What to do if you have gone through designated elevation of approaching plane

MooseJam

I was watching one of the new aircrash shows on discovery - it was the midair collision between a Saudi Jumbo and a Air Kazakhstan converted military Jet

The Kazakhstani was told stay at 15 the Saudi stay at 14 - they were approaching each other - the Kazakhstani thought they were to stay at 14 so they went down - actually a little bit below 14, then the radio operated spots the error and they pull up to get to 15 and hit the Saudi

I would have thought that was a terrible idea - if you have passed through the altitude of an approaching plane by mistake to then pull up and pass through it again, just looking for trouble if you ask me

My Dad was saying it was the right thing to do as there might be more planes below at 13 or 12 or whatever so they should have attempted to get back to their designated altitude

What is the right thing to do here ?

ch252

From what I can see there are 2 easy enough ways to sort it.
Climb the Saudi at 140 to 150 and make it expedite and the Kazakhstani that went below 140 to maintain that until the Saudi was level at 150 but that's dodgy for a few reasons, mainly the time restrictions, the time it takes for the Saudi to make it to 150 is about 45ish seconds if they're expeditiong, all the while the Kazakhstani is below 140 therefore if theres traffic below at FL130 he's a conflict for them. you could vector them both 10 degree's left, what the atco did according to the post is the last thing you do but the tcas should have picked it up?

It all depends on the traffic situation. Vectoring is the best option because its quick and instead of one moving away from the other, they are both moving apart simultaneously, but then again he could have an item either side of the planes in which case I would assume plan B would be used, which is climbing of the aircraft.

Anyway I'm not a controller but thats two ways of resolving it that I've seen real atco's use

diverdriver

The rule now is to obey the TCAS and not second guess it. That kind of accident shouldn't happen again. If there's conflict with the controller and the TCAS the TCAS should be followed. This of course assumes the other aircraft is equipped with TCAS.

therecklessone

Some reading:

http://en.wikipedia.org/wiki/1996_Charkhi_Dadri_mid-air_collision

beamwidth

MooseJam wrote: »

I was watching one of the new aircrash shows on discovery - it was the midair collision between a Saudi Jumbo and a Air Kazakhstan converted military Jet

The Kazakhstani was told stay at 15 the Saudi stay at 14 - they were approaching each other - the Kazakhstani thought they were to stay at 14 so they went down - actually a little bit below 14, then the radio operated spots the error and they pull up to get to 15 and hit the Saudi

I would have thought that was a terrible idea - if you have passed through the altitude of an approaching plane by mistake to then pull up and pass through it again, just looking for trouble if you ask me

My Dad was saying it was the right thing to do as there might be more planes below at 13 or 12 or whatever so they should have attempted to get back to their designated altitude

What is the right thing to do here ?

The correct course of action for the Kazak was exactly what they did - return to the cleared level as soon as possible. In this way 99.99% of the time, there are no major implications to safety. If FL150 was safe in the first place, then it still would be!
In this specific case, the aircraft never saw one another, and the Controller had only Primary Radar ( just a blip, no altitude info ). there was no way of the controller knowing that something had happened until it became apparent after the crossing point that there were no longer 2 blips on the screen. therefore no remedial action would have been taken ( vertically/laterally). TCAS would have helped, if they both had it.
In terms of vectoring against level change each scenario is different. This case has been used in Irish Controllers refresher training, and the opinions on what one might do vary from ATCO to ATCO. One certainty is that a turn to both aircraft of 10 degrees would not be sufficient. With such a short time frame, you would expect a controller to react with a turn AND a level change