Loss of seperation????

[MMENCLLBAMAN]

Hi,

My first post after a long time reading (and hopefully learning)

I work for a tour operator as a hotel contractor and fly regularly.

I am curious, flying back CGN-MAN this afternoon with HLX and something really unnerved me - flying in proximity to London (according to broadcast map), looking out of the window and enjoying a beer I saw another aircraft what looked like coming straight for us at same FL.
It kept coming to the point I seriously thought we were going to colide - I swear I could see the crew in the flight deck at the last moment.At what seemed like the last secoond we desended very, very quickly and went into a very steep left turn (much steeper than I have ever experienced after well over 3-400 flights) There was a noticeable increase in engine noise.
As we came out of the bank I could see the other aircraft above us at what must have been very close (was not a livery I recognised).

Purser was called to the cockpit afterwards but no announcement was made. However it seemed to me like a very near miss in UK airspace.

I could (and hope I am) wrong - please do not blast me for this, it really shook me and some of my fellow passengers up. Lets just say the crew made a few extra pounds of comission from whisky sales.

If anyone could shed any light I would be very happy,

Thanks guys - most of you do a pretty remarkable job keeping us SLF (and yourselves) safe.

Chris

[danishdynamite]

Can you please specify the date of the flight?

[MMENCLLBAMAN]

Date

Yesterday 1st June - 1925 flight CGN-MAN

Txs

[TheGorrilla]

Sounds like the crew may have responded to a TCAS RA.

[Tarq57]

Sounds like the crew may have responded to a TCAS RA.

The description does fit that, but a bit unusual that the engine noise increased during the descent. Sure it wasn't spoiler noise? Or did the engines power up after the descent was finished?

[Not to scale]

Would a TCAS RA involve anything other than a climb or descent?

A steep banking turn as well??

[jackbauer]

Definitely not, TCAS only directs you to climb or desend. Turning can only compound your problem. While you are climbing the other aircraft is directed to do the opposite. This assumes both aircraft are fitted with TCAS. Very clever system!

[NigelOnDraft]

Would a TCAS RA involve anything other than a climb or descent?
A steep banking turn as well??

Aeroplanes do have windows, and pilots do have eyes

[jackbauer]

Sorry Nigel but the first rule of TCAS procedure is NOT to maneuver based on TA alone. You must wait for the RA to trigger before you do anything. Relying on visual contact to avoid is not recommended as you can easily find yourself in a secondary RA and deep doo doo! It's getting to a point where we only need the windows for the last 50 feet of the approach, and even that's optional.

[Jerricho]

IF (big IF) it was a nasty, perhaps the turn was avoiding action issued by ATC?

Question from me - I'm led to believe that it's SOP for some operators out there if a an RA is received whilst in a turn some will stop the turn/adopt a more wings level attitude.

[jackbauer]

You NEVER EVER give priority to ATC over a TCAS RA!! Do I have to tell you about the Ueberlingen incident? You follow TCAS with wings level. This is a memory item guys, why are so many people asking if it's OK to do anything else? If you are flying in busy airspace with the idea you can do your own thing, it is very worrying.

[Citation500]

Well, Jack of course you are absolutely right, but I think Jerricho ment the crew probably followed an ATC command, BEFORE the RA kicked in.

[bomarc]

citation 500 is quite right. as to engine noise increasing, the passenger reported that the bank was very steep...perhaps the pilots were making darn sure they kept a safe speed .

I do think the passenger should take some solice in knowing that everything did work out. a miss is as good as a mile or should I say three miles.

[sudden Winds]

the turn could have been initiated after someone in the cockpit saw the intruder a/c, basically the PF follows the RA commands while the PM tries to spot the traffic and calls out any ommitted actions, then inform ATC.
The "engine noise" could have been the sound of the airflow increasing, and not the engines themselves. If description is right chances are it was an RA.
Regards,
SW.

[Jagohu]

The turn could have been given by ATC when they realised you're gonna get too close to the other a/c. Since we're also taught not to give vertical clearances if TCAS is involved, and we all know that vectoring is a much better idea than trying to push a climb/descent, the controller could have given an avoiding turn, to increase separation if this was the case.
Anyway, not that much, but still better to end up with 3 nm and a TCAS RA than with 0 nm and a TCAS RA...

[Basil]

<<the first rule of TCAS procedure is NOT to maneuver based on TA alone>>
Must say that I HAVE done so.
Level 330 in heavy classic.
Crossing traffic cleared climb 320 continues climb past 320.
I guessed they'd mistaken 320 for 330 and started climb.
ATC then told us to climb.
My reasoning was that, if his performance was greater than ours we were better to start climb sooner rather than later.
Command decision on the day

[MMENCLLBAMAN]

Thanks for info

Thanks for the info guys - appreciate it.

As for the engine noise - I have to admit that I think 'and overall increase of noise' would have been more appopriate to say - I have to say that I assumed rather than was sure.

And bomarc, believe me I was full of solice

Can anyone tell me how regular these type of instances are??

Safe flying

Chris

[Jerricho]

Thank you Citation500 , that's exactly what I meant. Avoiding action given by ATC then RA. Seen it happen.

As to regularity, in high density airspace RA can be triggered by high rates of climb/descent of closing traffic before they level off. As TCAS is timed based, the system ascertains a "closest point of approach" of the traffic and provides a resolution if required.........not knowing the other aircraft will be levelling off.

[Rainboe]

Before we get this done and dusted as a TCAS Loss of Separation incident and it goes down in the PPrune record as that, perhaps someone could confirm whether there has actually been an airprox incident in the London area on 1 June, or is this an overactive passenger impression?

[MMENCLLBAMAN]

Rainboe, I truly hope that indeed that was the case - but still this overactive passenger was less than impressed