Transponder failure at the Kuwait CTR boundary

Tell ATC first, and do not just switch the unit off and say nothing. The reasoning:

• The clearance is what authorises entry into controlled airspace; a transponder is an aid to the controller providing separation, not a licence condition in itself. A failure is not automatically a bar to entry, but it removes the service ATC was relying on, so the controller must be told and must agree.
• Tell Approach: the failure, when it happened, that the encoder, both VHF radios and the GPS are serviceable, what you want to do, and how much fuel you have (95 minutes). Give your position and level.
• Expect one of three outcomes: (a) identification by primary radar or by keeping you on a known position and issuing procedural separation with compulsory position reports; (b) a level or routing restriction, or a requirement to hold outside until the controller has sequenced you; (c) refusal of entry.
• Kuwait's AIP sets the equipment requirements for its airspace; if a specific transponder requirement applies, you may only enter if ATC explicitly approves an exemption. If in doubt, ask - the controller cannot waive rules you have not asked about.
• Do not select 7600. That code announces a radio failure you do not have and will mislead the controller. Leave the transponder off or in standby.
• Refuse or query any clearance you cannot comply with. You remain responsible for airspace compliance.

Set a hard decision point before the fuel situation forces the decision for you.

• Fuel at the boundary: 95 minutes. After 15 minutes of orbiting at 3,500 ft you have roughly 75 minutes left. Your divert aerodrome is 70 NM away; at about 110 kt groundspeed that is roughly 40 minutes, leaving about 35 minutes in hand - enough, but shrinking.
• Work the reserves backwards, not forwards. The planned reserve is your floor, not a target. Decide now the time on the clock at which you turn away if no clearance has been issued, and write it on your kneeboard.
• Communicate before you are in trouble. If it becomes apparent you cannot enter, state your intention clearly: 'Unable to hold further, diverting to X, request SAR/radar watch as I leave your frequency.' If fuel is genuinely becoming critical, declare PAN PAN - and if safety is compromised, MAYDAY - rather than quietly pressing on.
• Do not let the airline check-in influence the go/no-go. The ticket is a sunk cost; a landing fee and a missed connection are trivial against a landing at OKKK below final reserve.
• If ATC offers entry only with conditions you cannot meet, refuse and divert. If a clearance arrives after you have committed to the diversion, decline politely rather than reverse the plan in the turnaround.

A radio failure does not authorise a VFR flight to continue as if nothing had happened.

• Set 7600 if the transponder were serviceable; here it is not, so ATC may have no identification of you at all. Watch for light signals and keep a good lookout.
• In VMC, continue the flight under VFR, keep clear of cloud, land at the nearest suitable aerodrome and report your arrival by telephone to the ATC unit as soon as practicable so that they can close you down.
• Expect the approach to be cleared by light signals. In flight:
  • steady green - cleared to land;
  • flashing green - return for landing (followed by a steady green at the appropriate time);
  • steady red - give way to other aircraft and continue circling;
  • flashing red - aerodrome unsafe, do not land;
  • flashing white - land at this aerodrome and proceed to the apron after landing;
  • red pyrotechnic - notwithstanding any previous instruction, do not land for the moment.
• Position reports and light-signal acknowledgement are your only communication, so fly a wide, predictable pattern, keep the aerodrome in sight, and do not cut inside other traffic.
• Do not enter IMC to 'finish the flight'. If you cannot maintain VMC, that is an emergency and a change of plan, not a continuation of the clearance.