PPRuNe Forums - Change over point.

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alj87

18th May 2008 21:06

Change over point.

What are change over points?

Notso Fantastic

18th May 2008 21:21

They are points when you change over from one to the other.

Why not be a little more specific? A clue, perhaps?

toolowtoofast

18th May 2008 21:27

it's just after pulling out of a reverse cuban that you pulled through too early on, missing the ground by inches on the pull out, when you change over your undies for clean ones

alj87

18th May 2008 21:32

NOtso

That's the problem I don't have any clue what is it! I met this question on my test it goes like-the establishment of change over points should be limited to route segment of how many NM?

BOAC	18th May 2008 21:42

For those of more limited experience (where's you bin hidin', NSF? :p) ,Change Over Point (COP) is a point on a leg (airway etc) where the reference navigation system is changed eg between 2 VORs of equal DOC on an airway - some say half-way, some differ. As long as you change!

As far as the test question goes - I have not got a clue! I have a vestigial memory of 51nm, however. Anyone recall? Something to do with airway width and VOR errors?

Rather frighteningly, in the rather trying 'absence' of LNAV:eek:, I had to teach a QUALIFIED/RATED co-pilot how to fly an airway not so long back. 'How you do that' she said?

Quote:

when you change over your undies for clean ones

- isn't that Fridays, whether you need to or not? Obviously not been on a Harrier deployment...................................

Notso Fantastic

18th May 2008 22:25

They give that a name? Have they nothing better to do?

Intruder

18th May 2008 22:39

Half way between the VORs, unless a COP is published on the airway. For a high altitude route it will normally be published if the segment is >260 NM -- twice the "service volume" range of an 'H' rated VOR.

See FAA AIM 1-1-8 and 5-3-6.

BOAC	19th May 2008 06:48

Quote:

They give that a name? Have they nothing better to do?

- in view of some of the 'material' they have to allow for, it is probably not such a bad idea? Cue 411A.

point8six

19th May 2008 07:47

70 nms rings a bell for me- but it was nearly 40 years ago and I don't hear bells so well these days;)

411A	19th May 2008 15:53

Change over points, with respect to VOR navigation, are normally determined by the type of VOR transmitter installation, and the terrain over which the airways lies...mountains, etc.

Many variables involved.
Change over points are normally printed on the specific aeronautical chart, and where they do not exist, changing to the next VOR station should be accomplished at the half-way point.

Pretty basic stuff.

hvogt

19th May 2008 16:19

alj87,

ICAO Annex 2 defines what a changeover point is:

Changeover point. The point at which an aircraft navigating
on an ATS route segment defined by reference to very high
frequency omnidirectional radio ranges is expected to transfer
its primary navigational reference from the facility
behind the aircraft to the next facility ahead of the aircraft.

Note.— Changeover points are established to provide the
optimum balance in respect of signal strength and quality
between facilities at all levels to be used and to ensure a common
source of azimuth guidance for all aircraft operating
along the same portion of a route segment.

alj87

24th May 2008 05:29

thank you

Thank you very much!!!!! really appreciate your effort to help me out.
Wish you all clear sky :ok:

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