Extra fun Flashcards
What are the principles of GPS operation?
GPS operates using signals from at least 24 satellites in orbit, transmitting position and time data. A minimum of 4 satellites is required to determine a receiver’s 3D position (latitude, longitude, and altitude). The GPS receiver calculates distance to satellites based on signal travel time.
What is RAIM, and why is it important?
RAIM (Receiver Autonomous Integrity Monitoring) is a GPS self-check system that ensures the accuracy of navigation information. It works by using redundant satellite signals (minimum of 5, or 4 with barometric aiding) to identify and exclude faulty satellite data.
What are common GPS errors and irregularities?
GPS errors can arise from satellite clock inaccuracies, signal delays caused by the ionosphere or troposphere, multipath effects (signal reflection off surfaces), and ephemeris (orbital) errors. Systems like RAIM and WAAS help mitigate these issues.
What is the Wide Area Augmentation System (WAAS)?
WAAS is an augmentation system that improves GPS accuracy, integrity, and availability by using ground-based reference stations to monitor GPS signals and transmit corrections via geostationary satellites. It enables precision approaches such as LPV.
How does GPS mode sensitivity change during flight?
GPS sensitivity adjusts based on the flight phase: En Route mode uses ±5 NM CDI scaling, Terminal mode uses ±1 NM, and Approach mode narrows to ±0.3 NM for precise navigation during landing.
What must you verify before using GPS for IFR navigation?
Confirm that the GPS system is certified for IFR (TSO-C129 or TSO-C145/146), database currency is up-to-date, and RAIM is available for the intended route and approach.
What are GPS waypoints, and what types exist?
GPS waypoints are predefined coordinates used for navigation. There are two types: fly-by waypoints, where the aircraft begins a turn before reaching the waypoint, and fly-over waypoints, where the aircraft flies directly over before turning.
What is Direct-To navigation, and how is it performed?
Direct-To navigation allows pilots to navigate directly to a specified waypoint. This is done by selecting the Direct-To function on the GPS and entering or selecting the desired waypoint.
How does GPS handle waypoint sequencing?
GPS automatically sequences waypoints along a flight plan unless the pilot disables auto-sequencing to hold at a waypoint or modify the route.
What is the GPS Nearest Function?
The Nearest Function provides a list of the closest airports, VORs, NDBs, and other facilities to the aircraft’s current position, allowing quick access in emergencies or for diversions.
Can GPS substitute for other navigation radios under IFR?
Yes, GPS can replace DME, ADF, or VOR as long as the equipment is IFR-certified and its use is authorized in the Aircraft Flight Manual (AFM).
How do you use GPS to correct for wind during course tracking?
Adjust the aircraft heading to counteract wind drift, ensuring the CDI stays centered. This may involve flying a wind-corrected course that differs from the desired track.
What is the principle of VOR operation?
VORs transmit azimuth information via 360 radials emanating from the station. Aircraft receivers determine the radial being flown relative to the station using phase comparisons of the transmitted signals.
What is the Minimum Operational Network (MON) for VORs?
The MON ensures adequate VOR coverage at 5,000 feet AGL across the U.S. in case of GPS outage. Pilots can navigate using MON VORs to reach airports with instrument approaches.
How do you verify VOR receiver accuracy?
Conduct VOR checks using a ground checkpoint (±4°), airborne checkpoint (±6°), or dual VOR receivers (within 4° of each other). Record results in the aircraft logbook or other documentation.
What are the VOR service volumes?
VOR service volumes define their effective range: Terminal (T) VORs cover 25 NM up to 12,000 feet; Low (L) VORs cover 40 NM up to 18,000 feet; High (H) VORs have extended coverage up to 60,000 feet, depending on altitude.
What are common VOR errors?
Errors include cone of confusion directly over the station, reverse sensing when using incorrect OBS settings, and line-of-sight limitations preventing reception when terrain or obstacles block the signal.
How do you tune and identify a VOR?
Tune the VOR frequency on the NAV radio, then verify the station’s identity by listening to its Morse code identifier or checking for the correct name on the GPS.
How do you orient yourself using a VOR?
Rotate the OBS knob until the CDI centers with a TO or FROM indication. This shows your position relative to the selected radial.
How do you intercept a VOR radial?
Determine the desired radial, set it on the OBS, and turn to a heading that creates a 30° intercept angle towards the radial. Adjust as the CDI centers to track it.
How do you track a VOR radial while correcting for wind?
Maintain a constant heading that compensates for wind drift, ensuring the CDI remains centered. Adjust heading as needed based on drift.
What indicates VOR station passage?
Station passage is indicated by the TO/FROM indicator flipping and the CDI needle becoming erratic as you fly directly over the station.
What is the purpose of 14 CFR regulations for IFR flight?
14 CFR provides the rules governing IFR operations, including certification, maintenance, operational requirements, and safety procedures for pilots and aircraft.
What is covered in Part 1 of 14 CFR?
Part 1 defines key terms and general definitions used throughout aviation regulations, ensuring consistent interpretation of rules.
What does Part 43 cover?
Part 43 addresses maintenance, preventive maintenance, rebuilding, and alterations of aircraft to ensure airworthiness.
What is the significance of Part 61?
Part 61 outlines the requirements for pilot certification, including instrument rating eligibility, knowledge, and proficiency standards.
What are the key rules in Part 91 for IFR operations?
Part 91 includes general operating and flight rules for IFR, such as preflight requirements, minimum altitudes, IFR cruising altitudes, and ATC clearance requirements.
