Roll on Offset Airways Tracking
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Roll on Offset Airways Tracking
Collision in air averted
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By Our Staff Reporter
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KARACHI, Jan 17: A major air disaster was averted due to timely functioning of an automatic warning system in two passenger planes, which accidentally came face to face at the same altitude over Panjgur in the west of Balochistan.
An Air Blue flight was headed for Islamabad from Dubai. While flying at an altitude of 33,000ft altitude, it came in front of an Eva Airways flight bound for Hong Kong from Europe, on Tuesday morning.Fortunately, the planes escaped a head-on collision as the automatic warning system came into play when the two planes were five nautical miles apart, over Panjgur. Responding to the warning, the Air Blue plane descended while the Eva Air flight took an ascent.
Upon landing in Islamabad, the captain of the Air Blue flight reported the incident to the Civil Aviation Authority (CAA), which launched a probe to ascertain how the planes were flying on the same air route.
According to sources, preliminary findings attributed the matter to the negligence of Air Traffic Control.
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By Our Staff Reporter
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KARACHI, Jan 17: A major air disaster was averted due to timely functioning of an automatic warning system in two passenger planes, which accidentally came face to face at the same altitude over Panjgur in the west of Balochistan.
An Air Blue flight was headed for Islamabad from Dubai. While flying at an altitude of 33,000ft altitude, it came in front of an Eva Airways flight bound for Hong Kong from Europe, on Tuesday morning.Fortunately, the planes escaped a head-on collision as the automatic warning system came into play when the two planes were five nautical miles apart, over Panjgur. Responding to the warning, the Air Blue plane descended while the Eva Air flight took an ascent.
Upon landing in Islamabad, the captain of the Air Blue flight reported the incident to the Civil Aviation Authority (CAA), which launched a probe to ascertain how the planes were flying on the same air route.
According to sources, preliminary findings attributed the matter to the negligence of Air Traffic Control.
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Offset Tracking-if you can you should!
I wish ATC could make more use of offsets.
I occasionaly use them with High level overflights.
Saves using lots of headings and watching that pesky drift!
Technically we should have both Aircraft locked on radar headings when less than 15NM apart.Lateral offsets would let us go down to 5 without any hassle.
Oh well maybe we will catch up with technology sometime!
I occasionaly use them with High level overflights.
Saves using lots of headings and watching that pesky drift!
Technically we should have both Aircraft locked on radar headings when less than 15NM apart.Lateral offsets would let us go down to 5 without any hassle.
Oh well maybe we will catch up with technology sometime!
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Offset tracking is already authorised over India and Pakistan, but I've yet to pass ONE SINGLE aircraft using it (apart from me!) since it has been given the official OK, and I never cease to be amazed at the way 99% of my FOs can't wait to get back on the airway centreline the moment we pass out of Indian airspace.
Standing by for the (usual) "it won't save you in all circumstances" posts that always follow when this subject is broached.
Standing by for the (usual) "it won't save you in all circumstances" posts that always follow when this subject is broached.
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Sheep or Ship in the center !
I too can not explain, urge to flock in the very center of Airway,
except that many creatures tend to flock tight when in fear...
like sheep when the wolves are near
Wish to know if they drive their cars in the center of the road..
I mean just over the central line or lights ?
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Hi all
I wrote the following letter to Flight International back in 2004 and it was published in the mag:
The Editor
Flight International
Quadrant House
The Quadrant
Sutton
Surrey
SM2 5AS
22 March 2004
Dear Sir
I have decided to put in a letter to you a concern that I have fostered for some time.
I have just finished a 10hr flight back to Europe and have been watching traffic coming in the opposite direction approximately 1nm to my left.
With the advent of such accurate navigation systems I had an ANP of approximately 0.05nm and I suspect the opposite traffic had almost exactly the same performance due to their GPS. I do consider that as an industry we are allowing this superb accuracy to infringe upon our level of safety.
I flew the majority of the way offset to the right of track by 1nm and therefore well within the limits of the airway. Generally, airways traffic ploughs back and forth almost directly above and below each other and very rarely do I observe offset traffic. Personally, I would very much like to see some sort of universal safety advisory recommending that when the crew has the facility to do so, they offset their track. I offset to the right just as one does when following a line feature under VFR.
I do not mean to suggest that aircraft are about to start falling around our ears, however, it does seem a little short-sighted to voluntarily degrade ones margin for error.
With your assistance, it seems that your publication would provide a good forum for some professional discussion of this issue which could perhaps lead to safer skies for us all.
Yours sincerely
It does seem rather silly to ignore the problem, unfortunatly I think it will take a disaster to raise the awarness high enough for it to be taken seriously...
I wrote the following letter to Flight International back in 2004 and it was published in the mag:
The Editor
Flight International
Quadrant House
The Quadrant
Sutton
Surrey
SM2 5AS
22 March 2004
Dear Sir
I have decided to put in a letter to you a concern that I have fostered for some time.
I have just finished a 10hr flight back to Europe and have been watching traffic coming in the opposite direction approximately 1nm to my left.
With the advent of such accurate navigation systems I had an ANP of approximately 0.05nm and I suspect the opposite traffic had almost exactly the same performance due to their GPS. I do consider that as an industry we are allowing this superb accuracy to infringe upon our level of safety.
I flew the majority of the way offset to the right of track by 1nm and therefore well within the limits of the airway. Generally, airways traffic ploughs back and forth almost directly above and below each other and very rarely do I observe offset traffic. Personally, I would very much like to see some sort of universal safety advisory recommending that when the crew has the facility to do so, they offset their track. I offset to the right just as one does when following a line feature under VFR.
I do not mean to suggest that aircraft are about to start falling around our ears, however, it does seem a little short-sighted to voluntarily degrade ones margin for error.
With your assistance, it seems that your publication would provide a good forum for some professional discussion of this issue which could perhaps lead to safer skies for us all.
Yours sincerely
It does seem rather silly to ignore the problem, unfortunatly I think it will take a disaster to raise the awarness high enough for it to be taken seriously...
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unfortunatly I think it will take a disaster to raise the awarness high enough for it to be taken seriously...
400 people died in the Delhi crash, but they weren't from North America, so CNN didn't turn it into the talk fest it would have been had 400 Americans died. Sadly, I think it's going to take a mid air between two wide bodies carrying US or Western European citizens to shake the system up enough to address this problem - a problem, I hasten to say, very few within the Industry think exists.
I'm sure i've already offended some who've misunderstood my comments above, so I'll dig myself an even deeper hole. Would anyone care to comment on the CNN reporting of the Brazilian tragedy had the people and aircraft involved been switched to 100+ US citizens killed in the 737 and two Brazilian pilots in the Embraer?
It's funny how only recently there has been some movement on this issue: Strategic Lateral Offset Procedure (SLOP 
) on the North Atlantic. OK, good idea but this is last place this is needed considering all the aircraft on the track system have TCAS, are RVSM certified and are monitored closely from both sides of the pond. Much better to implement this enroute everywhere else.
Personally, I have flown offsets for the last 10 years or so, especially when over Africa/Middle East/Far East/South America. I did meet someone over Nigeria who was flying a 2nm left offset in riposte to my 2nm one to the right... luckily not quite at the same level.
410 mentions the 737/Embraer mid-air in Brazil - if either had been flying an offset...
(When the NA procedure was first brought out, I remember seeing "On OTS consider SLOP" printed on the flight plan. Neither of us had a clue what it meant until we got someone to explain it on 123.45)
) on the North Atlantic. OK, good idea but this is last place this is needed considering all the aircraft on the track system have TCAS, are RVSM certified and are monitored closely from both sides of the pond. Much better to implement this enroute everywhere else.Personally, I have flown offsets for the last 10 years or so, especially when over Africa/Middle East/Far East/South America. I did meet someone over Nigeria who was flying a 2nm left offset in riposte to my 2nm one to the right... luckily not quite at the same level.
410 mentions the 737/Embraer mid-air in Brazil - if either had been flying an offset...
(When the NA procedure was first brought out, I remember seeing "On OTS consider SLOP" printed on the flight plan. Neither of us had a clue what it meant until we got someone to explain it on 123.45)
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It's been years since I've been asked to fly an Offset track. Thanks for bringing the subject up - time to get my head back in the FMS manual again.
Can't imagine why ATC don't use them more often.
Sky God.
Can't imagine why ATC don't use them more often.
Sky God.
Can't imagine why ATC don't use them more often.
I've spoken with pilots who consistently report accuracy of a wingspan or less on GPS routes, as was tragically demonstrated by the collisions referred to above.
I totally support the idea of an offset being introduced in these cases, where it doesn't invalidate the airway separation being applied. Can't see how it would, in most cases.
It will, I think, fall to pilot's unions to make this one happen. Keep lobbying.
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V1R,
There's a body called [AFAICR] the ICAO Separation Standards Panel who deal with this stuff.
It's made up of mathematicians and NIH phobes who live in the past. They assign equipment and pilot tolerances to all the sep standards. They don't sit day-in-day-out [or night...etc] watching potential mid-air's pass continuosly within a half-wingspan or less at 1,000ft separation. They haven't worked out that in the high 90 percentile, there is NO equipment error nor pilot error and if someone blinks, they'll hit.
Safety Heights [or whatever name you choose] are calculated by using traditional methods for flight legs [not talking RNAV stuff here]; by flying, say, 1nm right-of-track, all the world's S/H's have to be recalculated. They can't get it throught their heads that [see above] there is NO error with GPS [or, at least, so small as to be almost ignored....half-wingspan after 14hr flight?]
GPS was "made in America" and it would be absurd for ICAO to trust it and base anything official on it until the rest of the "World" catches up by moving to GNSS [bit like GMT and UTC, if you get my drift], THEN we can start to see something happening! The Poms have never really got over Decca not being used worldwide over Loran?
Rant over. We see P-RNAV now and maybe we're getting there. Roll on a 1nm right bias above FL200 as an FMC et al norm in LNAV!
G'day
There's a body called [AFAICR] the ICAO Separation Standards Panel who deal with this stuff.
It's made up of mathematicians and NIH phobes who live in the past. They assign equipment and pilot tolerances to all the sep standards. They don't sit day-in-day-out [or night...etc] watching potential mid-air's pass continuosly within a half-wingspan or less at 1,000ft separation. They haven't worked out that in the high 90 percentile, there is NO equipment error nor pilot error and if someone blinks, they'll hit.
Safety Heights [or whatever name you choose] are calculated by using traditional methods for flight legs [not talking RNAV stuff here]; by flying, say, 1nm right-of-track, all the world's S/H's have to be recalculated. They can't get it throught their heads that [see above] there is NO error with GPS [or, at least, so small as to be almost ignored....half-wingspan after 14hr flight?]
GPS was "made in America" and it would be absurd for ICAO to trust it and base anything official on it until the rest of the "World" catches up by moving to GNSS [bit like GMT and UTC, if you get my drift], THEN we can start to see something happening!
The Poms have never really got over Decca not being used worldwide over Loran?Rant over. We see P-RNAV now and maybe we're getting there. Roll on a 1nm right bias above FL200 as an FMC et al norm in LNAV!
G'day
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SLOP in NAT airspace is indeed an exisiting procedure, however the main difference between NAT SLOP and any in airways is that the problems are principally concerned with same, not opposite, direction traffic.
Informal studies done to determine the number of crews adopting it have indicated a single figure percentage uptake. Whilst attempts are being made to make crews more aware of the procedure with some operators actively encouraging their crews to adopt SLOP, I'm curious as to why so few apparently do - is it a reluctance to alter with the route held in the FMS, does it cause problems with waypoint cross-checking, does dispatch/ops have any influence or is it simply ignorance of procedures? Perhaps some here might offer an answer.
From: http://www.levelbust.com/articles/focus_aug_06_slop.htm
Informal studies done to determine the number of crews adopting it have indicated a single figure percentage uptake. Whilst attempts are being made to make crews more aware of the procedure with some operators actively encouraging their crews to adopt SLOP, I'm curious as to why so few apparently do - is it a reluctance to alter with the route held in the FMS, does it cause problems with waypoint cross-checking, does dispatch/ops have any influence or is it simply ignorance of procedures? Perhaps some here might offer an answer.
Figure 1. The SLOP intends to spread aircraft out laterally with the use of two offsets to the right.
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No issues with waypoint checking -- once selected, the offset function is automatic. The waypoint list itself remains unaltered.
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rab-K
In my view SLOP on the NAT tracks is more useful for avoiding wake than for avoiding collisions. The traffic flow is predominately one-way, so I can go months without seeing an aircraft going the opposite way to me and TCAS makes me aware of traffic going the same way. It seems pointless to offset on the off chance that someone is at the same level as me and going in the opposite direction undetected by ATC or TCAS or that an aircraft going the same way as me will be in the way for a few seconds as it or I change levels in an emergency whilst (inexplicably) disregarding the Atlantic Contingency procedures.
The reason I don't SLOP much myself is that 9 times out of 10 I need to offset LEFT to avoid the wake of the preceeding traffic and the current SLOP procedures have removed the ability to do that. In theory I am supposed to negotiate with the aircraft causing the wake to pursuade them to offset right, at which point the whole procedure becomes too much hassle for such little gain.
Bring back LEFT offsets and you might see more take up of the procedure. (In my opinion).
G W-H
In my view SLOP on the NAT tracks is more useful for avoiding wake than for avoiding collisions. The traffic flow is predominately one-way, so I can go months without seeing an aircraft going the opposite way to me and TCAS makes me aware of traffic going the same way. It seems pointless to offset on the off chance that someone is at the same level as me and going in the opposite direction undetected by ATC or TCAS or that an aircraft going the same way as me will be in the way for a few seconds as it or I change levels in an emergency whilst (inexplicably) disregarding the Atlantic Contingency procedures.
The reason I don't SLOP much myself is that 9 times out of 10 I need to offset LEFT to avoid the wake of the preceeding traffic and the current SLOP procedures have removed the ability to do that. In theory I am supposed to negotiate with the aircraft causing the wake to pursuade them to offset right, at which point the whole procedure becomes too much hassle for such little gain.
Bring back LEFT offsets and you might see more take up of the procedure. (In my opinion).
G W-H
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In my view SLOP on the NAT tracks is more useful for avoiding wake than for avoiding collisions - The reason I don't SLOP much myself is that 9 times out of 10 I need to offset LEFT to avoid the wake of the preceeding traffic and the current SLOP procedures have removed the ability to do that. In theory I am supposed to negotiate with the aircraft causing the wake to pursuade them to offset right, at which point the whole procedure becomes too much hassle for such little gain.
Bring back LEFT offsets and you might see more take up of the procedure. (In my opinion).
Bring back LEFT offsets and you might see more take up of the procedure. (In my opinion).
Could you clarify a couple of points for me:
If the preceding traffic is on track centreline and you are sat in its' wake would you, independently of the traffic ahead, move one or two miles right to remain in smooth air, or is it your understanding that you hold your track centreline and must contact the other aircraft on 123.45 to request that they move?
Furthermore, why 9 times out of 10 would you require to offset left instead of right to avoid wake? (Not a pilot so apologies if this falls into the realms of a 'dumb-assed' question).
It seems pointless to offset on the off chance that someone is at the same level as me and going in the opposite direction undetected by ATC or TCAS or that an aircraft going the same way as me will be in the way for a few seconds as it or I change levels in an emergency whilst (inexplicably) disregarding the Atlantic Contingency procedures.
Finally, the most alarming case I've ever seen in favour of SLOP was CAT over the ocean that induced a 1500' departure from the cleared FL of one aircraft, which twice passed through the level of the traffic above, (Going up and back down again). Fortunately, both had TCAS and were far enough apart not to cause more than mild alarm on the flight deck. (Heart failure in the Ops room mind you!). Afterwards, RVSM was suspended on that track and those too close for comfort were put back to 2K' sep'n.
My final question to those who are familiar with NAT crossings and SLOP: Do any of you offset as a routine or is it dependent upon traffic displaying on TCAS, traffic over/undertaking, traffic creating vortex or CAT?