Two aircraft near EDI last night

[Coffin Dodger]

Quick question for the more knowledgeable if I may.

I live around 12 miles south west of Edinburgh and depending on the wind direction, we get a lot of traffic passing overhead making the approach to EDI. Last night around 6.30pm I looked up and saw not one, but two aircraft - one almost directly behind the other. Both were of a similar size (757 or similar type). The thing that amazed me was that the separation between them was probably somewhere in the region of around 15 similar sized aircraft lengths, could have been less, but certainly no more. They were that close! I watched them for a full 30 - 40 seconds as they headed directly north, fully expecting one or the other to deviate but they continued flying on until I lost sight of them behind the rooftops. I remember thinking to myself, "somebody must have that on a radar screen somewhere".

Now I'm no aviation expert but I have read about wake vortices and separation distances. I've certainly never seen anything like that in the 20 years I've lived here. I've also no idea of altitude but I'd certainly say they were both at the same altitude and it looked very similar to the normal approach height for a civil twin engine 757 sized jet around 12 miles out from EDI. Engine pitch also suggested approach thrust.

I certainly didn't imagine it. Any ideas?

Thanks

[Munnyspinner]

I live in the city. If these aircraft were heading North together I suspect they may have been flying military cargo or refuelling a/c. It would not be ususal to rouet through the zone towards Leuchars. Civil airtransport would not be flying that close - although it may have been an optical illusion if there was vertical separation and one was going to turn West to GLA and the other Right for EDI I have been pretty close to northbound GLA traffic which follows the same routing from London. They usually well spaced horizontally tontally and vertically before they split up, near Lanark. Maybe one of the ATCOs from EDI can oblige with an answer.

[Coffin Dodger]

Thanks. Appreciated.

[NudgingSteel]

They might well have been being vectored towards final, in very close proximity, but one 1000' above the other. That's a relatively small distance which from the ground, frequently means two could look at the same level or even separated the other way round. After quite a few years as an aerodrome controller (looking out of the tower at traffic all day) I still find it hard to estimate altitudes above 1000', even in daylight. In the dark it's nearly impossible.

Some years back I had been holding three a/c awaiting a snow closure; they were at 3000', 4000' and 5000' over the beacon. Shortly afterwards I had the misfortune to answer a phone call from a chap in town informing me I'd just had an AIRPROX with two planes "jinking at the last minute" to avoid each other at the same height. To no avail I explained STCA, SMF and TCAS before he accused me of covering up an incident and slamming down the phone!