Primarily for general aviation discussion, but other aviation topics are also welcome.
By Fellsteruk
#1893725
Hey,

Firstly sorry if this is a stupid question I’m trying to recall my airlaw and find an answer online and thought I’d ask.

So when your in uncontrolled airspace flying VFR can you fly above the transition level whilst VFR? And if so do you then have to fly on flight level and change to 1013 or can you stay on regional pressure setting?

Thanks
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By Irv Lee
FLYER Club Member  FLYER Club Member
#1893727
When going up, you have 'altitude' to think about and qnh set so it is called transition altitude on way up. However, NOT compulsory to go to 1013 and flight levels if VFR in UK, which often exposes UK training 'holes'. On way down (have qnh ready) it is called transition level as you would normally (if not in UK) be on 1013 as you approach it
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By GrahamB
FLYER Club Member  FLYER Club Member
#1893731
Fellsteruk wrote:So when your in uncontrolled airspace flying VFR can you fly above the transition level whilst VFR? And if so do you then have to fly on flight level and change to 1013 or can you stay on regional pressure setting?


It's not compulsory to change to Standard Pressure Setting when above the TA when VFR but you'd be wise to, as above it all CAS floors/ceilings will be expressed as Flight Levels.

The TA will vary around the country - typically it's 3000' amsl when well away from TMA's and CTA's but can go higher when under them.

Top tip - don't use RPS when flying over or under CAS and close to the ceiling or floor respectively, as those altitudes will be based on the QNH of the controlling authority. Get the QNH from the appropriate ATIS or by radio.
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By Fellsteruk
#1893732
Thanks Irv,

So where I fly the transition altitude is 6,000ft so if I want to fly up, say 8,000 ft, I could stay on local QNH or RPG then no consideration on the way down through the layer to go onto QNH.

In your opinion though for GA VFR what would be best practice if going that high for any length of time.

I’ll be honest don’t often fly that high but if on a long leg and the weather allows I like to get up and poke over any lower clouds, mostly when heading north :)
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By Irv Lee
FLYER Club Member  FLYER Club Member
#1893733
Well you would think everyone flying on the same pressure and at different levels depending on direction would be safer, and does everyone flying flight levels have a uk false sense of security that everyone else is?
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By Rob P
#1893735
Fellsteruk wrote:In your opinion though for GA VFR what would be best practice if going that high for any length of time


Flight levels every time.

If I am just popping up there for a short while (I am a chicken and my aeros are performed very high) I don't bother, but in the cruise, definitely.

We have the luxury of two altimeter readings. The nice friendly round dial which we rely on and the Dynon digital readout which we hardly use. If setting off on a trip where I think I might be cruising above Transition Altitude I will set the Dynon to 1013. Saves faffing about.

Do I feel a false sense of security? No, I don't feel I am any more or less likely to bump into anyone.

Rob P
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By AndyR
FLYER Club Member  FLYER Club Member
#1893738
FWIW, I wouldn’t use RPS when aiming much higher than MSA. Too inaccurate and prone to level busts.

I would look at what the airspace is above my planned climb to a level higher altitude. If it is an altitude I would stay on a local QNH, if a flight level I would set Standard. Down south we have a mixture of altitude and flight levels as bases for the TMA, so best to stay cautious.
By BoeingBoy
#1893741
From the Air Pilot:

b) VFR. When flying under VFR, aircraft in level cruising flight and operated in accordance with the visual flight rules above 3000 ft amsl are not required to conform with the cruising levels at ENR 1.7 paragraph 6.1 unless flying in conformity with the conditions specified by the appropriate air traffic control unit. The latest and most appropriate lowest forecast Regional Pressure Setting value should be used for checking terrain clearance


This is summed up as fly at whatever altitude you want and use the nearest QNH to avoid controlled airspace. Use the Regional setting to avoid terrain. DO NOT use the regional to avoid controlled airspace. That will not end well!

There is no requirement for you to use the semi circular rule +500' when VFR, but it's no bad thing to to.

See AIP ENR 1.7
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By AlanC
#1893765
Strictly speaking SERA.3110 applies here, stating that:
The cruising levels at which a flight or a portion of a flight is to be conducted shall be in terms of:
(a) flight levels, for flights at or above the lowest usable flight level or, where applicable, above the transition altitude;
(b) altitudes, for flights below the lowest usable flight level or, where applicable, at or below the transition altitude.

There is scope for a red herring on whether an aircraft climbed and then immediately descended is ever at a "cruising level", but the general intent is clear enough. UK civil instruction has frequently been a little slack on this thanks to our luxurious Class G airspace, while military elementary instruction (at least 20ish years ago!) was far more rigorous in instilling a discipline of setting SPS when climbing past transition altitude, irrespective of VFR or IFR, then QNH or QFE for the descent.

The wisdom of (officially) relying solely on SPS below MSA is a sadly separate subject thanks to most of our hillier bits still having a TA of 3000', but hopefully sense will be seen at some point for a harmonised rather higher TA across the UK! In the meantime a spare altimeter is a handy extra for terrain awareness, where fitted.
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By russp
FLYER Club Member  FLYER Club Member
#1893798
Am I the only one that thinks that transition altitutes in the UK are a complete mess and consequently mostly ignores them preferring to look at my chart and see what's above me - if the airspace above me on the chart says FL and I'm within say 1000ft I'll swap to SPS. If the airspace above lower level is in feet I stay at QNH and if there's nothing I generally change when I'm at over 6000ft (and only then if I'm getting a service from someone which I rarely bother with away from congested areas as I'm only VFR). I can honestly say I've never been questioned by atc when reporting altitudes above 3000ft on QNH rather than FL. Life is too damn short to try to work out where the transition level is 3000/4000/6000 ft and where it changes. I just went to look in the Skyway code to find out where this information is given having looked on skydemon and not found it and apparently we're expected to look at each individual AIP for the aerodrome under whose airspace we are flying!!!!
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By JonathanB
FLYER Club Member  FLYER Club Member
#1893803
There was going to be a European-wide TA harmonisation project, but I don’t know what happened to that. It would have raised the TA considerably. I believe it would also have involved binning RPS and moving to a similar system based on actual QNH.
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By ls8pilot
#1893817
Most electronic gadgetry should be able to show multiple altitudes (given a barometric feed eg from Flarm or SE2). My gliding stuff can show Flight Level, QNH altitude, estimated height AGL (based on the terrain database) and GPS altitude.

Having multiple values visible means you can easily use the appropriate reading for Airspace and Terrain avoidance.... of course you need to chose your cruising height (not relevant to gliders), but I've always wondered if, separation wise, you are not safer at a random cruise height (eg 2700 ft) rather than an exact multiple of 500ft ?

(As a source while Flarm is not a certified instrument, the barometric readings are calibrated for sporting purposes, so it's probably more accurate than most ageing pressure altimeters!)
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By JAFO
#1893821
ls8pilot wrote: I've always wondered if, separation wise, you are not safer at a random cruise height (eg 2700 ft) rather than an exact multiple of 500ft ?


I think you might have a point. Luckily, no matter what level I choose, I am rarely actually at it. :D
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