Northolt Inbounds

[trafficcontrol]

Hi Everyone,
Im still training on my PPL at EGTB or wycombe at the mo, i was just wondering what Northolt inbounds are in which airspace. We were coming back to EGTB overhead stokenchurch at 2000QNH on 7000 mode C . When a BAe146 Passed right infront of us,(well i say that, it actually came at a diagonal right to left, from behind. We visuled with the traffic at about 2-3 oclock) at between 160-180 kts. I'd say it was definatly within 3 miles of us, again roughly at 2000ft. What i really wanted to know, Would we be flashing together on radar. We were in class G Im not sure whether the BAe146 was too, or in another type.

Any info would be great.

Cheers
Sam

[eyeinthesky]

Some Northolt inbounds (particularly the Royal flight ones when positioning) join from outside CAS via the Stokenchurch area. They are beneath CAS and are subject to the same see and avoid rules as you are. They are limited to 250kts max.

To answer your direct question, then yes you would have been shown on radar and on the aircraft's TCAS. You were both in Class G airspace. There may or may not have been conflict alert alarms showing on Northolt's radar. I dont know how they have it configured. The 146 would have had the traffic called to him by radar and may have used TCAS to spot you, so provided he missed you and obeyed the rules of the air, he could go as close as he liked.

[Warped Factor]

You can see the non-airways arrival routes into Northolt here. (http://www.ais.org.uk/aes/pubs/aip/pdf/aerodromes/32WU0701.PDF)

The Northolt traffic would be getting a radar service from Northolt Radar who, incidently, when open are usually happy to give a radar service to traffic operating outside CAS around the northern boundary of the London Zone.

WF.

[TheOddOne]

Northolt Radar who, incidently, when open are usually happy to give a radar service to traffic operating outside CAS around the northern boundary of the London Zone.

oo-er, new one on me. I fly from Denham - I'll give it a try!!! Normally if going East, I'll call Elstree, west, Booker or north, Luton for a Flight info service, so I'm not sure the brief time that Northolt would be useful is worth it.

I see inbounds have to be 2,000' or below by zone boundary. I often route round the NW edge of the Heathrow zone at about that level, normally talking to Booker for traffic info. Don't fancy my chances of 'see & avoid' with something doing 200kt +. Incidentally we've no mode charlie on our transponder - presumably that renders it useless for TCAS avoidance purposes...

We sometimes see Northolt outbounds routing through the Denham overhead @ about 1500', no confliction as our circuit is 1,000' QNH, 750' QFE.

Cheers,
TheOddOne

[Warped Factor]

With no Mode C ACAS equipped traffic will still be able to see you on their display but they won't get an RA on you should you end up quite close.

Not as good as if you had Mode C but better than nothing at all.

Your circuit height restriction is there to separate you from WU traffic, both airways and non-airways.

WF.