Crew ignored TCAS RA
How would any of you TCAS users have reacted in the same situation? Remember, only 2 aircraft within miles (you and the F-16), both visual, the F-16 flying VFR, you flying IFR in VMC conditions.
If you're not going to follow an RA then perhaps you should have gone 'TA only' so 'his' TCAS then knows your TCAS is not going to be giving you a profile you're going to ignore! If you're going to keep the TCAS in TA/RA then you have to follow it!
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n the military hardware I flew (Global Express) if visual with traffic that we could see would shortly cause an RA, we would invariably go 'TA only'
strange concept..
strange concept..
On the military hardware I flew (Global Express) if visual with traffic that we could see would shortly cause an RA, we would invariably go 'TA only'. We invariably did the same in our instrument pattern when you knew ATC-coordinated traffic was likely to result in an RA which would just spoil everyone's day.
If you're not going to follow an RA then perhaps you should have gone 'TA only' so 'his' TCAS then knows your TCAS is not going to be giving you a profile you're going to ignore! If you're going to keep the TCAS in TA/RA then you have to follow it!
If you're not going to follow an RA then perhaps you should have gone 'TA only' so 'his' TCAS then knows your TCAS is not going to be giving you a profile you're going to ignore! If you're going to keep the TCAS in TA/RA then you have to follow it!
Hi, you are going to have to explain under what regulations you followed these "proceedures"?
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The problem with just saying "In all cases follow the RA" is that the TCAS system only operates correctly if certain parameters are kept within. There is a reason that there are caveats.
Military aircraft doing very high rates of climb and descent for example are more than capable of confusing the system because it was not designed to cope with them.
OAP.
re your question to H Peacock.
Imagine for a second you are flying orbits/racetrack patterns over a dusty unpleasant country. Imagine further that you are in a stack of other aircraft all orbiting at various levels. Occasionally one of the smaller ones might suddenly dive or climb through your level. Under those circumstances, TA can be a good idea, as can ignoring RA. RA does not mean you are on a collision course at all, it merely means that another aircraft is going to encroach on a very large bubble with you at the centre. Military pilots are trained to be able to operate with other aircraft in that bubble, indeed that is the entire point of many of them.
Military aircraft doing very high rates of climb and descent for example are more than capable of confusing the system because it was not designed to cope with them.
OAP.
re your question to H Peacock.
Imagine for a second you are flying orbits/racetrack patterns over a dusty unpleasant country. Imagine further that you are in a stack of other aircraft all orbiting at various levels. Occasionally one of the smaller ones might suddenly dive or climb through your level. Under those circumstances, TA can be a good idea, as can ignoring RA. RA does not mean you are on a collision course at all, it merely means that another aircraft is going to encroach on a very large bubble with you at the centre. Military pilots are trained to be able to operate with other aircraft in that bubble, indeed that is the entire point of many of them.
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Military aircraft doing very high rates of climb and descent for example are more than capable of confusing the system because it was not designed to cope with them. ... RA does not mean you are on a collision course at all, it merely means that another aircraft is going to encroach on a very large bubble with you at the centre.
Otherwise, TCAS computes what is known as the Closest Point of Approach (CPA). Version 7.0 introduced a filter called "Horizontal Miss Distance" (HMD). The HMD differs with altitude, but basically tracks another variable called DMOD which varies from 0.2nm at 2000 ft to 1.1nm at FL200 and above. Note that these values are considerably smaller than ATC separation minima.
TCAS also computes the time to the CPA, called tau. Above 10,000ft, the tau threshold for an RA is around 30 seconds.
So if you're in cruise level at FL360 and there's an intruding aircraft (military or otherwise) climbing from below at brisk rate (say at 8000 fpm), then an RA will be issued if the intruder is predicted to cross inside 1.1nm of you horizontally within about 30 seconds. That could be a 1nm "near miss", or a direct hit collision -- there isn't enough precision to know.
What TCAS can't measure is intention. Maybe that intruder, currently at FL280, will level off at FL320. In that case the RA would have been unnecessary. But perhaps it was cleared to FL400? You just don't know. That's why you always follow the RA.
Canute
HP does not state that he was operating in Mil airspace or regulations. He needs to clarify if he is talking about operating in Civilian airspace? Also, I am not aware of exemptions within UK Civil or Military airport zones or areas for the random selection of TA ONLY to avoid RA in the instrument pattern?
HP does not state that he was operating in Mil airspace or regulations. He needs to clarify if he is talking about operating in Civilian airspace? Also, I am not aware of exemptions within UK Civil or Military airport zones or areas for the random selection of TA ONLY to avoid RA in the instrument pattern?
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OAP.
Military aircraft don't have to obey normal civilian rules just because they are in civilian airspace. I'm not suggesting that it is done casually, but there are many reasons for different rules.
PK as I'm sure you are aware from your name, RAs are triggered around military aircraft a lot. I operated a military type with TCAS, and to have obeyed RAs would have been dangerous on many occasions in theatre.
TA,
I quite agree. I was merely giving an example of why the caveats are there. In my opinion TCAS should be linked to autopilot in all civil aircraft.
TCAS is excellent at what it was designed to do, but it is a simple system and limited in scope. That is why there will always be the caveats with this current system.
Military aircraft don't have to obey normal civilian rules just because they are in civilian airspace. I'm not suggesting that it is done casually, but there are many reasons for different rules.
PK as I'm sure you are aware from your name, RAs are triggered around military aircraft a lot. I operated a military type with TCAS, and to have obeyed RAs would have been dangerous on many occasions in theatre.
TA,
I quite agree. I was merely giving an example of why the caveats are there. In my opinion TCAS should be linked to autopilot in all civil aircraft.
TCAS is excellent at what it was designed to do, but it is a simple system and limited in scope. That is why there will always be the caveats with this current system.
CANUTE.
Military aircraft don't have to obey normal civilian rules just because they are in civilian airspace.
Military aircraft don't have to obey normal civilian rules just because they are in civilian airspace.
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Not necessarily in Europe, if the military aircraft are flying under Operational Air Traffic (OAT) rules as opposed to General Air Traffic (GAT) who follow the civilian ANSP rules.
"
Operational Air Traffic (OAT)
Description
The term Operational Air Traffic (OAT) is applied in Europe to all flights which do not comply with the provisions stated for general air traffic (GAT) and for which rules and procedures have been specified by appropriate national authorities. (EUROCONTROL EATM Glossary of Terms)
Most OAT flights are operated by military agencies."
Operational Air Traffic (OAT) - SKYbrary Aviation Safety
"
Operational Air Traffic (OAT)
Description
The term Operational Air Traffic (OAT) is applied in Europe to all flights which do not comply with the provisions stated for general air traffic (GAT) and for which rules and procedures have been specified by appropriate national authorities. (EUROCONTROL EATM Glossary of Terms)
Most OAT flights are operated by military agencies."
Operational Air Traffic (OAT) - SKYbrary Aviation Safety
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yes, generally, but only generally and I notice that you limit it to UK military. It is a choice, not a requirement.
But for example, most military pilots don't have a civil pilots license, medical or IR yet they bimble around in civil airspace.
Most/many military aircraft don't have anything even approaching the correct Nav/Comms fit.
Many are not even talking to the civil ATC.
But for example, most military pilots don't have a civil pilots license, medical or IR yet they bimble around in civil airspace.
Most/many military aircraft don't have anything even approaching the correct Nav/Comms fit.
Many are not even talking to the civil ATC.
Ian W
OAT/GAT has little to do with it. UKMil TCAS proceedures closely mirror Civ but, will depend on what the Mil aircraft are tasked to do and what it says in their SOP and RTS. I am not going to talk about that.
OAT/GAT has little to do with it. UKMil TCAS proceedures closely mirror Civ but, will depend on what the Mil aircraft are tasked to do and what it says in their SOP and RTS. I am not going to talk about that.
Canute
I go back to this from HP,
This cannot be SOP for all operation of the Global Express by UKMil.
I go back to this from HP,
On the military hardware I flew (Global Express) if visual with traffic that we could see would shortly cause an RA, we would invariably go 'TA only'. We invariably did the same in our instrument pattern when you knew ATC-coordinated traffic was likely to result in an RA which would just spoil everyone's day.
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yes, generally, but only generally and I notice that you limit it to UK military. It is a choice, not a requirement.
But for example, most military pilots don't have a civil pilots license, medical or IR yet they bimble around in civil airspace.
Most/many military aircraft don't have anything even approaching the correct Nav/Comms fit.
Many are not even talking to the civil ATC.
But for example, most military pilots don't have a civil pilots license, medical or IR yet they bimble around in civil airspace.
Most/many military aircraft don't have anything even approaching the correct Nav/Comms fit.
Many are not even talking to the civil ATC.
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 only!
Now, A few examples of when I'd go TA only.
1. Airways transit to Southwold (TA/RA), descent into formation hold then flypast (TA only). Flypast complete, split & rtb (TA/RA)
2. Transit through CAS along a defined mil corridor with numerous other mil AC at similar alt (TA/RA). Faster mil aircraft closing to pass at same alt and less than 1nm, (TA only)
3. Visual circuit when routing downwind to Initials (TA only)
4. Recovering to Cranwell from complex sortie (TA/RA). Joining TACAN hold with numerous Tutors, KingAirs etc in vicinity (TA only)
5. Supersonic airliner loitering at 2000ft overhead Leuchars waiting 15 min for the Red Arrows to appear (TA/RA). A Tucano calls visual and asks to format in fighting wing on said airliner ( TA only)
Now, A few examples of when I'd go TA only.
1. Airways transit to Southwold (TA/RA), descent into formation hold then flypast (TA only). Flypast complete, split & rtb (TA/RA)
2. Transit through CAS along a defined mil corridor with numerous other mil AC at similar alt (TA/RA). Faster mil aircraft closing to pass at same alt and less than 1nm, (TA only)
3. Visual circuit when routing downwind to Initials (TA only)
4. Recovering to Cranwell from complex sortie (TA/RA). Joining TACAN hold with numerous Tutors, KingAirs etc in vicinity (TA only)
5. Supersonic airliner loitering at 2000ft overhead Leuchars waiting 15 min for the Red Arrows to appear (TA/RA). A Tucano calls visual and asks to format in fighting wing on said airliner ( TA only)
Nope. Unless practicing a max-rate descent, descending out of CAS was always TA/RA as was the recovery (joining the hold) until it got so busy with a mix of Visual and instrument traffic. If that traffic wasn't there, you could comfortably stay TA/RA throughout, but if it was there and a spritely Tutor got 'too close' the implication of a full RA could have been far more of an issue than simply 'seeing and avoiding'.
Of course if it got too busy you may have been better to have gone elsewhere!
Of course if it got too busy you may have been better to have gone elsewhere!
At least one other that requires TCAS to be operated in TA/RA at all times in airspace frequented by fare-paying passengers! All that stuff might be OK flying in amoungst his RAF jet jockey mates but when he's mixing it with airliners/other civvies, he can use the TCAS properly: giving and coordinating RAs.
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?
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 only!
Now, A few examples of when I'd go TA only.
1. Airways transit to Southwold (TA/RA), descent into formation hold then flypast (TA only). Flypast complete, split & rtb (TA/RA)
2. Transit through CAS along a defined mil corridor with numerous other mil AC at similar alt (TA/RA). Faster mil aircraft closing to pass at same alt and less than 1nm, (TA only)
3. Visual circuit when routing downwind to Initials (TA only)
4. Recovering to Cranwell from complex sortie (TA/RA). Joining TACAN hold with numerous Tutors, KingAirs etc in vicinity (TA only)
5. Supersonic airliner loitering at 2000ft overhead Leuchars waiting 15 min for the Red Arrows to appear (TA/RA). A Tucano calls visual and asks to format in fighting wing on said airliner ( TA only)
Now, A few examples of when I'd go TA only.
1. Airways transit to Southwold (TA/RA), descent into formation hold then flypast (TA only). Flypast complete, split & rtb (TA/RA)
2. Transit through CAS along a defined mil corridor with numerous other mil AC at similar alt (TA/RA). Faster mil aircraft closing to pass at same alt and less than 1nm, (TA only)
3. Visual circuit when routing downwind to Initials (TA only)
4. Recovering to Cranwell from complex sortie (TA/RA). Joining TACAN hold with numerous Tutors, KingAirs etc in vicinity (TA only)
5. Supersonic airliner loitering at 2000ft overhead Leuchars waiting 15 min for the Red Arrows to appear (TA/RA). A Tucano calls visual and asks to format in fighting wing on said airliner ( TA only)
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At least one other that requires TCAS to be operated in TA/RA at all times in airspace frequented by fare-paying passengers! All that stuff might be OK flying in amoungst his RAF jet jockey mates but when he's mixing it with airliners/other civvies, he can use the TCAS properly: giving and coordinating RAs.
It is also more than the majority of military aircraft that "mix it with airliners" have.
TCAS works perfectly well with one aircraft in TA mode. just as it does against transponding aircraft without TCAS