Mr Spaceman From Canada, joined Mar 2001, 2786 posts, RR: 9 Posted (12 years 2 months 1 day 4 hours ago) and read 12636 times:
A while back, I was involved in a discussion in the Tech/Ops forum about a skydiver who was going to try to beat the world record for the longest "Freefall" from a weather balloon. The conversation was about the kind of equipment the skydiver would need, such as a High Altitude NASA spacesuit, etc, to protect against the extremely low pressure, low temperature, ultraviolet rays, and so on.
Fighter Jet pilots were mentioned in the many postings, regarding how their cockpits are fully pressurized, partially pressurized, or not pressurized at all.
This got me wondering. Of all the performance charts I have read on many types of fighter jets, I don't recall any stats about whether their cockpits were pressurized or not. My own feelings tell me that fighter pilots only wear G-suits to protect against High G forces. You don't see them wearing spacesuits like the pilots of High Altitude RECON aircraft like the SR-71, and U2.
So my question is...Are any of the aircraft listed below pressurized at all?
LY744 From Canada, joined Feb 2001, 5536 posts, RR: 10 Reply 1, posted (12 years 2 months 1 day 2 hours ago) and read 12552 times:
Well, fighter pilots have those breathing masks, so I think that should be sufficient and not require a fully-presurrized cockpit, unless they are flying at high altitudes (above 60,000ft ) where a "space-suit" is required.
Hope it helps.
Mr Spaceman From Canada, joined Mar 2001, 2786 posts, RR: 9 Reply 3, posted (12 years 1 month 4 weeks 1 day 3 hours ago) and read 12497 times:
Thanks for your replies guys.
> LY744, I understand that fighter pilots breath Forced 100% Oxygen. This enables them to inhale while surrounded by unpressurized air, as long as the mask is tightly fitted. I'm mostly curious about what keeps the pilot's "body" tissue, and blood from expanding at high altitude, if their cockpits are not pressurized. A fighter pilot's blood will actually start to "BOIL" if his body isn't pressurized at very high altitude.
Do most Fighter Pilots ever fly high enough to need a pressurized cockpit?
> Staffan, when you say that the Gripen is pressurized...do you mean FULLY? Also, are the Saab Draggen and Viggen fighter's pressurized? Regarding the Gripen, is the cockpit pressurized by using bleed air from it's engine, like the airliners do?
LY744 From Canada, joined Feb 2001, 5536 posts, RR: 10 Reply 4, posted (12 years 1 month 4 weeks 1 day 2 hours ago) and read 12475 times:
As I said, pilots who are going to fly at altitudes of over 60,000ft. (very high for a fighter pilot, a mission at such altitudes will almost always be a reconaissance mission) have to wear a "space-suit", which is fairly similar to what austronauts have to wear. Therefore, I assume that the human body can sustain the pressure difference without any special equipment under 60,000ft, or, that fighter jet cockpits are partially pressurized, but I think the first one is more likely. Many fighter jets (F-16, for example), can't even reach that kind of altitude, so it is not a concern for their pilots. The "space-suits" I'm talking about are the funny orange suits that you always see U-2 pilots wearing. It takes half an hour or so to put one on!
Mr Spaceman From Canada, joined Mar 2001, 2786 posts, RR: 9 Reply 6, posted (12 years 1 month 4 weeks 1 day ago) and read 12473 times:
Hi guys. Thanks for your replies.
Like I said, I've never read info about cockpit pressurization in any performance charts of the Fighters that I listed below. That's why I'm curious.
I quickly typed up that list of fighters with the hopes that someone would come along and pick off which ones are pressurized and which are not. Maybe this will still happen...maybe it won't. What the heck eh! My girlfriend sure doesn't know the answers!
Mr Spaceman From Canada, joined Mar 2001, 2786 posts, RR: 9 Reply 8, posted (12 years 1 month 4 weeks 2 hours ago) and read 12455 times:
Hi USAFHummer. Thanks for your reply.
That's pretty interesting. It makes perfect sense to me to have the cockpit of a fighter pressurized to an altitude of only 25,000 ft when the aircraft is actually flying at say 50,000 ft. This lower ALT would definetly be easier on the pilots body, regarding it wanting to expand in very low pressure. Perhaps 25,000 ft is near the maximum ALT the human body can survive without medical problems acting up. If you think about it, people who climb to the summit of Mount Everest are over 29,000 ft high! Although they take many days to get there.
Perhaps 25,000 ft is the chosen cockpit pressure altitude limit (toward sea level presure), because of structural limitation of the canopy glass. A higher pressure differential might cause a canopy failure.
Some other questions: Does anyone know whether or not the Forced O2 flowing through the pilots mask is heated or not?
Also, does anyone know what type of class is used for a fighter jet canopy? By this I mean...are they made from special Plexi-Glass, that use special compounds, epoxy's, etc?