The International Cessna^® 170 Association

Hi everyone!
I’m a new TIC 170 member from Italy and I just bought a C170A.
The plane has and “old style” propeller spinner and i would like to change it for a conventional one.

Do you guys recommend any particular brand o you know where can I find one?

Thanks

Gabriele

Gabriele,

Congratulations on your new plane. Does it have an “N” number or is it an Italian registered aircraft? I ask because the rules for installing a different spinner may be different in Italy.

In my opinion, here in the US, it is a minor alteration to install the later model “bullet” spinner on a C-170A. You’ll find a link to Cessna Service Letter SL 7-24-53 which covers this alteration here.

According to the FAA website there are only two companies authorized to duplicate the 0550162-7 bullet-style spinner: TCB Composite Company and Aero Fabricators. TCB Composite show they have spinners available for various Cessnas, Pipers, and Grummans, but they only show backplates available for Pipers and Grummans. Both Univair and Aircraft Spruce show they have spinner p/n U0550162 available. Both websites say that these spinners have a FAA PMA (Parts Manufacturer’s Approval). The “U” on the part number indicates to me that it is manufactured by Univair so it’s strange that this part number doesn’t show up on the FAA PMA database. The O-300A and O-300B have 8-bolt flanges, while the C and D models have 6-bolt flanges. The bulkheads for the spinners listed above will not fit 6-bolt flanges.

Gabrielle, you should be for-warned that removing the screws that hold the top cowl to the bottom cowl easily removed with the skull cap spinner, are not so easily removed with the bullet style spinner. Yes there are tricks to do it with special tools and techniques. But compared to the skull cap, it is a pain.

I agree with Bruce. I switched back to the skull cap spinner for the reason Bruce mentioned and I love it that way.

Thank you all for the good tips.
My C170 has an experimental certificate here in Italy so I can install also non certified parts. But anyway….
I didn’t get the part of the screw. So if I remove the skull spinner, I’ll have to do major modifications to the spinner plate?

Gmonti91 wrote: ↑Tue Apr 22, 2025 7:05 pm I didn’t get the part of the screw. So if I remove the skull spinner, I’ll have to do major modifications to the spinner plate?

No. The spinner you call conventional is wider at the backplate and does not match your cowl. The spinner back plate will cover several screws theat hold the top of the cowl to the bottom of the cowl. You will need special screw drivers and techniques to remove your cowling without removing your spinner and prop. It is not impossible, but it is a pain.

Of course we are assuming your 170A has a cowling from a '52 or earlier 170. If you have a later cowl on your 170, you will be ok.

Ohhh, I got it now!

You’re absolutely right! I’ll be a pain remove those screws… the one just behind the plate, maybe 2 or 4.

Thanks for sharing those important tips guys!