with regard to "turn right **degrees"

[mxwbuaa]

hello ,when using " turn left (or right) **degrees" to vector an aircraft, can I direct the aircraft make a turn of less than 10 degrees? say ,5 degrees. I wonder if the pilot can execute this type of heading direction accurately.

[ferris]

The answers are; Yes, you can issue the instruction, and It depends. A modern airliner has highly accurate navigation systems, a light aircraft being buffeted by wind....well, sort of, but how would you know? It's groundspeed means that it will take a long time to find out.


Out of interest, why do you ask? Are you playing a game, a student, the director of Chinese air navigation?

[mxwbuaa]

hey ,guy, you are clever, i'm a radar control trainning instructor who never really controll the aircraft in real enviornment. thanks for your answer, are you a controller or a pilot?

[BOAC]

Old RAF story
ATC "XXX Turn right 1 degree"
XXX " I cannot fly to 1 degree!"
ATC "XXX turn right 5 degrees"
XXX "Right 5 degrees, XXX"
ATC "XX Turn left 4 degrees"
XXX "..........:mad::mad::mad:"

[mxwbuaa]

is it a real story?

[HEATHROW DIRECTOR]

In SRAs you'll find 3 degrees used quite a lot..

[chevvron]

When carrying out a Surveillance Radar Approach (SRA), it's normal to use 5 deg heading changes when the approach (a non-precision procedure) terminates at 2nm or less than 5 deg when the approach terminates at less than 2nm.

For an approach using Precision Approach Radar or PAR (which includes an electronic glidepath display), heading changes are usually 2 or 3 deg, however the British Royal Navy often use 1 deg heading changes (or certainly used to).

The problem with modern pilots is they tend to feed heading changes for these types of approach into the autopilot rather than fly them manually; the autopilot however might not recognise a heading change of 5 deg or less, hence it doesn't turn the aircraft until more than 5 deg has been dialled in.
A bizjet pilot (ex military) told me he always teaches his FOs to fly SRA/PAR by flying the appraoch manually and cancelling the yaw damper.

[mxwbuaa]

Ok, 3 degrees is common in SRA, but what for radar vectoring at positions in terminal area 30nm far from the threashold? is it sound to instruct the aircraft to turn left 5 degrees? thanks man

[chevvron]

I'm not current in Area Radar or Terminal, but given the limitations of the autopilot I mentioned, I would say it's not unreasonable to expect a crew to accept a 5 deg heading change.

[eastern wiseguy]

radar vectoring at positions in terminal area 30nm far from the threashold? is it sound to instruct the aircraft to turn left 5 degrees?


Yes ...and is done frequently. Sometimes 5 degrees is all that is required for a long "base leg" prior to issuing a closing heading.

[ferris]

i'm a radar control trainning instructor who never really controll the aircraft in real enviornment How is that working out for you? Did your manager receive a large bonus for coming up with that idea?

[mxwbuaa]

no ,not for bonus , i just want to make it clear. thanks

[belk78]

awesome...
Welcome to the new ATC era.

[eastern wiseguy]

How can you teach Radar control with no practical experience? :confused:

Do you mean you are no longer current....or you have NEVER done it for real?

[Standard Noise]

awesome...
Welcome to the new ATC era.

How can you teach Radar control with no practical experience?

I think we've already started down this road.......

[mxwbuaa]

glad to meet you all, thanks

[wiggy]

**Warning ** off topic but one of the most inovative uses of degrees I've heard.

On ground at LHR a few years back, Non-english speaking airline pilot verses the LHR Ground controller:

Ground: "XXX push approved, face west"
Pilot: " push approved say again direction"
Ground: "Face west"
Pilot: "say again"
Ground "Face west"
Pilot "say again direction"
Ground " sigh.....push approved...............face 270 degrees...."
Pilot " Ah, OK push appoved face west"

Well it made us smile......

[jackieofalltrades]

I very often have told a pilot to turn left/right 5 degrees, and have never had them come back to say they can't do that.

[Lon More]

Even if the pilot can't the average FMS can fly accurately to one degree IIRC

Yhree Degrees? are we talking abouy in-flight entertainment?

[ron83]

I do also quite often use 5 degrees turns,because sometimes it's what is only required. Never had a pilot refused such a turn apart for weather avoidance,but it's another story.

[allrounder99]

I am upperairspace enroute in Europe. Often used 5 degrees, now we see the mode S heading, and I will give exact headings eg. 186, if I see it is the heading I want to use.

aircraft fly 186 just as easily as they do 185.

[fly_ebos]

Often we have aircraft on parallel headings, same levels ofcourse, and you see that due speed difference the track are actually slight converging. I have no problem in turning one of them 2 degrees so the actual tracks go parallel.

Pilots often come back with a "confirm 2 degrees", but why not, the computer can fly any heading you dial in.

[blissbak]

Do you air traffic surgeons also get benefits by 1KT speed adjustment or what ? :hmm:

[Catwalk Dweller]

Not only an unhelpful comment, but a non sequitur to boot.

[allrounder99]

1 KT speed adjustment? No reason why it wouldnt come in useful from time to time. Often M.005 adjustment, but that is worth around 3 to 4 knots.

It may sound rediculous to you pilots, but I am sure you would rather gain fewer miles from vectors than more miles right? So that is the reason.

[blissbak]

Catwalk, there is no logical issue, the 1° adjustment is useless as much as the speed example, no benefit.
Trying to turn it to an helpful participation, I do wonder how come 2 planes made parallel are going to meet because of the speed...

[poldek77]

Trying to turn it to an helpful participation, I do wonder how come 2 planes made parallel are going to meet because of the speed...


Because when the headings are the same with the same crosswind but TAS vary - then their crab angles will be different as well, so the tracks may converge.

[blissbak]

Poldek, if one of them is that faster determining an important DA difference, I wouldn't care about because the separation issue will be solved very very shortly without urgency to move people by 1/2 degrees (overtake).
If the speed difference is not that big, the DA is not that rilevant unless they are flying parallel lifelong.

[fly_ebos]

If I have 2 AC on parallel with 6nm in between, for the next half hour and my separation tool tells that in 10 min I will have only 4nm, then I prefer the 2° turn rather than the paperwork!

[poldek77]

Poldek, if one of them is that faster determining an important DA difference, I wouldn't care about because the separation issue will be solved very very shortly without urgency to move people by 1/2 degrees (overtake).
If the speed difference is not that big, the DA is not that rilevant unless they are flying parallel lifelong.

I have just tried to play with some numbers (to check my brain that got used to accept computation done by FMS :confused: ) and I hope they are correct.
Two airplanes: SlowJet - Ma=0.72, TAS=400 and FastJet - Ma=0.82, TAS=460, X-Wind 100kts (not everyday's but possible), no HeadWind or TailWind. So the difference in Drift Angles is just 2 degrees.
The case starts when FastJet is 10NM behind and ends when 10NM in front. With such a speed difference it takes 20minutes.
During this time the airplanes' tracks get closer by almost one NM. Of course it's not much but as fly_ebos said it may result in some paperwork...
Greetings

[blissbak]

Poldek, once you put two planes 5/6 miles apart on parallel heading, and this situation last for 20/30 minutes AKA 200/250 NM, you must monitor them very carefully all the time, it's difficult when you have a busy sector, you can "forget" them, or forget the others 30, both dangerous situations, and few degrees won't save your ass from paperwork despite the separation machine, the numbers game or anything else.

[1Charlie]

If you're a pilot that complains about getting a 1* heading change, you've been doing it too long

[raraa]

1 degree enroute is fine by me, I would love it instead of taking me 5 then sending me back direct to the exit point

[Viking101]

I had that one on appr to paris Orly haha

I asked if she wanted the full degree or if 2 degrees was close enough.

The female controller got back with a angry voice " no I said 1 degree left"

Fine I replied.....

Shortly after I got the left turn by 30 degrees to intercept the Loc....

Well well