MEDIA RELEASE

2004/10

7 April Airspace Incident Interim Factual Investigation Report

21 April, 2004

An ATSB interim factual investigation report has found that the airspace incident near Brisbane on 7 April involving a B737 and a Lancair aircraft was not an ‘airprox’ event.

In this incident, the two aircraft passed with 600 feet vertical and 0.4NM (about 1 km) lateral separation in new Class E airspace, but were not in danger of collision.

Unlike the Launceston airprox last Christmas Eve, in this incident the smaller Lancair aircraft was on air traffic control radar and in communication with controllers and the B737 aircraft had initiated a change of flightpath before receiving two TCAS alerts.

The Lancair pilot informed the controller that he had the B737 in sight. While the B737 crew were unable to see the Lancair, they noted its presence on TCAS prior to the TCAS traffic advisory (TA) and resolution advisory (RA) alerts and they also received three reports of traffic from the air traffic controller.

The ATSB’s interim factual report states that the Boeing 737-7BX, operating under the instrument flight rules (IFR), was en route from Townsville and descending for a landing at Brisbane, while the Neico Lancair IV-P, operating under visual flight rules (VFR), was en route from Maroochydore to St George, on climb to flight level (FL)165.

As the B737 was approaching FL 157, the crew noted the Lancair via the aircraft traffic alert and collision avoidance system (TCAS). At that point the crew reduced the rate of descent. Thirty seconds later they received a TCAS TA. Recorded data from the B737’s flight data recorder indicated that the crew levelled the B737 at FL 153, and then climbed to FL 154 and commenced a right turn away from the Lancair.

About 22 seconds later, the crew received a TCAS RA instructing them to climb. They subsequently climbed the B737 to FL 166 and continued the right turn to about 15 degrees right of track. Recorded radar data indicated that the Lancair passed behind and below the B737. The minimum distance between the two aircraft was about 600 feet vertically and 0.4 NM laterally.

Information obtained from the crews of both aircraft, the Airservices ATS controller, recorded flight data from the B737, ATS audio recordings and radar data, is consistent and indicates that the crews of both aircraft and the ATS controller complied with the published procedures for Class E airspace under NAS 2b.

The investigation is continuing.

The report is available from the website: http://www.atsb.gov.au.

Media contact: Peter Saint B: (02) 6274 6590, M: (0408) 497 016

Interesting how the 737 turned right without being able to see the other aircraft. TCAS procedures require you to follow vertical commands only to avoid collision and to maintain lateral track unless VISUAL contact requires other action.

Was this only because the 737 TCAS issued a Resolution Advisory commanding the 737 to climb to avoid the danger of collision?

Therefore, near collisions avoided by the pilot correctly responding to a TCAS Resolution Advisory are now not considered to present a "danger of collision"?

Looks like a miss is as good as a (0.4) mile!

They say it was not an "airprox event". They have to be kidding don't they! I mean 600ft and 0.4 of a mile. Would it have been an airprox event if they had got that close and the lightie had been flipped over due to the wake turbulence. They really are forgetting how dangerous it is for two aircraft (with one being reasonably large) to be this close to each other. The world has gone absolutely flipping crazy, if this is considered to be ops normal. Very very scary state of affairs.

As no prescribed separation standards are applicable in Class E airspace, there was no infringement of separation standards.

600 feet vertically and 0.4 NM laterally. Wake turbulence separation standard is 5NM!! Oh, I forgot, there are no prescribed separation standards applicable in Class E airspace.

Yeh, crazy isn't it Missy. I guess the laws of physics in relation to Wake vortices and what they can do to a light aircraft cease to exist in E airspace. Why... cos Dick says so thats why! I also assume that if the Virgin 737 had hit severe turbulence as it overflew the lightie by 600 ft (or 400ft whatever it actually was) and could not maintain altitude, that would have also been ok. And I also guess that since the 737 mode C could legally be 200 ft incorrect from what is displayed when verified and IF the lightie also had his mode C verified it also could be 200ft out, that this still isn't a problem in E airspace. Guess all these reasons we have a 1000ft and 5NM standard again cease to exist in Class E airspace.

A question for Dick Smith :

Dick - would you be satisfied under this present system to have your wife and kids on board and incurr separation standards such as those in this incident???

Under the previous system the Lancair would not have been allowed anywhere near that 737.

This is indicative of a flawed system that needs serious rectification and Professional Pilots and airlines to band together and insist on its removal.

Any comments Dick before you call out the spin-doctors???

I find it frightening that the ATSB, the organisation that is supposed to be indedpendent, above politics, has put something like this on paper. This is clearly an influenced statement. The question is, influenced by whom? No prizes for guessing.

ATSB, just how "independent" are you? If you are going to publish trash like that, what on earth is the purpose of the organisation....

From the report:-
"Please do not make broadcast transmissions or engage in chatter on an ATC frequency. The safety of others depends on you not doing this.

Pilots are not precluded from responding to any ATC or pilot transmission when they believe their safety is at risk from another aircraft.


When you are flying in Class E airspace you are responsible for separation from other aircraft. The onus is on you to look out and see and avoid other aircraft."


In this instance the Lancair pilot ONLY stated that he saw the 737 - it appears that at NO TIME did either of the VB pilots see the Lancair.
But of course Dick will maintain that this was the fault of the (VB) pilots, and not the system.

It was a TCAS RA that prevented this from becoming a mid-air collision.

A TCAS RA is effectively an emergency manoeuvre.......and it would appear that in Australia that is why this airspace has been delegated "E".

Very Interesting.

Did the VFR pilot make any changes to his flight tragectory once he had the 737 visual?

If not, why not? Again leaving separation to the lowest common denominator!!

If the pilot of the VFR aircraft had the Virgin jet in sight, why in heavens name did they get so close?

If nothing else, they should consider wake turbulence in their track clear of the other aircraft for their own safety.