Total communication failure on an IFR clearance into a radar environment

Altitude:

• The last assigned level is FL180. The rule is to maintain the last assigned level or the minimum flight altitude, whichever is higher.
• Between XYZ and ABC the MEA is FL200 (terrain). FL200 is higher than FL180, so on reaching XYZ you climb to FL200. Before XYZ the MEA is 6,000 ft, so FL180 remains correct.
• "Expect FL200 at 1220" is not a clearance, but it is useful: it confirms ATC intended you at FL200 and tells you what traffic to expect.

Timing:

• Maintain the last assigned speed and level (or the minimum, if higher) for 20 minutes after failing to report at a compulsory reporting point. Your failure occurred at 1207, 30 NM before XYZ; the missed report at XYZ is the reference point. Until then, stay at FL180/flight-planned levels as applicable.
• Thereafter, adjust level and speed in accordance with the filed flight plan, keeping the minimum flight altitude rule always on top.

Route:

• Fly the current flight plan route: XYZ VOR, V12 to ABC, then DCT Mumbai. Do not take shortcuts, because ATC will be clearing traffic on the assumption that you are on that route.
• In IMC, this is the correct course. If you encounter VMC, the rule changes: continue in VMC and land at the nearest suitable aerodrome, and tell ATC if you can.

At the clearance limit (Mumbai, a terminal area):

• Proceed to Mumbai and hold over the destination if required, at the last assigned/minimum level.
• Descend as soon as practicable to the higher of the last assigned level and the minimum IFR altitude, then begin the approach within 5 minutes of the ETA. Your filed ETA is 1305; the approach should therefore begin by about 1310.
• Descending early, before the destination, is wrong: there is traffic below you and you have no clearance. Descending only at the last moment is also wrong: you will arrive high and unstable.

The practical profile:

1. At Mumbai, hold at the minimum safe level (for the area, probably 6,000–7,000 ft) rather than at FL180.
2. Start the let-down at the ETA or as close to it as possible, and fly the published ILS to runway 27.
3. Because the weather is 2,000 ft broken, 6 km, an ILS approach is appropriate; a visual approach is not guaranteed.

There is a further safeguard: ATC can see your transponder code and your Mode C. Squawking 7600 tells them exactly what has happened, and they will separate traffic from you. Do not change the code to something else, and do not switch the transponder off.

Transponder:

• Select 7600 immediately. This is the primary signal; in radar contact it tells the controller both that you have a radio failure and where you are.
• Keep Mode C on. Altitude readout is what allows ATC to keep other traffic clear of you.

Restore communications:

• Try the second radio on the last assigned frequency and on 121.5, and check the audio panel, headset, intercom and frequency transfer - the audio panel is alive, so the fault may be in the antenna, coax or a common power feed.
• Try a blind transmission on the last frequency and on 121.5: "Mumbai Control, [callsign], transmitting blind, radio failure, squawking 7600, estimating Mumbai 1305, maintaining FL180/FL200."
• Try the emergency frequency and any standby radio or handheld set carried.

Attract attention:

• Watch for light signals from the tower once in the circuit/approach - a steady green means cleared to land; a red means give way/continue circling.
• Make your aircraft conspicuous: landing lights on, and fly a predictable, published profile so ATC can plan around you.
• If in VMC at any stage, the safest course is to continue VFR and land at the nearest suitable aerodrome, then telephone ATC. That is faster and safer than flying a full IFR lost-comm procedure in visual conditions.