Cessna 337 with Robertson Stol Kit

[Alainb]

Hello to all
I am a pilot who flies mainly from Switzerland to Sardinia where we live part of the year.
I currently have a Cessna U206G that I will sell to buy a Cessna FT337GP 1974 Reims.
This aircraft is equipped with the Robertson Stol kit.
Are there any 337 owners who have experience with this stol kit?
Is it a real advantage? I often take off and land on relatively short fields like 600 / 700 m at an altitude of 1800 feet.
I have read that it requires a specific technique?

Thank you for your feedback and advice


Alain

[JimC]

I have owned and flown both an unmodified U206F and an R/STOL T337E, and I'd rather fly the R/STOL out of a short strip with the same load. The useful load is about the same on both planes, but it's harder to get to gross on the 206 because the tanks are smaller. The 337 may end up with a higher payload for the same mission because of the extra fuel.

There is NO QUESTION that I'd rather have the T337 over the mountains and water. Not only do you have the second engine, but the 206 loses climb performance very quickly at higher altitude on warmer days.

Do you have the Robertson STOL manual? It gives advice on technique for maximum performance. In short - land at stall speed, take off 1 knot above stall speed and accelerate in ground effect. The stall warning will be going off at takeoff if you follow book procedures. The deck angles at these speeds is extreme. Forward visibility disappears in the last few moments before landing, although visibility on the approach is good. Visibility on takeoff goes to zero as you crank the nose up and slowly returns as you accelerate. If you have an engine failure on takeoff between liftoff and Vxse, you'll have to put it down straight ahead. You can fly it without going to such extremes if you don't need maximum performance.

My manual says I can take off and land in under 400 ft at sea level. Note the book numbers for TO and landing are NOT at gross. I've personally never been that short, but I have tried very few max performance takeoff & landings at sea level.

600/700 m at 1800 ft altitude should be easily doable with plenty of margin.

Hello
I deeply thank you for your information .
I do not know yet if It is a manuel robertson . I am waiting the result of a pre buy next week I have also in mind another 337 but this one is in US .

https://skymaster.com/product/1977-c...essurized-337/

It is written it has a stol kit but there is no detail on whch one .

Thanks

Alain

[Alainb]

Hello
I deeply thank you for your information .
I do not know yet if It is a manuel robertson . I am waiting the result of a pre buy next week I have also in mind another 337 but this one is in US .

https://skymaster.com/product/1977-c...essurized-337/

It is written it has a stol kit but there is no detail on whch one .

Thanks

Alain

[JimC]

Originally Posted by Alainb

It is written it has a stol kit but there is no detail on whch one .

Thanks

Alain

Aside from asking the seller, there are 3 ways to tell which STOL kit an airplane has using just the internet:

1) Look for a detailed picture of the airspeed indicator. A Robertson STOL kit provides a new airspeed indicator with a much lower stall speed. The Horton kit does not.

2) Look for the 5 bolts protruding from the bottom of each wing outboard of the flaps. These are the mounting points for the bellcranks that allow the aileron droop of the Robertson kit. Robertson planes have these 5 bolts, Horton planes do not. This thread has an example in the last message: http://www.337skymaster.com/messages...ead.php?t=4077

3) Get a copy of the aircraft records from the FAA (this takes about a week in the US, I expect it's more in France.) Go to https://aircraft.faa.gov/e.gov/ND/ and request the records. The serial number for N62NA is P3370269.

I can't tell from the pictures of N62NA that are available online. It honestly doesn't look like a STOL leading edge on the wing. The tail boom fairings that are labeled "STOL" are from Aviation Enterprises and do not make the plane take off or land any shorter than stock fairings.

[Alainb]

It is so interesting to get all your advises... You seem to have a lot's of experience and I am happy to read you .
The N119XU (the one i am interested in in Europe) has the robertson stol kit but I do not see another Air speed indicator ....

The one in EUROPE is a Reims FT337GP 1973 , the one in USA a 1977 P midel do you know if there major improvement ?

Thanks

Alain

[JimC]

Alain,

N'hésitez pas à rédiger vos questions en français. Je répondrai en anglais.

I don't think there are significant differences between Reims and Cessna on the standard models. - the Reims FTB model has the hardpoint structures in the wing as well as the two additional observer windows in the lower door - but the Reims FT models are very, very close to the US models. I believe the French models have better corrosion proofing, but I'm not certain.

I suspect the original airspeed indicator on N119XU was replaced with a remarked one when the Robertson kit was added, and the replaced again when the panel was redone with Aspen. You can tell by the panel cutout above the indicator that it's not original. Robertson STOL did not add a second airspeed indicator - they replaced the original factory one. A Robertson STOL airspeed indicator will show a stall speed (bottom of white arc) of about 50 mph or 43 kts. Robertson kits haven't been installed in decades - the R/STOL kit certainly predates Aspen avionics. One other way to tell if a plane has a real STOL kit is to look for the small leading edge fence at the wing root where the STOL cuff meets the old leading edge. I've circled it in the picture of N199XU below. I don't think N62NA has that fence.

One other change in technique with a Robertson STOL kit is that your flap extension speeds for 2/3 flaps and full flaps are much lower, because of the added stress on the aileron cables. You have to get more creative when you slow down and start a little farther out. It's minor, but worth noting.

As far as N119XU vs N62NA, I'd put a deposit on N119XU right now. It looks great on the surface, it has low engine and prop times, it's in annual, it's flown recently, it still has the heated windshield plate, it has an updated panel, and it's already in Europe.

[Alainb]

Hello Jim,

I am impress with all your knowledge. If you come in Switzerland or in Sardegna Italy you are my guest.
I just receive the tecnical documents for the N119XU from 1986 until now. I just transmited them to the guy who will provide the pr buy .

Any special tips to check on the pre buy ?

So according to you the N119XU has a real Robertson Stol kit ? Anyway it should be seen on the technical files or it has been mounted from the begining ?

The history of the N119XU is a bit special as the plane stayed in the ground for years but the engines had been stocked properly according to the maintenance office.

Of course I would prefer the N119XU as he is close and easier to deal. For me the most important is the plane and engines ... paint and interior are nor my main concern.

I am very grateful for the time you dedicate to help me.

If you prefer you can write me on my mail sky@osud.ch

Where do you live in the US I would love one day to meet you ?

Warm regards

Alain