Manchester Runways

[Devlin Carnet]

OK, so The runway numbers at EGCC have gone from 24/06 to 23/05, I dont understand why, if Manchester has changed, then why not the rest of the country, Because I am sure the runways hav'nt moved with respect to the ground.
Can some clever person please enlighten me?

[JetSetJ]

I believe this is due to the magnetic variation. At the EGCC the rate of change is approximately 0.15E. The Easterly variation reduced the actual runway heading to 234. Henceforth this new value is nearer to 23 as apposed to 24 and therefore the runway assignments have changed.

I hope this answers your questions,

JetsetJ:ok:

[Rainboe]

It happened at Heathrow some 25 years ago too.

[GOLF_BRAVO_ZULU]

JetsetJ is exactly right. Woodford's runway 25/07 was not so very long ago 26/08 for the same reason.

[Devlin Carnet]

OK, I understand the magnetic variation changing, but what I dont get is why it only affects Manchester, and not the country as a whole,
mmm.. Maybe I'm just being really stupid.

[Rainboe]

It affects every runway in the country! But not all of them will tip over to the next 10 degree magnetic alignment. Then of course, it has to be confirmed it is definitely into the next band. Then if the poles flip altogether, aviation is really in Queer Street!

[Spitoon]

Runways are normally designated by rounding the magnetic alignment to the nearest 10 degrees (i.e. a direction of 238, 241 or 243 will become runway 24). Magenetic variation is not constant but varies, sometimes over quite short distances (although not in the UK). The combination of true direction of the centreline and the local magnetic variation and the rounding of designators means that designator changes appear to be almost random. In reality, because the designator is only an approximation of the direction of the runway, changes are sometimes deferred for operational or administrative reasons, until a planned repainting of the markings is carried out or some new flight procedures are published, for example.

[Devlin Carnet]

OK, that has cleared it up, Thanks very much for your time.

[Old Smokey]

Aha! That's why I always have a controlled crash when landing on 24R, I've been landing with 1° of drift!:E

It can't be the hump, one of the Prooners promised to bludgeon the hump into submission some time ago, and a Prooner wouldn't lie, would he/she?:=

As others have said, Runway numbers are rounded up or down to the nearest 10°, e.g. 232° with a Magnetic Variation change of -1° becomes 231°, and remains as Runway 23, similarly 239° becomes 238° and this Runway number is unchanged as 24. When the runway is midway between the two multiples of 10°, e.g. 235°, a 1° change will 'tip' the Runway direction in one direction or the other. A few runway numbers will change, many others will remain unchanged.:ok:

Regards,

Old Smokey

[MancRed]

How many other airports had to change due to this?

[cottam approach]

We have! 31/13 now at Valley

[BOAC]

OS - it may have been me that 'promised' - I have given it my best shot, I can assure you - I've even landed with drift on which MIGHT, of course, have turned the runway just that little bit.:)

[FLCH]

Then if the poles flip altogether, aviation is really in Queer Street!
Speaking of that I was in EGCC a couple of months ago and the street sign for Canal St. (in a particularly fruity area of the city) was altered by some smartie who used a black marker pen to rub out the letter "C" on Canal St. (Before you ask our layover hotel is very close to the street.):ooh:

[TopBunk]

Wouldn't you have to use a white marker pen to wipe out the 'C':p

[perkin]

Depends if the sign is white letters on a black background, or black letters on a white back ground, doesnt it? One would require a black marker pen, the other a white one... :E

[GOLF_BRAVO_ZULU]

I suspect this, http://www.manchester2002-uk.com/gay/gay-vill1.html , is why the sign was interfered with.

[bantam1]

Oh some of you out there have too much time on your hands!!!!!!!!!!!!

[mbcxharm]

In my Uni days, not so long ago, the S from the second word used to be removed too...