First, aircraft equipment — Page 122, Lesson 197

Let's pick up right where we left off — we've covered the general rules for IFR flight, and now we're moving into the specific equipment and altitude requirements that apply to an IFR flight, tied to the aircraft category. First, aircraft equipment. This is rule 6.67. Every aircraft flown under IFR must be equipped with suitable instruments and navigation equipment appropriate to the route to be flown. The word "suitable" and "appropriate" are doing real work here — the equipment isn't just whatever happens to be installed; it has to match the demands of the specific route. The detailed list of what's required is laid out in JAR OPS-1, which is the Joint Aviation Requirements for Operations. I won't go through that list now because it's covered in your Operational Procedures lectures, but I want you to know where that detail lives. Now, minimum levels — rule 6.68. This is a critical safety rule. An IFR flight must be flown at a level that is not below the minimum flight altitude established by the state whose territory is being overflown. There are two exceptions: when it's necessary for take-off and landing, or when specially authorized by the appropriate ATS authority — that's Air Traffic Services. So the default is: you fly at or above the state's published minimum. But here's the important part — what happens when no such minimum altitude is specified? The rule gives you two scenarios, and they depend on the terrain. First, over high terrain or mountainous areas — and note, the rule doesn't define "high terrain" further, it just says mountainous areas. In that case, the minimum level must be at least 600 metres, which is 2000 feet, above the highest obstacle located within 8 kilometres, or 5 nautical miles, of the estimated position of the aircraft. So you're not just clearing the obstacle directly beneath you — you're clearing the highest obstacle within that 8 km radius around your estimated position. Second, in areas other than high terrain or mountains — so flat or low-lying terrain — the minimum level is 300 metres, which is 1000 feet, above the highest obstacle within that same 8 km, or 5 NM, radius of your estimated position. So the key contrast here: 600 m / 2000 ft over mountains, 300 m / 1000 ft elsewhere, and both use the same 8 km / 5 NM obstacle clearance radius. That's a classic exam distinction, so hold onto it. Now let's move to IFR flight plans — rule 6.69. An IFR flight plan must include the letter I in item 8 of the flight plan form. Item 8 is the field where you state the type of flight — IFR, VFR, or a mix. If you intend to change from IFR to VFR at some point during the flight, you insert the letter Y in item 8 instead. The rule gives you a neat way to remember it: I → V = Y. So I to V gives you Y. That Y tells ATC in advance that you plan to switch from IFR to VFR mid-flight. Finally, changing from IFR to VFR — rule 6.70. This is the procedure when you decide to cancel IFR but your flight plan was not annotated with Y in field 8. In that case, you must notify the ATS authority that flight under IFR is cancelled, using the exact phrase: "cancelling my IFR flight." Then you pass the necessary changes to the current flight plan. ATC will respond with: "IFR cancelled at … (time)." So there's a specific phraseology on both sides — you say "cancelling my IFR flight," and they confirm with "IFR cancelled at" followed by the time. And there's a crucial condition attached to this: an IFR flight may only cancel IFR when it encounters VMC — Visual Meteorological Conditions — and only if it is anticipated and intended that the flight will continue in VMC. So you can't cancel IFR just because you're momentarily in clear air; you have to expect to stay in VMC for the rest of the flight. That's the safety gate on the whole procedure. Let me show you the flight level structure that ties into this — the IFR and VFR flight levels up to and including FL, and above FL. So to pull it together: equipment must match the route, minimum levels give you a hard floor based on terrain and obstacle clearance, and the flight plan and cancellation procedures tell ATC exactly what you're doing and when. That's the complete IFR operating framework from these rules.