f-22 obogs update, 2 july

[flaps]

http://www.nytimes.com/2012/07/03/u...gen-problems-elude-air-forces-fixes.html?_r=1

 

[wlawr005]

Why pull the emergency O2 after landing? Must be a typo.

 

[Swanee]

Why pull the emergency O2 after landing? Must be a typo.

I've "heard" a couple of stories from the old man that at least one of the of the guys at Langley decided to pull the O2 ring on the ground rather than stop, open the canopy and take the mask off.

 

[Brett327]

I take it from reading a lot of these articles, that the F-22 guys wear some kind of pseudo pressure suit in order to operate at higher altitudes - I.E., not the regular G-suit most of us are used to.

 

[Treetop Flyer]

I've "heard" a couple of stories from the old man that at least one of the of the guys at Langley decided to pull the O2 ring on the ground rather than stop, open the canopy and take the mask off.

Why wouldn't he just take the mask off?

 

[insanebikerboy]

Why wouldn't he just take the mask off?

If you take the mask off with the canopy closed then you have to smell all the farts you let that were trapped in during the flight....

 

[Harrier Dude]

Why pull the emergency O2 after landing? Must be a typo.

I've done it.

I had to shut the motor off on landing at about 130 knots. I had accumulator pressure for brakes and hyd pressure (residual and hyd accum) for about three inputs of NWS.

With the motor off, OBOGS quit and the mask was suffocating me. I thought that the mains were blown and I wasn't certain that I was going to stay on the runway, and if I was going to leave the paved surface at high speed I was going to have to eject.

I didn't want to eject with my mask off because I didn't want the 10,000 pieces of broken canopy glass to destroy what little natural handsomeness my face had.

So I pulled the green apple.

I stayed on the runway and got it stopped without blowing the tires.

I felt bad that the seat shop guys had to refill the bottle, but they didn't seem to mind. They were just happy I didn't use their seat.

 

[flaps]

great headwork, dude.

 

[armada1651]

I've done it.

I had to shut the motor off on landing at about 130...(tale of V/STOL badassery)

I get the impression the Raptor guy was in somewhat less extremis.

 

[Flash]

I take it from reading a lot of these articles, that the F-22 guys wear some kind of pseudo pressure suit in order to operate at higher altitudes - I.E., not the regular G-suit most of us are used to.

Not a pressure suit but a more 'complete' G-suit than we use to include a 'Combat Edge vest' that goes over their upper body. It is that they just had the pilots stop wearing, thinking that may be a contributing factor in the accidents. Another possible factor that was mentioned in the article is the pressure of the O2 flow, they think it may be too low and that is what they have been talking to Navy dive physiologists about.

I got a buddy in the Air Force safety office and they have spent a lot of time and effort trying to fix it, contrary to opinions of some.

 

[usmarinemike]

I've done it.

I had to shut the motor off on landing at about 130 knots. I had accumulator pressure for brakes and hyd pressure (residual and hyd accum) for about three inputs of NWS.

With the motor off, OBOGS quit and the mask was suffocating me. I thought that the mains were blown and I wasn't certain that I was going to stay on the runway, and if I was going to leave the paved surface at high speed I was going to have to eject.

I didn't want to eject with my mask off because I didn't want the 10,000 pieces of broken canopy glass to destroy what little natural handsomeness my face had.

So I pulled the green apple.

I stayed on the runway and got it stopped without blowing the tires.

I felt bad that the seat shop guys had to refill the bottle, but they didn't seem to mind. They were just happy I didn't use their seat.

Were you on fire? How much runway did you use to stop? Did you melt the tire plugs getting it stopped?

 

[Harrier Dude]

Were you on fire? How much runway did you use to stop? Did you melt the tire plugs getting it stopped?

Not on fire. I had a dual lane DECS failure AND a manual fuel failure. No shit.

Fired the manual fuel battery. Nothing.

Engine stuck in the low 90% rpm range and decelerating. Throttle did nothing.

Did a VNSL and had the gear stripped for 21R at KNYL. VV showed 3 degrees short of the numbers at 10 units alpha.

Kept bumping the nozzle lever aft to get more speed, but whenever I did, it drove the SAMSU motor which drug down N1 even more. The result: higher ground speed with the same alpha.

Crossed 32nd street at less than 50' at 17 degrees alpha and landed 10' from the end of the runway. Shut off the motor with the LP cock. Easy on the brakes (I only had 13k' of runway left, so not worried about going off the end) and the fuse plugs held.

No damage to the aircraft. In fact, the next day it went into manual fuel just fine. The wire bundle going to the manual fuel solenoid had something like 8 out of 10 wires cracked. The in flight vibrations were enough to not allow current flow.

The Nf pulse probe had come disconnected because (thanks NADEP!) it was only tightened one turn, vice nineteen like it was supposed to. I'm sure that dude got promoted.

Lesson learned: In the Harrier it is ALWAYS easier to piss away airspeed than to get it back. Fly VNSLs fast. From then on I always set the power, pulled the nozzles in to get the flaps to program full down 62, then moved the nozzle lever back to 50 and kept it there until short final. Flew the rest of the pass with the nose ridiculously fast. Much mo better.

In the sim you should practice doing VNSLs down to the deck instead of taking over with power at 50'. You never know when you might have no choice.

I'm convinced that's why it worked out. I'd been screwing around in the sim doing stuff like that.

Also, if you ever have to shut down the motor on rollout, make sure your APU is on. It was nice to still have a HUD until I got it stopped.