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VFR over-the-top

Updated: May 24, 2022

Prior to the implementation of the Standardised European Rules of the Air (SERA) in the UK, VFR pilots were required to maintain sight of the surface. However, following the implementation of SERA, it was noticed that the requirement to maintain sight of the ground was only required when operating below 3,000ft AMSL or 1,000ft above the terrain, whichever is the higher.


This means implicitly that VFR flight is permitted on top of an overcast providing the aircraft is above 3,000ft AMSL and maintains the required vertical and horizontal separation from cloud (1,000ft and 1,500m respectively).


Can I do this safely?

Although it is legal, it is not always a good idea. The first consideration a pilot should think about is how they will descend below the cloud again. If you find that the holes in the cloud below you are starting to close up, then you should consider the weather at your destination. It would be a difficult situation to find that you arrive overhead the aerodrome with no way of descending whilst maintaining VMC.


Another consideration is what you would do in the event of a loss of power, or any other reason that would cause you to perform an emergency descent. A descent through cloud is a risky situation for a pilot who is not qualified to do so. In fact, a recent experiment in simulated conditions showed that the average VFR pilot who enters IMC conditions can only maintain spatial orientation for 2 minutes and 57 seconds.

Another consideration is what you would do in the event of a loss of power, or any other reason that would cause you to perform an emergency descent.

Consider descending below the cloud if the holes seem to be closing
Consider descending below the cloud if the holes seem to be closing
Following the magenta line has become the primary method of navigation for many VFR pilots

Children of the magenta line.

These situations aside, a VFR pilot who

does not have sight of the surface cannot navigate by map and compass. It can be said that almost all aviators use tablets or phones with applications such as SkyDemon as their primary navigation method, so perhaps this is less of a problem than it was in the past. However, it is worth pointing out that intense sunlight such as that found when flying on top of cloud, frequently causes these electronic devices to overheat and shut down. This is sure to cause alarm if the pilot has no other means of navigating.


A sloping cloud layer.

Another potential threat of flying on top of cloud is ever-increasing cloud tops. If the pilot cannot find any hole to descend below the cloud, their only option in order to maintain VMC is to climb in order to keep on top of the cloud (or turn back).

An encounter with ever rising cloud tops is most likely when flying over cumuliform clouds.

An encounter with ever rising cloud tops is most likely when flying over cumuliform clouds. If the cloud ahead grows rapidly, the pilot may find that it out-climbs their aircraft and the pilot is forced to enter IMC.


Airspace ahead.

Flying on top of the cloud prevents the pilot from descending. If there is airspace ahead, the pilot can only hope that they are granted a clearance to enter it. Otherwise an awkward radio exchange may occur where the pilot has to explain that they are unable to descend because they made a bad decision 30 minutes ago. Another potential outcome of this situation is that you have to divert a long way to avoid the airspace completely.


There are reasons why you would choose to go above the cloud too. Smoother conditions exist above and hands-off flying is most likely. When an inversion layer exists, the pilot will find better forward visibility above too. But in case you missed the negative tone: If you are considering flying VFR over the top for more than a few minutes, the decision is best approached with a combination of paranoia and pessimism.

VFR over-the-top (sometimes referred to as VFR on-top).
VFR over-the-top (sometimes referred to as VFR on-top).

VFR over the top can be done safely but a lot of planning is required and an understanding of what can go wrong. If in doubt, descend whilst you still can.







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