altitude and hypoxia

[Jon Hewitt]

looking at threads in the past ,i see some microlight pilots have flown to 10000 feet .

what is the permissable hight allowed ,i flew at 5000 the other day ,would like to go higher ,how safe is it

jon

[MILO]

I've been up to 10 000, through the JBG tma at 7200 unannounced. Dumb.
I was there around 3-5 minutes. It was unpleasant & pointless. It takes forever to get there and coming down again is also time consuming and trust me you soon want to get down to a reasonable level and in hindsight pulling the bar back and throttling right back is not good at all.
I suspect I super cooled the motor pushed the VNE limit & ended up dealing with the power station thermals and smoke stream.
Its a log way up, feels like you are not moving.
Totally kak idea
When I landed I told a greybeard what I had done and he asked why I did it. I didn't have an answer.
Been there done that - crap tee shirt.
Re the Hypoxia, all info I have is you won't notice it, you get giggly, happy and stupid, vision narrows and then you pass out. I am sure that's at higher levels. I'd be a fool to say I was not affected in some way even by being 5000ft agl. If anything I might have experienced a mild panic to get down to a reasonable level again.
Don't waste your time and fuel.

[justin.schoeman]

looking at threads in the past ,i see some microlight pilots have flown to 10000 feet .

what is the permissable hight allowed ,i flew at 5000 the other day ,would like to go higher ,how safe is it

jon

Obviously be aware of vertical airspace limits. Other than that:
<=10,000' = OK
10,000' -> 12,000' = max 2 hours
12,000' -> 19,500' = O2 required
>19,500' = IFR only

Nobody who passes a basic flight medical should show any real hypoxia deficit up to around 15,000'...

[Bundy]

I think the VFR flight rules state you are limited to fly below FL190 (obviously dependant on the airspace)

In a trike you are more limited by the aircraft, but I have heard of guys going right up to 16000ft....

...When I did my skydive, I started feeling lightheaded as we got to about 14000ft...so at least I know where my personal limits are I guess?

Never been higher than 9600ft myself....pretty boring up there.

[FO Gyro]

In a gyro I've been up to 12 500 and felt fine, but didn't stay there long.

In my more younger, stupid inexperienced days of commercial flying, when flying a Piper Seneca 2 (turbocharged twin), I thought it would be clever to climb up to 17 000ft. The problem with hypoxia is you start feeling euphoric and don't realise your performance is seriously degraded. I could feel the lack of O2 up there almost like a light headed sort of feeling.

[PeterGrant]

Hi Jon,
....and the other guys who have forgotten their air law...
You are allowed to fly for a maximum of two hours above 10 000ft but never above 12 000ft without supplemental oxygen (or a pressurised aircraft).

According to some medical information I have read this actually applies to density altitude but the SA law does not say this.
Also everyone reacts differently to hypoxia and their actual physical state at the time.
Some effects apparently become measurable as low as 6000ft but this was for coastal pilots.

It's also very boring and lonely above 2000ft AGL, there is nothing to see.

[FO Gyro]

You must try FL370 where there is even less to see, unless you happen to go over Kilimanjaro like I did yesterday at FL210, 1 500ft above the crater which was quite fun.

[Turbo]

i have been up to 11500ft with permission by ATC in the hoedspruit area three times now and with no problems -- i was up there for around 15 minutes MAX

remain up there above 110-12000ft and suffer the consequences!

[Bundy]

unless you happen to go over Kilimanjaro like I did yesterday at FL210, 1 500ft above the crater which was quite fun.

Post some pics for us next time!

That must be an awesome sight,

[FO Gyro]

Will do, normally one whizzes past there at 300kts plus, so I normally slow down to 220 kts, just to give us time to take a few photo's. Will post those soon.

[FO Gyro]

Here are those shots of Kilimanjaro from FL210.

[HansH]

Drove up to the summit of Mt Evans in Colorado. Alt 14,260'. This is the highest road in the USA. Spent over an hour walking and climbing around the top with no adverse effects. Also quite a few few old geezers wandering around who all looked pretty normal.

[Bundy]

Here are those shots of Kilimanjaro from FL210.

Wow!

[nicow]

Here are those shots of Kilimanjaro from FL210.

Very nice

[PeterGrant]

Nice pictures of the mountain, I would also fly there if I could take a stroll to the jazz and order some coffee.

The first post asked if it is safe to fly at 10 000ft in a micro-light,
The answer is probably, but it might not be - you should read some real medical data on hypoxia and make your own decision.

I went to the top of Pikes Peak in Colorado also somewhere around 14 000ft and did experience some high altitude effects.
After 1 hour at the top, three of the 5 people got headaches and two developed coughs (fluid in the lungs = "mountaineers altitude sickness" ) that disappeared half way down
We had spent a week or more at high altitude in the vicinity and it took over an hour or so to get to the top.
In an aircraft you get there very much quicker and have little time to acclimatise.

Here is an extract from an article I read:

FSA issue 94 - Do not go gentle: the harsh facts of hypoxia
There’s only one good thing to be said for hypoxia. It probably doesn’t hurt as much as the many other ways in which committing aviation can kill you.

....the effects of hypoxia do not begin promptly at 10,000 feet, but rather that they start very subtly at lower altitudes....
...The first effect of mild hypoxia is reduced colour perception and visual acuity. This becomes noticeable in night flights at altitudes as low as 5000 feet. For night flying, the US Federal Aviation Administration recommends using supplemental oxygen when flying above 6000 feet MSL.