Navigation Systems practice questions

Answer: B) Unreliable

• AIncorrect. It is erratic overhead.
• BCorrect. The cone of confusion makes indications erratic overhead.
• CIncorrect. It swings.
• DIncorrect. This is a different instrument.

Answer: C) Cross-track error from the desired course

• AIncorrect. That's GS.
• BIncorrect. That's DIS or DTW.
• CCorrect. It shows how far left or right the airplane is.
• DIncorrect. That's ETE.

Answer: A) A low-powered NDB colocated with an ILS marker

• ACorrect. It helps pilots find the approach course.
• BIncorrect. It is a radio beacon.
• CIncorrect. It is an NDB.
• DIncorrect. That is a VOT.

Answer: C) A curved path that drifts downwind

• AIncorrect. That describes an arc.
• BIncorrect. That would require tracking with correction.
• CCorrect. Homing doesn't correct for wind drift.
• DIncorrect. Homing produces a curved track.

Answer: B) 30° to 45°

A 30°–45° intercept angle, often 45°, is the standard technique for joining a VOR radial. It closes on the course efficiently while leaving time to lead the turn. Very shallow angles are slow, and angles beyond 90° head partly away from the course direction.

• AIncorrect. An angle this shallow closes on the course very slowly and may hardly close at all if there is a crosswind. It wastes time and distance.
• BCorrect. A 30°–45° intercept (45° is the usual textbook value) closes on the course at a reasonable rate and leaves time to lead the turn onto the radial.
• CIncorrect. An angle greater than 90° means the aircraft is heading partly opposite the course direction. Such angles are normally used only when a procedure turn or holding pattern will be flown to reverse course.
• DIncorrect. The wind correction angle keeps the aircraft on course once it is established. It is usually only a few degrees and is not a method for choosing an intercept angle.

Answer: A) Four times more sensitive

• ACorrect. A localizer is about 5° wide versus about 20° full scale for a VOR.
• BIncorrect. It is more sensitive.
• CIncorrect. It is more sensitive.
• DIncorrect. It is more sensitive.

Answer: A) The receiver compares redundant satellite ranges to detect a faulty signal, which needs at least five satellites

RAIM is the GPS receiver's own integrity check. It uses redundant satellite measurements and needs at least five satellites with acceptable geometry to detect a fault.

• ACorrect. AIM 1-1-17 explains that RAIM uses extra pseudorange measurements to detect a faulty satellite and needs at least five visible satellites with acceptable geometry.
• BIncorrect. That describes WAAS (SBAS). RAIM is done entirely by the receiver, which is why it is called 'autonomous'.
• CIncorrect. Four satellites give a 3D position with no redundancy. Fault detection needs at least five satellites with acceptable geometry (or four plus barometric aiding).
• DIncorrect. A RAIM alert means the receiver can't assure the integrity of its position for the current phase of flight, not that all signals are lost.

Answer: C) The wingtip reference

• AIncorrect. That would fly away from the station.
• BIncorrect. That would fly to the station.
• CCorrect. Keeping the pointer near the wingtip (90° to the heading) keeps the arc.
• DIncorrect. This is not the method.

Answer: A) Its Morse code identifier on the VOR frequency, which some stations alternate with a recorded voice ID

A VOR is positively identified only by its Morse code identifier or its recorded automatic voice identifier. The tuned frequency, FSS voice transmissions, and flag status do not identify the station.

• ACorrect. AIM 1-1-3 says the only positive identification of a VOR is its Morse code ID or its recorded automatic voice ID (the station name followed by "VOR").
• BIncorrect. The AIM warns pilots never to rely on voice transmissions from the FSS or approach control facility to identify an omnirange.
• CIncorrect. Tuning the published frequency does not confirm that you are receiving that station or that it is transmitting a usable signal. The identifier must be checked.
• DIncorrect. The flag only shows that a usable signal is being received. A station under maintenance can still radiate a signal after its identifier has been removed, so a missing flag does not prove which station it is or that it is reliable.

Answer: A) Normal sensing

• ACorrect. Steer toward the needle on the front course.
• BIncorrect. That is a back course without an HSI.
• CIncorrect. It works normally.
• DIncorrect. It is normal.