eyeinthesky.. Your comments about the use of SSR in the hold prompted some interesting discussions in TC the other afternoon. Upwards of a dozen of us - ranging from long experienced people, including examiners, OJTIs, LCEs, etc, to young whizz-kids who know the book backwards - all readily admitted that we use SSR on a regular basis in the hold to determine when levels are free. So, the inevitable question: Where does it say we can't? SSR is totally different to primary radar, on which the rule about the use of radar separation in the hold was probably based when it was written a hundred years ago. There is no sensible reason why SSR should not be used, provided it isn't garbling. NODEL in TC has a facility to expand certain holding patterns precisely so that garbling may be reduced and the labels read clearly. If that facility has been provided - no doubt at vast expense - surely it means we can use it? As I'm sure you'll agree, the whole of the UK would stop if we had to get level checks every time we dropped someone in a hold..
The other point, which several controllers brought up, is that the SSR info is more reliable than crew reports. Everyone of us can relate stories of crews reporting vacating a level but not doing so for at least thirty seconds - it happens every minute of every working day. Without SSR there would have been many, many dangerous situations. The opinion was that it's actually far safer to use SSR than R/T in checking level vacations.
Maybe time for a Part 1 clarification?
[This message has been edited by HEATHROW DIRECTOR (edited 07 July 2001).]