a methodology for intelligent performance testing

[Zigrat]

Hey guys,
I see alot of people putting alot of work into performance testing. The thing is, IMO they go about it the wrong way. Here is how to extract USEFUL data from doing these performance tests.

1) select a test altitude
2) determine the stall speed of your airplane at said altitude in clean configuration
3) add 100 % to its stall speed, then establish the airplane in steady level flight at stall speed +10% . To do this type .speed (calculated speed) then adjust the throttle until you reach the correct alt and are not climbing or descending
4) film on.
5) auto level (you were on auto speed (eg climb) go to auto level.
6) firewall throttle
7) let aircraft accel to max speed (about 2 min in most cases)
film off

film on
aircraft is at max speed
8)throttle idle
9) film off when aircraft stalls

ok now you have 2 films. go to the external film viewer and play the films back on time lapse (mabye 1/5 time) and each time the second changes record the airspeed (have an excel window open).  do this for both acceleration and deceleration. from this you can get instantaneous accelerations, climb rates, minimum power speed (endurance) best lift to drag. all sorts of info.

it is great so many people want to spend time doing tests. well this is the 100% best way to do em.

[Blue Mako]

A request to make testing data collection easier:

I'd like to see HTC include an option on the film viewer to output a text file giving time, altitude and airspeed (and maybe engine settings) for a given time step.  It seems the viewer already processes this info to display it, maybe it could be output easily?  

HiTech, Pyro, etc?  How about it?

[Blue Mako]

Originally posted by Zigrat
2) determine the stall speed of your airplane at said altitude in clean configuration

This is a test in itself.  Select autolevel with partial throttle and allow the speed to stabilise.  Close the throttle.  When the auto level function cannot keep the aircraft level, note the speed.  (Due to the new function where the autopilot will not cause the aircraft to exceed the stall Angle of Attack, the aircraft will not enter a full stall but this method will give you consistent results).

3) add 100 % to its stall speed, then establish the airplane in steady level flight at stall speed +10% . To do this type .speed (calculated speed) then adjust the throttle until you reach the correct alt and are not climbing or descending

Zigrat do you mean to say "add 10% to it's stall speed"?  You say establish at stall speed +10%...

[Mister Fork]

Zigrat, instead of standing on a soap box with a speaker horn yelling at us testers, how about rising to the challenge yourself and post some data before someone throws an apple at your head?

[Steve]

Zigrat, I cannot believe how insulting this post is.  Thankfully, I personally haven't done any testing or I'd be at your throat.  If you can find any classes in your area that teach how to be tactful, sign up and send me the bill.

[Zigrat]

i did do testing, did the bf-109 g2 for an example but i dont wave webspace to upload the results. as for tactful wtf are you talking about. all i said was alot of guys are spending alot of time to generate results which are of limited use, where if these steps are followed you can extract a lot more information for only a small bit more time invested.

For the stall speed question thats what I meant, so if you stall at 100 mph start your testing at 110 mph (very close to stall speed is it extremely hard to maintain altitude, thats the reason for the margin)

[Steve]

Since you don't know "wtf" I'm talking about... look into the class.  By the end of it, perhaps you will.  Until then, I'm done.

[Ductape]

Maybe I should sign up for those classes too because I don't know wtf Steve is talking about.  
I went back and read the posts again and again. I can see nothing in any of them that should get anyone's panties in a bunch until I get to Steve's post. Different strokes for different blokes I guess.
Thanks zigrat for taking the time attempting to explain preformance testing to us ignorant folk. I never had any inclination to spend time doing test pilot type stuff. I just get in'em and go. I don't know that actually testing the planes would help me improve my ranking or not. Maybe if someone DID post the testing results, peeps like me could benefit without actually cunducting our own testing.

[Steve]

It's the title of the post Ductape.  It insinuates other test weren't intelligent.  I just think it's foolish to insult people who have taken the time to run such tests, I mean it  has to be somewhat time consuming, a commodity that most folks don't have in excess.
Perhaps neither you nor the original poster have had to deal with people from a leadership level so you wouldn't understand what I'm talking about.

[Ductape]

Originally posted by Steve
Perhaps neither you nor the original poster have had to deal with people from a leadership level so you wouldn't understand what I'm talking about.

I think being =CO= of a Squadron for 7 years, working as foreman on several crews, running my own business for 5+ years, and being stage manager for a band for 6 years has definetly put me in some leadership roles. I still don't see what warranted your post. The title didn't appear insulting to me, or anyone else that posted evidently. I didn't intend to get into a verbal furball with anyone over it either.
As I said before "Diffrent strokes for different blokes."

[Mister Fork]

I'm not going to haul out my dick and measure it, but Duc - look at this statement from Zig...

The thing is, IMO they go about it the wrong way. Here is how to extract USEFUL data from doing these performance tests.

Is that suppose to give me a warm fuzzy feeling? He's referring to my tests.

If he had of said:

"The problem is, there are a lot of criteria that could make the tests look one sided.  Here is how you can silent those nay-sayers when you do performance tests."

then there would of not been any 'forking' issues.   It looks like a 'slight' and I wish Zig had been more careful how he worded it.  And posting it just AFTER I posted my acceleration results, it doesn't look good.  

His methods are sound however, but diplomatic like a dump truck changing lanes on a busy freeway.

[Ductape]

Well, once again I seem to have stepped in a big pile of shiznitt. I apologize to anyone that was insulted, I didn't see it. Once again I learn the lesson to keep my nose in my own business. I suppose I could get upset at the insinuation I don't have enough skills to be insulted by the post, but as I said I didn't intend to get into any verbal furballs. I will apologize and attempt to gracefully bow out of this one. Anyone got a stick or something I can use to scrape this off my shoe?

[MwXX]

This is a GAME right?





2 +  2 = 4

"pending weather + air speed - attitude / wife yelling = death"

[sax]

Zig

[Steve]

Ductape don't go away mad dude!  I was stating my opinion on how I felt the message came across.  If you don't see it that way, cool!  I'm not saying I think everyone should view it as I did.
My interpretaion of the message is that it was heavy handed and condescending... I certainly understand if your view is different.  I'm not trying to change your view sir, just clarifying mine.