What is the centre fix.
Joined: May 2001
Posts: 10,804
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About 4 to 10 miles out on the center line of the runway in use.
You then self vector yourself onto what ever approach you want to use.
If you have a FMC onboard its a couple of inputs and it will sort it all out for you.
But even flying an old heap you can do it with the application of the 1/60 rule and a bit of wag (wild arsed guess) Basically you just use the DME along with either a NDB or VOR on the field to position yourself where you want.
After a few goes its not uncommon to be able to hit the distance +- 0.1DME everytime with out the aid of a gps or ramming through the localiser etc etc. If now traffic around it allows the ATCO to contiunue eating there curry/ watching telly and the crew to manage there own profile so its a win win situation
You then self vector yourself onto what ever approach you want to use.
If you have a FMC onboard its a couple of inputs and it will sort it all out for you.
But even flying an old heap you can do it with the application of the 1/60 rule and a bit of wag (wild arsed guess) Basically you just use the DME along with either a NDB or VOR on the field to position yourself where you want.
After a few goes its not uncommon to be able to hit the distance +- 0.1DME everytime with out the aid of a gps or ramming through the localiser etc etc. If now traffic around it allows the ATCO to contiunue eating there curry/ watching telly and the crew to manage there own profile so its a win win situation
Joined: Oct 2002
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From: frozen norff
Through experience, a centrefix tends to vary from airline to airline.
Shame that ATCOs are not permitted to initiate any conversation regarding centrefix; there are times when it assists both the ATCO & flight crew...
Shame that ATCOs are not permitted to initiate any conversation regarding centrefix; there are times when it assists both the ATCO & flight crew...
Joined: Jan 2008
Posts: 2,003
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From: The foot of Mt. Belzoni.
JustaFew,
"Shame that ATCOs are not permitted to initiate any conversation regarding centre-fix"
Bloody good thing too.
Why?
IFR traffic is generally: -
a), On its own navigation to an exact reporting point.
b), on a radar heading assigned by a radar controller.
Send an aero to the 'centre-fix' and ATC has no idea where it is going, unless of course the centre-fix range is specified in the clearance.
Also, who is responsible for terrain clearance here and what is the RTF failure procedure if the a/c has passed abeam the normal clearance limit?
Area radar controllers do initiate centre-fix routings though.
Why?
Because they can't be arsed to work-out the base leg headings that approach radar controllers frequently offer.
It's all a bit of a grey area.
Similar in fact to the immediate environs of Eyjafjallajökull.
"Shame that ATCOs are not permitted to initiate any conversation regarding centre-fix"
Bloody good thing too.
Why?
IFR traffic is generally: -
a), On its own navigation to an exact reporting point.
b), on a radar heading assigned by a radar controller.
Send an aero to the 'centre-fix' and ATC has no idea where it is going, unless of course the centre-fix range is specified in the clearance.
Also, who is responsible for terrain clearance here and what is the RTF failure procedure if the a/c has passed abeam the normal clearance limit?
Area radar controllers do initiate centre-fix routings though.
Why?
Because they can't be arsed to work-out the base leg headings that approach radar controllers frequently offer.
It's all a bit of a grey area.
Similar in fact to the immediate environs of Eyjafjallajökull.
Last edited by ZOOKER; 16th May 2010 at 19:49.
Guest
Posts: n/a
Years ago there was a SI to the UK's MATS Part 1 on the subject. I recall that it went into quite a lot of useful detail - most of which was lost when the current MATS Part 1 entry replaced it. I also recall a CAA man telling me that the SI was not really necessary because aeroplanes did not do centrefix approaches......
Joined: Jul 2003
Posts: 208
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From: North
Centre fix
Sect 3 Chp1 page 9
9.8 Self-positioning of aircraft
9.8.1 Controllers should exercise caution when approving self-positioning to final approach and are not to initiate reference to the 'Centrefix' or other locally used term.
9.8.2 If controllers are in any doubt about the location of the 'Centrefix' or other position referred to by a pilot, they are to ask the pilot to define this position and take this definition into consideration when carrying out their controlling duties.
It works too, although some ATCO's dont like it "cos its not an approved procedure".
9.8 Self-positioning of aircraft
9.8.1 Controllers should exercise caution when approving self-positioning to final approach and are not to initiate reference to the 'Centrefix' or other locally used term.
9.8.2 If controllers are in any doubt about the location of the 'Centrefix' or other position referred to by a pilot, they are to ask the pilot to define this position and take this definition into consideration when carrying out their controlling duties.
It works too, although some ATCO's dont like it "cos its not an approved procedure".
Joined: Feb 2001
Posts: 206
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From: Sunny Scotland
9.8.1 Controllers should exercise caution when approving self-positioning to final approach and are not to initiate reference to the 'Centrefix' or other locally used term.
guess its flight plan route from now on people
Joined: Oct 2002
Posts: 215
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From: frozen norff
ZOOKER
'a), On its own navigation to an exact reporting point.'
Yes, the centrefix.
'Send an aero to the 'centrefix' and ATC has no idea where it is going, unless of course the centrefix range is specified in the clearance.'
You have solved the problem.
'who is responsible for terrain clearance here?'
ATC still.
'what is the RTF failure procedure if the a/c has passed abeam the normal clearance limit?'
New clearance limit replaces the previous clearance limit, as usual.
See AIP, STAR chart, MATS pt.2 for RTF details.
Define normal clearance limit...
Can be a grey area. With a few questions, though, where is it geographically, what altitude do wish to be at over the centrefix, it can be a useful technique.
As far as ATC are concerned, there exists an approach, and a centrefix.
Centrefix approach does not exist.
But is it centre fix, centrefix, or centre-fix?
(Just don't spell it centER) !!!!!
'a), On its own navigation to an exact reporting point.'
Yes, the centrefix.
'Send an aero to the 'centrefix' and ATC has no idea where it is going, unless of course the centrefix range is specified in the clearance.'
You have solved the problem.
'who is responsible for terrain clearance here?'
ATC still.
'what is the RTF failure procedure if the a/c has passed abeam the normal clearance limit?'
New clearance limit replaces the previous clearance limit, as usual.
See AIP, STAR chart, MATS pt.2 for RTF details.
Define normal clearance limit...
Can be a grey area. With a few questions, though, where is it geographically, what altitude do wish to be at over the centrefix, it can be a useful technique.
As far as ATC are concerned, there exists an approach, and a centrefix.
Centrefix approach does not exist.
But is it centre fix, centrefix, or centre-fix?
(Just don't spell it centER) !!!!!
Joined: Jan 2008
Posts: 2,003
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From: The foot of Mt. Belzoni.
Q. But is it centre fix, centrefix or centre-fix?
A. None of the above.
It's actually 'centre-line fix'.
And I promise never to spell it "center-line fix".
- Unless of course, it's 'nite-time'.
A. None of the above.
It's actually 'centre-line fix'.
And I promise never to spell it "center-line fix".
- Unless of course, it's 'nite-time'.
