WesWorld

Gentlemen,

I just noted that I probably overestimated the speed of the JFM F-12K Super Sparrow as posted in my encyclopedia. On that data sheet I credit her with a speed of 778km/h which seems excessive on second glance. It´s higher than the OTL world record of the Me209 (755km/h) which was only beaten 30 years later by a modified F8F Bearcat (777km/h).

On the other hand I found this in the net about the P-51H:
The Rolls Royce Merlin V-1650-9 was chosen. Take-off horsepower was actually down from the -7 series to 1,380. But, the new -9 Merlin used water/alcohol injection and was able to up the war emergency power to 2,200 at 10,200 feet. This was the fastest production P-51 clocking 487 mph at 25,000 feet.

If I´m right, 487mph is about 783km/h - achieved on 2200hp boost. So the stats for the F-12K do no longer seem to be too far off on 2130hp boost. But it also raises the question, why the official world record of the Me209 was never broken by the P-51 if the series production P-51H already made 783km/h....

So can somebody please validate the speed value of the P-51H given above?

Speed tests for the absolute speed record were taken at sea level, rather than the speed at altitude values usually quoted for combat aircraft. From memory, the P-51H was doing around 650km/h at sea level, rather lower than for the contemporary racing aircraft. It's still pretty fast though.

Where's the radiator on the F-12H aircraft?

Quoted

Originally posted by HoOmAn


On the other hand I found this in the net about the P-51H:
The Rolls Royce Merlin V-1650-9 was chosen. Take-off horsepower was actually down from the -7 series to 1,380. But, the new -9 Merlin used water/alcohol injection and was able to up the war emergency power to 2,200 at 10,200 feet. This was the fastest production P-51 clocking 487 mph at 25,000 feet.



So can somebody please validate the speed value of the P-51H given above?

Reference to William Green's Warplane of the Second World War, Fighters, Volume Four provides the following information on the performance of the P-51H-5-NA - Maximum speed 444 mph at 5,000 feet, 463 mph at 15,000 feet, and 487 mph at 25,000 feet.

The high altitude speed with boost seems to be in the category of a 'dash' speed, and not necessarily one that could be sustained for any length of time. How much armament and/or external stores were carried under those conditions is not explicitly addressed - I'd infer normal internal loads but no external loads, but that is not certain.

Quoted

Where's the radiator on the F-12H aircraft?

There is a nose inlet and one in her right wing root (think Hawker Fury). As there is no turbo charger in this variant I expect this to suffice....

I understand now, that I simply misinterpreted the data I had - forgetting the fact that world records were flown on sea level.

Thanks for helping. I will keep the data sheet as is.