Clearway at UK airports
 

From CAP 168:-

I'm pretty sure that at some UK airfields the clearway extends outside the airport boundary (e.g. LTN RW 26). I'm interested to know how in these cases "under control of the airport authority" is exercised? One presumes that "aerodrome boundary" is the limit of land owned by the airport.

Thanks for any help.

means they have control over what goes in the area.

Ie nobody can poke things into the protected area.

You can have restrictions in place which means the airport can veto things happening outside its owned land.

If I remember correctly, the minimum clearway you can declare is 60m, however this is all some airport operators do declare even when the first significant obstacle is much further from the end of TORA.
Why is this I wonder; airport owner too lazy to get a survey done?
Unfortunately the operators have to use the published figures and I have known this to cause an aircraft to have to depart with a reduced fuel load then make a tech stop to pick up more fuel for the journey, rather than go non-stop.

Presumably the cost of doing so is judged to be more than the perceived benefit, from the airport's point of view. If so, that's just business.

I'll take comfort from that fact, next time I fly. :O

Happens at LCY six times a week ...

Maybe but for a 737 BBJ to go to Heathrow to take on extra fuel it gets a bit expensive!(Yes this has happened)

'Kept clear of obstacles'... Does this mean non-frangible obstacles, such that vehicles and sheds are not permitted, but hedges, fences and grazing animals are permitted.?
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The floor of a declared clearway (in FAR-land, at least) is allowed to slope upwards at a maximum of 1.25%.

So a grazing cow (which I wouldn't class as a frangible object!) that's, say, 1.5 m tall would be OK provided that it's at least 120 m from the start of the clearway. :O

I understand it's any obstacle whether frangible or not. I think the term frangible relates to being on the ground rather than airborne. I seem to recall somewhere in CAP168 it mentions 0.9m metre height being the limit before something is considered an obstacle in a clearway.

ILS localiser doesn't count, nor does approach lighting for the reciprocal runway.

If an operator has declared 60m its to do with the runway strip where;
Length of runway strips
3.4.2 A strip shall extend before the threshold and beyond the end of the runway or stopway for a distance of at least:
— 60 m where the code number is 2, 3 or 4;
— 60 m where the code number is 1 and the runway is an instrument one; and
— 30 m where the code number is 1 and the runway is a non-instrument one.

A clearway has to be under the control of the airport operator, so if there is anything outside the strip that is under the control of the adjacent land owner then the airport cant declare this, even if obstacle free.

But then most runways require a RESA
3.5.1 A runway end safety area shall be provided at each end of a runway strip where:
— the code number is 3 or 4; and
— the code number is 1 or 2 and the runway is an instrument one.

Annex 14 says objects in the strip should as far as practical be removed. So I guess if the adjacent land owner doesn't remove his objects then they can't be forced to.