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DGCA CPL AIR REGULATIONS · ASKED IN REAL EXAMS

Transponder & emergencies

12 questions on this topic, recalled by candidates after DGCA sittings between 2021 and 2026. Together they were asked 38 times; the most repeated come first. Pick a year to see only what was asked that year.

Asked in:
Q1Asked in 11 sittings:Feb 2021May 2024 · OLODE 04Jun 2024 · RegularNov 2024 · OLODE 08Jan 2025 · OLODE 01May 2025 · OLODE 04Jul 2025 · OLODE 05Oct 2025 · OLODE 07Apr 2026 · OLODE 03May 2026 · OLODE 04Jul 2026 · OLODE 05

On losing two-way radio communication, the transponder is set to

  1. A.Mode A 7500
  2. B.Mode A 7600 with Mode C
  3. C.Mode A 7700
Show answer

B. Mode A 7600 with Mode C

Radio failure is 7600, keeping Mode C on so ATC still sees your level. ATC can then check how far the failure goes by asking you to squawk IDENT or change code.

Q2Asked in 7 sittings:Sep 2023 · Regular 03Nov 2023 · OLODE 08Jun 2024 · RegularJan 2025 · OLODE 01Oct 2025 · OLODE 07Jul 2026 · OLODE 05Aug 2026 · OLODE 06

When acknowledging a mode or code setting instruction, the pilot shall

  1. A.Say ROGER
  2. B.Say WILCO
  3. C.Read back the mode and code to be set
Show answer

C. Read back the mode and code to be set

SSR codes are on the list of items that must always be read back, like clearances, runway instructions and altimeter settings. ROGER or WILCO alone is not enough.

Q3Asked in 4 sittings:Sep 2023 · Regular 03Apr 2025 · Regular 01May 2025 · OLODE 04Jul 2026 · OLODE 05

The transponder code for unlawful interference is

  1. A.7500
  2. B.7600
  3. C.7700
Show answer

A. 7500

7500 unlawful interference, 7600 radio failure, 7700 emergency. If ATC asks you to confirm 7500, you may confirm it or simply not reply - either tells them it was not selected by mistake.

Q4Asked in 4 sittings:Feb 2021Sep 2023 · Regular 03Oct 2024 · OLODE 07Dec 2024 · Regular 04

A radar controller instructs "fly heading 030". The pilot flies

  1. A.030 degrees magnetic, with no correction for wind
  2. B.030 degrees true
  3. C.A heading that makes the track 030
Show answer

A. 030 degrees magnetic, with no correction for wind

A radar vector is a magnetic heading. You fly the heading as given; the controller watches the track and adjusts for wind. Pilots do not correct radar vectors for wind.

Q5Asked in 3 sittings:Dec 2022 · Session 04Oct 2025 · OLODE 07Jul 2026 · OLODE 05

An aircraft subject to unlawful interference cannot notify ATS and no regional procedure applies. In airspace with a 1000 ft vertical separation minimum, it should fly at a level that differs from the normal IFR cruising levels by

  1. A.Nothing - it keeps its assigned level
  2. B.150 m (500 ft)
  3. C.300 m (1000 ft)
Show answer

B. 150 m (500 ft)

Offset 500 ft from the normal IFR levels where 1000 ft separation is applied (such as RVSM above FL290), and 1000 ft where 2000 ft separation is applied. You then sit halfway between other traffic.

Q6Asked in 2 sittings:Jan 2026 · OLODE 01Apr 2026 · OLODE 03

Which of these is NOT a valid transponder code?

  1. A.7777
  2. B.5678
  3. C.7500
Show answer

B. 5678

Transponder codes are octal - every digit runs from 0 to 7, so the range is 0000 to 7777. Any code containing an 8 or a 9 cannot be set.

Q7Asked in 2 sittings:Jul 2025 · OLODE 05Apr 2026 · OLODE 03

In the absence of any ATC instruction or regional agreement, the transponder is set to

  1. A.Mode A 2000 with Mode C
  2. B.Mode A 7000
  3. C.Mode A 7600
Show answer

A. Mode A 2000 with Mode C

Code 2000 is the default - for example when entering an FIR where no code has been given. 7000 is a European VFR convention, not the ICAO default, and 7600 means radio failure.

Q8Asked in:Jul 2026 · OLODE 05

The transponder code for a general emergency is

  1. A.7700
  2. B.7600
  3. C.7500
Show answer

A. 7700

Squawk 7700 for an emergency unless ATC has already given you a code to use - and you may still select 7700 if you think it is the best course of action.

Q9Asked in:Apr 2026 · OLODE 03

A pilot shall operate the transponder on the Mode A code

  1. A.Assigned by the ATC unit in contact
  2. B.Of his own choice
  3. C.2000 at all times
Show answer

A. Assigned by the ATC unit in contact

First the code the ATC unit gives you; failing that, the code set by regional agreement; and only in the absence of both, code 2000.

Q10Asked in:Oct 2024 · OLODE 07

An aircraft carrying a serviceable transponder shall operate it

  1. A.At all times during flight
  2. B.Only in controlled airspace
  3. C.Only when ATC asks
Show answer

A. At all times during flight

Operate it at all times in flight, whether or not SSR is used where you are - with Mode C on so other aircraft's ACAS can see you too.

Q11Asked in:2022 · Regular 03

An aircraft being intercepted should, unless otherwise instructed by ATS, set its transponder to

  1. A.Mode A 7700
  2. B.Mode A 7600
  3. C.Mode A 7500
Show answer

A. Mode A 7700

An intercepted aircraft follows the interceptor's instructions, tries to call on 121.5 MHz and, if it has a transponder, selects Mode A 7700 unless ATS says otherwise. 7600 is radio failure and 7500 unlawful interference.

Q12Asked in:Dec 2022 · Session 04

The special purpose SSR codes are

  1. A.Distress 7700, unlawful interference 7500, radio failure 7600
  2. B.Distress 7600, unlawful interference 7500, radio failure 7700
  3. C.Distress 7500, unlawful interference 7700, radio failure 7600
Show answer

A. Distress 7700, unlawful interference 7500, radio failure 7600

7700 is emergency, 7600 is radio communication failure, 7500 is unlawful interference.

These are candidates' recollections, not official DGCA papers: wording can differ from the paper as set. Every answer was checked against the DGCA CARs, AIP India, ICAO documents or worked calculation (independent check completed 17 Oct 2026). Spotted a mistake? Tell us and we will check it against the source.