The International Cessna 170 Association

I have a Bush STOL kit on a 53B model. Does the kit change the spin characteristics of the airplane compared to a stock 53B?

Good question, the Horton prohibits spins after install

The original STC for Bush was SA1371SW.

From an NTSB accident report:

According to STC SA1371SW, an airplane with the STOL kit installed must not be placed in a spin and must contain a placard prohibiting spins. Discussions with the Cessna Aircraft Company revealed that a similar Cessna single-engine airplane, with a leading edge cuff, similar in shape to the Bush Conversions cuff, was stall- and spin-tested to evaluate its performance at low speed. During this testing, conducted by Cessna around 1970, the airplane could not be recovered from a spin without a spin chute. As a result, Cessna elected not to offer a STOL option for its single-engine airplanes.

Here's the report summary: http://www.ntsb.gov/safety/safety-recs/ ... 77_180.pdf

I realize that spins can be fun. But do you really want to subject your 65-year old modified airplane to the trauma of spins? Are you absolutely certain your W&B report is sufficiently up-to-date and accurate to be in utility-category? Are you a wannabe test pilot without a blow-off-door, spin-chute, and survivor-insurance?

Cessna test-pilot WD Thompson described a spin-test on an ordinary Cessna that would not recover from a spin and nearly killed him when it was discovered the leading edge of the horiz stab had been assembled with jigs which had been relocated from one factory to another without re-calibration. Close, visual preflight inspection could not distinguish the difference. Are you certain all of your airplane's flying surfaces still meet original specification?

Don't get me wrong, I'm not afraid of spins in aircraft that still meet spec and are properly maintained. I was trained and am experienced in mild aerobatics and for a time worked as a production test pilot (not engineering) for a major airframe mfr. I will not intentionally spin my 170B despite the fact it underwent extensive and professional restoration by Textron (Cessna) people on their own time. If I want to "play", I rent or borrow and aerobatic qualified aircraft. Not trying to be didactic,... just trying to "preserve and promote".

I dunno, George. 170s appear to be pretty good aerobatic performers.

https://www.youtube.com/watch?v=VtWdI68zGVo

Thank you George for the information. I had been unable to find any flight data on the subject.

Is this true for the Horton STOL kit as well?

Ryan Smith wrote:I dunno, George. 170s appear to be pretty good aerobatic performers.

https://www.youtube.com/watch?v=VtWdI68zGVo

Well, Ryan...there are TWO things noteworthy about that demonstration:

1) I notice that despite the wonderful aerobatic performance.... NONE of the maneuvers were SPINS.

2) The airplane is RED!

lowNslow wrote:Is this true for the Horton STOL kit as well?

I think the only way to really answer that is to look in the STC paperwork.

In a word "Yes" for the Horton, if desired I'll upload the document

c170b53 wrote:In a word "Yes" for the Horton, if desired I'll upload the document

Our glider club has a C150-150hp with the Horton kit and it is not placarded for no spins, if you could either send me an email attachment or post it here I'd greatly appreciate it.

If CESSNA tested STOL kits and found their STOL-equipped single engine airplanes could not be recovered from a spin without a spin-chute.... do you really want to spin it, even if your STOL kit doesn't have a placard against it?
Do you want to slip your B-model with full flaps because your next-door neighbor's brother-in-law said he's done it lots-of-times...?
Come ON Guys! I do not want to have to start handing out Darwin-Awards at conventions!

This does not have much to do with a 150 but it does explain the limits on 170 with a Horton Stol Kit installed

My '53 B has the bush STOL and is placarded "no aerobatic maneuvers including spins approved". I believe the STC states it is a required placard.

lowNslow wrote:...
Our glider club has a C150-150hp with the Horton kit and it is not placarded for no spins, if you could either send me an email attachment or post it here I'd greatly appreciate it.

gahorn wrote:If CESSNA tested STOL kits and found their STOL-equipped single engine airplanes could not be recovered from a spin without a spin-chute.... do you really want to spin it, even if your STOL kit doesn't have a placard against it?
Do you want to slip your B-model with full flaps because your next-door neighbor's brother-in-law said he's done it lots-of-times...?
Come ON Guys! I do not want to have to start handing out Darwin-Awards at conventions!

George, just MAYBE Karl is looking for information so he can see that the 150 gets properly placarded??

cessna170bdriver wrote:
George, just MAYBE Karl is looking for inflation so he can see that the 150 gets properly placarded??

Yes, just trying to determine if we should have a placard and no I don't need to spin it.