Cleared direct / Own nav.

[Sidney Hawker]

Can any of you ATC boys clear up an argument?

I have always believed that "cleared direct" means go direct to point X from your present position and "own nav" (when in the vicinity of an airway centreline) means re-intercept the centreline and route to point X.

The conflicting argument is that they both mean route directly (in a straight line without regaining the airway centreline) to point X.

Comments would be received with interest.

My next question would be: What bible could I find the above rules/terminology in?

[ATC Watcher]

"cleared direct" is non-ICAO R/T to start with. It should be : proceed direct to . Means you set course to the point given (direct line of sight from your present position to that fix.)
Resume own navigation is only given after ATC has taken over navigation from the pilot by assiging a heading. the phrase " resume own navigation " should not be used on its own but always followed by a fix (or an airway , but that is extremely rare in todays environement )
If cleared own nav to a fix, the same applies as proceed diect to.
If cleared to rejoin an airway, then you get back to centerline provided you can do this on your own (not everyone has an FMS)
You will find that in Europe at least, if sending you own nav to a point would take you outside controlled airspace , or in a zone you are not welcomed in, ATC tends to vector you back inside an airway before clearing you own nav to that fix.
The bible is ICAO Doc 4444.

[Sidney Hawker]

Thanks for the reply ATC watcher.

Just to clarify the above. Am I correct in understanding then, that "own nav" is the same instruction as "proceed direct to", ie: go directly from point a to point b. And is used after the aircraft has been on radar vectors? And would this apply, for example, if the radar vector had taken the aircraft a couple of miles out of an airway.In other words, there is no requirement to take up an intercept heading for the airway centreline before proceding then directly to the next waypoint.

[This message has been edited by Sidney Hawker (edited 14 August 1999).]

[ATC Watcher]

Correct, except that " resume own nav" should not be used on its own it should always be "resume own nav TO xxx"
If a controller tells you only " resume own nav", you should reply : "own nav to where ?"
I have seen some trainees say on the R/T " resume own nav.." then look frantically for the strips or the data display (where the rest of the plan should be ) and because they cannot find it, stop the r/t conversation at this point.But it is not the norm.

[PPRuNe Radar]

Sidney,

The topic was aired a couple of weeks back so there is more to be found at http://www.pprune.org/ubb/NonCGI/For...ML/000119.html

But what ATC Watcher says is correct.

------------------
PPRuNe Radar
ATC Forum Moderator
[email protected]

[Sidney Hawker]

Thanks for all the replies. I have also looked up the last links and have decided that the majority vote seems to be that both phrases communicate the same instruction.

[Night Freight]

While on the IOM yesterday I went and had a long chat with the ATC unit ( thanks for all your help & the vectors around the weather on departure (wx radar U/S)if anybody is on the island with time to kill go up and see ATC they are always glad to see you and very friendley ) and we read the relevant parts of ( PANS-RAC-DOC 4444 )
and it states as follows

" 6.5.5 In terminating radar vectoring of an aircraft , the radar controller shall instruct the pilot to " Resume own Navigation " giving the pilot the aircrafts position and appropriate instructions , as necessary , in the form prescribed in 6.4.2 b), if the current instruction has diverted the aircraft from a previously assigned route . "

and 6.4.2b reads

" Magnetic track and distance to a significant point , an en-route navigation aid , or an approach aid ."

well I think that says it all and we can now put this debate to bed

one last thing then the subject is closed taken from another document

Manual of air traffic services Part 1 " Pharseology "

Quote " Resume own navigation for ( position ) , magnetic track ( three didgits ) degrees , distance ( miles ) .

OK thats it what shall we debate next ?????

[Fox in sox]

Night Freight,

That may be what the book says, but when was the last time you were told your position and magnetic track to the beacon in question?

[Pointer]

just press Direct twice, That'll solve al your Questions. (Or: What's with the theoretical Q. if you have a Practical awnser)plus i gues we have enough reading materials in the "office".