Crew ignored TCAS RA

[Onceapilot]

Canute

Exactly how many different Glex SOP do you imagine the RAF have?

I do not know. However, there seems to be something worth exploring here, not to criticise specific Mil use of TCAS but, to inform the majority of airspace users.

[H Peacock]

Thanks for those points. The question remains, do your examples of "when I would use TA ONLY" reflect a coherent RAF strategy of TCAS use that is reflected in your Orders, SOP and Aircraft manuals or, are you making your own choice when to use TA/RA? Here is another question, would you do the same flying into Brize?

I'm not sure the RAF has a coherent strategy on TCAS. I know of some guys who'll not get airborne without it! It's a great tool to have, but like so many other bits of kit we have, you need to use common sense and airmanship. I know the latter is being steadily removed by the desire to have all-encompassing SOPs.

You're probably guilty of going off-thread here so suggest you open one elsewhere if you want to pursue a discussion on SOPs!

As for Brize - Yep, led a 3 ship through the zone, so my PF's Airmanship decided to go TA only. A very busy piece of airspace that day as multiple formations split up, so trusted ATC and my fellow aviators to do their jobs as briefed. If we'd had an RA I very much doubt we'd follow it, therefore TA only.

[Canute]

OAP

The problem with SOPs is that whilst they are perfect for civil operations, ie they should follow a script where ideally nothing unusual ever happens etc, the growth/expansion of SOPs hinders flexibility in military operations which by their very nature should not follow a script and ideally should be different every time..

[Capn Bloggs]

TCAS works perfectly well with one aircraft in TA mode. just as it does against transponding aircraft without TCAS

Yep, the coordinated RAs work well...

[Square Bear]

[QUOTE]OAP, the point I'm making is that if I knew I was in a situation where I'd no intention of following an RA, I'd go 'TA only'. Exactly as the designers of TCAS decreed and why they put a TA only option on the box! If you're not going to follow the RA (why?) you should be in TA on/QUOTE]

H PEACOCK, maybe you don't want to follow the RA instructions, but the other guy and his hundred plus pax might...

Not sure how it could be justified to be simply a one sided decision.

[deltahotel]

TCAS in the massively dynamic military environment (eg the environs of Cranwell's circuit) would be an amazing SA tool, but useless and possibly dangerous in RA. In the slightly more benign environment of civ CAS, airways etc for which it was really designed please please please follow the RA.We lost an aircraft at Uberlingen because our guys did and the other bunch didn't. The manoeuvre is simple, gentle and over very quickly and is there for when every other traffic separation method has failed for whatever reason.

[H Peacock]

H PEACOCK, maybe you don't want to follow the RA instructions, but the other guy and his hundred plus pax might...

Oh dear Square Bear, I'm not sure you fully understand how TCAS works. If both aircraft are operating in TA/RA, have a conflict and follow their respective RAs, all should be well. One of the TCASs probably initiated its RA first, telling its pilot where to go and also through mode S telling the other aircraft's TCAS what it's doing. This second aircraft's TCAS now knows what the first aircraft is doing/going to do and issues a suitable RA based on the dynamics of the situation and what it understands the profile the first aircraft is now following. If the pilot of the first aircraft has decided to ignore his TCAS then the second TCAS won't know until it detects that the dynamics of the situation are deteriorating rather than improving. It may then have to amend its proposed RA. All very uncomfortable and possible too late to avoid a collision.

So, if the first aircraft has a reason that it's not going to be flying any RA (as previously stated, it needs to have a valid reason) by selecting his TCAS to TA-only he tells the second TCAS it can do as it sees fit from the outset to produce a more timely RA. This avoids the crucial delay caused by having to detect that the first aircraft is not following its RA.

The second aircraft operating in TA/RA will always get it's RA from the first aircraft, but it gets significantly more time to produce a better outcome. Ie, you don't need both aircraft to be operating in TA/RA to generate an RA in the second aircraft. It's important that you understand that.

The point I'm trying to make (obviously not clearly enough for some) is that ignoring an RA is significantly more dangerous than that aircraft operating in TA-only. The decision of if/when to go TA-only is complex and I suspect not something many commercial-only operators would have thought about. However, had I not operated TA only in the examples quoted in my earlier thread, then I simply could not have achieved the mission objective!

[Onceapilot]

Well, if the present use of TCAS in parts of the RAF is as HP states, then I am surprised. Any incident involving TCAS use will look for adherance to laid down proceedures and best practice. Can anyone else who knows comment? Last time that I used Brize, the airfield and zone expected the use of standard TCAS proceedures by aircraft so equipped.

[H Peacock]

OAP

Not sure how long ago you were a pilot, and I strongly suspect from your comments you have very little understanding of the world of military aviation, but just because you don't understand a concept, please try to avoid telling the world it's wrong!

You clearly can't comprehend the reasons stated for using TCAS in TA-only. I can do no more than tell you that many RAF aircraft fitted with TCAS will at times be required to fly close enough to other squawking aircraft which would cause, when operating in TA/RA, an RA to occur; they'd be forced to follow an RA that would move them away from another aeroplane that needs to be close!

It's not appropriate to divulge many of the numerous tactical situations where an 'inadvertent' RA could occur, but for a peacetime one have a google of 'Queens Birthday Flypast'. It may even be on YouTube. Lots of aeroplanes all quite close to each other flying through the middle of the London TMA. Now tell me how that would work if all the heavies fitted with TCAS flew in TA/RA? I believe one year we even took the entire flypast through the Brize overhead. I don't recall ATC asking or even expecting us to be in TA/RA!

[Onceapilot]

Please don't rant HP. I do hope that your description of "TCAS in the RAF-use it how you wish" is not reality in your corner of the Air Force? If it is, someone needs to get a grip and write you some Orders! No more from me, Thanks.

[Capn Bloggs]

It's not appropriate to divulge many of the numerous tactical situations where an 'inadvertent' RA could occur

Tickets...

Lots of aeroplanes all quite close to each other flying through the middle of the London TMA. Now tell me how that would work if all the heavies fitted with TCAS flew in TA/RA?

Yep, TA it should be. "Traffic Traffic Traffic Traffic Traffic" "Derek, tell that thing to shut up!" "I can't Nigel, as you told me to put it in TA!" "Orright Nigel, tell the king to move away from us a bit!"

[Max Angle]

is that ignoring an RA is significantly more dangerous than that aircraft operating in TA-only.

Spot on, can't believe so many people are having trouble with that concept. Pretty obvious that there are situations in the military world where you would be unable to follow an RA, civil aircraft set TA in engine failure cases for the same reason. As you rightly point out setting TA means you are still fully interoperable with other TCAS equipped aircraft which can generate their own RAs if required.

[framer]

There will be orders written down. Whether or not individual squadrons are adhering to them is largely dependent upon leadership within and above the squadron. A good example of how a squadron specific 'we don't have to follow the rules' culture evolves to a dangerous level is the RNZAF ANZAC day Iroquois crash of 2010.
If anyone reading this is leading a squadron, you need to know the orders, understand your responsibilities to your men, women, and the nation, ( in peacetime and at war), then have the courage to enforce the orders that have been written. It is surprising to me how few 'military leaders' have this fortitude and simply run the show like the last guy did ( ie perpetuate what ever culture they inherited).

[Square Bear]

[QUOTE]Oh dear Square Bear, I'm not sure you fully understand how TCAS works/QUOTE]

Just love the sanctimonious "straw man style of debating." When all else fails comes to mind.

Anyway...enjoy your Biz Jet style "fast jet" Global Express playing with your TA/RA switch.