MH17 witness in jail in Russia, page-62

Catgut, the only limitation is in the SU25's ability to fly.....
People have flown to 40,000 ft unpressurised and with only supplemental oxygen.
Above that, pressure oxygen is a must..
In fact, an altitude record was set in 1972 in a Lama helicopter, with only a bubble canopy, to over 40,000ft, with the pilot using only supplemental oxygen.
"The helicopter had been stripped of all unnecessary equipment prior to the flight to minimize its weight and the pilot was breathing supplemental oxygen."
http://jetav.com/sa-315b-lama-helicopter-altitude-record-horder/

So, in the case of the SU25, oxygen/pressurisation was not a factor. Only the need to get the aircraft up there...

I dont think many realise that there is a big difference in flying up to and at 40,000ft unpressurised and on oxygen.... and flying at 40,000ft pressurised and having an explosive decompression.....in the later case you have physiological effects despite donning masks after the event.

A ww2 P51 mustang set a record of 42,500 ft "in an unpressurized, unheated propeller aircraft that's almost 70 years old."
http://www.eaa.org/en/eaa/eaa-news-...-30-doug-matthews-sets-world-records-in-p-51d

GZ