Your in the soup, and the forcast was wrong, again. The breifer said freezing level was supposed to be at 9000, and your at the MEA of 6000. Tops are reported at 17000. You are over mountains, and the nearest airport is 40 minutes away, along with the possibility of a lower altitude. You can't turn back because it's getting worse behind you. Do you deal with the ice, which is going to cripple you airplane, or do you climb up above it and deal with Hypoxia? The airplane you are flying is turbocharged with a service ceiling of 25000. The O2 bottle is empty.
Ice or Hypoxia?
- Thread starter mshunter
- Start date
jynxyjoe
Queso King
Lol. Just crash it in.
If you can't get turned around you've gotta go up and pray it gets cold quick so there is less ice buildup. Although if it's daytime and you think you might have a chance at a break in the clouds at 6k and you can drop out of it into a valley and vfr it home that might work.
You say the ice is gonna cripple the airplane and you can't turn around, I'd say you've left no option but more altitude. It'd all depend how familiar I am with the area. If the worse is behind me but I know the MEA's are a ton lower I'd turn around anyway, get through it and if I start losing altitude i know I'm away from cumulogranite.
As I say though, you've left us no real options here.
Thats the point. When out of options, what do you do? Is Hypoxia that bad at those altitudes? I have been at 13k w/out o2 for short periods, and have noticed after the flight I was probably hypoxic. Does it change all that much in a few thousand feet? Either way, I think you'd have to declare.
ppragman
No pasa nada.
I figure you have no choice but to climb in this situation. Be advised, at 18,000 you have roughly half of the air available that you'd have at sealevel, so it'd be sketchy.
Orange Anchor
New Member
Composition remains constant. Pressure is half.
You don't get hypoxic because there is less air but because there is less pressure to push those little O2 molecules into you.
ppragman
No pasa nada.
Isn't pressure a measure of the amount of molecules available at this point?
Orange Anchor
New Member
I can respect that argument. Not what is most often taught in aviation physiology but go for it.
ppragman
No pasa nada.
I dunno, its been awhile since I've been in a pressurized airplane, so just curious. I know that the ratio of molecules is the same, but I'm unsure about the specifics.
dasleben
That's just, like, your opinion, man
Just like Orange Anchor said, hypoxia is caused by reduced partial pressure of oxygen, causing less oxygen to be pushed into your bloodstream.
Anyway, how bad is the ice? Severe icing, or are you just clenching the seat cushion while hitting the boot switch every 30 seconds?
Anyway, how bad is the ice? Severe icing, or are you just clenching the seat cushion while hitting the boot switch every 30 seconds?
You are already in the cluods. Scud running would involve a descent out of the clouds below the MEA.
ppragman
No pasa nada.
Do you have a sectional and a handheld GPS, or is your panel mount equipped with moving map? If so you'd be golden, and you could descend to warmer temps.
scooter2525
Very well Member
Deal with the ice. Take 1000 foot increments on the climb and see what the ice is at all levels. 6k-25k of severe ice? Not likely or a terrible day to fly.
jynxyjoe
Queso King
Changing altitude by 4k outa get rid of anything serious on that icing thing. That'd put you at 10k. Then you don't have to worry about being at the tops of the clouds, the most ice, and you aren't piling on that ice at 6k.
Orange Anchor
New Member
From the web
My point is the percent of oxy remains the same. One often hears there is less oxygen which implies to most the content of the atmosphere changes It does not.
Yours, I believe, is molecules are farther apart.
Either way the effect is that fewer oxy molecules get into the blood.
cmill
Cold Ass Honky
Given that situation, and knowing i wont escape the ice untill 18000, id be landing the plane. It would be sketchy over the mountains, but depending on the area, you could probably at least make it to a highway. Use a gps if you have one, if not ask ATC for vectors.
If there terrain was absolutely unforgiving, Then id be going up to 18000. By the time you climb up there, i would count on 15-20 minutes, and that should get you close enough to the airport that you could get it there.
I just dont like the idea of trying to climb up to 180 with the ice stacking on the entire time. With the options, id much rather bust mea and land on a highway than hope i can make it up to fl180, ice up, and stall all the way to the ground.
If there terrain was absolutely unforgiving, Then id be going up to 18000. By the time you climb up there, i would count on 15-20 minutes, and that should get you close enough to the airport that you could get it there.
I just dont like the idea of trying to climb up to 180 with the ice stacking on the entire time. With the options, id much rather bust mea and land on a highway than hope i can make it up to fl180, ice up, and stall all the way to the ground.
AviatorGator
Well-Known Member
This is what I was thinking. I certainly wouldn't want to stay in severe icing at the MEA of 6k in hilly/mountainous terrain. A climb up to 12/13k ought to change something for the better. At worse you'll be higher when you are forced to come back down.
In very controlled settings (of course) I have experimented with the effects of hypoxia (at night) at 13k, 15k, 17k, and 19k. Hypoxia is handled differently by different people. A whole array of factors including your age, your fitness level, whether you smoke or not, etc. all go into the equation. If I was forced to, I'd go to 13k or 15k in a heartbeat without O2. 17k is dicey but it beats the heck out of just staying at 6k and planning on scud running.
This is also an excellent reason why the airplane should always have O2 in the bottle.