Runway Selection Question (specifically at EGNT)
 

Forgive me for what may be a 'stupid' question, but I've searched the forum and other sources without finding an answer. Mods, please move this topic if you feel it is more appropriate elsewhere.

My query relates to EGNT procedures, but there may be a common answer that is equally applicable at other fields.

I have noticed that the preferred runway at EGNT is 25, somewhat unsurprisingly, as I understand that westerly operations are most common in the UK due to the prevailing winds.

However, when operating in conditions less than VMC, the preferred runway appears to be 07, even when there is no obvious wind component affecting this change. So even on a 'calm' day, by looking out of the window I can hazard a pretty reliable guess as to the direction of ops at my local airfield.

So what factors, other than wind direction, influence the runway in use, and am I right in thinking VMC/IMC is a major factor, based on, for example, obstacle clearance?

Any replies appreciated!

My instructor came up with this acronym which seemed to serve me well for the exams...

M- Manoeuvring Area Serviceability
A- Availability of Approach Aids
S- Surface wind (If calm 2000' wind)
T- Traffic Pattern
R- Runway length
A- Airfield Lighting
W- Weather (Fog, Clouds etc.)

Hope this helps :)

I'll start with a simple one: approach aids available e.g. ILS, approach lighting.There may be better available on one runway as opposed to the other.
There are many other factors such as noise abatement. I will leave the others to someone else.

Not so much because it's IMC but generally when the weather is rubbish that means rain. A wet runway gives you worse performance than a dry runway.

25 has a hill which is considered in perf. calculations but 07 doesn't. 07 is generally better performance wise and quite often it's better to take 07 with a tailwind when it's wet.

That's my best guess as there aren't really any other differences between the two.

I'm also local to EGNT and I suspect that on the 'calmer' days, where the westerlies aren't prevailing, the predominant wind is a sea breeze.

I've quite often travelled out early morning/back in the evening and it's very rare to use 07 in the morning but seems a lot more likely in the afternoon/evening, which would back this theory up as the sea breeze will become stronger as the day goes on and the land mass warms up.

Thank you for all responses. Chesty Morgan, are you referring to Callerton Hill, which is at the end of 25? I know that aircraft have to be 'light enough' to safely clear the hill when climbing out.

I don't know the specific name or the specific hill, that whole ridge line will have an effect as far out as the performance considers it but I don't have access to that information at home.

The hill poses no problem for take offs, most aircraft (even the emirates 777) pass this at ease with 2000ft to spare.

Could it be that 07 has a preferred "overshoot" area than 25. 07 being flat and level into a farmers field (notwithstanding the B road), whereas 25 would have to clear an embankment, a railway line and a major trunk road just west of the airport.

Yes, we pass it with ease but the hill is considered an obstacle for performance purposes (which is worst case ie. single engine) and, therefore, it does impact on lifting ability from 25.

There are no close in obstacle on either runway.

Just adding to this thread as my question is on topic.

Over the last month or so about 90% of the time 07 has been the active runway at EGNT. That's substantially more often than usual.

Is anyone aware of a specific reason for this (eg navaid maintenance) or is it just coincidence based on the the recent wx/wind?

I would imagine it is based on recent weather as EGPH has been on Easterlies for a similar duration recently too.

Most airports in northern Europe have this year been on easterlies significantly more then on average. I have heard it said that this has something to do with El Nino.

Runway in use
 

Could be longer runway and proximity to terminal facilities?

After spending 18 years working in ATC at NCL/EGNT, plus flying as a PPL, I can say its purely wind direction with 25 being into the predominant wind! Except at this time of year with a High pressure over the UK bringing easterlies hence the time recently spent on 07!
Plus the 25 take off is slightly effected by Callerton hill but it only really effected older heavy departures, Airtours transatlantic 767's would take up 8kt tailwind on 07 rather than depart 25! But that's a long time ago!! Most airlines still I believe publish an emergency engine out turn on runway 25??

10d you're correct regarding emergency turns, each airline has a different procedure and I always find it strange that ATC isn't informed what they are. There is also an emergency turn on 07 but it's not a requirement to follow it as there is no terrain as such.

The hill off the end of 25 still affects performance even on modern stuff and as you say sometimes we get better performance on 07 with a tailwind.

10 DME ARC that takes me back, was a pax in an Airtours 767 NCL-MCO, oh, 18 years ago maybe, had to make a fuel stop at Bangor due IIRC the pilot saying something about high ground to the west of NCL limiting his take off/climb performance or somesuch.