High Altitude Combat

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Glider

Captain
8,911
5,072
Apr 23, 2005
Lincolnshire
I wonder if anyone can help me with this detail.

I have been looking at some high altitude versions of the Spitfire and noted that a Ju86 P2 was shot down at 42,000 ft on the 24th August 1942. What is described as a successful interception was carried out at 50,000ft (note careful choice of words = may not have shot it down) over the Suez Canal a few weeks later.

This got me thinking, what was the highest altitude interception that resulted in a plane being shot down. Does anyone have any examples? What about the P47's over Japan

PS a fairer fight was a Fw190 shot down by a Spit VII at 38,000ft 15th May 1943.
 
My Guinness Book of Aircraft makes mention of this event as the Highest known interception by an unpressurised aircraft ever! G. Reynolds flew his specially prepared Spitfire Mk.Vc to 49,500 ft before shooting down the Ju-86P-2, so the junkers was shot down, this took place from No.103MU near Alexandria, there will no doubt be a higher interception by a pressurised fighter however................
 
I think at about 45,000 ft or so, you need a pressurized oxygen sytem rather than the regular "on demand" system.

I think its due to the low pressure at about that altitude makes the lungs less able to inflate and deflate properly.

I could be wrong, so if I need correcting, please enlighten me.
 

When I flew in the F-4 we were about 45,000, it had a normal diluter-demand system but we were pressurized. I switched it to 100% when we started doing aerobatics...
 
Heres something to ponder.

Space Equivalent Zone
From a physiological viewpoint space begins when 50,000 feet is reached since supplemental 100 percent oxygen no longer protects man from hypoxia. The means of protecting an individual at 50,000 feet or above, are such that they will also protect him in true space (i.e. pressure suits and sealed cabins). The only additional physiological problems occurring within this zone, which extends from 50,000 feet to 120 miles, are possible radiation effects and the boiling of body fluids (ebullism) in an unprotected individual. Boiling of body fluids will occur when the total barometric pressure is less than the vapor pressure of water at 37o C [47 millimeters of mercury (mm Hg)] which is reached at an altitude of 63,500 feet (Armstrong's Line).


The Armstrong Limit is the altitude that produces an atmospheric pressure so low, that water boils at the normal temperature of the human body: 37°C (98.6°F) [1].

The altitude, also sometimes referred to as Armstrong's Line, is variously reported as being between 18,900 m - 19,400 m (62,000 - 63,500 feet) [2] [3]. At or above this point, exposed human fluids will boil without a pressure suit, and no amount of breathable oxygen, delivered by any means, will sustain life for more than a few minutes. A human would, eventually, boil in their own body fluids (a process known as ebullism), though death from asphyxiation would occur first, as the barrier of the skin and control of blood pressure would prevent blood from boiling immediately [4].

A NASA technical report, Rapid (Explosive) Decompression Emergencies in Pressure-Suited Subjects, discussing the brief accidental exposure of a human to near vacuum notes the likely result of exposure to pressure below that associated with the Armstrong Limit: "The subject later reported that ... his last conscious memory was of the water on his tongue beginning to boil." [5]
 
If I brush off the old brain cobwebs I think the demand regulator would provide 100% oxygen at about 27k ft. Above 40k it would provide pressure breathing, which is a bit uncomfortable. USAF requires pressure suits above 50k, even when pressurized. I have been above 50k in a T-38 but it was pressurized, no sweat and it wasn't very long (not approved, we didn't have pressure suits). We did acro with the pressure regulator set at normal, so I don't know why FlyboyJ switched to 100%. Of course our acro was limited to below 25k. I can't remember if we flew formation acro above 25k. In the C-141, with rapid decompression, we crash dove to 10k before leveling off (the C-141 could go down fast. I have seen 18k on the VVI, not bad for being limited to 60 degrees of bank).
 
We had access to the Edwards MOA (2508 ) and would go up to 40K for high speed work (we were allowed to go Mach 1 there). I do remember us around 20,000 feet when we were playing - Edwards also allowed us to go in there for touch and goes...

here was one of our birds...

 

Wow! You must have been excited. What a thrill to have a flight in one of the worlds greatest fighters! In the T-38 we were always prohibited to exceed Mach 1 without authority. It seems it kept the minks from mating. We did go on couple of Mach 1 flights, one of which was in formation. It is amazing how easy the modern jets go through Mach 1. The only way we knew we had gone Mach 1 was a 1 on the Mach meter and a dip in the air data instruments (alt., a/s, etc.).
 
The only way we knew we had gone Mach 1 was a 1 on the Mach meter and a dip in the air data instruments (alt., a/s, etc.).

YEP-I sat there and watched for it - didn't feel anything but saw the airspeed indicator and mach meter "jump."

I did several flights there, a few in a T-33, but only when over mach 1 (mach 1.3) once.
 
YEP-I sat there and watched for it - didn't feel anything but saw the airspeed indicator and mach meter "jump."

I did several flights there, a few in a T-33, but only when over mach 1 (mach 1.3) once.

You've got me beat. The T-38 could only eke out 1.2 Mach (I think we went 1.1) due to the canopy design. Of course, in the F-4, 1.3 Mach is just cruising. Was the F-4 clean or did it have tanks on board? One thing we did have to watch was exceeding Mach 1 in extended trail formation. The T-38 was so clean that if you got your nose low and your airspeed was up, as in entering a loop, it would slip right through Mach 1. In trail you were busy watching lead and not your Mach meter.

Actually that cool that you got to fly in the T-33, the trainer version of the first practical US jet. That plane, in one form or another has been around for sixty years.
 

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