Future Air Navigation Systems (FANS)Navigation — Instrumentation — DGCA CPL practice questions
Question 1 of 6
What is the primary limitation of ATC over oceanic regions that FANS is designed to overcome?
All 6 questions — Future Air Navigation Systems (FANS)
Navigation — Instrumentation · DGCA CPL. The correct option is marked on each.
Q1. What is the primary limitation of ATC over oceanic regions that FANS is designed to overcome?
- A.Excessive radar coverage requiring too many controllers
- B.Lack of VHF/radar leading to procedural separation and infrequent position updates✓
- C.Overloading of SATCOM frequency bands
- D.Pilot inability to communicate in English
Why: Over oceans, deserts and polar regions, VHF (line-of-sight) and radar are unavailable. ATC must provide procedural service using HF, resulting in large separations and position reports only every 30–60 minutes. FANS solves this with GNSS position accuracy and satellite data links for real-time communication. See Section 1 . — The 30–60 minute update interval is the key figure that underscores the urgency of FANS development.
Q2. FANS A operates over which network and is it operated by whom?
- A.ATN, operated by SITA
- B.ACARS network, operated by ARINC✓
- C.SATCOM network, operated by INMARSAT
- D.VHF Data Link Mode 2, operated by Eurocontrol
Why: FANS A is designed for oceanic and remote airspace and is transmitted over the ACARS network operated by ARINC (USA). FANS B uses the ATN operated by SITA. See Section 8 and Section 9 . — FANS A = ARINC/ACARS/Oceanic. FANS B = SITA/ATN/Continental. This distinction is a classic exam question.
Q3. What does OOOI stand for?
- A.On Approach, On Descent, On Instruments, In Cloud
- B.Out of gate, Off the ground, On the ground, In the gate✓
- C.Over ocean, Over obstacle, On ILS, Inside marker
- D.On track, Off track, On altitude, Inside airspace
Why: OOOI messages are the four key flight event reports sent automatically to the AOC via data link, allowing the airline to track each aircraft through its full cycle. See Section 6 . — OOOI reports are also used by maintenance to track engine cycles and aircraft utilization.
Q4. Regarding ADS-C, which statement is correct?
- A.The aircraft automatically initiates all ADS-C contracts without crew input
- B.The controller sets up the contract; flight crew have no associated workload✓
- C.The pilot must manually update ADS-C position every 10 minutes
- D.ADS-C emergency mode can be declared by either the ATSU or the flight crew
Why: ADS-C is a controller-set contract with the aircraft's FMS. The controller establishes all contract parameters without any pilot input — flight crew have zero workload. See Section 8 . — The exclusive flight-crew control of ADS-C emergency mode declaration is a specific DGCA exam point.
Q5. A message transmitted from an aircraft to the ATSU while the aircraft is still on the ground is called a:
- A.Uplink, because the aircraft is below the satellite
- B.Downlink, because the convention is aircraft-to-ATSU regardless of aircraft position✓
- C.Ground link, a special category for ground operations
- D.Uplink, because messages from aircraft always go upward
Why: In FANS/CPDLC, aircraft-to-ATSU messages are always called Downlink (DL) and ATSU-to-aircraft messages are always Uplink (UL). This is a fixed convention that applies even when the aircraft is on the ground. See Section 7 . — The "even if on the ground" qualifier is the classic trick in this type of question.
Q6. At what approximate latitude does geostationary SATCOM coverage become unreliable?
- A.Above FL350 at any latitude
- B.Beyond approximately 80° of latitude (polar regions)✓
- C.When aircraft exceeds Mach 0.85
- D.Below 10,000 ft altitude
Why: Geostationary satellites orbit above the equator. Their coverage is limited to approximately 80° of latitude . Polar regions (beyond 80°) require satellites in lower-altitude inclined orbits to provide coverage. See Section 2 . — This is why HF was added to ACARS in 2001 and why lower-orbit satellite constellations (LEO) are being developed for polar aviation.