i have a CG extra 330 with a DL-50 on it and i did not have a spinner on it because i liked how it looked but i have been getting all kinds of crap about how it's not compling with AMA rules and it's not safe, so i put a spinner on it and all i have to say is this thing is going to punch a 3 inch hole in your head if it hits you now. what i want to know is why is there or is there even a rule about this. if you get hit with a 14.5 pound aircraft it's going to mess up no matter what. does anyone els agree with me or am i the only one who likes the look of a prop hub with 4 bolts?

Did they show you in the safety code where a spinner is required? I have not seen
such language in the code.

I believe the 'safety nut' requirement was used for competition models....someone feared your shirt sleeve or some piece of clothing would get snagged on the threads of the crankshaft and pull you into the prop. I agree, it is NOT in the safety code, but can be found somewhere in the competition rules.

ya thats what i thought i dont like how it looks with it. and it cost me $51.70 i guess i should have looked it up but i'm going to print off the rules and show these people

Straitnate, i think the spinner rule is in IMAA rules, not AMA. Me thinks someone got the two confused.

BTW. The purpose is to restrain the prop nuts. Keeping things from flying out of he prop and hurting someone.

There is no general AMA safety rule that requires a spinner or special prop nut. As one person pointed out one set of competition rules do require at least a rounded nut, but this has nothing to do with day to day flying.

Regards,

Steve Kaluf
Technical Director, AMA

There is nothing that I can find in the IMAA documents http://www.fly-imaa.org/imaa/about/bylaws.html that mandates a spinner.

Red, you may be right. From the site you posted i found the safety code. Nothing in there about a spinner. OTOH, When i built my Top Flight GS P-47 three years ago, included in the build instructions was a copy of the IMAA rules for competition. In included the need for a spinner or other type of prop nut locking type of device. It is possible that they have dropped it or top flight is just dissemination old information.

Like others have said, it's not in the AMA rules. But, I will disagree, I think an Extra looks silly without one.

Do you happen to still have those instructions. If so can you scan them. I would like to have for file.
You can send to [email protected] if you would please.

AH!!!! The old "AMA SAFETY PROP NUT" argument rises again........Just about everything already posted is right, I think. The only place in AMA rules IS in competetion and then only one, not even mentioned in generals rules.... In that requirement is the shape of the spinner, a ratio of the lenfth and dia at the base and a radius at the tip. Some of the pointy ones out there now would not be allowed. I personnaly use a higleys hub or spinner to make use of a starter eaiser.... BUT!!! Your club may have such a rule if they so desire,could they not?

i'm going to check to see if it's in the club rules and bring it up at a meeting for change if it is. it's on a 50cc so you dont need a starter and i like how it looks

straitnate14, It seems like each few weeks I post these basic rules herein and still all your advisors, heck even Ol Steve K. up there if he really means "ONE" and good ol' anonymouse with his ratios, etc. all flunked the quizz.

Lots of folks depend on memory which is the first thing to go and I forget the second thing:

Pattern:

6.5. All planes must have rounded prop
spinners or blunt faced hubs such that no
propeller shaft protrudes. Rounded devices shall
have a radius of point not less than three (3)
millimeters.

Pylon:

7.4. Spinner or prop nut. On all
aircraft, the front end of the engine crankshaft
shall be covered with a rounded spinner or safety
nut. A spinner with a flat, oval, or Allen (hex)
head of at least 3/16-inch diameter on the front
fulfills this requirement. The use of a spinner of
any size in Quickie 500 or Sport Quickie shall
not be considered streamlining of the engine.

[RC Scale (and CL)

2.4. All planes entered must have
rounded prop spinners or some sort of safety
cover on the end of the propeller shaft (such as a
rounded “acorn nut’’).

There may be others but why must I copy more right now? Don't you all have the rules on your confuser?

If you like that big gas burner without anything purty on the front of it, heck it's yore flyin' machine, so fly it as you wish,
unless of course your club has some rule, then you're caught short. Sorry 'bout that one!!

the main reason i like it witout a spinner is because i have a CG 77inch extra 330 with DL-50 mounted to it, and the back of the prop sticks out about 3/4 inch from the cowl, it doesnt stand out without a spinner but with the spinner it's like hey my engine is stiking out to far come look at how bad it looks [:@] or at least thats what it tells me

HOSS!!!!!! Picky..Picky..Picky.... BUT a comprehensive answer, it does clarify the point. The memory thing, I don't trust mine anymore and I just related what I remembered (a mistake)about the radius of the pointy end of the spinner / nut. My real point is that in the "general" rules there is no requirement for a non existant "safety prop nut", meaning other than those specific requirements cited.

I really don't understand the issue here except if you put a nut (or some other spacer) on between the spinner backplate and the engine. With a spinner backplate flush against the thrust washer there could only be about 1/8" (the thickness of the backplate) difference in the prop position. From the photo it appears to me that either the engine is too far forward or the cowl is too far back. On my 80" Midwest Extra 300XS there's less than 1/4" between the cowl front and the spinner backplate. My spinner, by the way, is Tru-Turn.