Weight Questions

[f1rocket]

Originally Posted by f1rocket

2) My Rocket will cruise at the same speed as a RV with LOWER fuel flow.

3) My Rocket will cruise at least 10 KTS faster on the SAME fuel flow.

I've had a number of people respond to me privately saying, in essence, I'm full of "stuff" with regards to my comment above, so I'll elaborate.

I have to admit that the actual flight testing to prove the above statements were performed at a speed that favored the Rocket, although that was the original intent of the test to begin with. The RV-6 was flown at WOT (wide open throttle) and both the speed and fuel flow were noted. The Rocket was then flown at the same airspeed and the fuel flow noted, and then at the same fuel flow, and the speed was noted. In both cases, the Rocket was either faster or more efficient.

Now, a couple of caveats. Sure, the RV can get down to less fuel burn than the Rocket because it has fewer cylinders, but at a speed penalty. The test favored the Rocket in that the speeds and fuel burn are right in the area of maximum efficiency for the IO-540, and WOT is not the most efficient spot for the O-360, so all these favor the Rocket.

With regards to drag and weight, the Rocket and RV are very close to each other in both regards. So obviously when you strap 260 HP to the front and the rest is about the same, you're going to gain something.

In closing, I'm not suggesting that the Rocket is faster or more efficient at ALL settings, just at the one at which the actual flight test was performed.

[svanarts]

Originally Posted by chuck

One of the things that I find over and over again is that people say to build RV's light.
I'm curious as to your experience and opinions.

Chuck

I'm not an aeronautical engineer or a professional pilot or anything else glamorous. Just a guy who has built and flown an RV-4. But I would think that any time you are building something that has to fight against gravity, you'd want it as light as possible.

My RV-4 came in at 876 lbs. I haven't painted it. I have a wood prop. I don't have any fancy doo-dads in it. I don't have nice upholstry. I don't have a CD player or an XM radio. I tried to build it as light as I could.

Does it fly any better than any other RV-4? I couldn't tell you. But I'm very happy with it. That's the beauty of building your own airplane. You make it the way you want it. Everyone thinks their way is the best way. I think going light is the best way. Others want flying easy chairs with all the bells and whistles and they think that's the best. All this acedemic debate is interesting but ultimately it's your airplane, these other guys won't be flying it. It's all good. Just build the airplane you want.