Roll-rate is easy... E-retention is not.

[fscott]

We have flight test data on roll-rates at different speeds with various aircraft, but how much data is out there that tells you how much E a plane can maintain?  I would be interested in any books or web sites that have actual flight test on E-retention for the various aircraft. I would suspect there is very little in raw numbers, and even more scarce for planes like the Niki.

fscott

[fscott]

But if nayone could recommend a book that covers this area I think it would be interesting reading.

fscott

[Bombjack]

'E-retention' is the inverse of drag. It's possible to calculate drag from the aircraft specs - there are aero engineers here (like Wells) who have done it.

Bring out the numbers, guys  

[StSanta]

I think we should all contribute into making 1:1 replicas of these planes and then test them   .

And yell "they're PORKED!" if they don't match AH  .


------------------
StSanta
9./JG 54 "Grünherz"
while(!bishRookQueue.isEmpty() && loggedOn()){
30mmDeathDIEDIEDIE(bishRookQueue.removeFront());
System.out.println("LW pilots are superior");
myPlane.performVictoryRoll();
}

[This message has been edited by StSanta (edited 12-05-2000).]

[bowser]

"I would be interested in any books or web sites that have actual flight test on E-retention for the various aircraft."

You don't have any data?  What were you basing your complaints about E-retention on?  I just assumed that you and the people who were complaining had data that conflicted with HTC's.

bowser

[wells]

The tests I did were to measure the increase in induced drag by pulling G's, then use that force to calculate a deceleration or rate of decent that would be a direct measure of energy loss.  All planes were tested at the same speed and G load.  The idea being that you end up flying a spiral dive, keeping the speed and G factor constant.  The plane that loses altitude faster, bleeds more E, so to speak.  The procedure was as follows:

a)  Trim for 250 ias at 10000 ft, set power accordingly.  This is the average altitude of the test.  Then climb to 20000' and set the same power.

b)  Roll to just past 90 degrees and pull to 5G's at 250 ias.  Maintain speed and G load as best as possible.  This means keeping constant bank angle (constant aileron input) and constant nose down attitude (nose down about 10-15 degrees).

c)  Time the descent over a 10000 ft interval, from 15k to 5k.  There's a 5k buffer to set up the conditions properly.

The idea is not to measure absolute performance, but to check that induced drag increases appropriately for each plane as compared to calculations.  That's why power is set to maintain 250 ias at 10k, to cancel out the profile drag and isolate the induced drag, since the latter is low at 250 ias.

Here's the link:
 http://bbs.hitechcreations.com/smf/Smileys/default/Forum9/HTML/000906.html

[This message has been edited by wells (edited 12-05-2000).]