E, F and G grounded

[whitesoxnation]

I cringe every time I cycle the bleeds with the canopy down or move the ECS switch between AUTO and MANUAL.

 

[xj220]

Whys thay? What would happen? For the uninitiated.

 

[MIDNJAC]

Whys thay? What would happen? For the uninitiated.

You often get a pretty intense pressure surge as the ECS adjusts. While I have experienced a lot of F/A-18A-D ECS surging at altitude in weaker jets, the E/F seem to do it a lot more on deck than I ever saw in the legacy, and not just in the "weak" jets. Also, ECS manual up high in the 30's+, if you move the throttles back anywhere farther than about Mil, you are asking for a massive pressure surge/momentary depressurization, at least in a Legacy bird (which is now a defined downing gripe).

 

[Python]

^

What he said. FA-18 ECS has been responsible for a number of issues. Can't specifically say the statistics, but anecdotally it seems to be the most troublesome NATOPS issue. Numerous hypoxia and DCS episodes, as well as the recent event in Whidbey.

 

[Brett327]

I won't speculate, but the "explanation" given so far seems suspect, or at best, incomplete.

Once you see the data/evidence, it will make perfect sense to you.

 

[xj220]

Thanks for the info, I remember reading/hearing about the Hornets issues with that and OBOGS. Without speculation or revealing info that shouldn't be, was this a DCS episode then?

 

[Brett327]

No

 

[sevenhelmet]

I cringe every time I cycle the bleeds with the canopy down or move the ECS switch between AUTO and MANUAL.

I sort of understand what you mean, but if it's due to something the jet is doing I wouldn't take it flying, or- at minimum- down it when I got back. I have to assume you're talking about a C, since moving the ECS switch to Manual in a Rhino is prohibited (can cause the avionics cooling fan to grenade and foul the whole system, resulting in loss of OBOGS...)

You often get a pretty intense pressure surge as the ECS adjusts. While I have experienced a lot of F/A-18A-D ECS surging at altitude in weaker jets, the E/F seem to do it a lot more on deck than I ever saw in the legacy, and not just in the "weak" jets. Also, ECS manual up high in the 30's+, if you move the throttles back anywhere farther than about Mil, you are asking for a massive pressure surge/momentary depressurization, at least in a Legacy bird (which is now a defined downing gripe).

Not sure why you're seeing surging on deck, but that sounds like a down gripe. Anything described as "intense" certainly should be, IMHO. I haven't had that issue in a Rhino though, strange. Legacy surging is unfortunately more common. ECS Manual in the chuck has always been a "get home" mode to me, and I'll descend before selecting it, if at all possible. I hope the days of "select ECS Manual, and fly the jet" are gone, but with the age of the jets and operational demands, I have to wonder...

Once you see the data/evidence, it will make perfect sense to you.

Roger that.

 

[insanebikerboy]

So for those of us unfamiliar with jets, is the thought of explosive decompression akin to what happens if an astronaut hops out of a spacecraft without a spacesuit on, just to a lesser degree?

 

[MIDNJAC]

I'd say to a much lesser degree. I had a massive decompression from ~37k ft (basically to that altitude almost immediately, with surging prior to that), and did not end up having any DCS symptoms. Did tell the wife that night that if I started acting weird, take me immediately to the chamber at Reno Renown. She was psyched.

 

[Gatordev]

The last time I did a chamber ride, we still did the 25K decompression. Do they still do that? I thought I had remembered they were saying they were stopping it to eliminate the (much reduced) potential for DCS there, as well.

 

[Uncle Fester]

...Did tell the wife that night that if I started acting weird, take me immediately to the chamber at Reno Renown. She was psyched.

Shit, man, you coulda milked that one for a while.

"Did you stop at the store on the way home like I asked?"
"Sorry, babe, I forgot...still suffering from DCS, probably."

 

[scoolbubba]

The last time I did a chamber ride, we still did the 25K decompression. Do they still do that? I thought I had remembered they were saying they were stopping it to eliminate the (much reduced) potential for DCS there, as well.

No. They only did the rapid decompression to 10000 feet; the ride to 25000 was a gradual decompression.

The last two times I've gone through swim/phys, I've done the ROBD. Jax NASTP said all the chambers are decommed; they're too expensive to maintain. That, added to the risk of dcs vs. how effective the ROBD is at training someone to recognize the symptoms of hypoxia, made them obsolete.

 

[HuggyU2]

No. They only did the rapid decompression to 10000 feet; the ride to 25000 was a gradual decompression.

Ask SevenHelmet: you haven't lived until you rapid d to 70,000+.

 

[sevenhelmet]

So for those of us unfamiliar with jets, is the thought of explosive decompression akin to what happens if an astronaut hops out of a spacecraft without a spacesuit on, just to a lesser degree?

To a much lesser degree, in the sense that getting hit with a baseball bat is generally less severe than getting his by a bus. That doesn't mean the former can't cause permanent damage, though.

Ask SevenHelmet: you haven't lived until you rapid d to 70,000+.

Too true. That was definitely a huge confidence booster in the pressure suit. Watching the water boiling in its beaker 2 feet away during the chamber profile was unnerving. One of the few chambers left that probably isn't going away, at least as long as the U-2 is operational.