Kitfox ii 568 lbs ?

[Dravenelle]

I buy my first kitfox ii with hks

And i have a surprise when i check the weight of the plane 568 lbs empty

Is normal? On the kitfox web site say the empty weight is 450 lbs? Diff of 118lbs

If i put 36 lbs of fuel on each wing ,and 7.2. Lbs for,upper tank and my weight is 175lbs.

950-568-36-36-7.2-175= 125 lbs for copilote:(

What the solution.....put half fuel on my tank, increase gross weight , never fly with a copilot.

Dave

[Dave F]

a bit heavy -- but should work well

once you get over 700 they really lose perforamance

Check my youtube videos

show you how they should perform

[DBVZ]

568 is a little heavy for a 2, but your situation is not unusual for a plane with just a 950 gross. Full fuel solo, or something less than full fuel with a passenger. Not unusual at all. This is why you do a weight and balance, to know what you you need to adjust to fly.

Raising the gross weight limit is a bit more complicated as I understand it. It is a Major Change, and would require a new Phase I period of at least 5 hours to test it. You may also be expected to have some engineering basis to determine the additional load will not compromise safety. Perhaps not. I know of at least one Avid Mk 4 that has a gross of 1320, and the DAR let that pass without objection.

Odd thing though. I don't think the builder determined max gross is recorded by the FAA on any permanent record of the aircraft. Someone know different? And I understand a lot of builders leave the max gross line on the data plate blank to leave that up to the current owner. I looked at a Kitfox 5 with a blank, where the seller assured me it was LSA legal since it had always been operated at 1320 or less. Not sure the FAA would agree, since anyone could having flown heavier. The aircraft can certainly handle more than 1320, and if the max gross is open to question...

[Dravenelle]

I check with skystar if he can boost my gross weight.

I need a extra 100lbs. Is just for insurance ...if i have a accident with a groos weight over ...insurance don't pay.

[Dravenelle]

I check with skystar if he can boost my gross weight.

I need a extra 100lbs. Is just for insurance ...if i have a accident with a groos weight over ...insurance don't pay.

You say my kitfox is a bit heavy? What your weight of your kitfox ?

[Dave F]

I doubt you find anyone that will sign off a Gross increase.

A model 2 is 950 but heck who know where it breaks or deforms.

I can tell you that alot of the 4130 tube is thinner wall on the 2's than a 4

Here is one I flew yesterday -- under 500 lbs mod 2



BTW what engine you got -- I bet suberu : it heAvy .

[Dravenelle]

You think anyone accept to increase gross, with decrease number g

The normal g is 4g + with increase the gross weight the g decrease of 3.5 g

Sorry for my poor english , is not easy to explain that.

Dave

[rogerh12]

He is a previous posting I made on increasing the gross weight of a Kitfox model 4 (two ways outlined). I think this method of increasing the gross weight could apply to your model 2 as well:

A while back, I proposed building a Kitfox Model 4-1200 with a gross weight of 1250 lbs. I justified this because the current load specification of an ultimate wing loading of 7200 LbS (1200 lbs x 6 G’s) would become an ultimate wing loading of 5.76 G’s at a gross weight of 1250 Lbs, which still placed the kitfox within the “NORMAL “ category for wing loading as outlined in FAR Part 23. For example, if this was a certified plane and the Kitfox was designed to comply with the FAA specification for NORMAL category, it would need to operate at up to 3.8g’s, and be built with a safety factor of 1.5 (as outlined in FAR 23.303), which corresponds to a ultimate positive G load of 5.7. As mentioned above, at a gross of 1250 Lbs, the model 4 would have an ultimate wing loading of 5.76 G’s. However, having said all that, a 1250 Lbs gross kitfox was kind of boarder line. But now I have a better idea:

I noticed that the model 4 speedster has a shorter wing, and that it is rated with an ultimate load limit of 9 G’s at an operating gross weight of 950 Lbs (for aerobatics). This corresponds to an ultimate wing loading of 8550 lbs. If I figure on using the shortened speed wing, the kitfox 4 at a 1250 lbs gross would now have a ultimate positive wing loading of 6.84 G’s, which places it well with within the NORMAL category with a safety factor of 1.8. In fact, with this level of safety factory, the kitfox 4 COULD be operated in the UTILITY category of 4.4 G’s, and still have a 150% safety factor.

Note: the load limits are outlined in a document I saw on a previous posting. It is from a Denney news letter outlining the evolution of the kitfox, starting with model 1 and ending with the model 4 speedster. This document outlines the speedster as bring “capable of positive G aerobatics, ultimate load limits of 9 G + and 4.5 G –“. This is what I am basing my calculations on. My bird has the grove gear, and model 7 type noise wheel, so the gear should handle the extra gross weight increase. The news letter is from Denny, so I guess it’s accurate, but the news letter is not dated and I only have a hard copy (anyone got a link to the downloadable version ?). A thicker windshield is the only other structural change noted, outside of the shorter wing.

[Dave F]

Kitfox 2 @ 560 lbs + just NEEDS a diet.
What engine is it it?: This must be the culpirt.

Tube walls thickness vary alot from model 1,2 and up.

You can out down whadt ever you like I guess but it not rights.

DIET!!

If you want to fly heavier get a mod 4 or higher.

MOd 4 built light will wieght close to 500 lbs - 582
or about 600 lbs with 912

HArd to beat that combo.