So much for ultra light...

Hi all,
Well, I weighed 727MM yesterday, and I must admit I was a little disapointed.
Empty weight with simple glass panel, no lights, no paint, 0-360, Catto Prop, was 953 lbs (certified scales). I was hoping for 15-20 lbs. less than that.
The good news is the empty CG is .2" forward of the forward limit, so when I add fuel, me, and a BIG passenger, I'm still within limits, if I certify it at 1625 gross.
Question is, has anyone certified an RV-4 at 1625?

Merle,

Even though you didn't "make weight," I'm sure your 4 will fly much better for all of your effort. Besides, if you (or your passenger) gains any weight, you'll still be covered.

So look at it this way Merle - if you REALLY want to be 15-20 lbs lighter, you can take the pounds of of YOU and have the bonus of keeping the AME off your back. Of course, if you're already at ideal weight, then disregard...and take 3 gallons less fuel....

Gross Weight

There have been other threads on this subject, but the upshot is that gross weight is a calculation based on flight loads and the strength of the airplane (wing spar, landing gear, etc.) I would not change the recommended gross weight arbitrarily by just picking a number. On the other hand, if I was going on a long cross country, and had a little extra weight at take off, I wouldn't be afraid to go, expecially in smooth weather. But a 5 g gust at cruise speed over gross is not a good thing. My 2 cents.

N999BT said:

But a 5 g gust at cruise speed over gross is not a good thing.

Click to expand...

Why not? I'd more worried flying light in this case. Let me remind Force = Mass * Acceleration (F = m * a), where a is the gust. If you have smaller mass, the F becomes larger while you are overweight the F becomes smaller.

Landing is another thing though.

But in any case, everyone going to exceed the given numbers of Van's, should really be able to justify and understand what they are doing. This has been discussed already too many times.

HUH?

Pirkka said:

Why not? I'd more worried flying light in this case. Let me remind Force = Mass * Acceleration (F = m * a), where a is the gust. If you have smaller mass, the F becomes larger while you are overweight the F becomes smaller.

Landing is another thing though.

But in any case, everyone going to exceed the given numbers of Van's, should really be able to justify and understand what they are doing. This has been discussed already too many times.

Click to expand...

Dr. Calandra is rolling over now I'm sure. If either factor on the right increases then the left side of the equation increases as well.

Bob Axsom

Weight a minute...

Merle,

Van's guidelines for GW were always sufficient for me. My first question to you is why would you want to exceed them? The numbers on the airplane are still impressive compared with any airplane of equal HP and weight. My advice, keep it stock, keep it light and travel light.
You'll enjoy it much more.

Smokey
http://www.vansaircraft.com/public/rv-4per.htm

Bob Axsom said:

If either factor on the right increases then the left side of the equation increases as well.

Click to expand...

My bad... ment to refer Va's formula, but in a hurry mixed things.

So I still claim, that it's necessarily not bad thing to have overweight, in case of gust. Found a good discussion relating that matter: http://www.airlinepilotforums.com/flight-training/44778-explaining-va-maneuvering-speed-3.html

So if flying lower weight than max. gross your Va will be less as it's usually given at max. gross. Therefore flying over the given gross will actually make plane safer (in one way...).