After reading the near collision report I have a few observations:
1.
Training. The declarations of the captain and the first officer differ. The captain reports “As I know, pilots in our company receive TCAS training at least
once every three years”. The FO must have had a different training schedule: “As I remember, the company regulated the flight crew receiving the TCAS training
once every half year.” The report contains data and statements only. More clarity would be required before one can draw conclusions that TCAS training seems not to be working in that region.
2.
Confusion. The TCAS RA brings a lot of confusion and agitation, perhaps panic, both in the cockpit as well as at the radar screen.
a. When the controller observes the traffic conflict, he uses the wrong callsign (EF308 instead of EF306) and utters an unintelligible phrase (stop eh immediately clear and descend), which is interpreted as level off. When the controller receives the verbal message about the TCAS RA, he gives an instruction to the opposite.
b. The Pilot in Command overreacts the descent after an unclear visual contact, to 8000’ a minute.
c. The First Officer reports TCAS climb instead of descent.
The human reactions are understandable. More than criticising the controller and the pilots for being inarticulate and overreacting, it shows again that a lot of work and investment is required to get TCAS real safe.
3.
Time lapse RA-ATC. Between the TCAS RA and the FO’s advice to the controller the time lapse is 13.8 seconds. That is a pretty good reaction time, far better than the average, but it is still more than could be achieved with an automatic message to ATC, connected to the RA instruction to the pilot.
4.
Visual contact. The instructions in the manuals (both from the company and Boeing) to try and get visual contact does not enhance safety, but gives rise to further misunderstanding. The captain has stated that "When the RA aural warning tone ‘descend, descend’ was issued, I followed the TCAS red T-bar on the ADI and pushed down the aircraft smoothly. Afterward the TCAS issued an ‘increase descend’ aural warning,
at the same time I looked outsight from the left to the right and visual contacted that there was a flying object approaching rapidly in front us. So I pushed down the aircraft hard to avoid the traffic. At that time I neither know what the flying object was nor identify the distance between us."
This incident obliges the air traffic community once again to look into some necessary refinements of TCAS, beyond its version 7.0. It will require initiative and it will cost money. But look at the alternative, pilots and pax, not to forget the controller, will not always be so lucky as EF306 and TG659. As a minimum the following is required:
1. An automatic TCAS-RA signal to the ground is urgently required so that the controller within 0.1 to 8 seconds knows that something is going on in which he should not intervene anymore. This is technically feasible through the transponder.
2. The manuals about getting visual contact should be reconsidered. Visual contact dates back to the piston engine era, it may still be useful close to ground but it is counterproductive for jets at cruising level.
3. International rules should be refined to indicate that controllers should cease to instruct aircraft after reception of the message that TCAS RA has instructed the pilot to take safety action. If the ATC system has made mistakes leading to the TCAS RA, they should be held resposible for these mistakes (in line with the Swiss verdict after Uberlingen, not so much the individual but the total system). But ATC should not be held responsible for what happens as a result of the RA.
As Armchairpilot has said:
ATC advising against TCAS. Not helpful and similar situ has caused accidents in the past when pilots couldnt decide who to follow
Songbird