Thread: Confused over "Empty Weight"

I'm a fairly new student pilot, and I've learned that "Empty Weight" includes unusable fuel.

However, the CTLS AOI Weight and Balance sheet does not include the 2 Gallons of unusable fuel ( it states specifically 0 Gal ) in the calculation of Empty Weight.

It would seem to make sense that the total fuel would then be used in W&B calculations.

So this an exceptions to the definition/rule?

Thanks folks!

When draining the fuel for weighing, all the fuel comes out. In flight a slip or skid might make it harder for all fuel to drain, so some fuel is considered unusable for flight planning purposes.

John

Thanks for the reply John.

I understand both points you are making.

I think Flight Design is in fact computing the "Empty Weight" will all fuel drained, however this is rather more like "Zero Fuel Weight".

According to FAA-H-8083-1A "Aircraft Weight and Balance Handbook",
Empty Weight: Weight of the airframe, engines, all permanently installed equipment, and unusable fuel

Perhaps the CTLS being an LSA ( not 14 CFR certified ), or the term "Empty Weight" not completely standardized, either of which I'm just guessing, may account for the difference.

Its not zero fuel weight. I think that is the weight above which all load must be fuel. WF

Well WF, so it's not zero fuel weight either.

Hmm, I may simply accept Flight Design's usage, while realizing they're different. This is going to nag me though

think of it this way, unusable fuel generally remains when fuel is drained. the ct's unsuable fuel is really usable, it is more an allowance for a little bit of slipping.

As a Washingtonian who's yet to see a CT "live" :) I have a question about "useful load" of SW and LS.

I see LS is being quoted with a lesser useful load than SW in various places. Is this true? Is this because of a different geometry or equipment differences?
Is LS worth the loss in a "useful load" as compared with SW?

I'd be very interested to hear both from SW and LS owners of their quoted in AOI and/or actually weighed "useful load". -

Thanks!
Alex.

Alex,

The LS weighs a slight bit more then the SW hence the less useful load. It's not by much however and of course you can put a little less fuel in and carry more. Full tank takes you 1000 miles, 1/2 five hundred. I'm sure you'll get more answers here as the post gets out...

In the mean time if you want to see one or talk to the Northwest Rep - he's a great guy - his name is Chris Eichman and his phone number is 503-272-1515.

Welcome,

Roger H

older ctsw's are lighter then newer ctsw's. my early 06 weighs 719lbs and its well equipped.

Originally Posted by CharlieTango

older ctsw's are lighter then newer ctsw's. my early 06 weighs 719lbs and its well equipped.

Thanks, CharlieTango - I appreciate the number. This leaves you with a very respectable 600+lbs of a useful load.

On the other hand I've seen new CTLS consistently quoted with only 540lbs of a useful load - where did 60lbs go? Loss of 60lbs in a LSA can mean significant loss of applications. ( For ex. loss of all needed luggage for 2 on a x-c trip or third of all fuel/range) On top of that these heavier CTLS-s seems to be only CT model offered new by dealers... Did they completely stop importing/making much lighter CTSWs? Was something wrong with them?

The situation with "useful load" of LSAs on the market is currently so vague that it is extremely frustrating for prospective buyers looking to optimize the plane performance wrt useful load. I think for LSA industry - all configurations price lists should be mandated to carry not only prices but total installed weights side by side.