First, let's look at the answers themselves — Page 196, Lesson 201

I want to walk you through the answers and supporting material for Exercise 2, which deals with North Atlantic navigation planning. This is the start of a new topic — the answer key and the chart descriptions that follow. First, let's look at the answers themselves. Question 1 gives a distance of 1087 NM — that's nautical miles, the standard unit for flight planning over the ocean. Question 2 gives a true track of 288°(T) — the direction over the Earth's surface relative to true north. Question 3 gives a longitude of 12°W — that's 12 degrees west of the Greenwich meridian. Question 4 gives another true track: 270°(T) — due west. Question 5 gives a magnetic heading of 318°(M) — that's the heading you'd steer on the compass, accounting for magnetic variation. Question 6 gives a time of 1126Z — that's 11:26 Zulu time, which is UTC. Question 7 gives 1206Z — 12:06 Zulu. Question 8 gives a Mach number of .72 — that's Mach 0.72, meaning 72% of the speed of sound. Question 9 gives a true track of 250°(T) and a distance of 358 NM. Question 10 gives 1256Z. Question 11 identifies two airspace/control authorities: GANDER OCEANIC CTA/CZQX and GANDER DOMESTIC CTA/CZQX — CTA stands for Control Area, and CZQX is the ICAO code for Gander Centre. Question 12 gives 103 NM. Question 13 is Reduced Vertical Separation Minima — that's RVSM. Now, the excerpt provides a detailed definition for RVSM. It says the equipment required is: two fully serviceable independent altitude measurement systems; one automatic altitude-control system; and one altitude alerting device. Additionally, a functioning Mode C SSR Transponder is required for flight through radar-controlled RVSM transition airspace. Mode C means the transponder reports pressure altitude. And here's a critical operational rule: when checking altimeters, pre-flight or in-flight, at least two primary altimeters must agree at all times within plus or minus 200 feet. That's the tolerance — if they disagree by more than 200 feet, you're not legal for RVSM airspace. Question 14 is North Atlantic Minimum Navigation Performance Specification — that's MNPS. The excerpt then lists the required equipment for MNPS. Aircraft must be equipped with two fully serviceable Long Range Navigation Systems (LRNS). An LRNS may be one of the following: one Inertial Navigation System (INS); one Global Navigation Satellite System (GNSS); or one navigation system using inputs from one or more IRS — Inertial Reference Systems — or any other sensor complying with the MNPS requirement. Each LRNS must be capable of providing to the flight crew a continuous indication of the aircraft position relative to track. And it is highly desirable that the navigation system used for steering guidance is capable of being coupled to the auto-pilot. Now we move into the chart descriptions. The section is titled Airways - Miscellaneous Charts, specifically North Atlantic & Central North Atlantic Blow-up Plotting Chart - Introduction. Both charts are Lambert Conical Conformal projections — that's a type of map projection that preserves angles well, making it suitable for navigation. They are designed for three purposes: ETOPS — Extended-range Twin-engine Operations — and the excerpt notes this chart has been produced for an Airbus 330; EQUAL TIME POINT (ETP)/CRITICAL POINT (CP) calculation and plotting; and position and route plotting. The NORTH ATLANTIC PLOTTING CHART has a scale of 1 inch = 200 NM. Its bottom right-hand corner contains an EQUAL TIME POINT (ETP)/CRITICAL POINT (CP) graph with instructions for its use. On the reverse side — the obverse — is the CENTRAL NORTH ATLANTIC BLOW-UP AREA with a scale of 1 inch = 120 NM. The ETP graph and instructions apply to this chart as well. Then we have Range and Time Circles. Both charts show still air range/time circles — these are circles drawn around diversion airfields, showing how far you can fly in still air in a given time at a given true airspeed. There are two sets: circles of 820 NM/120 MIN at 410 kt TAS — that's 410 knots true airspeed — and circles of 1220 NM/180 MIN at 406 kt TAS. These are centred upon suitable diversion airfields: Shannon (EINN) in Ireland, Lajes (LPLA) in the Azores, Gander (CYQX) in Newfoundland, and Keflavik (BIKF) in Iceland. These airfields are open 24 hours a day and can provide appropriate facilities for all types of aircraft. Finally, the excerpt ends with the beginning of a question section — Example 4 — which says: "On the CENTRAL NORTH ATLANTIC BLOW-UP AREA chart: a. Plot the route:" — but that's where the excerpt stops. That would be a practical plotting exercise using the chart we've just described.