EZY6942 - reversal turns

[NorthSouth]

Not sure if this is the right place to post this, but I was flying Keflavik-Edinburgh last night on EZY6942 and witnessed some strange manoeuvres. I'm not an airline pilot but have been an instructor for some years and also know a reasonable amount about ATC.

I wonder if anyone can shed light on the following?

About 20 minutes after departure from Keflavik, and I think just after levelling at FL390, we rolled into a right turn through at least 30 degrees. But when we rolled out of that turn, we continued rolling straight into a left turn through about the same heading change.

Then, about halfway into the flight, and just before crossing some opposite direction traffic below us, we rolled into a left turn through at least 30 degrees then once again immediately reversed the turn and kept that right turn going on to a new more southerly heading. It also looked like, after more or less levelling the wings, the aircraft was actually sitting right wing low for at least a minute after that turn, i.e. still in a gradual right turn. I got the impression that the aircraft may have been under manual control rather than AP.

On the initial approach into Edinburgh we had another reversed turn - although not as clear as the previous two. Then, when we finally emerged into VMC, we were on a left base leg for 24 from the SOUTH.

All very strange, so when I got home I did a playback on Flightradar24. This showed the "jink" 20 mins after takeoff, and also showed that there was no other traffic anywhere in the vicinity that might have explained the turns.

The playback doesn't show the second turn reversal, although it does show the heading change to the right just as we crossed the opposite direction traffic (which was 5000ft below us).

As regards the manoeuvres on approach to Edinburgh, we appear to have been initially under vectors to STIRA (initial approach fix) then on to an easterly heading, which would be normal for vectoring to a right base for 24. But then we turned right, crossed the final approach at 4000ft, and were then descended and turned left to join a left base. No obvious traffic reasons for sending us to the other side of the approach (although some aircraft don't show up on FR24).

I would have asked the captain as we left the aircraft but he was busy talking to someone else.

Anyone got any ideas?

[Pilatipus]

Maybe weather avoidance.

[737aviator]

Sounds like a normal SLOP in when entering and leaving Oceanic airspace. This is when pilots select an offset from the airway by a certain distance, usually to the right of track and usually 1 or 2 miles. This is a normal safety procedure as this is procedural airspace.

[sapperkenno]

Was this "seat of the pants" guesswork, based on feel while in IMC? If so, you might as well discount anything you felt or thought you were doing.

[OhNoCB]

Or it could just have been heading changes from ATC. THis is not uncommon (at least to me) and I often think it must make the passengers wonder what is going on. Quite often we get something like:

"Turn left heading 120"
"Sorry change of plan turn right heading 170"

Or even sometimes when changing frequency to another ATC unit, on leaving the first one they will tell us to resume our own navigation to XYZ which might be a left turn, then on contacting the next unit we are told to turn right back to the original heading.

[JeroenC]

Or you just turned after passing a waypoint, and then were given a direct to another.

[Office Pest]

Having flown that very route many times it definitely sounds like SLOP to me. You can of course change a few settings in the FMGC to make the turn not quite so abrupt.

[NorthSouth]

Thanks, all interesting. As regards SLOP:

(a) the first reversal turn occurred at or not long after the INGO VOR, but that's not on a designated Upper ATS Route as far as I can work out - and in any case, it's not in Oceanic airspace, it's in the Reykjavik CTA where there's full radar cover so why fly an offset?

(b) the second reversal turn was in the opposite direction - left then right. That would put the aeroplane on the left side of the centreline (if there was one) - so conflicting with anyone applying the standard right hand offset in the opposite direction.

(c) not long after the second reversal turn, we passed directly over opposite direction traffic 1000ft below us. That would suggest we were not flying any lateral offsets but were flying under radar control. Radar cover at FL390 looks like it is pretty much continuous between Scotland and Iceland, at least with SSR.

I wonder if this might have been an aircraft with a transponder failure, and the turns were radar identification turns?

[Crazy Voyager]

You still haven't answered one question, where these turns based on you seeing the horizon move out the window, or you "feeling" the turns?

I've flown in IMC into airports where I know the routes and procedures by heart, at one time I could've sworn we made a 360 on the way in. Like you I actually was so curious I mentioned it to the flightcrew, who said it'd been a perfectly normal STAR with no vectoring.

My point being, if you based it on feeling things, and FR24 does not even show one of the turns, they most likely never happened.

[Amadis of Gaul]

He's a highly experienced instructions, he can feel the m turns with his very being.:cool:

[neila83]

I'm interested in this as well, it's something I've noticed on a lot of flights - sitting in the window and looking at the actual wings banking, so definitely not a mistaken seat of the pants feeling.

Often a shortish turn in one direction, before then making a larger turn in the opposite direction. Or vice versa. And on clear days without any visible weather around. I've noticed it more on short haul where I have a window seat more so it's not about entering oceanic airspace. I've always wondered, what else could it be?

I also have noticed the other situation the OP mentions, where the aircraft sits wing low for a loooong time after a turn. I've noticed both these things quite a lot so assume you guys can fill us in, thanks! :ok:

[NorthSouth]

Crazy Voyager: no, sir, I was not "feeling" the turns while in IMC. But thanks for your helpful suggestion.:)

[BOAC]

I used to carry out that manoeuvre sometimes when I or P2 wanted to look below at something.:)

[NorthSouth]

On reflection I think those of you suggesting SLOP are probably right, even though this was not in NAT airspace. What I saw would be compatible with:

1. On reaching VOR INGO, opting to take up a track 1nm or 2nm right of track
2. On reaching RATSU, opting to go back to a direct track en route to the STN VOR

[fantom]

Larson has the answer:

http://lolbot.net/pix/20938.jpg

[Amadis of Gaul]

I'm glad NorthSouth figured out the answer, I know I was fixing to start losing sleep over it.

[SR-22]

NorthSouth, the whole BIRD area is indeed oceanic by definition and inside MNPS even though most of it around Iceland is covered by radar. Flying from Iceland to northern Scotland, and between Iceland and Norway south of around 66N is fully covered by radar. Nevertheless a oceanic clearance is still required even though being covered by radar the whole route, as per above.


This sounds a bit like a SLOP was being done as other posters suggested.
Having said that, I would put a big questionmark to doing a SLOP when under radar and on a random route. The SLOP is intended and strongly recommended for oceanic flights when NOT under radar and especially on the NAT tracks where you have multiple aircrafts on the same route. I do not see the point in doing that on a random route. In rare cases the NAT tracks do go over Iceland, then and only then it is recommended to stay on a already established SLOP if that is being utilized when transiting through a mid ocean radar area which makes sense if you are on a NAT track.


So I would say doing a SLOP on a "Blue Spruce" route from Iceland to Scotland is a HUGE overkill

[Check Mags On]

8.5.3
Consequently, SLOP is now a standard operating procedure for the entire NAT Region and pilots are required to adopt this procedure as is appropriate.


That said you can always offset zero should you wish.


In section 8.5.3 subpart
F: Aircraft transiting ATS Surveillance-controlled airspace mid-ocean should remain on their already established offset positions.

[SR-22]

Yes but I would say this section is referring to non-radar area, hence the "as appropriate" and also as per section 8.5.1. even though one cannot really say it is crystal clear.

The locals do not utilise SLOP in that area. Only maybe when westbound and out of radar area as for them it is always a random route.


Iceland AIP wording is a little different:
ENR 1.8.11.7.1. section 5:


"Aircraft transiting oceanic radar areas may remain on their established offset positions."


Keyword here is transiting. Therefore I would say that for a flight to/from BIKF would not be appropriate to do a SLOP in that area and under radar.

[NorthSouth]

Thanks SR-22. So the plot thickens! No doubt the answer is in EasyJet's ops manual so unless we get some EZY pilots answering the question we may remain in the dark.

[INeedTheFull90]

The sigwx chart for that day gives moderate icing and turbulence below FL180 in a band if weather stretching from the north of Iceland to the Midlands, with jetstreams at FL290 just south of Iceland and FL350 mid way between Iceland and Scotland. Although the chart forecasts moderate turbulence and icing below FL180 I would be very surprised if the vertical development simply stopped at FL180 and there may have been cloud tops much higher if this occurred at 20 minutes after departure.

I can't go into specifics, SLOP could have been used on the route (nothing to preclude its use technically) but I'm going to say either weather avoidance or being put on to a heading temporarily in order to climb clear of traffic, which happens a lot. SLOP isn't too relevant when you're under radar control, and even on the blue source routes it is rarely done. If it is then the turns are usually pretty gentle especially if the SLOP is only a mile.

The 22:50Z matar for EGPH that day shows CB reported, and the TAF for that evening forecasts CB so you could have flown overhead the field onto a left downwind for 24 or even flew through the localiser then onto a left downwind for 24

Either way, I'd put my money on saying it was weather avoidance or following ATC guidance.

[FlyFree]

Was there a NOTAM out at the time for degraded ATC coverage?

In this case SLOP can be used outside of African airspace....as in EUR/SAM

But, as said with a NOTAM, and ATC must also inform of this, before entering....

As somebody mentioned, one is nearly always under radar, for this specific route.

[Check Mags On]

Yes but I would say this section is referring to non-radar area, hence the "as appropriate" and also as per section 8.5.1. even though one cannot really say it is crystal clear.

That section is referring to MNPS Airspace. Of which that corner up to Iceland is a part of. It is crystal clear to me.
As for Random Routes, all flights in MNPS Airspace are random routes unless they travel the full length of a NAT Track and pass through 30W during the hours of operation of a track.
If you are "transiting" as you put it Oceanic Airspace, you must comply with the rules for that Airspace and these are set by ICAO Paris with differences. And on the many times I've been up there, we transited Shanwick which Iceland has no jurisdiction over. And always requires an Oceanic clearance.

[ESQU]

U2 usually route KEF to the UK via OSKUM RATSU UN610 STN, so if you are sure that you were over INGO VOR, it may of been due to weather avoidance.

[halfofrho]

No doubt the answer is in EasyJet's ops manual so unless we get some EZY pilots answering the question we may remain in the dark.

It's a tricky one because technically speaking, from BARKU/RATSU until ALDAN you are in oceanic airspace, even if you are under radar control from Reykjavik . We have to call Iceland Radio 20-30 minutes before entry at BARKU to receive our 'oceanic clearance'.

The guidance is to use SLOP in any oceanic airspace, however the basic idea of SLOP is for improved separation when your not in radar airspace, ie the Atlantic.

I've seen captains adopt it, where as some think its a load of rubbish... Generally I always suggest we do it, even if its just to see the bus doing something a little different than usual. :}

[SR-22]

That section is referring to MNPS Airspace. Of which that corner up to Iceland is a part of. It is crystal clear to me.
As for Random Routes, all flights in MNPS Airspace are random routes unless they travel the full length of a NAT Track and pass through 30W during the hours of operation of a track.
If you are "transiting" as you put it Oceanic Airspace, you must comply with the rules for that Airspace and these are set by ICAO Paris with differences. And on the many times I've been up there, we transited Shanwick which Iceland has no jurisdiction over. And always requires an Oceanic clearance.


Tthe rules say nothing of that a SLOP must be done, only that it should be done, e.g. "strongly recommended". Indeed Reykjavik CTA is inside MNPS, and keep in mind that it is one of very few areas which is defined Oceanic despite having radar. Would it be wrong to do a SLOP under radar? In that area, maybe not no but definetely not neccessary. Out of radar is a different story, but entirely up to the pilots.

The sigwx chart for that day gives moderate icing and turbulence below FL180 in a band if weather stretching from the north of Iceland to the Midlands, with jetstreams at FL290 just south of Iceland and FL350 mid way between Iceland and Scotland. Although the chart forecasts moderate turbulence and icing below FL180 I would be very surprised if the vertical development simply stopped at FL180 and there may have been cloud tops much higher if this occurred at 20 minutes after departure.


Highly doubtful that they were avoiding weather at FL390. Sure it can be cloudy, but in the mild climate in Iceland CB's rarely go above FL200 and never above FL300.

U2 usually route KEF to the UK via OSKUM RATSU UN610 STN, so if you are sure that you were over INGO VOR, it may of been due to weather avoidance.


There is actually a requirement of routing via OSKUM if crossing 010W between 64N and RATSU inclusive. So routing via ING seems very strange to me and a longer one instead of OSKUM DCT RATSU. To be honest I am surprised they don't fly further to the west and going via RATSU is a bit longer and more expensive. But then there are the winds of course to be kept in mind.

[Check Mags On]

Sorry but the rules do very much say that a SLOP must be done.
It has a been a Stabdard Operating Procedure since 2004.
Section 8.5.4 refers.
You can offset zero if you wish. You might say that is sematics.
The strongly recommend bit refers to aircraft capable of offsetting (which is almost everyone these days.) leaving the centreline available for those unable to offset.

[NorthSouth]

Yes, the route could have been via OSKUM - INGO was just a guess on my part based on elapsed time and being able to see land directly below us not long before the first turn. KEF-OSKUM with a rw 29 departure is about 65nm so I guess a turn after 20 mins would be compatible with being over OSKUM, albeit perhaps a little slow?

So if it was SLOP, taking up a track right of the centreline from OSKUM, the turn at RATSU appears to have been a return to the centreline (because we were exiting Oceanic airspace?).

NS