London-Melbourne Challenge 2009 Aircraft Performance Q&A

All the testing we have done to date is with the weather cleared. As far as AFSD, I like to compare it to the Shift+Z numbers but they are rarely more than a number or two different (at least on my system).
 
I can't say for the others as it's never come up but when I'm testing I use auto mixture to reduce variance between tests.
 
I would also think the air temperature would make a difference as colder air has a higher density than warmer air. Also the baro pressure setting would effect the altimeter reading, so knowing what the testers air temp and baro setting were would help duplicate test conditions on a different computer, otherwise the results are gonna be off minutely. 3 kts certainly falls within that category IMHO.
 
We use cleared weather for testing to remove the variables there and recommend average temps. Cleared weather will give you a barometer of 29.92.

Ed, are you testing in FS9 or FSX? The two sims read flight models a bit different and if we've tested in one and you're testing in the other, then you will get different readings from what we got.

ETA: I just took this screenshot of the weather screen showing the correct setting for flight testing and circled the important bits. Notice that in addition to calm winds, it sets up standard air pressure and temperature.
 
In the GA table the Flight1 Cessna 441 Conquest is shown as "Needs Test". I have a team of guys that want to fly it in the challenge (in fact about 7 people, so maybe 2 teams!), so I'll get it tested and post the data at the weekend, when I'm back home with my FSX pc.

Regards, Martin.
 
What season Willy ? My sim defaults to Winter, or does selecting 'clear sky's' change the season also ?

Thanks in advance.
 
MaddogK said:
What season Willy ? My sim defaults to Winter, or does selecting 'clear sky's' change the season also ?

Thanks in advance.
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won't matter. Clear skies is ISA (15deg C as sea level, 29.92 " Hg) and temp drops 1.8 [1.9?]Deg C for every 1000 ft of altitude. Winter in southern Alberta at 3500 ft temp is 8.2 C; summer in Mexico is 8.2C (ISA = International Standard Atmosphere)

Note, default c172 is tested at 119.1 KTAS at 3500 ASL ISA

Rob
 
Legacy 2000 (Legacy 4/5) by Robert Christopher

stock build
273 @ 3000
262 @ 8000
'book' is 261 @SL
a bit hot

with legair.zip installed
281 @ 3000
268 @ 8000
too hot period

I'd love it but it's just a wee bit on the warm side
 
Hey All,

Willy that is exactly the testing environment I use - clear weather. MM was your test in FSX or FS9? I do everything in FS9. I have finally installed X on a fairly high powered computer (x48, E8400 3 ghz, 4 gigs ram) but still fly fs9 on a 2ghz, 1 gig ram computer because of all I have invested in the sim. Maybe over time I'll come to using both simulators.

To be straightforward I'd be happy with a reference speed of 161 like MM got as then I'm only 45 mins behind at the start of the race compared to 90 mins. Each Kt represents almost 25 mins of time over 10100nm in a 160 kt aircraft so in slow planes it is important to really nail those numbers and I think that the committee should want feedback on their numbers just to see what others are getting and make it as fair as possible. I'm not criticizing just saying hey - I don't get what you got.

Irrespective I specifically want to commend this committee for at least trying a handicap system! :ernae: I have argued for this over classes for years as some of you might know. This race should give you the raw data to look at the results given other handicapping systems as well and I urge you to take advantage of that. I think handicapping the only way to truly equalize aircraft in a race as has been recognized and done in real life for at least 80 years.

-Ed-
 
There's more than one way to skin a cat. Or to legally cut time off in a race. Sometimes you just have to get a little creative like I did in the Evita. ;)
 
Willy said:
There's more than one way to skin a cat. Or to legally cut time off in a race. Sometimes you just have to get a little creative like I did in the Evita. ;)
Click to expand...

Yep, people on the ground at airports get "creative" looking down the muzzles of Merc Air! :tgun2: hehe ;)
 
Flight1 Cessna Conquest C441

273 @ 18000
272 @ 17000
270 @ 16000
268 @ 15000
262 @ 12000
252 @ 9000

Not as fast as I thought, and maybe just allowable...?

I know a bunch of guys who'd love to fly it to Melbourne as a team... :icon_lol:
 
Flight 1 Cessna 441

I tested this one once before with the other group I posted but aborted the test as too fast.
Just flew it again. 2 screens show:
Full throttle
Full RPM (condition lever)......293KTAS

2nd screen is checklist cruise power setting:
1738 ft/lbs torque
96% RPM......288KTAS

To achieve 273KTAS @ my 17,800ft test altitude required 1325ft/lbs or 64% throttle.
That's what I get. Can't explain the difference in test numbers to Spookster...
 
OK, so I got my RTW data sheet out, and discovered that I too had tested the C441 and got 293 ktas at 18,000 :confused: . Then I re-ran the tests just now, and realised how I managed to only get 273 ktas. I had the gear down! :redf: Oops. In my hurry to get it tested, I just slewed it up to 18,000 and never checked the gear.

So, the C441 is too fast.
 
I fly in FSX. I might enter for the race, it depends if i get my gaming computer back from the repair shop. If i do, i will use miltons puss moth but i have changed the cfg file so its top speed is 186mph!!!!
 
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