Learning to fly, or thinking of learning? Post your questions, comments and experiences here

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By flyingearly
#1773634
I'm posting this here as although it's not strictly a 'training' question, I'm very newly qualified and it relates to attitudes set during training - and I'd be glad to get other people's views.

This may be a really stupid question, BUT: what are the issues with flying above 3,000 feet AMSL?

It sounds ridiculous, I know, but I've sort of got it into my head that general aviation tends to mean flying below 3,000 feet, or that you shouldn't really be flying above 3,000 if you don't need to.

When I've spoken to others about this, I've sort of got the impression that you can't go wrong if you stay below 3,000 feet, and that above 3,000 is more complex.

I understand that VMC above 3,000 feet is different to below 3,000 feet. I understand that above 3,000 feet you use 1013 on the QNH. And I get that controlled airspace starts at 5,500 feet.

I understand that speed restrictions exist (140 knots?) below 3,000 feet, so staying under there means less chance of meeting something fast coming towards you.

But is that it? Am I missing something?

Why do I have it in my head that it's bad practice on a clear, cloudless day for a microlight to climb up to 5,000 feet to get a better perspective? I'm feeling like it's akin to taking a bike to pedal on the M25.

I'd really appreciate other opinions on what sounds like a really stupid question, because on recent flights I've been tempted to climb higher but felt like I was doing something wrong if I did so, or that the correct 'place' for a microlight is below 3,000 feet.

In the US, I read lots of reports of VFR flights at 8,000 feet or similar, so I'm not quite sure whether it's just me, or a UK thing.

Opinions very welcome, even if it's just to correct me!
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By Morten
#1773639
Nothing wrong at all.

The air is generally calmer and navigation becomes easier on longer legs as you see more of the countryside/seaside. There's also a TAS benefit and there may even be a better wind up there to get somewhere quicker.
On straighter legs I quite often fly up to whatever level I can as long as I avoid the CAS above me. I suppose I could always ask for transit of the CAS but have never bothered as I also like to be off radio... and I would prefer staying below CAS to actually being controlled inside it...

Once you're away from the London TMA and the 'legs' radiating out of it, things get quite easy

However, you do need to get back down again so make sure you don't get caught on top of an overcast layer.
Also, there is often an inversion layer around 2,500-3,000 feet so visibility may be great straight down and straight ahead but not so much at the slant angle you would use to spot ground features by, so even on a 'clear' day you do need to be careful.

But the view is different. You see less detail and it is the detail many people find attractive. It also takes you a while to get up there and back down again, so a bit more advance planning is required.

Anyway, the are no dragons there as long as you stay outside CAS. Although, if you want to go above 10,000 ft you should carry (and use) Oxygen.
By johnm
#1773641
Where Class A controlled airspace starts varies a lot, round London it gets down to 2500 ft. As you can't fly VFR in Class A you need to stay below it. However as long as you do that you can fly as high as you like. I'm a fan of flying high because I quite often fly at 10,000 ft in the airways IFR and I routinely fly at 5000 to 7000ft VFR on top.

Edited to add: Try and find an experienced pilot or two at your base airfield and discuss these issues with them and even go flying with them. I did that in my early days and it's paid dividends.
By low&slow
#1773658
flyingearly wrote:I understand that VMC above 3,000 feet is different to below 3,000 feet. I understand that above 3,000 feet you use 1013 on the QNH. And I get that controlled airspace starts at 5,500 feet.

I understand that speed restrictions exist (140 knots?) below 3,000 feet, so staying under there means less chance of meeting something fast coming towards you.

VMC below FL 100 remains the same for all aircraft but, if you are flying slower than 140kts IAS, you are allowed to fly in greatly reduced horizontal visibility. If the viz is > 5km, you may still come across aircraft flying at up to 250kts, even at altitudes below 3,000'.

Airspace above Headcorn starts at 5,500', in other places it starts at ground level, in some places (usually away from London & the other big cities) there may be no airspace at all. You need to be able to look at an aviation chart and interpret where airspace starts and ends.

The transition altitude is at 6,000' in many places. The requirement to cruise at flight levels only applies to aircraft operating under IFR. It, and the semi-circular rule, is recommended for aircraft cruising under VFR, so good to know, but if you're just popping up to have a look and then descending again, don't worry about it. Airspace that starts above 6,000' will be classified as having a base at a flight level so if you are planning to get anywhere near it would be good practice to set 1013hPa well before reaching it.

So long as you are sure of where you are in relation to nearby airspace, there is no problem in flying above 3,000'. If you are planning to cruise above the transition altitude, setting 1013 and using the semi-circular rule would be good practice. Flight above FL 100 requires a Mode S transponder.

Edit: just realised that airspace above Headcorn starts at 3,500', the 5,500' starts a few miles SE.
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By VRB_20kt
#1773695
Up North we’re fortunate in having rather less controlled airspace and flights over 3,000ft are common - particularly over mountainous areas where the terrain elevation frequently is over 2,000ft. It’s generally great up there. The air often feels silky smooth and even if the inversion layer is high you can often climb over it and experience phenomenal visibility. The gotchas are limited but I suppose the most important is not to find yourself above a solid layer of cloud and needing to descend. Also, if the inversion is creating a thick fug it’s possible to lose the horizon - though that’s extremely rare.

Visual Flight Rules are different above 3,000ft and it’s worth refamiliarising yourself with those.

Otherwise... Enjoy!!!
By rdfb
#1773721
Morten wrote:Anyway, the are no dragons there as long as you stay outside CAS. Although, if you want to go above 10,000 ft you should carry (and use) Oxygen.


While we're on this topic, is there any specific regulation on this? I get the impression the US has specific rules around oxygen at altitude. What's the UK/SERA equivalent?

I ask because I routinely* fly to 15000 feet or so to skydive without oxygen, though I understand that there are mitigations such as the time we're up there. I've skydived from higher, but only with oxygen - so I'm quite conscious of the dangers. As a pilot I would also wear a pulse oximeter to mitigate, and my group aircraft has oxygen arrangements available too (that I've never used). So I'm not short of caution here; I'd just like to know what the legal boundaries are.
By flyingearly
#1773727
Thanks for your replies. Once I'm clear to the South of the Gatwick airspace, it's Class G and I've very much wanted to climb higher - glad that there is actually nothing stopping me.

It was more whether it was good practice etc - I've also been given the impression that light aircraft on a bimble should stick to below 3,000 feet.
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By lobstaboy
#1773728
The simple answer to the OP is that it's not a stupid question (there are no stupid questions), but there are no issues with flying above 3000'.

Other replies have identified things to be aware of (but you'll find them below 3000' too) and what to look out for much higher.
But 3000' is not special in any way.

I think people just never experience going any higher than that in their training - it takes time to get up there, so instructors mostly don't do it with pupils (in the same way that instructors know every field within 20 minutes of the airfield, and get instantly lost if they go further).

3000'+ is good - easier visual navigation and less traffic about. And you're much more likely to meet fast pointy things low down by the way. The matt gray coloured ones.
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By GrahamB
#1773734
rdfb wrote:I ask because I routinely* fly to 15000 feet or so to skydive without oxygen, though I understand that there are mitigations such as the time we're up there. I've skydived from higher, but only with oxygen - so I'm quite conscious of the dangers. As a pilot I would also wear a pulse oximeter to mitigate, and my group aircraft has oxygen arrangements available too (that I've never used). So I'm not short of caution here; I'd just like to know what the legal boundaries are.

Assuming an EASA operation:

Part NCC.OP.210 requires use of oxygen when cabin altitude is above 10000' for more than 30 minutes, and whenever above 13000' at all.

Part NCO.OP.190 essentially says the same thing, but leaves it open for a commander to assess need for both crew and/or passengers.
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By johnm
#1773744
@GrahamB Had to refuse a climb requested by Genoa for precisely that reason though I've happily been to 14,000 ft in the Andes on just coca sweets :-) MrsJohnm did not fare so well sadly :-(
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By GrahamB
#1773749
Paul_Sengupta wrote:Remember to lean the engine properly at any altitude, but especially so as you climb higher.

Are there any microlights that have engines that can be leaned (genuine question)?
#1773766
GrahamB wrote:
Paul_Sengupta wrote:Remember to lean the engine properly at any altitude, but especially so as you climb higher.

Are there any microlights that have engines that can be leaned (genuine question)?


For all reasonable purposes, no. I have seen a couple of after-market mods that provided limited mixture control, but they all seem to have been evolutionary dead ends.

I've taken 2 and 4-stroke microlights to 10,000ft feet enough times, and the only issue has been an occasional sense of "what the f**** am I doing here" at that height in a flexwing.

G
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#1773768
flyingearly wrote:I'm posting this here as although it's not strictly a 'training' question, I'm very newly qualified and it relates to attitudes set during training - and I'd be glad to get other people's views.

This may be a really stupid question, BUT: what are the issues with flying above 3,000 feet AMSL?

It sounds ridiculous, I know, but I've sort of got it into my head that general aviation tends to mean flying below 3,000 feet, or that you shouldn't really be flying above 3,000 if you don't need to.

When I've spoken to others about this, I've sort of got the impression that you can't go wrong if you stay below 3,000 feet, and that above 3,000 is more complex.!


Slightly different VFR minima.

IF the transition altitude is now below you, set 1013.25 on the altimeter subscale.

Climb rate will drop off a bit.

Less traffic.

If you get above the inversion layer, which is often around 3000ft, horizontal visibility will be much better, you'll still be able to see stuff directly below you, but at a slant often not.

That's basically it. Climb to any height you like below the oxygen requirements, it's really not an issue.

G
Last edited by Genghis the Engineer on Mon Jun 01, 2020 4:31 pm, edited 1 time in total.