Ground Proximity Warning SystemNavigation — Instrumentation — DGCA CPL practice questions
Question 1 of 6
The GPWS the alert/warning information is provided by a radio altimeter with:
All 6 questions — Ground Proximity Warning System
Navigation — Instrumentation · DGCA CPL. The correct option is marked on each.
Q1. The GPWS the alert/warning information is provided by a radio altimeter with:
- A.A downward transmitting beam 60° and 30° (fore/aft and athwartship)
- B.A downward transmitting beam 30° and 60° (fore/aft and athwartship)
- C.A forward transmitting beam
- D.A downwards transmitting radio beam✓
Why: The GPWS takes height above terrain from the radio altimeter, which transmits a radio beam downwards. The beam widths sometimes quoted describe the antenna pattern; the answer asked for is simply a downward-transmitting beam.
Q2. Mode 5 of GPWS is triggered when the aircraft is:
- A.Below 500 ft RA with flaps not in landing position and speed below Mach 0.28
- B.Below 500 ft RA with flaps not in landing position and speed below Mach 0.35
- C.Below 200 ft barometric altitude with flap not in landing position and speed below Mach 0.28
- D.Below 1000 ft RA and more than 1.3 dots below the ILS glide path✓
Why: Mode 5 is the glide slope deviation alert. It is armed with a valid glide slope signal, gear down and at or below 1,000 ft radio altitude, and triggers when the aircraft is more than 1.3 dots below the glide path. The options that quote flap position and Mach number describe Mode 4B, not Mode 5; some printed answer keys mark one of them.
Q3. GPWS Mode 3 will give a "Don't Sink" alert during a go-around when altitude loss equals approximately:
- A.5% of existing barometric altitude
- B.10% of existing barometric altitude✓
- C.15% of existing barometric altitude
- D.200 ft absolute
Why: Mode 3 activates when accumulated barometric loss equals approximately 10% of the existing barometric altitude. See Section 5 .
Q4. Mode 4 (ground proximity with gear/flap not in landing configuration) — the arming altitude is:
- A.500 ft RA
- B.700 ft RA✓
- C.200 ft RA
- D.790 ft RA
Why: Mode 4 (both 4A and 4B) is armed after take-off upon climbing through 700 ft RA . See Sections 6 and 7 .
Q5. GPWS Mode 7 (windshear warning) takes priority over:
- A.Mode 5 only
- B.Modes 5 and 6 only
- C.All other modes✓
- D.No priority — all modes equal
Why: Mode 7 windshear warnings take priority over ALL other modes. Windshear is considered the highest-priority terrain/proximity threat because of its immediate effect on aircraft performance. See Section 11 .
Q6. When the aircraft receives a GPWS warning, the FIRST action is to:
- A.Identify the cause of the warning and report to ATC
- B.Consult the QRH for the correct procedure
- C.Level wings and initiate maximum gradient climb✓
- D.Disengage the autopilot and pull up
Why: The immediate response to ALL GPWS warnings is: level the wings + maximum gradient climb. Establishing the cause takes second place. The response must be positive and immediate. See Section 12 . — This is the critical operational rule. GPWS response drills: Level → Pull → Climb. Cause analysis comes after terrain clearance is assured.