ATC Flight Plan — Page 238, Lesson 240

I want to walk you through the ATC Flight Plan — specifically, how we describe the route, the significant points along it, and any planned changes in speed or level. This is the language we use to tell Air Traffic Control exactly where we intend to go, and it has to be precise and standardised. Let's start with the ATS Route field. This is a coded designator, between 2 and 7 characters long, that identifies the route or route segment we plan to fly. It can include the coded designator for a standard departure or arrival route — for example, BCN1, B1, R14, UB10, or KODAP2A. So if you're flying out of an airport on a Standard Instrument Departure called "KODAP2A", that's what goes in this box. The rules for how these route designators are constructed come from Annex 11, Appendix 1 of the ICAO documents, and if the route has a Required Navigation Performance, or RNP, type applied to it, that guidance is in the Manual on Required Navigation Performance, Doc 9613. Next, we have the Significant Point field. This is between 2 and 11 characters, and it identifies a point along the route. There are several ways to express it. First, if the point has a coded designator — a name like LN, MAY, or HADDY — that's 2 to 5 characters, and you just use that. Simple. If no coded designator has been assigned, you have three other options. The first option is degrees only, which takes 7 characters. You write 2 figures for latitude in degrees, then N for North or S for South, then 3 figures for longitude in degrees, then E for East or W for West. If you need to make up the correct number of figures, you insert zeros. For example, 46N078W means latitude 46 degrees North, longitude 78 degrees West. The second option is degrees and minutes, which takes 11 characters. You write 4 figures for latitude in degrees and minutes — so the first two are degrees, the next two are minutes — then N or S, then 5 figures for longitude in degrees and tens and units of minutes — the first three are degrees, the next two are minutes — then E or W. Again, insert zeros where necessary. For example, 4620N07805W means latitude 46 degrees 20 minutes North, longitude 78 degrees 05 minutes West. The third option is bearing and distance from a navigation aid. You start with the identification of the navigation aid — normally a VOR — in the form of 2 or 3 characters. Then you write the bearing from that aid as 3 figures giving degrees magnetic. Then you write the distance from the aid as 3 figures expressing nautical miles. Insert zeros where necessary. So, for example, a point 180 degrees magnetic at a distance of 40 nautical miles from VOR "DUB" would be expressed as DUB180040. Now, the last item in this excerpt is the Change of Speed or Level field, which has a maximum of 21 characters. This is the point at which you plan to change your speed — by 5% TAS or 0.01 Mach or more — or change your level. You express that point exactly as we just covered — using the significant point format — then you put an oblique stroke, which is a forward slash, and then both the cruising speed and the cruising level, expressed exactly as we've seen before, without a space between them. This is true even when only one of these quantities will change. Let me give you the examples from the book so you can see the pattern. LN/N0284A045 — that's the point LN, then a slash, then N for true airspeed in knots, 0284 knots, then A for altitude in hundreds of feet, 045 meaning 4,500 feet. MAY/N0305F180 — point MAY, slash, N0305 for 305 knots true airspeed, F180 for flight level 180. HADDY/N0420F330 — point HADDY, slash, 420 knots, flight level 330. 4602N07805W/N0500F350 — that's a degrees-and-minutes point, slash, 500 knots, flight level 350. 46N078W/M082F330 — a degrees-only point, slash, M082 meaning Mach 0.82, flight level 330. DUB180040/N0350M0840 — a bearing-and-distance point from DUB, slash, 350 knots, Mach 0.84, and note the level here is M0840 — that's metric, meaning 8,400 metres. So in every case, the format is: the point where the change happens, a slash, then the new speed and the new level, all run together with no spaces. This is how we tell ATC exactly where and when we intend to change our speed or altitude.