F-22 Grounded

[EODDave]

The Hornet OBOGS has been the #1 concern at the SSWG for the last few years. It looks like the fix we (NAVAIR) found for the Hornet is actually being looked at by the Air Force. The main reason is that the Navy has known of the problem for some time and has been trying to figure it out. Hopefully, they fix our problem and we can get them to the fleet soon rather than later.

 

[MasterBates]

I hope so, the E-2D went from LOX to OBOGS. Not that I wear my mask that much, but when I do, it'll probably be fucked.

 

[KBayDog]

I hope so, the E-2D went from LOX to OBOGS. Not that I wear my mask that much, but when I do, it'll probably be fucked.

"I don't always wear my mask, but when I do, I prefer LOX."
-MasterBates, the Most Interesting Aviator in the World

 

[jt71582]

Just fly slower, stay below 10K, learn how to hover, and you never have to worry about any of it!

What he said.

Scraping the trees isn't really THAT big of a deal. That's nuts.

 

[phrogdriver]

I roll with OBOGS. Just wished it gave 100% O2 and not 90%. Supposedly that can give you the bends.

 

[Harrier Dude]

I've seen reports of all kinds of OBOGS issues in the Hornet community for years, but almost none in the AV-8B. Why? Are the systems that different?

I was talking to one of my Hornet buds and mentioned that it was fairly common to get an OXY caution light on deck with your mask off. He was incredulous that we would takeoff after that. Evidently that's a NOGO for them. True?

As far as I know, we've never had a hypoxic event in the Harrier attributable to OBOGS. Is that because we don't fly as much above 250? Why is this the one thing that never seems to break in our aircraft yet plagues the Hornet?

 

[MIDNJAC]

I was talking to one of my Hornet buds and mentioned that it was fairly common to get an OXY caution light on deck with your mask off. He was incredulous that we would takeoff after that. Evidently that's a NOGO for them. True?

In OBOGS a/c that I have flown, if you have flow on and mask off your face, then you will get false O2 cautions due to the system incorrectly sensing that the flow concentration/quality has dropped below the allowable threshold. Is that not something that you had in the Harrier?

 

[RHPF]

In OBOGS a/c that I have flown, if you have flow on and mask off your face, then you will get false O2 cautions due to the system incorrectly sensing that the flow concentration/quality has dropped below the allowable threshold. Is that not something that you had in the Harrier?

^ Emply plenum, right? I don't think it actually can detect the quality (which is the issue), but I'm not sure since I mostly fly LOX. Either way, yes, flow on, mask off, you'll pop a caution/warning for it.

 

[Harrier Dude]

In OBOGS a/c that I have flown, if you have flow on and mask off your face, then you will get false O2 cautions due to the system incorrectly sensing that the flow concentration/quality has dropped below the allowable threshold. Is that not something that you had in the Harrier?

Honestly, I don't know.

About 90% of the time you can taxi around with your mask off and you won't get a OXY caution light. The other 10% of the time it goes out when you put your mask on and it's no big deal. If it won't go out at all, the jet's down. You can also run up the power and see if that helps (not that I've ever done that, of course).

My buddy said that anytime the light came on in the Hornet with the switch on, the jet was down. Not true?

Still, it's not a big problem in the Harrier community (as far as I know anymore).

 

[pilot_man]

Honestly, I don't know.

About 90% of the time you can taxi around with your mask off and you won't get a OXY caution light. The other 10% of the time it goes out when you put your mask on and it's no big deal. If it won't go out at all, the jet's down. You can also run up the power and see if that helps (not that I've ever done that, of course).

My buddy said that anytime the light came on in the Hornet with the switch on, the jet was down. Not true?

Still, it's not a big problem in the Harrier community (as far as I know anymore).

Yeah, that's not true. I'm willing to say it's about the same. With the mask on, if the caution light comes on, then it's down. If you don't have the mask on before takeoff, then it's probably 10-20% of the time that you'll get a caution, but it usually goes away pretty quickly. We do have lots of issues and a pretty good number of hypoxia events recently.

 

[Harrier Dude]

Yeah, that's not true. I'm willing to We do have lots of issues and a pretty good number of hypoxia events recently.

Why is this? I'd imagine that the systems are almost identical, along with the T-45. What is different? Altitude? Engines? Under-reporting by the Harriers (like our GPWS debacle).

It doesn't make sense.

Your version (as opposed to my buddy) makes more sense to me. I had a hard time believing that they would down a jet for that, but you never know.

 

[MIDNJAC]

Why is this? I'd imagine that the systems are almost identical, along with the T-45. What is different? Altitude? Engines? Under-reporting by the Harriers (like our GPWS debacle).

It doesn't make sense.

Your version (as opposed to my buddy) makes more sense to me. I had a hard time believing that they would down a jet for that, but you never know.

My *guess*....and this is not from a whole lot experience, so take it with a grain of salt.....but our ECS systems on the older early lot jets really suck, and it isn't uncommon for the cabin pressurization to dump in a manner directly proportional to throttle movement (at least at the extremes). Maybe bad OBOGS plus this plus pulling G's? That would be my jab at a guess

 

[MIDNJAC]

^ Emply plenum, right? I don't think it actually can detect the quality (which is the issue), but I'm not sure since I mostly fly LOX. Either way, yes, flow on, mask off, you'll pop a caution/warning for it.

Yeah I think you are right.....at least I remember hearing that from our T-45 days. We have like 3 OBOGS jets on our line, so I mostly fly LOX

 

[pilot_man]

Why is this? I'd imagine that the systems are almost identical, along with the T-45. What is different? Altitude? Engines? Under-reporting by the Harriers (like our GPWS debacle).

It doesn't make sense.

Your version (as opposed to my buddy) makes more sense to me. I had a hard time believing that they would down a jet for that, but you never know.

Yeah, I think MIDNJAC is on the right path. Our ECS in general sucks. I don't think the Rhino has the same number of issues, but I'm pretty sure things aren't fixed completely in the Super. I would think that having two engines would help out, but it doesn't seem to.

 

[Harrier Dude]

Yeah, I think MIDNJAC is on the right path. Our ECS in general sucks. I don't think the Rhino has the same number of issues, but I'm pretty sure things aren't fixed completely in the Super. I would think that having two engines would help out, but it doesn't seem to.

I always thought you guys had a great ECS. Ever notice that we always taxi with our canopies open? Ever wonder why? Our ECS is worthless on the ground.

The only in-flight ECS issues I've ever had were in the two seaters. One explosive decompression and numerous weak canopy seals in -406 two seaters during the windup turns on FCFs (40k').

Never had a legit O2 problem, either personally or as a witness.