MK2 empty weights and weight & balance

[Smiffy]

I'm slowly putting a mk2 582 back together and have just spent a few hours going through the weight & balance calcs passed on by the previous owner.

The empty weigh he had was 510lb with CoG 12.9" aft of datum.

The kitfox handbook suggests an empty weight of 440lb. Any ideas where on earth 70lbs could have come from?

She was recovered with Polyfiber in 2006 which is when she was last weighed, but I don't have any previous calcs other than one letter suggesting 617lbs which was being queried at the time!

She will be re-weighed once back together as some changes have been made.

Oversized battery 16lb replaced with smaller 11lb one, and moved from behind seat to the firewall. Battery box lightened.
Aluminium firewall mounted header tank replaced with plastic tank behind RH seat (sb29). She has 1 x13 gal and one 6 gal wing tanks
Radio replaced
Repairs to cowls


The doors are fully glassed. The built manual suggests 0.030" lexan, but that is based on half fabric. What thickness is everyone else using for fully glassed doors? Mine need replacing and are currently 0.060". Thinking there might be a pound there!

I expect her to be a few pounds lighter than previous but not loads, any thoughts?

I've not named her yet but "FatFox" is looking possible!

Regards
Kevin
UK

[KitfoxSS]

Welcome!

I'm in the process of doing the same as you.
My mkII weighed in at 530lbs but I expect to have it cut down a few pounds with the work i'm doing.
510 is respectable. The 440 number is the bare, bare minimum weight. No paint on the fabric, only the basic instruments required by law installed, no radio, no antenna. It was as light as they could get the plane so they could advertise a very low weight. If you do a little searching here on the fourms you'll find old threads of people talking about how their mkII's and III's ended up weighing and it seems these planes averaged in the 510 to 530 range with the Rotax 532/582 package.

.03 is just fine for the side doors. Mine was .09 so I saved some weight swapping them out for .03.
Best of luck on your build!

[Smiffy]

Thanks KitfoxSS

Never really considered it as a bare bones weight, so if 510 - 530lbs built is typical I'm happy.

Hoping to be ready for weighing by end of next month so will post up results. Having said that, I planned to be ready for end of March and April as well!

Thanks for note on Lexan, sheet of 0.03 ordered.

Have you got much more to do to yours?

[KitfoxSS]

I'm a good 1-3 months out till it's flying again.
But it's getting there.

[Smiffy]

Hi Folks

probably should have followed this up with a bit of a progress report!

We've just weighed it and I think I'll officially be christening this one as "FatFox"! I'll confirm later what the empty weight is, but already looking at what else I can do !

Having a bit of an issue at the moment over weight and balance calculations with my inspector (UK)

We have different figures for calculating the moments for Pilot, Passenger and Fuel tank.

All I have to go on for these is a previously calculated, hand written W&B. Does anyone have an official figure?

I have

Pilot - 15.8"
Passenger - 15.8" (obviously!)
Fuel - 15.97" (wing tanks with plastic, rear header tank )

Are these correct?

Cheers
Smiffy.