[TEST] TO distance / gross weight / temperature

Recently I've stumbled upon the F-51D manual and had a closer look at it.

 

 

Amazon link: Pilot's Manual P-51D Mustang Flight Handbook 1F-51D-1 formerly AN 01-60JE-1 (Reprint of 15 July, 1952 Edition)

 

 

In there you can find an interesting chart which contains data for various TO distances in relation to the plane gross weight, altitude and temperature. In addition, TO parameters are clearly defined. I was curious to find out whether there is a connection between these values and our DCS P-51D. So I built a mission and went on testing...

 

 

 

 

 

On the current DCS map there are only two airfields that match rounded values of 0 and 1000 ft elevation and feature perfectly flat runways (with no difference in elevation on both ends). The first one is Batumi @ 33 ft and Mineralnye Vody @ 1050 ft. First I opted for SL tests on Batumi, and built a "ruler" out of available containers. Since lining them up accurately was a pain to say the least, I ended up only doing SL (Batumi) tests - GROUND RUN:

 

 

Large red containers denote every 500 ft, white containers stand for 100 and gray ones for every 50 ft in between.

 

TESTING METHODOLOGY:

• Flaps UP unless otherwise noted
• Trim: 5-6° right rudder & 1° nose down
• No brakes, power up from stand still
• 61" Hg and 3000 RPM TO power
• Weight matching the chart as close as possible
• Temperature according to individual column
• QNH set to 760 for standard atmosphere
• Zero wind

 

Selected tests shown here:

 

 

 

 

 

NOTE: From the values shown below it was possible to shave off ~50 ft by pulling up too soon. That resulted with the loss of directional control and sometimes even a crash (especially on #3 where flaps were used). Only controllable take offs with full directional control were taken into consideration. Each test was performed several times until I was happy with an average value.

 

 

TEST #1: 9000 lb | 1000 ft | +15°

result: MATCH

 

 

 

TEST #2: 10000 lb | 1250 ft | +15°

result: MATCH

 

 

TEST #3: 10000 lb (flaps 20°) | 1100 ft | +15°

result: MATCH

 

The purpose of this test was MINIMUM-RUN distance as described earlier in the manual on pages 32 and 33:

 

 

TEST #4: 9486 lb | N/A | +15°

result: ~1050 ft

 

The purpose of this test was to find out the distance for almost full wing tanks, the maximum I would use when flying online.

 

 

 

TEST #5: 9000 lb | 850 ft | -5°

result: MATCH

 

 

 

TEST #6: 10000 lb | 1050 ft | -5°

result: MATCH

 

Perhaps ~ 15 ft longer, but enough to round it up as 1050 ft.

 

 

 

TEST #7: 10000 lb | 1450 ft | +35°

result: shy ~20 ft

 

On each test I was few feet over or under the distance, but in this one I was consistently lifting off before the 1450 ft mark. Perhaps this has something to do with my trim settings. All in all, it still is in the ball park.

 

 

 

TEST #8: 11914 lb | 1950 ft | +15°

result: MATCH

 

The heaviest loadout possible was 11914 lb. This is the result.

 

 

 

 

 

 

All tests I performed almost perfectly match the values from the chart. I am not sure how well other sims fare in this regard but it seems ED & Yo-Yo did their homework. Color me impressed.

 

Here are the tracks for anyone interested: P-51D TO TESTs (right click and save as)

Edited April 18, 2021 by [DBS]TH0R
links and images

Awesome! Too many of us sim pilots (myself included, I'm afraid) don't do the tests we should, to help ensure the sim's accuracy. We need more virtual test pilots!

Whow!

 

Thx for the time you spent doing it. It's great to find such accuracy being matched by our p51d!

Thank you!

 

TBH I wasn't planning on doing the tests in this scale. First I put one container at 1000 ft to see if there is a connection (TEST #1), when the plane took off right on the mark I knew I had to do more of them. One of the reasons behind the "container ruler" was to prevent me from pulling back on the stick when I saw the container (mark) approaching.

Edited April 28, 2015 by T}{OR

Good job Thor I know how much you love the P-51 from 1946.