Hi guys.

 

Can someone help me out with the text in bold below, contained in vroute flight plan? I'm guessing 'N' is for a ground speed and 'F' is for a flight level? If so, are they speeds/level requests, or restrictions? I assume the former. Many thanks.

 

LIFFY UL975 MALUD/N0403F290 UL6 KEPAD/N0373F230 UL151 TELBA L151 KIDLI

At Malud your speed is 403TAS and your FL is 290,

 

At Kepad 373TAS and FL230

 

Alex

From PANS-ATM (ICAO doc. 4444): "The point at which a change of speed (5% TAS or 0.01 Mach or more) or a change of level is planned, expressed exactly as in (2) above, followed by an oblique stroke and both the cruising speed and the cruising level, expressed exactly as in (a) and (b) above, without a space between them, even when only one of these quantities will be changed.

Examples: LN/N0284A045

MAY/N0305Fl80

HADDY/N0420F330

4602N07805W/N0500F350

46N078W/M082F330

DUB180040/N0350M0840"

 

Regards

@aceridgey

 

thank you I've always wondered what's that.

 

@kingfosco

 

thank you too :rolleyes:

You are welcome. Moreover, from IFPS: "Changes to speed/level shall be specified at each point at which either a change of speed and/or level is planned to commence."

 

Have a nice flight.

You have to remember that FP's from vRoute containing these have usually been originally produced (possibly months previously) based on a historic weather forecast and GTW neither of which you can be aware of. You can pretty much guarantee that your OAT will be different, that the wind will be different and your weight will be different and therefore your performance will not match that of the original flight from which the FP was sourced.

 

In other words, there is no point copying these parameters from vRoute because they will be meaningless on your own flight. Just use the route itself and if you want to include such figures then you will have to calculate your own based on your own weather and weight.

I can agree with BillC, also if the vroute flightplan represents the plan that dispatcher sends to ATC. This said, a CFMU validated plan (like those of vroute) contain often level changes required as example by RAD and CDR to avoid "forbidden route" messages or to comply with odd-even cruise levels required by the airway or shifted-standard cruise levels. A detailed flight plan with step climbs for wind is provided to the crew, especially on long routes.