London-Melbourne Challenge 2009 Aircraft Performance Q&A

[srgalahad]

There will be some debate and questions about what constitutes an eligible aircraft for the event. The Committee is building a list (which will likely never be "complete") to assist would-be entrants. To do this we need performance reports and simply cannot fly them all ourselves.

This thread is the place to post your test results (done in accordance with recommended procedures in the Rules and FAQ), or to ask for help about testing or alternative aircraft.

To begin, there are a number of payware aircraft that have been listed as "possible" but still need first or second tests to confirm data. If you have one or more of these - even if you don't intend to use them - and can spend a few minutes grabbing the numbers, please help us out.
Note: Only the specific model listed needs testing.

General Aviation Category:

Carenado:
Beech Bonanza F33
Cessna 206
Cessna 210
Piper PA-28T Arrow IV
Piper Seneca II

Dreamfleet:
Beech Baron B58
Beech Bonanza A36
Cessna 177 Cardinal RG

Eaglesoft:
Cessna 400
Cirrus SR22

Flight One:
Piper PA-46 Meridian

FSD:
Commander 115TC
Piper Navajo
Piper Saratoga II TC
Piper Seneca V

Submit your test results as follows:
Model name/variation, producer, max speed (TAS), altitude tested (18,000 or critical altitude if lower - specify).
Eg. Enterprise, NCC-1701C, Starfleet, 17M KTAS, 18,000 ft

One test per model should be sufficient (dignified debates may be entertained).

Other aircraft may be suggested and reported here but all are subject to the Committee's decision of eligibility. Last date for submissions will be 2359UTC, October 19, 2009.
Please keep all persuasion gentle and bribes under the table.

Rob

[Highmike]

Here are my test results for the Digital Aviation Cheyenne IIXL. This is a superb simulation which I'd really like to enter in the race. I think the following documentation shows that it is pretty close to the numbers observed in the real thing.

Observations: 16000ft - 278 kts, 18000ft - 276 kts, 20000ft - 275 kts.

Here's my Duenna:
http://www.fsrtwrace.com/track/ShowF...Ub3NtB83BM6D14

Here are performance figures for the real thing:
http://www.risingup.com/planespecs/i...plane367.shtml

Here are screen shots taken at 16000ft, 18000ft and 20000ft and the Duenna text file:

[jkcook28]

I have a bunch of those I can knock out over the next couple days.

Highmike: are you running the IIXL at full power and rpm? I tested that to 285KTAS @ 18K.
The I and IA in the same package with less powerful engines hits the 270KTAS right on the number.

[Highmike]

Highmike: are you running the IIXL at full power and rpm? I tested that to 285KTAS @ 18K.

It may be a force of habit, but I've never flown that bird at full throttle. I always keep a bit before the barber's pole. In any case overspeed would invalidate the Duenna in race conditions so the redline is worth observing. Looking at the screen shots you'll see that I'm as close as I'd like to get in trouble free air.

[srgalahad]

OK Highmike, thanks!

...but you get to play test-pilot for a day (without pay). The requirement is to test MAX speed. Therefore, it's push hard forward on the go levers. You MAY hit an overspeed before the TAS tops out and that's fine ( it establishes a 'maximum') but for the handicapping we need to have that maximum speed at altitude. That way we can compare to the published specs.
There are two considerations: that the model flies within the rules,
and as importantly, that the model flies as close as possible to historical data.

Example: an aircraft model tests repeatedly at 200KTAS and is well within limits of the event. However, the published data repeatedly says a max. speed of 187 KTAS. This shows it has been modeled "hot" compared to the real aircraft. Numerous models have been ruled out based on hot airfiles, while others have been allowed if a legit (see Rules) fix is provided on a timely basis by an established modeler or based on test data.

In your specific case (Cheyenne IIXL) the numbers are close to "book". However the IIXL may still be deemed too fast for what we see as a target group of aircraft. If so, you may be able to fall back on the Cheyenne I/Ia. More on this in a day or so.

Rob

[Highmike]

...but you get to play test-pilot for a day (without pay).

Roger, Rob. Will follow up tomorrow. (I'll disable crashes and damage for the test!)

Mike

[salt_air]

Cessna 206/Stationair (no floats or cargo pack)

Carenado

152kts TAS

11000'

Critical Altitude not shown in cfg file....found no difference in performance between 10500 and 11500, but suffered at any change in altitude higher or lower.

MSFS GPS readings, clear WX, automixture-on, 100% fuel, minumum of 5 min after stable at each altitude check.

[salt_air]

Cessna 177RG/Cardinal

Dreamfleet

170kts TAS

8000'

No difference in performance between 7500 and 8500, but suffered at any change in altitude higher or lower.

MSFS GPS readings, clear WX, automixture-on, 100% fuel, minumum of 5 min after stable at each altitude check.

[Willy]

Just for grins...

Cessna 337D Skymaster

FSD

CA = 0

tested as follows:

1000' 190kts
2000' 189kts
3000' 188kts
4000' 187kts
5000' 186kts
6000' 185kts
7000' 183kts
8000' 182kts

Testing conducted with wx cleared.

[jkcook28]

Here's a wave of flight test for ya. These naturally-aspirated 200-300 hp singles as you know are obviously fastest at sea level. So I chose 2500ft as an altitude out of the trees. The turbo models are obvious.

Carenado:

Bonanza F33 195KTAS @ 2500ft
Cessna 210 184KTAS @ 2500ft
Piper Arrow IV 143.5KTAS @ 2500ft (round that which ever way you want:d)
Piper Seneca II 219KTAS @ 14800ft

Dreamfleet:

Bonanza A36 185KTAS @ 2500ft
(I have a Dreamfleet-supplied turbo upgrade of this model also I can test if you need it.)

FSD:

Piper Saratoga IITC 198KTAS @ 15800


I can do the Cessna 400 if it's the same model as the Columbia 400. Anyone know?

[Highmike]

Here are test flight results for the Digital Aviation Cheyenne I and IA:

Cheyenne I:

16000ft - 265kts
18000ft - 269kts
20000ft - 272kts
22000ft - 276kts
24000ft - 261kts

Cheyenne IA:

16000ft - 267kts
18000ft - 270kts
20000ft - 274kts
22000ft - 277kts
24000ft - 265kts

[EasyEd]

Hey All,

Anybody test the Tailwind that could post some numbers? I don't have it but thinking I may get it and try it out this weekend - some numbers would help with that decision.

Kind of considering flying it using 1934 rules - more interesting that way even though it couldn't be officially entered that way.

This in addition to a modern plane in the modern class.

-Ed-

[EasyEd]

Hey All,

Since nobody posted a response I bought the Tailwind and here are the numbers as best I could get keeping throttle and rpms maxed out. This is the W10 model not the W8.

kts TAS @ ft Altitude
156 @ 12000
158 @ 11500
162 @ 10500
165 @ 9500
167 @ 8500
169 @ 7500
172 @ 6500
173 @ 5500
177 @ 4500
179 @ 3500
180 @ 2500
183 @ 1500
183 @ 0500

Nice little plane. Funner to fly than I thought. As I indicated I right now plan to fly this plane to Australia following the 1934 rules while I fly a modern plane (probably a PC-12 maybe a Kodiak) under the modern rules. While this plane can't be officially entered using the 1934 rules (and that is fine) I'm curious to see how it might score. From my perspective it simply represents a different challenge from the modern rules.

-Ed-

[Bry Rosier]

Heres my figures for the CR22
FSX Eaglesoft Cirrus CR22G2 Turbo
230 KTAS @ 13,800 ft (critical )
226 KTAS @ 18,000 ft

I was going to fly this in the GA class but , seeing the Cheyenne and PC-12 are included , it looks like the little GA`s are going to be left behind .

[EasyEd]

Hey All,

Simple question

How cast in stone are your reference speeds in the Golden Age Race?

For example I'm looking at the Me 108

No way and I've tried 3 times to get 163 kts at 6000 - best I can get is 159 kts.

The implications are simple.

10100/163 = 61.96 hours

vs

10100/159 = 63.52 hours

63.52 - 61.96 = 1.56 hours

so by these numbers in the handicap event an Me 108 at 159 kts starts out 90 mins behind an Me 108 at 163 kts.

At slower speeds a few knots matters in terms of reference times.

-Ed-

[Willy]

Ed, those speeds are what we got when we tested the aircraft.

[Spookster67]

If I flew exactly the same aircraft in FS2004 and FSX, using exactly the same conditions, would it perform identically?

I note that the default MSFS DC-3 is listed with 2 different speeds in the data table. The FS2004 version is quite a bit faster. Is that because Microsoft changed the airfile for the FSX DC-3, or do aircraft fly slower in FSX?

[salt_air]

If I flew exactly the same aircraft in FS2004 and FSX, using exactly the same conditions, would it perform identically?

I note that the default MSFS DC-3 is listed with 2 different speeds in the data table. The FS2004 version is quite a bit faster. Is that because Microsoft changed the airfile for the FSX DC-3, or do aircraft fly slower in FSX?

Most of us flew the DC-3 so much when it came out in FS9 that it's just simply was worn out when FSX came along....

[MM]

The aircraft Reference Speed tests are approximate.

For each one, we tried a maximum speed test at the listed Critical Altitude. And then varied it a bit to find a good reading. All that at full tanks (or full enough for 600nm flight--more recent tests are at full tanks except for the very long range aircraft).

Trying again, I now get the following readings for the Günter Kraemer Messerschmitt Bf 108:
.....161 KTAS @ 6,000 feet
.....166 KTAS @ 3,000 feet
.....170 KTAS @ 300 feet

Note that the Bf 108 critical altitude is 0. By convention, we're testing those normally aspirated aircraft at 3,000 feet to allow for the fact that the pilot won't want to be flying in the valleys and dodging trees for 10,000nm.

If you want us to retest aircraft--with a keener eye on precision--please let us know before the race. Some of the earlier tests were made a couple of years ago for a different purpose.

BTW. A retest of the FS9 and FSX DC-3 gives the same results as in the spreadsheet:

FS9 DC-3 .....209 KTAS @ 7,000 feet
FSX DC-3 .....200 KTAS @ 7,000 feet

Finally, please understand that the Handicap portion of the race will be only roughly equalized across aircraft. The Reference Speeds will be slightly imprecise. But the aircraft performance over the race course will depend also on the capability to fly at high altitudes to cross mountain ranges and chase tailwinds; the range to fly long distances to "cut corners" and minimize time-losing stops; the flying characteristics of climb, descent, and landing stability; the tradeoffs between speed, range, and fuel-consumption available to the pilot; and the physical structure of gear configuration, visibility, and so forth. Lots of stuff here.

We hope that you will pick an aircraft that you will enjoy flying--one that is challenging, rewarding, and of personal interest.

(Finally, IMHO, the Taifun would be a wonderful addition to the Race. In 1934 it was entered but later withdrawn by Wolf Hirth, who raced it instead in the Challenge 1934. And it's a truly historic aircraft.)

[EasyEd]

Hey All,

Were the test conditions FS9 all weather cleared? Did you autolean or lean at all. For real testing I don't use AFSD - I do use it to get a quick snapshot of what I can expect - but when your actually flying the sim engine decides what you get not AFSD so I prefer the sim engine numbers (shift z and GPS GS which with all weather cleared is TAS). I'm wondering if sim engines (9 vs X), test conditions and individual computers can play a role in this.

I guess the point is 4 kts difference in the 160 kts range of speeds equates to about 90 minutes while 4 kts difference at the say 270 kts range in speed equates to about 30 mins. Is an hour significant?

-Ed-

[Moses03]

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).

[Willy]

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.

[MaddogK]

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.

[Willy]

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.

[Spookster67]

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.