dark light

  • lauriebe

Tech advice please!

For the past few years, I have been following with great interest, the rebuilding of VS Seafire FR Mk. 47, VP441, in the US. I have recently received from the restorers, Ezell Aviation, several photos showing the latest developments.

Both props have now been fitted to the aircraft. These have drawn comment from several people who have seen the photos. As these props are ex-Shackleton units, as is the engine, their original diameter is too large and they have had to be cut down. This has been done by cutting off a section of the tip of each blade. The squared off prop tips have drawn comment from those that have seen the photos.

I am no technical guru, and would never profess to be one. However, it seems to me that this is probably the only way to go. By cropping just the tips of the blades, I would think that it is possible to achieve a far better balance of all of them (exact amounts cut from each tip) and alleviate any possible problems later from blades that are not balanced. To try and remove exact amounts from the leading and trailing edges of the blades in order to give them a more pointed profile towards the tip might, I think, lead to all sorts of problems when trying to balance all six.

I would be interested in the comments of the technically minded members of the board.

Regards,

Laurie

Member for:

19 years 1 month

Posts:

525

Send private message

By: lauriebe - 15th September 2003 at 14:26

Thanks for that, Mark12.

Have just found the photo (Flypast, April 2002, page 8) of the Spitfire PRXIX, also in the US, that has been fitted with the same units. It also has squared-off tips to the props.

Regards,

Laurie.

Member for:

19 years 1 month

Posts:

9,127

Send private message

By: Mark12 - 15th September 2003 at 14:13

Even though they are metal DH props, I personally think they should have been profiled like the wood laminate Dowty-Rotol blades as fitted to the contra-prop Seafires. I don’t think this would be a big deal to the prop shop overhauling and certifying the blades. Reprofiling is quite a normal procedure along with individual blade and assembly, static and dynamic balance.

I can’t believe that there are any ‘end grain’ effects in cropping down. Anybody know different?

Mark

Sign in to post a reply