Forum: General F-22A Raptor forum

http://www.defensenews.com/article/2012 ... |FRONTPAGE

Geez, what is it? Something about the F-22's high ceiling? Could it be a psychosomatic thing after all the publicity? Maybe the pilots should be put in space-suits like the Soviets used to do.

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Pardon my ignorance, but what oxygen related issues are ground maintainers suffering from in relation to the Raptor? My personal theory is that the Raptor is an incredible aircraft with an incredible flight envelope and this may push some more than others to the limit, regardless of how well the on board oxygen system is performing.

I think, based on purely what I have read that the AF is doing a good job of addressing the problem. Of 14 issues, several were found to not be hypoxia. So they are covering all bases. And I respect the pilots who have concerns.
It appears the OBOGS system has tested over and over to do the job, given the right maintenance [Link pending approval]

One item I read, fwiw, is that most came from Elmendorf. Where AC have been started in the hangar. To me, this is logical and ties into the same reason the NAVY had 64 occurances of this same type. Bleed air being sucked back into the engine causes degradation in the way OBOGS can generate.
The F-18 suffered these when pilots stacked behind the JBD or other AC awaiting their turn to taxi to the catapults.

64 occurances over a longer period. But when figured out, changes in ground procedures stopped the problem.

Don't flame me. I think the F-22 program is fantastic. It has taken the issue seriously enough to ground AC. I don't blame pilots for being wary.
Safety is #1. But I think there is more to the issue. Tens of thousands of sorties is a solid record. Maybe later we will find out more about the pilots personal insights.

I saw the 60 Minutes report today on this issue, and it raised some concerns for me.

The first one was on the location of the OBOGS itself. The report stated that the OBOGS was positioned behind the engine. Is this a common arrangement for the OBOGS?

If this is a common position for the OBOGS, is the OBOGS on the F-22 the same model as used on older jets or is it new? If it is new, has there been testing of what the composition of the air going to the pilot is?

And no, I don't consider these dumb questions, because the same people that designed the F-22 also designed the F-35....which they didn't leave room for a tailhook on a jet that was designed for CATOBAR carriers.....

The OBOGS is not positioned behind the engine, it's positioned very close to the cockpit. And the rumor that this is caused by the ACFT warming up in the hangar is a complete myth. We actually have CO monitors in the hangars themselves and they are accurate to 1 PPM. When launching out jets, they don't even think about going above 0 PPM. The way the hangars are designed, there's actually a wind tunnel like effect. The wind actually forces from the front of the slot and out the back making it much windier inside of the slot and not allowing any of the exhaust to come from the back of the slot to the front. You can easily tell because it's always freezing in the slots due to the wind, but the wind is significantly less once you leave the slots.

And this is at both Holloman and Elmendorf. I don't know about Langley, but I'm sure they've had a few incidents where their planes warmed up on the ramp.

ptplauthor wrote:

I saw the 60 Minutes report today on this issue, and it raised some concerns for me.

The first one was on the location of the OBOGS itself. The report stated that the OBOGS was positioned behind the engine. Is this a common arrangement for the OBOGS?

The 60 Minutes report was confusing becuase it showed the OBOGS using air "after passing through the engine". The air for the OBOGS is actually bled off of the the compressor before any the air passes through the combustor and burns.

The way they explained that probably caused a lot of people to wonder why those "idiots" at Lockheed can't figure out why breathing jet exhaust is making pilots sick, when the problem is waaaaay more complicated than that.

I figured it was more complicated than they were letting on, I don't trust the mass media to get stuff like that right usually, so I just stopped by here to see.

Forum: General F-22A Raptor forum

‘Small Number’ of Pilots Wary of Flying F-22