model.
The limitations listed include "for amphibian version only" & "aileron droop for takeoff only",
as well as an aft CG limitation and a max weight limitation.

Unfortunately, it turns out that the STC is owned by Bob & Barbara Williams of Bush STOL & Avcon fame--
they are notorious for poor customer service and being generally non-responsive to inquiries.
 
I looked up the STC on the FAA DRS (library) website, it's applicable only to the A185E model.
The limitations listed include "for amphibian version only" & "aileron droop for takeoff only",
as well as an aft CG limitation and a max weight limitation.

Unfortunately, it turns out that the STC is owned by Bob & Barbara Williams of Bush STOL & Avcon fame--
they are notorious for poor customer service and being generally non-responsive to inquiries.
It took me a couple of phone calls. He admitted on my second call that he hadn't thought I was serious. He then agreed to sell me the drawings. There is a lot of labor in making the parts and in performing the installation. This can be classified as owner produced parts since they were made in accordance with the approved drawings. I amended the installation on the 337 for the A185F, the only difference from the A185E being the leading edge contour which is called for on the drawings. I flew them for 40+ years and never for a minute regretted anything about them. Since they are only approved for take off, the FAA approval process is relatively easy. They made no performance change claims. If it interests you, it would be worthwhile to talk to your local FAA about a single use for your airplane. As I've said, there is a substantial 10-12 knot reduction in take off speeds and also it climbs better with ailerons drooped and flaps up than it does with the ailerons up and flaps 10. I have tried it for landing, it makes the nose heavier. I never flew it into anywhere which would have needed the lower speed for landing.
 
Here's one which doesn't need approval for $6.97. There really isn't any gap which needs filling on the 180/185s.
I thought about that tape trick for a short test....but if it works then what? Some cheap tape deteriorates or detaches when exposed to sun and weather. The Sportsman aileron gap seal does help in my experience before and after installation.

Gary
 
I thought about that tape trick for a short test....but if it works then what? Some cheap tape deteriorates or detaches when exposed to sun and weather. The Sportsman aileron gap seal does help in my experience before and after installation.

Gary
Did you place the tape underneath where the sun doesn't see it?
 
Never tried the tape deal, just seen it done. The problem with a full seal is the potential for water and then ice containment. Snow or rain falls or blows then freezes along the hinge line and can enter the aileron cavity. The Sportsman seal leaves a slight gap that allows some drainage. Even if using winter wing covers water gets into that area if it daily melts then refreezes. Crunch crunch flipping the ailerons during preflight walkaround can detect and allow removal, or at least assure full travel. I'd not completely seal that gap up here.

Gary
 
Never tried the tape deal, just seen it done. The problem with a full seal is the potential for water and then ice containment. Snow or rain falls or blows then freezes along the hinge line and can enter the aileron cavity. The Sportsman seal leaves a slight gap that allows some drainage. Even if using winter wing covers water gets into that area if it daily melts then refreezes. Crunch crunch flipping the ailerons during preflight walkaround can detect and allow removal, or at least assure full travel. I'd not completely seal that gap up here.

Gary
A properly installed aileron has very little gap.
 
Not sure how much tighter this is than factory gap. Less is better but a gap is set.

Step #3: Aileron Gap Seal Installation: Installation drawings SPI-400, View A-A, sheet 2 of 4. While our blocks are drying in place proceed to install the aileron gap seals by drilling out the #3 rivets ahead of the aileron.
PICT0823_large.JPG

Step #3a: After drilling out the rivets remove the original stiffener material between the top and bottom skins and cut the aileron gap seal stock to length and insert into position.
Step #3b: With the trimmed aileron gap seals in position place the aileron in the full up position and set the gap to .020 between aileron and aileron gap seal and drill and cleco into place.
Step #3c: Remove aileron gap seal, debur, paint, reinstall, and rivet the aileron gap seals into position. Note: We commonly remove the aileron to rivet the aileron gap seal into position.
 
STOL mods at Vso 1.3 are wasted.

Limiting a Cessna to 20° flaps is sacrificing the airplane’s slow speed capabilities. Going around with full flaps isn’t a big deal. You should roll trim nose down and do some takeoffs at full flaps. It’s a useful tool. You’re missing what your plane has to offer!
I don't go anywhere that comes even close to needing anything like that. With NO flaps at 8000 DA the thing gets off in 1500 ft. That's way plenty for me. If I were going into 500 foot long strips at 11,000 ft geographic altitude, that might be a different story. But the 180 outperforms my need even when used conservatively - as I do. That's why I got the 180. I like BIG safety margins.

I do agree with you about the flaps though - I know it works just fine at 40 degrees. I consider it a non standard process that has little advantage in the arena I choose to operate in. I've done it in the 180 just to do it, but generally I like to keep within the envelope envisioned by the manufacturer. I have enough fun for me without going to the edges.

And yes maybe the cuff is pointless in my application, but it was there when I bought the plane and it certainly doesn't hurt anything. I do like landing more slowly.
 
Go do a bunch of stop and goes using different flap settings and measure your distances. More flap will provide slower landing speeds and a better view over the nose. Especially with your cuff. I bet you’ll change how you land. Two notches is for standard takeoffs. Lots of guys use three notches for short takeoffs. Float guys pull three to pop the plane off the water all the time. Full stop 40° flap takeoffs without re-trimming after landing will prepare you for a 40° flap go-around. It’s good training. It will require doing a pushup against the yoke. I can’t remember the last time I landed with less than full flaps or took off with less than two notches.

If Wagons had electric trim I’d use more flap for takeoffs. I’m surprised nobody’s ever done an STC to convert the trim to electric assist. It could keep the manual trim as a backup.
 
Yes an electric trim and fuel totalizer with GPS link would help. I wore out a set of wing flap tracks and a couple sets of rollers in a C-185. Lots of low level maneuvering about while doing pushups and leg extensions plus re-trimming, especially on draggy floats. Maximizing how far or how long we could stay airborne would have been great.

Gary
 
Electric trim in the 180/185 series is on par with the utility of an autopilot as both are net negatives. They add weight and complexity to the aircraft yet neither actually do anything to enhance aircraft capability. I put items such as these in the “pilot mod” column as they are typically installed to cover for the pilot (my opinion based on 40 years of teaching, instructing and evaluating).

When discussing opinion, it is important to understand the perspective from which it is drawn. I have flown my 180H for over 4000 well documented hours, (mostly on skis), with over 3000 of those hours loaded with 110 gallons at T/O, full survival gear, scientific gear and the scientist (in the back seat) while doing low level work for 7 hours straight. Never did I desire electric trim. Load the 180/185 with a more efficient and performance improving CG (hint, it’s aft) and you will reduce the demands and movements of the trim system. If flying is a workout, the aircraft is telling you that it is not in harmony with the laws of physics in which it was designed.

I did require more fuel along with precise fuel management to increase both range and endurance (as well as the 3190 up gross to stay legal). An Alaska SkyPod belly tank mated with an EI FP5 fuel flow solved that along with the Kenmore 3190 STC. No need for GPS interface, a simple watch does fine. These are three examples of modifications that increase aircraft capability for this specific mission.

As for the thread title, I am a fan of the Sportsman/Micro combination. These provide me with what I deem solid control authority in maneuvering flight while operating in the lower speed portion of the envelope, another of my requirements to effectively accomplish my mission. They do this while adding negligible weight and no complexity to the airframe. The improvements in takeoff and landing performance are welcomed, however, that is not my primary objective. I have the Cub for that requirement when needed. And yes, I flew this 180 for hundreds of hours before installing these modifications.

Wing extensions are often discussed. I did not extend the wings nor place aux fuel in the wings due to the moment arm and resultant reduction in roll control which is an indisputable fact of physics. This is a mission specific decision. There is a place for wing extensions, I presently run them on our Ag-Cat, different mission, much different terrain and maneuvering requirements, however, there is no fuel out in those extensions for obvious reasons.

Let the mission drive the mods. If the mod in question does nothing to enhance aircraft/mission capability, it is best to convert that allocated money into fuel thus improving one’s ability and proficiency. I include these thoughts with the objective of balance, demonstrating there is typically more than one route to the destination. The most important piece is actually knowing where one is going.

TR
 
Well said, TR. I operated one 1985 185 for ten years (literally to the day) as a working airplane, lots of load and people hauling, radio telemetry and wildlife survey work. Early on, I had a fuel flow computer installed, and one of the very first aircraft mounted GPS units. After that aircraft’s crankshaft broke, the plane was totaled, no pretty places to park.

Our Aircraft folks asked me how I wanted the replacement aircraft configured. My response was a panel mounted GPS and a fuel flow computer and Robertson STOL/Sportsman, in that order of priority.

I liked the trim system, call me masochistic, but as a working airplane, with frequent changes in configuration, I found that very powerful trim system to be a real benefit. I’ve always said the 185 is a muscular airplane. As such, that strength has to be manages with finesse, but at the end of the day, this pilot was frequently ready for cocktail hour and a bit of relaxation.
 
Speaking of trim, I was looking at a friends C172K,
it has the trim wheel mounted below the center of the panel in kind of a pedestal.
Looks much handier to use than the tunnel mounted trim in my 53 180,
esp if you have short arms like I do.
 
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