Spinners

[Wairau]

Folks

Can anybody provide any suggestions for substantiation of repairs to aluminium propeller spinners. I amagine the main issue are centrifugal out of balance forces.

Thanks

Graham Murphy

 

[Sparweb]

What happened to it, and what have you done about it?

Steven Fahey, CET
"Simplicate, and add more lightness" - Bill Stout

 

[Wairau]

SparWeb

We have been asked re the feasibility of repairing a spinner. So far I havent seen the damage (have asked for it). My question is more of a general inquiry as to what matters Engineering wise.

Wairau

Graham Murphy

 

[Sparweb]

It's not a structural member - spinners are more like fairings. The fact that it's spinning would lead me to consider the impacts of the damage and the repair scheme on:
1. Angular momentum
2. Balancing
3. Vibration
4. Aerodynamic loads (probably extremely small when compared with others)

1, 2 & 3 are interrelated, so watch out.


Steven Fahey, CET
"Simplicate, and add more lightness" - Bill Stout

 

[HSThompson]

Wairau,

Just a note on spinners. While it may not seem to be structural, some prop a/c have the spinner listed in the POH as "Required Equipment". Usually to allow for proper cooling of the engine.

What I am getting at is that while a spinner may not seem to be significant structure, you do not want to loose it during flight.

Therefore, do not take your substantiation lightly.

 

[thruthefence]

I have seen a "repaired" spinner fail, and take out the leading edge of the horizontal stabilizer.

 

[Nigel]

I would avoid repairing a spinner unless you are confident it can be balanced. The resulting virbaration of an unbalanced spinner is likely to cause cracking, fastener problems and maybe even propeller and engine crankshaft virbation problems. The point is, unless you know what the effects will be, I would just buy a new spinner.

Nigel Waterhouse

http://www.canamaero.com

 

[WKTaylor]

wairau...

Take a look at AC20-37D "Metal Propeller Maintenance" on the FAA AC website:

http://www.airweb.faa.gov/Regulator...rgAdvisoryCircular.nsf/MainFrame?OpenFrameSet

There are specific warnings regarding spinner affects on props. In general, it states that the prop or airframe manufacturers' guidance on spinner repairs is critical, to insure satisfactory prop operations, such as spinner tracking & dynamic balance. Discusses most elements of spinner structure. Does NOT provide specific repair guidance but does give insight to interaction with prop.

Regards, Wil Taylor