High altitude flying

[DieselFan]

Hi all

I've seen some pics where ML's are flying above mountains and according to the site the summit is roughly 11300', which would put the ML at about 11600ish...but what is the highest one can go without needing a "mask"? or that one can safely do even if it's just for 10 mins or so?

[krusty]

DF, I stand to be corrected, but I believe that SA airlaw allows you up to 12000' for 2 hours without supplemental oxygen. (Or something close to that).

[krusty]

DF, I stand to be corrected, but I believe that SA airlaw allows you up to 12000' for 2 hours without supplemental oxygen. (Or something close to that).

PS. Having said that - each individual is different and I wouldn't recommend it without a safety pilot who's done it before. Some people suffer from "altitude sickness" at lower altitudes than that.

[krusty]

Cold is the bigger problem than altitude

The easiest way to detect altitude sickness is your fingernails start to go blue. Problem is, flying in the berg, your fingernails start to go blue as soon as you take off, but for other reasons

[Microwave]

In the Berg at those altitudes your fingernails go blue from the cold. I've never noticed whether the altitude has made a difference.

Also it is a matter of fact, that despite perfectly stable air one tends to squeeze the bar a lot harder for some reason or other This also makes the fingers go blue.

[CloudBase]

The regs say:

No owner or operator of a non-pressurized aircraft shall operate the aircraft at altitudes between 10000 feet and 12000 feet for longer than 120 minutes intended flight time, or above 12000 feet, unless such aircraft is equipped with the supplemental oxygen as prescribed in Document SA-CATS-OPS 91.

[krusty]

The regs say:

No owner or operator of a non-pressurized aircraft shall operate the aircraft at altitudes between 10000 feet and 12000 feet for longer than 120 minutes intended flight time, or above 12000 feet, unless such aircraft is equipped with the supplemental oxygen as prescribed in Document SA-CATS-OPS 91.

Woo-hoo, I got something right. What do I win?

[krusty]

krusty Woo-hoo, I got something right. What do I win?

15 mins at 12100 feet without oxygen

Done that. Oops... Shhhh!

[Morph]

PS. Having said that - each individual is different and I wouldn't recommend it without a safety pilot who's done it before. Some people suffer from "altitude sickness" at lower altitudes than that.

It depends on your fitness levels, whether or not you smoke etc. The worst part of it is that you don't know it's happening untill it's too late, remember what happened to Payne Stewart the golfer. Something went wrong with the oxygen system and everyone on the plane fell asleep and the plane flew it'self into the ground after flying halfway across America.

[Redeye]

I was sitting on the ground at Dragon peaks when the Buzzard took a trike
to 16000- his voice got very sweaky and he was talking absolute rubbish on the radio-

[Redeye]

has never been the same since

he he- you are right - Maybe thats what went wrong

[gertcoetzee]

When I am asked how high a Trike can go the answer is either until I pass out, in which case I will glide down and wake up, to resume flying or until the Rotax pass out, in which case I will glide until the Rotax can be woken, to resume flying.

A great (and almost unbelievable) story about a paraglider that got sucked into a thunderstorm to an altitude of 6500 meter (documented on hisbarograph) can be read at:

http://www.poweredparaglidingontario.co ... ked_in.htm

[kb]

it's called Hypoxia, (see, I remember somefink from ground school). The main peoblem with hypoxia, is that the pilot himself is the last person to notice that he is suffering from hypoxia. First symptom is a feeling of europhoria, similar to the feeling you get after a bottle of JD, and you telling everyone, even the car guard that you love them, and they are your best mates, and and and. It is caused, as we know, from a lack of oxy to the brain. As krusty said, lips, fingernails turn a pale shade of blue, this is a sign of hypoxia in the late stages. Before this, pin's and needles, numbness in the limbs (not always) and possibly even dizziness. Under 10k ft, the chances are lowered quite abit. however, if you are a smoker, (as Morph said), you MIGHT be susseptible to it at a lower alt. Also, another interesting fact, chances are greater of getting hypoxia at night. DOes anyone out there have a clue as to why?? Just out of interest.

[gertcoetzee]

First symptom is a feeling of europhoria

Europhoria? I thought that is the joy a Souf African feels when he gets paid in Euros

another interesting fact, chances are greater of getting hypoxia at night.

Not true

[krusty]

another interesting fact, chances are greater of getting hypoxia at night.

Not true

There are two types of photoreceptors that we have in our eyes; they are Rods and Cones. The Cones are the cells that we mainly use during periods of high illumination. They are use for color vision and center vision. The Rods are what we use during periods of low illumination. They are used for black and white vision and peripheral vision. The eyes have three physiological and one structural blind spot. The nose, the optic disk and the aircraft frame cause blind spots that are commonly refereed to as Day Blind Spots. By having vision in both eyes and looking around the aircraft frame, we eliminate the Day Blind Spots. The Night Blind Spots include the day ones and also center vision. This is due to the majority of the cones being located in the fovea. The only way to eliminate the Night Blind Spot is to use a technique know as "Off-Center Viewing." By scanning around objects, you cannot only see them, but you can also pick up their motion.

Hypoxia is a term used a lot in aviation, but not too many people have tied it into night flight. Hypoxia is the condition that results from the insufficient amount of oxygen reaching the cells and tissues. Since the rods are being called upon at night to provide 100% of the vision, the oxygen demand placed on the body significantly increases. The onset of hypoxia can begin as low as 5,000-ft. pressure altitude. Even lower altitudes for smokers.

10) Consider use of 100% oxygen at night, even at low altitudes. Hypoxia can affect night vision, and it's not always easy to tell when hypoxia may be creeping up on you.

The effect of altitudinal hypoxia on night vision is primarily one of an elevation of the rod and cone threshold. Although decreased cone function is clearly demonstrated by the loss of color vision at hypoxic altitudes, the decrement in central VA is usually insignificant. However, scotopic night vision at altitude can be significantly reduced. Scotopic vision has been reported to decrease by 5% at 3,500 feet, 20% at 10,000 feet, and 35% at 13,000 feet, if supplemental oxygen is not provided. Thus, the use of oxygen, even at low pressure altitudes, can be very important at night.

1. None of this matters if you only fly garden chairs.
2. kb, it appears that the truth of the matter is that hypoxia is more dangerous at night due to the effects on your vision, rather than it being it being more common at night.