Super Puma/Nimrod Airprox

[212man]

Not sure if this has had a thread already. Page 8 onwards is an eyewatering account!

http://www.caa.co.uk/docs/423/04_07_assessed_airprox.pdf

(Another good reason for TCAS!!!:ugh:)

[AlanM]

"eyewatering"??? Blimey mate - come and see what is being allowed in the same airspace during Royal Ascot week - with the helicopters on freelanes not talking to radar!

[212man]

Well, that's great, and good luck to them, but if I'm cleared on an IFR departure from an airport, I tend not to expect a clearance to climb into a 4 engine heavy jet: call me old fashioned!

[Thud_and_Blunder]

Not old-fashioned at all, 212 - those crews had a lucky outcome which everyone was able to learn from.

Excellent reading in the next report after the Nimrod vs 332; I'm glad I wasn't one of the fellas dangling underneath the Merlin as matey-boy bimbled below in his Grob. You need a lot of faith in your Carabiner under those circumstances. :eek:

[HeliComparator]

Clearly some mistakes were made on various sides but I would prefer not to make a big deal out of it - otherwise those nice chaps at EGQK might not invite us lot to come visiting their calm training haven again. And that would be very bad news!

It prompted me to read the Safety Sense leaflet mentioned, and I learned something.

HC

[TipCap]

TCAS for helicopters is still in its infancy. I believe TCAS 1 is fitted to some helicopters but has limited application. TCAS 2, is on trial but I hear likely to be approved soon :)

[212man]

Had both aircraft been equipped with TCAS (1 or 2) the Nimrod would have seen the Puma from the hover onwards, and the Puma may well have been able to see the Nimrod on approach. The TCAS returns would have changed from blue open diamonds, to filled diamonds, to yellow circles and an aural alert "Traffic, Traffic" during the subsequent event (all the while showing relative altitude and trend). A Traffic Advisory, assuming the Puma was TCAS 1 equipped.

I'm curious as to why this is considered of "limited benefit".

The benefit afforded by TCAS 2 on both aircraft would have been a Resolution Advisory, most likely telling the Puma to decrease his rate of climb, and the Nimrod to increase his.

Regardless of the relative benefits hypothetically derived, the tangible benefit is that one is available now, and the other is not. I agree that it would take a Fleet upgrade for the Puma, but the S-92 is a different story:ugh::ugh::ugh::ugh:

[Non-PC Plod]

TCAS - limited use it may be, but sufficient to save me from having a Jaguar inserted in the side of my EC 135 at 400 knots a couple of years ago. Dont leave home without it!:ok:

[HeliComparator]

212 - of course TCAS 1 would have been beneficial, though perhaps its not the universal panacea you like to think it is. In this particular incident, once they had departed, things would have been sticky with or without TCAS 1 as its difficult to know how best to handle a conflict in IMC especially when you are doing 80kts at low level in IMC and the threat is doing 200+kts coming from behind.
Ideally it would have stopped them taking off in the first place, but one could argue that they would have had to look at the display to get that information, when in fact there was aural information (the blind RT transmissions from Tower) that gave them the same information, and normally one would expect aural information to "get through" more easily than a display icon.

I am not saying that TCAS 1 is a waste of time - far from it - its just that its not perfect and TCAS 2 is better.

Its interesting to note how the CAA have contributed to safety in this area. First of all they blocked attempts by helicopter operators in the N Sea to fit TCAS1 citing a spurious technical argument about the effect on TCAS 2 equipped fixed wing (which are of course far more important in their eyes). I say "spurious" because they have recently backtracked on their stance and are now aligned with the rest of the world. Then there is the CAA, EASA and Eurocontrol's stance on TCAS2 - its totally unsuitable for helicopters. Something that Bristow have proven to be rubbish with their trial. Hopefully we will soon have the STC to prove it (currently held up by EASA's creeping sluggishness of their approval process aided by some sour grapes no doubt).

HC

[flyingbricksh]

praise to all you rotorheads that can see the benefit of TCAS.2
but remember this Its only a fail safe and it doesn't always get it right.
Both have to have functioning transponders that are switched on! for at least the A/c with ACAS fitted to see the other. If its only sq mode a then which way do you go???????
:ugh:and it will only give a TA effectively below 1A. the other thing is How many mill a/c do you know with TCAS fitted?:\

Yes it has to be of benefit and all praise to the BHL boys for pushing it through thats if it gets there, and one in the eye:ouch: for the yanks how said it couldn't be done all those years ago.:{