RV-3: Quick ?Wow? Climb Data

[Ironflight]

I won't claim this to be scientific (more of a "grab sample"), but I did an initial cut at a climb test this morning with Junior (RV-3B, 160 HP TMXIO-320, WW 151 Prop) and am truly amazed at the numbers!

1,000 ? 10,000 climb took 4:51 (just under 5 minutes), for an average ROC (averaging the 1 Hz data) of 1927 fpm (initial ROC was over 4,000 fpm).

10,500 ? 14,500 took 3:20, for an average ROC of 1105 fpm. Yup ? better than 1,000 fpm ABOVE 10,000?. That was with about half fuel. And it is a "heavier" -3....

(And we haven't even figured out the best ROC speeds yet - I just used 110 - 115 knots, like I do in the -8.)

Paul

[Danny King]

That sounds like too much fun! I predict more 3 tail kits going out the door at Van's in 2012.

[Alan Carroll]

Originally Posted by Ironflight

10,500 ? 14,500 took 3:20, for an average ROC of 1105 fpm.

Very impressive! I think its actually even better than that though; 4000'/3.33 min = 1201 fpm?

[Kevin Horton]

That's great climb performance! I suspect that once you do some more testing that the 4,000 ft initial climb rate you saw on this flight will prove to be an aberation, probably due to wind shears, or a bit of a zoom to get the IAS back to your target speed. I bet the true, stabilized initial rate of climb (i.e. at constant IAS and with no wind shears) will be less than 3,000 ft/min. But it'll still be a great performer.

Note: the standard way to remove the effects of wind shear from the climb test data is to do two runs at each speed, on headings 180 degrees apart, at 90 degrees to the predicted wind. Average the rates of climb from the two runs.

It would be interesting to eventually hook up some O2 and see what the absolute ceiling is.

[n5lp]

Originally Posted by Kevin Horton

It would be interesting to eventually hook up some O2 and see what the absolute ceiling is.

That would be fun.

[Ironflight]

Originally Posted by Kevin Horton

That's great climb performance! I suspect that once you do some more testing that the 4,000 ft initial climb rate you saw on this flight will prove to be an aberation, probably due to wind shears, or a bit of a zoom to get the IAS back to your target speed. I bet the true, stabilized initial rate of climb (i.e. at constant IAS and with no wind shears) will be less than 3,000 ft/min. But it'll still be a great performer.

Note: the standard way to remove the effects of wind shear from the climb test data is to do two runs at each speed, on headings 180 degrees apart, at 90 degrees to the predicted wind. Average the rates of climb from the two runs.

It would be interesting to eventually hook up some O2 and see what the absolute ceiling is.

Oh yes - I don't want to mislead anyone - the initial ROC was a zoom, most certainly. All I did to get the "average" in this case was to average the second-by-second data - I was curious how that would come out. It doesn't really mean anything, because the data is not weighted properly - but as I said, I don't know where I was relative to Best Rate anyway.

We'll be doing tests with O2 for certain - but clearly, the ceiling will be in the flight levels, and we can't do that under Phase 1 restrictions....

[TS Flightlines]

you are having way too much fun Paul!
Tom

[fatherson]

Originally Posted by TS Flightlines

you are having way too much fun Paul!

And so are we, vicariously. Thanks, Junior!

--
Stephen

[Michael White]

Originally Posted by fatherson

And so are we, vicariously. Thanks, Junior!

--
Stephen

Yeah, it's too bad Junior's too young to speak yet. I'd be interested in what he has to say about all this.

Hmmmm....what do you suppose his first words will be? Momma? Daddy?
Nope....my guess is....
Van!

[AX-O]

Originally Posted by Michael White

Hmmmm....what do you suppose his first words will be?

More fuel...