Turn without permission - did it happen to you too?

[Jagohu]

Hi everyone,

I was just wondering if it ever happened to anyone else, that a flight turned from the assigned track (own nav to a point) without any permission.
It happened to me two times in the last 24 hours, thank God there was no traffic in the immediate vicinity, but it was quite a surprise.
The second one was more nasty, since the pilot decided to turn AFTER having been transferred to the next sector's frequency, but BEFORE calling in there. He just called in there on his avoiding heading (a turn of 30-40 degrees!), going straight into the Paris departures - fortunately there were no AMS departures climbing there.
In both cases, the pilot said it was due to weather. I don't think this was safe, and I explained it to the pilot yesterday already, that at least they should ask before they turn, but it seems like more and more that it's a common practice at this certain major European airline.
I've made an official complaint through the appropriate channels, but I'm wondering if it ever happened to any of you too.
Cheers!

[Waterfall]

Had the same a couple of times -didnt like it at all:=.i think they should AT LEAST NOTIFY us bout their INTENTIONS if not ask for a permission.Complying with what ATCO says is better than RA!!!:E:E:E

[anotherthing]

There's a discussion about that very thing here

http://www.pprune.org/atc-issues/376887-flipping-runways-thunderstorm-conditions-lhr.html

from post 5 onwards

[bookworm]

Complying with what ATCO says is better than RA!

Which in turn is considerably better than this
http://media.nowpublic.net/images//ed/4/ed4c8b6f40b4afd7253ee081762c9ecf.jpg

I'm sure that pilots could make much better efforts to make it a sensible negotiation, but I do sometimes get the impression from this forum that controllers get into the mindset that mid-air collision is the greatest, or even the only, threat to aircraft safety. While that mindset is perfectly understandable, history tells us otherwise.

[anotherthing]

Bookworm,

having read the thread about asking for turns, I don't get the impression you seem to have that ATCOs don't understand the implications of weather.

Every ATCO I know will give a turn unless there is a very good reason not to. However pilots should ask INCAS, but at the very least they should inform the ATCO that they are turning (asking is always better - after all the weather radar gives a long enough range to give adequate warning).

If a pilot was to turn without asking or saying anything it could have very serious implications on the safety of several other aircraft. ATCOs do not monitor individual aircraft 100% of the time, they make plans, implement them and expect adherence. Therefore pilots cannot expect ATCOs to notice the minute they deviate from their clearance. A clearance or instruction is not done in isolation, it is done taking other aircraft in the vicinity into consideration.

In a previous career (flying) I was involved in a MAYDAY due to severe downdrafts during a low level mountain flying exercise - I know what weather can do from a pilots perspective, been there, done that, got the T-Shirt and at one point during that flight, didn't think I'd have the chance to wear it!

That said, I would still expect pilots INCAS to ask before turning. ATCOs would have to have a very good reason to say no and would have to justify it if the pilot MOR'd the incident.

It's a team game, but neither side can operate effectively if not given the information they require!

[bookworm]

It's a team game, but neither side can operate effectively if not given the information they require!

Well put.

I won't comment on your debates with DFC in the other thread, but will point out that whatever my impression from reading this forum, my impression from the real world is that controllers do a fabulous job of accommodating everyone's needs on those very stressful convective days.

[BeT]

I sat down on the NCC just after this happened - did you call AFR ops in the end?

Its not acceptable and it happens more often than you think - I have had a certain German national flag carrier do it to me too.

[Mister Geezer]

The problem is that it is actually rare for you fine ATCOs to refuse any request to avoid weather and some drivers get into the nasty habit of turning without requesting. That is done purely on the assumption that they always get what they want when avoiding weather so why ask in the first place. It is a classic example of complacency and it is a poor show really. A short sharp word on the R/T might work if the frequency is quiet but failing that then report it. :ok:

[Jerricho]

A few weeks ago a departure made a turn by themselves in response to "TCAS" (that's what the pilot said). Now this is not the first time I've seen this happen.

There was traffic (no Mode C) well below them in the circuit of another airfield, but this had a few of us scratching our heads. The pilot was asked to confirm what he said ...."Uh yeah, we had traffic on our TCAS...uhhhh, yeah the TCAS went off" I wish the Departure guy who was working had made the pilot spell out if they received an RA or TA, but unfortunately the pilot was being a little cryptic, and there was a bit going on.

[Jagohu]

Yes we did call their OPS. After several transfers got to a pilot, who promised to pass our message on to the pilot involved and the pilot involved will call us back. Needless to say, he didn't.
We've got a promise though that our complaint and our request to ask for permission before they turn will be put on their briefing sheet. I hope they'll read it.

[Jagohu]

so why ask in the first place

Well, one good reason for that - not squawking/military traffic. It might be there, it's not on the TCAS, it won't trigger any alert.
And if we're talking about TCAS already - it'd be nice if pilots would start to notice that it's not a radar and shouldn't be used for self-separation.
Another one is that if the guy's flying through military airspace, he might have been checked for that route +-1-2 nm and outside of that it's the big bad world of all the militarys got... I've had an AirBerlin once flying IN an active firing range, coordinated with mil (it was their screwup, they didn't know about the navy's firing range being activated right when the BER was in the middle), so they only said tell the pilot they're not shooting at them but they must stay exactly on route for their own safety. In that case I did tell the pilot about all this, but I wouldn't if it was just a "simple" crossing of a TRA or something.
Not talking about turning into a firing range...

Thanks for all the answers!
One more thing - strictly speaking it's a deviation from the clearance isn't it? In some countries I believe you get the fighters behind you much quicker than here for this... I wonder if they do it there too... I know that in the old days in Eastern Europe it worked like that - air defense was looking at the civil traffic all the time looking for the one that's not going on-route and in the moment they saw something that wasn't planned/coordinated they've launched the MiGs... And it wasn't just a friendly wave and then go home kind of interception, but forcing the guy to land...

bookworm:
I'm sure that pilots could make much better efforts to make it a sensible negotiation, but I do sometimes get the impression from this forum that controllers get into the mindset that mid-air collision is the greatest, or even the only, threat to aircraft safety. While that mindset is perfectly understandable, history tells us otherwise.
Could you just tell me on what range do you usually have your wx radar set? How often do you look at the picture displayed? Do you look out the window sometimes? I think unless you've been sleeping in the last 10 mins of flight you can see things well ahead and not only when you actually need the turn.

[bookworm]

Could you just tell me on what range do you usually have your wx radar set? How often do you look at the picture displayed? Do you look out the window sometimes? I think unless you've been sleeping in the last 10 mins of flight you can see things well ahead and not only when you actually need the turn.

I understand that you're frustrated that pilots often ask for deviations late (or don't ask at all). I guess there are three things to bear in mind:

* Weather is dynamic. 10 minutes is a long time in the life of a thunderstorm

* Radar is imperfect, and in particular, flyable precipitation can hide the stuff that it's necessary to avoid.

* Pilots are human. They want the plan to work. Sometimes, they take a little too long to realise that it's not going to work and they need to ask for something different.

I'm not trying to excuse poor communication, or no communication. I hope your feedback has the desired effect. But I stick by my comments that some contributors seem to over-estimate the relative importance of collision risk.

[L337]

One of the most challenging situations you get with thunderstorms is on departure. The reason for this is that quite often it is difficult to get a good idea of what is out there, because very often the departure calls for a big turn after departure, and the radar is not painting the departure route very well. You can try and get an idea as you taxi out. But not always.

You sit on the end of the runway and assess it all. Look out the window. Watch a departing aircraft, and compare tracks. Having made a plan, discussed it, spoken to ATC and kept them in the loop. Consider going back to stand and going home saying "it is all to difficult, and I miss my children". You finally blast off down the runway.

As you get airborne the situation can change very rapidly as new information becomes instantly available. As you change to a departure frequency, fly the SID, watching the radar, trying to work a very dynamic situation, then you transmit... blocked, again transmit... blocked. Now you are staring a CB in the face....

I have 360 tonnes of 744 strapped to my rear, absolutely no spare performance, still got the flaps out as you have still not got the thing clean because of the noise abate.

What do you do?

Well of course, you manage to get through, you state your intentions, and try your best to keep everyone informed. But, it is very dynamic. And at it's most dynamic on departure.

[anotherthing]

L337

Understand that totally, unfortunately due to the interaction of SIDS, particularly in the LTMA, any turn off the SID without asking/warning the ATCO could be extremely dangerous... possibly worse than when at higher altitudes/levels! I do appreciate again what you say about not getting in on frequency... maybe a 7700 squawk would work?

Bookworm

* Weather is dynamic. 10 minutes is a long time in the life of a thunderstormTotally agree and that is one of the reasons why I personally think it is pointless for ATCOs having weather on their individual displays - it's nice for us (ATCOs) to know it is in the vicinity and how quickly/where it is moving, but other than that I'd rather have the pilots asking for (and me giving them) what they want. After all, avery ATCO who has encountered weather will have experience of two aircraft in trail, same company, same type having different atitudes to what their weather radar is showing... the first one might sak for a turn whilst the second sails through.

ATCOs should leave the piloting to the experts and not try to second guess them, much in the same way that Pilots should leave the controlling to the ATCOs (see Jerrichos post about a TCAS turn above :ugh:). By talking to each other one would hope that a safe all round operation was achieved, including the provision of avoiding weather.

[DFC]

Well put L337.

Everyone needs to remember that airborne weather radar normally looks 60 degrees left and right of the nose and in a very small vertical angle. The pilot can adjust the vertical to get a picture of what is above or below the aircraft but it takes time and skill to get a full picture of what is ahead which may be changing from second to second.

Of course as soon as a turn is required due to routing or the controller assigning a heading that picture is worthless and a new one must be aquired.

The "look out the window" argument is valid - but only when the aircraft is not in cloud or reduced visibility already!

Imagine being the controller on a sector from surface to FL155 where you could only see aircraft on the radar that were in bands of 3000ft and had to adjust the picture to see traffic higher up or lower down.

I would hope that pilots only turn without asking as a last resort to ensure the safety of the aircraft rather than simply turning to avoid a few bumps.

However, it happens and since both Pilots and controllers are required to have full knowledge of the weather affecting their operation, it seldom can be claimed to be unexpected that CB's are about.

Personally, I would say that the probability of having to make a turn without asking is higher in the area of communication transfer than elsewhere. The reason for this being not just that the pilot will have left the current frequency and not yet been able to check-in on the next but the situation often is that communication is transferred prior to the transfer of control point and even if the pilot asks the new controller, they often have to coordinate a change of track with the previous controller so the pilot (who has probably left it to the last minute) has no option but to turn.

I would be very surprised if controllers did not take that into account when weather avoidance could be required.


And if we're talking about TCAS already - it'd be nice if pilots would start to notice that it's not a radar and shouldn't be used for self-separation.



I think what should be said is that TCAS should not be relied upon to determine the horizontal position of other aircraft relative to one's own.

TCAS is a very important self-separation tool but only in the vertical.

Regards,

DFC

[Kiltie]

Jerricho I sympathise with your frustrations. TCAS pilot training and rules to follow are simple and have not changed much over the last decade. In particular the old adage is to never use TCAS as your own personal radar and only take avoiding action under radar control when in an RA situation.

I guess the pilot concerned was being a little cryptic because he has disregarded the rules and his training and made an a*se of himself. You mention this is not the first time this has happened. I'm surprised in this day and age we are still banging our heads off the wall trying to get the message through.

(From a pilot, not an ATCO).

[Unexperience]

it was once for me, when a pilot changed heading approximately 10 -15deg. without permission. I asked why he did that. The answer was to avoid cumulus cloud. I asked why without permission turn was initiated; the answer was that it is a small turn within airway limits. It was very difficult to prove that he was wrong as there was no reference regarding this.

[DFC]

the answer was that it is a small turn within airway limits


Only a valid excuse if they were not on an ATC assigned heading.

These days I think that everyone has become conditioned to the traffic following the airway centerline +/- a few metres. That was unusual when we tracked NDB's and aircraft could wander a few miles left and right of the centerline even when there was no weather about.

However, on RNP routes pilots need to remember that RNP 5 means that the aircraft will be +/- 5nm 95% of the time that the indicator shows the aircraft to be on track. Unlike the VOR when one could wander from -5 to +5 degrees (a 10nm cross track distance at 60nm from the VOR) and remain "within limits", with RNP being 1 dot left of track could mean that one is actually more than 5nm from the track already!!!

The other side to this example is that if one changes course slightly to avoid a CB and regains track the other side without saying anything then in most cases, ATC will not be aware that the CB is even there. Far better to let ATC know that there is a CB worth avoiding.

Regards,

DFC

[dublinpilot]

I was just wondering if it ever happened to anyone else, that a flight turned from the assigned track (own nav to a point) without any permission.

What's the significance of the "own nav to" part? I'm not an IFR pilot, but a lowly VFR pilot, but I've always understood "own nav to" meant that I was on my own navigation. ie. I could wander on/off track as I like. (It's usually given to me as I leave controlled airspace).

If you wanted the pilot to go directly to the next point then why not use "direct to" instead?

Presumably I'm missing some IFR meaning here.

[Blockla]

If you wanted the pilot to go directly to the next point then why not use "direct to" instead? The implied meaning of "own nav" would be directly to the next appropriate tracking point. We use this phrase when terminating a vectoring service; to confirm to the pilot to stop flying the heading even if it happens to be the exact same track... From a controller perspective it wouldn't mean "free to wonder" it would mean proceed direct to "X". An example would be "Resume own Navigation to Dublin" this means point directly at Dublin... Some are lazy and just say "own nav" but the intent would be the same.

Generally we consider the capabilities of the user regarding ability to track direct; eg a C152 VFR will not be treated the same in terms of nav ability (expectations) as the A380 etc.

[dublinpilot]

Thanks Blockla,

Always good to learn something new ;)

[Guzzler]

Blocka - just wondering if you are sure that is right.

My lowly ill-educated impression was that Direct to meant Direct to and Own Navigation meant you can either route direct to or return to the flight plan route.

The difference between the two is subtle and only really comes in to play when the waypoint concerened is further down the route. ie NOT the next waypoint.

On a separate issue and I ask only out of curiousity (promise) what is the smallest turn you can pick up on radar? I guess this probably depends on a few factors like windspeed and climb rates etc but would be interested to know a rough figure.

[anotherthing]

Guzzler,

I used to fly professionaly, and now work as an ATCO in the LTMA.

I agree with your interpretation having worked both sides of the mic.

'Route direct to XXX' means, (in my book), that you go direct to the point specified, even if it is 3 or 4 waypoints down the route. You are still under your 'own navigation' i.e. you are responsible for getting directly to that point without radar vectors from me.

'Resume own Navigation to XXX' means, (again as far as I am concerned), that you are no longer having to maintain radar vectors, and that you are on your own navigation to the point specified (and beyond).
If that point happens to be 3 or 4 waypoints further down the route, you are within your right as a pilot to either route direct to the specified point (then pick up the rest of the route), or go via the 3 or 4 waypoints that precede it on your route.

The two instructions are distinctly different IMHO, if an ATCO wants you to make your next point a waypoint 3 or 4 fixes down the line, they should, IMO, say 'route direct to XXX' (thereby instructing you to miss out the waypoints in-between). The instruction 'Resume own navigation' means you can pick up the full route to the point specified if you wish.

I believe (if through no other reason than plain old pedantry) that a lot of ATCOs who have never flown, or who haven't thought it through, use the two phrases incorrectly.
Although it is quite pedantic, if an ATCO tells you 'resume own navigation to XXX' (expecting you to go directly there) and you go via the intervening waypoints A,B and C, you may be doing something that the ATCO has not expected, but only because they don't understand the instruction they have given you, not because you have done anything wrong!

I also often hear the phrase 'resume your own navigation direct to XXX', again I think this is used due to ATCOs not understanding what the separate instructions actually mean in the cockpit.
What they are really saying is 'route direct to XXX' but using more words than required, possibly because they don't understand that both phrases mean that you are under your own navigation to the specified point, it's just what happens in between your present position and the specified piont that (may) differ(s).

'Resume your own navigation direct to XXX' is actually a contradiction if XXX is 3 or 4 waypoints further down your route (if really being pedantic)!

As for the smallest turn you can see on radar - realistically about 10 degrees plus. If you have Mode 'S' though, that figure goes down to 1 degree, if monitoring the Mode S readout.

The main thing is ATCOs get very used to the profiles of routes on their sectors, and even what headings look like on a particular day (giving variation for wind), therefore it is not so much the degree of turn, but the deviation from the SID/STAR/Route that will get picked up - much easier to spot small deviations on routes defined by aircraft track than it is to spot subtle wanderings from assigned headings.

[Capt Pit Bull]

However, on RNP routes pilots need to remember that RNP 5 means that the aircraft will be +/- 5nm 95% of the time that the indicator shows the aircraft to be on track. Unlike the VOR when one could wander from -5 to +5 degrees (a 10nm cross track distance at 60nm from the VOR) and remain "within limits", with RNP being 1 dot left of track could mean that one is actually more than 5nm from the track already!!!

not really.

I think you're confusing regulatory RNP requirements with practical ANP.

The vast majority of B-RNAV boxes will deliver accuracy far in excess of the 5nm 95%. More like .03 nm 99.99% of the time for GPS based, and not much worse for non GPS, in most populated parts of the world anyway.


re: the OP. Yes, its bad form and should generally be avoidable. Having said that, sh1t happens. More likely on a busy freq after a SID turn >60 degrees as other have mentioned.

[DFC]

Blocka - just wondering if you are sure that is right.

My lowly ill-educated impression was that Direct to meant Direct to and Own Navigation meant you can either route direct to or return to the flight plan route.



Perhaps the wording is confusing. However, there are a number of related issues that both ATC and a pilot need to be aware of;

1. A pilot is required to comply with an ATC clearance.

2. Unless otherwise authorized by the appropriate
ATS authority, or directed by the appropriate air traffic control
unit, controlled flights shall, in so far as practicable:

a) when on an established ATS route, operate along the
defined centre line of that route; or

b) when on any other route, operate directly between the
navigation facilities and/or points defining that route.

At the end of vectoring you are cleared "own navigation abc". In that case the two points defining your cleared route are your current position and abc.

Taking the above, when ATC have finished vectoring they issue a clearance to a specific point - (they are supposed to provide position info as well as magnetic track etc to the point but that is seldom complied with these days and in RNAV airspace is not really necessary).

According to b) above it is clear that when cleared to a point by ATC the flight is expected to operate directly between current position and the point one is cleared to. If flying a C172 with just VOR and ADF, you are entitled to ask ATC for either vectors back to the original route so that you can use the VORs or vectors to the waypoint if it is not a VOR or NDB within DOC.


On a separate issue and I ask only out of curiousity (promise) what is the smallest turn you can pick up on radar?


That depends on many issues. However, for a single plot extracted and processed radar feed, it is possible in a relatively slow aircraft to turn (agressively) left and right 60 degrees and provided your progress along track is not below the threshold for the moving traget indicator, it will show you on a constant track i.e. ATC will not see a track change however the position symbol may wander about a bit but that can happen for several rasons other than the aircraft moving about. Again in something like a Pits if you don't have mode C, you can do a quick loop and the person would have to be looking very closely at your position symbol to detect what you did. (the moving target indicator filters out radar returns that are not moving above a certain speed i.e. ground clutter).

With primary radar you can take advantage of tangental fade and other issues to play hide and seek with ATC. :D

However, the important point is that unless ATC are vectoring you they do not care about your heading and do not care if you are turning provided that your track complies with the clearance - If you fly on a constant track initially with a tailwind then into an area with 50 knots from the left then a headwind followed by 50Knots from the right think of how your heading will be changing (you will be turning) but ATC will not see it or care.

So I think that we should be talking about non-compliance with ATC clearance which better describes having to make a turn to avoid weather without first obtaining clearance.

Regards,

DFC

[Guzzler]

anotherthing and DFC - thank you for your thorough responses.

Clears things up nicely.

The reason I asked about what turns are normally detectable is that sometimes (particularly on departure) a turn of 2 or 3 degrees for a mile or so may be really handy for dodging a cloud. When the frequency is really busy it seems ridiculous to add to the controllers workload and equally stupid to fly through the cloud!

[DFC]

The reason I asked about what turns are normally detectable is that sometimes (particularly on departure) a turn of 2 or 3 degrees for a mile or so may be really handy for dodging a cloud.


I would only turn without asking if it was necessary to ensure the safety of the aircraft.

Having said that, you are expected to fly the aircraft +/- 5 degrees of the required heading so being 2 or 3 degrees from your chosen heading is not unusual for a time.

However, these days you have to fly the departure as accurately as possible not just for safety but to ensure that the noise to cash generating machines dotted round under the departure don't send your company a bill.

Regards,

DFC