Max Altitude For Oxygen Breathers
 

Sorry if this is the wrong forum, but I amcurious.

What is the maximum altitude an oxygen breathing aircraft has flown at?

Oxygen breathing engines particularly designed for the upper atmosphere find it tough going without lots of intake and compression.

The gas turbine is gasping at much above 90,000 ft - doesn't have much thrust up there either.

Some one else will no doubt come up with the numbers.

Aviation lost an accomplished test pilot recently with the passage of Pete KNIGHT to the big hangar in the sky. For more years than I can remember he holds the world speed and altitude records in an X15.

I believe 3954 Kts or 6.7 Mach
354,200 feet where he would have been seeing all the stars against a black sky.

In a full pressure suit of course.

90,000 is optimistic for an air breather. The various fighter record altitude attempts typically involved shut down of the engine below 70,000 feet to reduce gyro effect over the top - since the engine would have flamed out anyway at about 75K.

The X-15 of course was not an airbreather.

I believe the highest altitude maintained by an airbreather was by an SR-71.

To reiterate an anecdote from another thread "found over the door at Beale AFB - the saying 'Yea though I fly through the valley of death, I fear no evil, for I am at 80,000 feet and climbing'"