Runway End Safety Area

[VC8]

I have read the section in CAP 168 about Runway End Safety Areas but can't find the answer to a three questions.
Firstly, does anyone know if RESAs can or do extend outside the airport boundary?
Secondly, are RESAs divided into take-off overrun RESAs and landing over-run RESAs?
Is a frangible ILS array considered to be an obstacle in a RESA?
Any information really appreciated.

[chevvron]

As far as I recall, a takeoff RESA (clearway) extends as far as the first significant obstacle, so an undershoot RESA would be the opposite. Some airport authorities 'under declare' their clearways just declaring the minimum length which as far as I recall is 60m
.Items connected with 'navigation' are not included in calculations of the dimensions of declared distances.

[VC8]

chevvron - thanks for the info.

Do I take it from what you say that the ILS array (even though it is frangible) constitutes an obstacle in this context?

Also, I can understand when you refer to a RESA in relation to a landing undershoot, but do you know whether there are two different RESAs that apply to over-runs - one for the landing over-run an one for take-off over-run?

I have looked in CAP168, CAP670 and CAP760 but can't find a reference.

[Musket90]

For information there's an updated version of RESA requirements published in Chapter 3 of the latest edition of CAP168 (March 2014) available on CAA web site.

Regarding VC8's questions:

Airport boundary - it could be inside or outside, as long as it meets the the design requirements. If a portion is outside and the land is not owned by the airport then there should be arrangement between the airport and landowner to make sure it meets the requirements.

Overrun RESA's - The overrun RESA dimensions can sometimes be different for landings and take-offs if the end of declared distance for landing (LDA) is in a different location to the end of take-off run available (TORA). Sometimes the end of TORA is before the end of pavement because of obstacles on the climb out whereras the end of LDA could be at the end of pavement. This situation would give a longer overrun RESA for take-off than for landing. Another consideration is if a stopway is provided beyond the end of TORA in which case the RESA starts 60m beyond the end of stopway.

Undershoot RESA's - Start 60m before the landing threshold, so if there is a displaced landing threshold then this would provide more undershoot RESA than a threshold at start of pavement.

ILS - The ILS array at many airports is considered to be the limit of the RESA as often they are located at least 300m from the end or start of declared distances. Those airports where the RESA encompasses an ILS array should assess the frangibility of the equipment to satisfy themselves that it minimises the risk of damage to an aircraft in the event of undershoot or overrun.

[VC8]

Musket 90 - thank you for the information.

You certainly know your stuff re RESAs.

I realised that the latest CAP 168 had revised the RESA requirements but your post seems to have more detail than is available in CAP 168. Are there any other CAA publications that cover the RESA regulations?

[Musket90]

VC8 - I believe a CAA Safety Notice was issued in 2011 detailing RESA requirements, but this has now been incorporated in the latest CAP168 version. The RESA requirements in the new EASA regs soon to apply to airports I think are the same and which I understand are based on ICAO Annex 14.