Aircraft Disasters (1 Viewer)
- Thread starter davparlr
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What's a pressure-breathing exercise?
Yikes, it seems the lesson is: "if in doubt, grab the oxygen mask"
I guess that does fairly accurately test judgement under adverse conditions: Bailouts are chaotic (if you survive it) and after that you still need to keep your head about you as you hit the water. At night, that's gotta be hard figuring out which way's up as you can barely see anything, in daytime you can at least see the bubbles, then there's that nice parachute that helped keep you from going splat, and now plans to drown you
The danger of hypoxia is not when you have a task to do, it is when you don't. If you are trying to do something and cant, losing coordination etc then you may well think "Oxygen starvation" the real danger is when you are just sat doing nothing in particular and feeling drowsy, suddenly you are gone, like falling asleep at the wheel of a car. It is hard to believe you can fall asleep while driving a car or truck but many do. Perhaps the most dangerous part is that it isn't unpleasant, quite the opposite, people who have survived it describe a pleasant sleepy feeling, hypothermia sometimes does the same.
At one time B-17 crews carried bailout oxygen bottles. That practice had been discontinued when I was there. The training theory was when bailing out at altitude you may pass out during free fall but regain consciousness in time ( 10,000 to 15,000 ft, ) to activate the parachute. Scary business. We were also told to stay with aircraft as long as possible if under controlled decent.
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I've watched them (there were a series of books written by MacArthur Job as well) mostly out of curiosity, and being an aviation buff.
The saddest ones to read were the ones where there was essentially nothing that could have been done (short of the pilot calling in sick)
It's sad that people use automation so much that they become incapable of doing anything on their own.
Was that the Crossair flight?
Those are the old radio-navaids with the needle pointing to the antenna, and using two to identify intersection points that form corridors?
While I understand procedures are to be followed, I tend to try and find out what's written on paper, and what you actually do (they should be the same, but they aren't always...): I was always under the impression that if a depressurization occurs, first thing you do is grab the mask, turn on the oxygen, and then sort out anything else...
It was in the list but it was like #8 or something...
All military... frankly it should be extended to commercial aviation too, but it ain't gonna happen.
Yes, but it's vital to make sure you convert kilos to gallons, and gallons to liters right or you'll takeoff with half a tank. I'm amazed nobody noticed the plane was climbing really well...
Yeah, that was profoundly screwed up...
For hiring or requiring everybody to go through the magnetometer?
No, the requirement was that employees could bypass screening, he was fired but due to a screw-up, they did not seize his ID...
If the ammo would not have the power to penetrate a body, you could be looking at some kind of covert op: There are many zip-guns that do not have rifling...
And on that note (I'm taking this as inspiration from a buddy from another forum)
- No matter how I die: It was murder -- even if there was a suicide note, even if there was a "suicide tape" or "suicide video" (those can be forged these days)
- If I am arrested for a criminal offense: I didn't do it, no matter what evidence was shown to the contrary
- If I disappear, it was not voluntary
Yeah, but look how many planes takeoff and land just at one airport in one day without incident?
Amazing, you'd think the fact that they were flying into the sun would tip them off... I was driving today and had to keep fiddling with the visor because some of my route had me pointing into the sun
Quite similar in some ways, they both deprive the brain of oxygen, but CO, HCN, KCN are actually worse as they not only bind to hemoglobin, but also disrupt the electron transport chain (that's the aerobic cycle that occurs inside the mitochondrion of our cells) which renders all of our cells anaerobic...
Good point...
You know, I was thinking of something: The B-52's sometimes hit altitudes of 55,000 feet, as did some of the V-Bombers.
Since they didn't wear pressure-suits, how did they remain breathing after bailout?
The first fatal DC-3 crash - from a dropped microphone...
List of accidents and incidents involving the DC-3 in the 1930s - Wikipedia
List of accidents and incidents involving the DC-3 in the 1930s - Wikipedia
I think you misunderstood.
The Dilbert Dunker is not about bailouts, it's about going into the drink off the flight deck without time to punch out. They swaddle you in all the paraphernalia of a jet pilot and strap you into a cockpit on top of a ski-jump-like tower over a swimming pool. Then the cockpit runs down the skijump, dives into the pool, summersaults inverted, and sinks. You have to free yourself from all the straps, harnesses, and hookups, get yourself out of the cockpit, figure out where "up" is amidst the cloud of bubbles, and struggle to the surface. It's funny how the immediate bouyancy that makes it difficult to exit downward out of the inverted cockpit evaporates once you're headed upward, making it a struggle to surface. Makes you appreciate the safety diver hovering down there with his shroud cutter and Bowie knife.
Cheers
Wes
Sorry...............Bill
Above approx 45K pressure altitude, even 100% O2 doesn't provide enough partial pressure of O2 for human survival, so if pressurization is lost, oxygen must be supplied to humans at pressure above ambient. This tends to inflate your chest like a balloon, and you have to struggle to exhale. Human musculature is designed to expand the chest while relaxing the muscles causes an exhale. Pressure breathing forces you to fight the pressure in order to exhale, a very tiring and claustrophobia inducing effort. I strained my very weak exhalation muscles in only 5 min at 46K, and my chest was sore for a week. Most of others in the chamber were highly fit fighter and attack pilots, and if I hadn't been doing a lot of scuba diving at the time, I would have wimped out.
Cheers,
Wes
Depressurization checklists for every pressurized aircraft I know of start with: "DON OXYGEN MASKS". I'm surprised that wasn't the case with the 1999 Learjet crash. I bet it is now.
The commuter airliner I used to fly was limited to FL250, but we practiced quick mask donning followed by an emergency descent procedure that would do justice to a JU87 or an SBD. (Mask on, power levers idle, props flat, at 200 knots one notch flaps, at 180 gear down, roll 80° left, let the nose fall through, roll wings level at 65-70° dive angle, stabilize at 180. Watch trees get bigger - fast!) We could get under 10K from FL250 in a little over 90 seconds. (At the cost of upsetting the passengers coffee!) Once established in the dive a cabin announcement was mandatory.
Cheers,
Wes
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Don't know about V bombers, but the BUFF had downward firing ejection seats with barometric parachute openers usually set for the low teens in altitude. My ex-SAC acquaintances tell me the seat was equipped with a bailout bottle that fed the mask while the seat was free falling under a drogue chute down to whatever seat separation/parachute deployment altitude was set in the barometric opener.
Cheers,
Wes
I did.
Yikes... I guess whatever way the bubbles go, that's the way you should go. At night that's gotta be brutal.
It's like you can't get the air out fast enough, and you'd be wondering if your lungs are going to go pop from it. I don't know how it'd induce claustrophobia, but it sounds very uncomfortable.
That sounds like it'd do it...
You can't exactly follow the bubbles because you have to swim away from the cockpit before surfacing to make sure you're well clear of the rapidly sinking aircraft and any fuel or hydraulic fluid it may have spread on the water.
There are a number of rather entertaining videos on YouTube under the search term "Dilbert Dunker". Most are from a couple decades more recent than my experience. I'm amazed at how much assistance these " modern" Dilberts are getting from the safety diver, how long it takes them to unstrap, and that they seem to have actual air in their mask/bottle. We had a dummy mask and bottle with no air or oxygen in it, and were drlled thoroughly on the unstrapping procedure, as we had to do it breath hold. (Five point strap release, O2 hose, G suit hose, audio cable, shed spurs, and heave out of the sticker clips.) The actual aircraft (not the Dunker) had an explosive guilotine that would release everything at once, but under water the bang would burst your eardrums and rattle your cage. We had a Dunker on base, and as the only scuba qualified guy in the detachment, guess who got to play safety diver? At least it was good for a free air tank refill courtesy of everybody's favorite rich uncle. Our Dunker was used rarely, as most aircrew needing recurrent certification needed the whole program, and we didn't have a boom bucket or an altitude chamber.
Cheers,
Wes
Don't worry, your lungs won't pop. The overpressure is regulated to a small amount above ambient, and the human ribcage is an amazingly strong structure.
The claustrophobia comes from the fact your mask is cinched tight to your helmet and it feels like your face is in a vise. This is necessary to keep the oxygen from leaking around the edges of your mask. It's called "having a good mask seal". That, plus you're straining to force out every exhale, and just as you get your lungs down to normal size, your aching muscles weaken, and suddenly you're a balloon again! Add that you're on the edge of hypoxia, and your vision is starting to tunnel and darken and the world is closing in on you, and your chest hurts and you want to rest but that incessant pressure won't let you, and panic is gnawing at the edges of your consciousness, but you're determined not to be the first to motion the chamber operator: "Enough! Take this thing down!". Sound like fun?
Cheers,
Wes
Zipper, biology was my favourite and best subject at school, however our minds work in different ways. I would consider Hypoxia to be much worse. That is because if you are overcome by Carbon Monoxide you are not at 50,000ft and there is at least a chance of someone finding you and getting you to safety.
Hi Wes. I use to work in ICU. I remember the CPAP days - always difficult when the patient had a NGT insitu.
I read the same principle is applied when you're buried in an avalanche and ya don't know which way is up or down - dribble, and start digging in the opposite direction to the slag.
Read this in one of those fact books - seemed hard to believe, but it also directs the reader to the appropriate site where they got the info from...
More than half of British pilots fall asleep on the job, says report - AOL UK Travel
https://www.aol.co.uk/travel/2013/0...ish-pilots-fall-asleep-on-the-job-says-balpa/
More than half of British pilots fall asleep on the job, says report - AOL UK Travel
https://www.aol.co.uk/travel/2013/0...ish-pilots-fall-asleep-on-the-job-says-balpa/
Been there, done that. 98% of my flying time was hand flown, but I did have a former student, a private business owner, who bought a tricked out Cessna turbo 210 and hired me to fly his people around and instruct any of them who wanted to get some stick time. This plane had a top of the line autopilot, area nav and flight management system, and flying became a matter of programming and monitoring rather than "driving the airplane". After three or four hours at FL230 unpressurized, with the nosebags on, the siren song of sleep became overwhelming. I would ask the guys in back to set their watch alarms to five minute repeat and check us in the front seats at each interval. As the only professional aviator in the bunch, I was the only one who couldn't afford one of those fancy dancy "aviator watches" that were so popular back then. Got woken up by ATC or the back seat guys on more than one occasion. Didn't help that the owner was a stickler for productivity, which meant long days, short nights, and multi day trips were the norm. Didn't have ALPA to fall back on, back then.
Cheers,
Wes
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