London Banter - View Single Post - "Jet and Turkish Airlines 777 in 'near-miss' over London"

Recliner[_2_] · September 10th 10, 10:40 AM posted to uk.transport.london

"Richard J." wrote in message

d wrote on 10 September 2010 09:29:29 ...
On Thu, 09 Sep 2010 20:33:29 +0100
Neil wrote:
On Thu, 9 Sep 2010 02:34:00 -0700 (PDT), Mizter
wrote:

---quote---
A business jet came close to a mid-air collision with a Turkish
Airlines passenger plane after taking off from London City
Airport, a report has said.

The Air Accidents Investigation Branch (AAIB) study described the
near- miss over London as a "serious incident".
---/quote---

http://www.bbc.co.uk/news/uk-england-london-11237496

Serious indeed, but "100ft to 200ft below and half-a-mile away" is
not "feet away" like the crappy reporting in the Standard (yes,
again) would suggest.

Is it even serious? Were the planes on a direct collision course or
would they have passed each other anyway if no one had noticed?

Yes, it *is* serious. The pilot of the business jet says he changed
his aircraft's heading to avoid the 777. The planes were heading
towards each other at a closing speed of at least 350 mph. That
suggests to me that without avoidance action, the planes would have
been between 0 and 4 seconds from a collision.

And this was not an isolated incident. The AAIB bulletin says that
"departures from London City Airport require crews to make full power
takeoffs before levelling off [at 3000 ft] less than one minute after
leaving the ground, which is unusual. It is critical that aircraft
comply with the level-off because there is a high probability that the
departing traffic will cross the track of an aircraft inbound to
Heathrow Airport, which might be only 1,000 ft above." But since 2004
there have been 21 instances where planes have climbed above the 3000
ft "step".

Presumably it's much more of a problem with executive jets than
airliners. The former are much more likely to have crew unfamiliar with
the unusual route, and lower levels of TCAS equipment, as in this case.