Offsetting - time to make it official just about everywhere

[Wiley]

... and as the man says in the movie, they can't convince 99% of pilots to do it. The movie points out very well how the increased navigation systems' accuracy has increased the danger should someone, just one person, make a mistake, but the vast majority of us seem to choose to ignore this undisputed fact.

[Danny]

Obviously, asking flight crews to "randomly" insert 1nm or 2 nm offsets isn't working so why not have a mandatory system whereby depending on the flight level being flown determines the offset. There are 3 choices of 0, 1 and 2nm offsets available so it is entirely feasible to introduce a mandatory offset that also guarantees that any 2 a/c on the same track or offset are separated by at least 3,000ft vertically.

FL410 = 0 R
FL400 = 2 R
FL390 = 1 R
FL380 = 0 R
FL370 = 2 R
FL360 = 1 R
FL350 = 0 R
FL340 = 2 R
FL330 = 1 R
FL320 = 0 R
FL310 = 2 R
FL300 = 1 R
FL290 = 0 R

Nah, it can't be that easy. Maybe the ICAO committee need to justify their jobs by somehow overcomplicating it before mandating such simple rules that would increase safety by such a large factor.

Of course, under the current "random" rules, they still have all the a/c converging on the same exit waypoint! If they were to introduce mandatory right-of-track offsets for all a/c equipped to do so, based on the above criteria for all flying, including airways then there wouldn't even need to be all that converging on a single waypoint at the very edge of radar coverage. Also, we wouldn't have to acknowledge every single a/c that is going to pass 1,000' above or below us in the opposite direction as some eastern seaboard US controllers feel the need to point out to us.

[410]

Danny, you're creation probably has more clout than even you realise. Maybe you could make an issue of this, perhaps get a few of your journo contacts involved. We all love to knock journos the way they sensationalise all things Aviation, but in this case, sensationalism might be what's needed.

I can just see tabloid headlines along the lines of "ICAO refuses to implement safety measures demanded by airline pilots group".

It's not as though the midair in Brazil is the first instance where this ultra accuracy has been the "final hole in the cheese" ensuring an accident occurs. I keep asking myself how many have to die before someone does something.

[Willit Run]

The 747 classic has a fairly decent PMS system that was available. Several of our aircraft have the PMS, it's used to save fuel and reduce pilot workload. It has a glitch in the system though. If the radio altimeter sensed 1500', the auto pilot will disengage from command to manuel. Do you see where this is going? Thats right, a longtime operator of 747 freighters were cruizing along one day/night and another aircraft passed right below them at 1000', triggered the auto pillot to manual. Well, the crew were obviously doing something else and did not notice the tilting point in the airway, and they just cruized merrily along their straight path in manual auto pilot. There is no warning if the auto pilot trips to "manual", only to "off". Hence, an " Airworthiness Directive" was published, that the only time the PMS can be used is in climb or decent or non RVSM environments. Had there been a mandatory offset, this little incident wouldn't have happened, and I would be able to sleep better on the PMS aircraft while making the old man lots of money on saved fuel.

I know this was a long story, but I think the Danny method would be a good thing to adopt.

[Engineer]

Obviously, asking flight crews to "randomly" insert 1nm or 2 nm offsets isn't working

Ask the question why?

Because this is a new operating system (if you consider 3 years new).

Yet if you ask any one what to do in the event of a technical failure which renders the aircraft incapable of maintaining the OTS the reply would be automatic (hope so ).

Because it has been drummed into you via the training department/operations manual.

So there is no need to set up any system to ensure compliance just annotate it in the operations manual (example shown below) and ensure every one is trained correctly.

My view the answer to the above question is Airmanship

Strategic Lateral Offset Procedure (SLOP)

With widespread use of GPS, lateral navigation accuracy has increased significantly. There has been a corresponding increase in the probability of critical traffic conflicts resulting from height deviations (altitude deviation errors, turbulence, etc...).

As a result, pilots should use the Strategic Lateral Offset Procedure as standard operating practice in the course of normal oceanic operations to mitigate collision risk and wake turbulence by distributing aeroplanes laterally and equally across the three available positions.

SLOP will be applied using the following guidelines :

a) Aeroplanes without automatic offset programming capability must fly the centreline.

b) Aeroplanes capable of being programmed with automatic offsets may fly the centreline or offset 1 or 2 NM right of centreline to obtain lateral spacing from nearby aeroplanes.

c) Pilots should use whatever means are available (e.g. TCAS, communications, visual acquisition…) to determine the best flight path to fly, and to benefit in randomly distributing traffic across the three available positions.

d) Any aeroplane overtaking another aeroplane is to offset within the confines of this procedure, if capable, so as to create the least amount of wake turbulence for the aeroplane being overtaken.

e) For wake turbulence purposes, pilots are also to fly one of the three positions at b) above and never offset to the left of centreline nor offset more than 2 NM right of centreline.

Note : It is recognized that the pilot will use his/her judgement to determine the action most appropriate to any given situation and has the final authority and responsibility for the safe operation of the aeroplane. The inter-pilot frequency, 123.450 MHz, may be used to co-ordinate the best wake turbulence offset option.

f) Pilots may apply an offset outbound at the oceanic entry point but
must return to centreline at the oceanic exit point.

g) Aeroplanes transiting radar-controlled airspace (ex : Bermuda, Guam, Vancouver centre...) are to remain on their established offset positions but must advise the radar controller on initial contact of their offset status.

h) There is no ATC clearance required for this procedure and it is not necessary that ATC be advised.

i) Voice position reports are to be based on the current ATC clearance and not the exact co-ordinates of the offset position.

It is simple it just needs a change of attitude and approach to flying in congested airspace. The only other place that this procedures is used is India (umbrella up )and this is a result of the booming airline industry that is apparent today.

[PPRuNe Towers]

It couldn't happen to me?

http://www.pprune.org/forums/showthread.php?t=287414

Rob

[1xxxxx1]

offset or RA your call

Interesting discussion and an eye opener that I’m following since some weeks.

Flying a bizjet puts me out of range most of the time when operating above FL410 but I started watching opposite traffic and the result most aircraft are right on centerline and thanks to RVSM at the right altitude.
Before I had the impression that all airline drivers are flying offset to the right when in non radar environment like over Africa or Indian Ocean etc.
I’m not talking about the NAT track system as this is one way traffic or flights under radar control what might make some problems to ATC. (actually I was already corrected by China ATC for offset flying)

But since I have an FMS or GPS function allowing to fly parallel track I use it.
Offset 1NM to the right on all enroute airways surely when out of radar controlled airspace.

This is good airmanship and would have avoided some accidents as stated before.
And 1NM to the right cost nothing more, makes no problems and is no work besides typing “R” “1” “enter” in most boxes.
Let’s be honest; what else you have to do in this phase of flight than drinking coffee and with much less possibility of an RA you might not have to spill it.

[PPRuNe Towers]

Reference my post back in August and the turbulence induced loss of separation.

I'm looking now at the paperwork triggered by another separation and height bust - 1500ft in this case and I've personally spoken to the crew involved - they could not stop it happening.

The facility, paperwork and permission is there for you to use. SLOP is described above and really should be considered a vital bit of self defence.

Rob

[Shanwick Shanwick]

Am I the only one doing this on a regular basis? I always offset to the maximum of 2 miles as no one else seems to bother. Always get strange looks from the FO's when I suggest it.

[Feather #3]

Apart from a UK professional body putting forward a random "fly-right" offset as part of the FMC program, offsetting is all the go down South after our company had two near-hits which this procedure would ameliorate.

Chinese ATC on B215 now TELL you to offset 1nm right [and this would fix the NAT issue too!]

However, pilot discretion may not always work. One of our a/c on the oceanic bit of Myanmar's airspace, flying 2nm right, had another carrier's a/c go precisely underneath them. They called the guy to ask why he was 2nm LEFT?

The answer was that everybody else flew 2nm right and he was going to be different to increase his collision risk margin!! Bit hard when confronted by that logic!!??

G'day

[overstress]

Am I the only person to wonder why the OTS is referred to as NAT Tracks?

i.e. North Atlantic Track Tracks

rather like SAM missiles

or PIN Numbers

ATM machines
PAC code
LCD displays

etc

overstress (1 mile R of track)

[misd-agin]

Centerline, R1, R2. It varies depending upon overtaking traffic.

I like the one mile seperation view, especially if I"m on the sun side.

The majority of guys don't offset so they pass on the sunny side and ruin our view. How about some consideration?

[Wiley]

At the risk of stripping my Pprune anonymity, and judging by comments from my FOs, I think I'm one of the very, very few captains in my airline who regularly flys offset.

I think - (if only after quite a few hundred more people die proving the point) - future generations of airline pilots are going to look back at 'old timers' like us and say in tones of utter incredulity: "You mean for years and years after IRS and GPS came into everyday use, you continued to fly on centreline? And some regulatory authorities actually forbade offsetting?"

And if it does ever change, (with the Chinese apparently leading the way - well done, China), I think we can all thank Danny and this site for playing a major role in pressing for its implementation.

[4Greens]

Outside radar cover, just do it.

[410]

Interesting the way Chinese ATC has adopted offsetting within radar coverage (I'm assuming) as a 'belts and braces' measure with their switch to metric RVSM. I've been told on two occasions now to offset two miles right by Chinese ATC and on another, to cancel the offset just prior to top of descent after I had left in after leaving Yangoon airspace.

I find myself asking if they haven't got the right idea and whether other ATC agencies shouldn't follow their lead. Let's face it; it's an unassailable FACT that if Brazilian ATC had done as Chinese ATC so often does, there'd be a hundred or more fewer grieving families in Brazil today. As I've said more than once here, I simply can't understand the set-in-concrete resistance so many people in the industry have to the idea - and let's bring on with minimal delay a built-in offset to all FMCs in RNAV mode when above 20,0000'.

[javelin]

Simple solution - when Shanwick or Gander give you your clearance, they state the offset. They are planning the Ocean, they know where you are, you can have just as big a problem with 2 following guys offsetting the same amount as flying the centreline.

[410]

True for the North Atlantic, Javelin, but there is an awful lot of sky out there that isn't on the NATS tracks. That's the sky most of us are talking about.

[javelin]

I think most operators over remote areas such as Africa/South America have been offsetting for years - the recent work has been on the NAT system. Our company have been trying to get us to do it either on a random basis or as advised by Flight Planning. This just doesn't make sense when the two authorities could allocate offsets so easily.

The future must be micro offsets when the boxes can sort out decimals of offset.

Then you get the gem of a report about one of our Seniors who insisted offsetting left

[rab-k]

Javelin

The only downside to your suggestion is that, as things stand, it is the 'random' aspect of the uptake which keeps the statisticians happiest.

However, the problem came about when some clever-cloggs deduced that the uptake of SLOP was less than 10% - hence the note on the track signal to try to encourage crews to adopt the procedure as a standard, not just for overtaking or wake vortex situations. Random is good, but not when +90% don't play ball.

A few more crews are taking up the procedure and we can 'see' those who are ADS equipped and who do set up an offset in Oceanic, as the ADS position report comes down to give the game away, so to speak.

The problem in us telling you whether to stay on track or offset 1 or 2 nm would not only affect the randomness of the whole thing, but we can't tell from the ground what capability the aircraft has and whether or not it would be feesable to instruct a flight to offset. (I know some FMCs allow for easier offsetting than others and a few don't cater for it at all).

We have discussed amongst ourselves a system whereby if you're at an odd FL you offset 1nm, evens 2nm, if unable remain on track, but as mere mortals we can only fire such suggestions up the chain, and who knows where they end up.

[javelin]

ADS, It's the future, bit like garlic bread !

Our big aeroplanes are about to get upgraded to.........................VHF ACARS

Great for clearances and weather but still not CPDLC although some are so equipped. Another course, another toy to play with.

How long before all traffic above FL XX needs to be ADS equipped for NAT crossings ?

In the meantime, I will continue to speak to the very nice folks at Ballygirreen