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The correct answer is (c) GDOP

Explanation: GDOP or Geometric DILUTION of Precision relates ranging errors to the dispersion in measured position. If three range measurements are MADE in the orthogonal DIRECTION, the standard DEVIATION in the aircraft’s position error is the same as those of the three range sensors.

Right choice is (a) Bearing

For explanation: The angle of ARRIVAL, relative to the airframe, of a radio signal from an external transmitter is CALLED bearing. Bearing is measured by the difference in phase or TIME of arrival at MULTIPLE ANTENNAS on the airframe.

Right ANSWER is (a) Dead RECKONING

To explain: Dead reckoning is the technique of calculating position from the MEASUREMENTS of velocity. It is the means of navigation in the absence of position fixes and CONSISTS in calculating the position by extrapolating MEASURED ground speed.

Right option is (a) True

The best I can EXPLAIN: Geocentric coordinates are SOMETIMES mechanized in short range dead reckoning SYSTEMS using spherical earth approximation. These are the spherical coordinates of the RADIUS vector R.

Correct option is (a) Earth centered, Earth fixed

For EXPLANATION: Satellite based radio navigation system USES ECEF COORDINATED to calculate satellite and aircraft position. The origin is at the mass center of the earth and its AXIS lies along the earth’s SPIN axis.

Correct choice is (B) Newton’s laws are not valid

Easy explanation: The Earth centered coordinate system has three navigational functions. First, Newton’s laws are valid in any ECI coordinate FRAME, SECOND, the angular coordinates of stars are conventionally tabulated in ECI. Third, they are used in MECHANIZING INERTIAL navigators.

Correct option is (a) Sonar

Easy explanation: The navigation system utilizes three types of sensor INFORMATION: position data from radio aids, radar and SATELLITES; Dead reckoning data from inertial sensors; Line of sight direction to STARS or celestial MEASUREMENTS.

The correct choice is (c) Geodetic LATITUDE

For EXPLANATION I would SAY: Geodetic latitude of a point is the angle between the normal to the REFERENCE ellipsoid and the equatorial plane. Geodetic latitude is our usual UNDERSTANDING of map latitude.

The correct choice is (a) True

Easiest explanation: The NAVIGATION EQUATIONS how the sensor OUTPUTS are processed in the on-board computer in order ti calculate the position, velocity and attitude of the aircraft. The navigation equations contain instructions and data and are part of the AIRBORNE software that also includes moding, display drivers, failure detection and an operating SYSTEM.

Correct answer is (b) EXCESS fuel

Explanation: A missed approach is initiated at the pilot’s option or at the TRAFFIC controller’s request, typically because of poor VISIBILITY, poor ALIGNMENT with a runway, equipment failure, or CONFLICTING traffic. A fuel dump is initiated when there is excess fuel in the aircraft.

Correct option is (b) Radio altimeter

The best I can explain: A radio altimeter can accurately MEASURE the altitude of an aircraft and works on the radar PRINCIPLE. Typically, radio altimeters PROVIDE accurate altitude MEASUREMENTS till 5000ft and are USED only during takeoff and landing.

The correct choice is (a) DECISION HEIGHT

Easiest explanation: Decision altitude is the altitude above the runway at which the APPROACH must be aborted if the runway is not sight. Decision height PUBLISHED for each runway at each airport.

Correct ANSWER is (a) True

The explanation is: A non-precision approach has electronic guidance in only in the horizontal DIRECTION. An aircraft executing a non-precision approach MUST abort if the RUNWAY is not visible at minimum descent altitude, which is TYPICALLY 700ft above the runway.

The correct option is (c) MINIMUM control speed on the ground

For explanation I would say: Minimum control speed on the ground is the minimum speed at which enough AERODYNAMIC FORCE can be generated in the VERTICAL fin by rudder deflection while the aircraft is still rolling on the ground to produce a yawing MOMENT on the aircraft.

Correct ANSWER is (c) Terminal PHASE

Easiest EXPLANATION: The terminal phase consists of the departure and the approach phase. Departure starts when the aircraft is in the ground and ENDS when it is out of the terminal area. The approach starts when the aircraft enters the terminal control area and ends when the aircraft intercepts the LANDING aids at approach fix.

Right answer is (a) 50FT

To elaborate: The height that the AIRCRAFT must cover during the AIRBORNE distance is different for different aircraft DEPENDING upon their usage. The height of the obstacle is generally specified to be 50ft for military aircraft and 35ft for COMMERCIAL aircraft.

The correct answer is (d) AIRBORNE distance

For explanation I would SAY: The EXTRA distance the aircraft covers airborne but before it covers an OBSTACLE of particular height is called airborne distance. Airborne distance is ALSO added with the ground roll to give the total takeoff distance.

Right answer is (b) Stall speed

Best explanation: At any speed greater than the decision speed, TAKEOFF is not aborted even when there is an ENGINE failure. Stall speed is LOWER than the decision speed and HENCE the takeoff is aborted.

Correct answer is (b) False

Easiest explanation: There are two types of dead RECKONING navigation system one USES the gyroscope and accelerometer while the other DEPENDS on radio stations that CREATE continuous ambiguous radio lanes that must be counted to KEEP track of the course position.

The correct answer is (a) True

Easy explanation: Dead RECKONING SYSTEMS USE gyroscope and accelerometer whose readings suffer from drift error as time progresses. THUS it is necessary to reinitialize after a particular time interval as errors accumulate and if the electrical power is lost.

The correct choice is (c) Celestial navigation

To EXPLAIN: In celestial navigation, the POSITION is COMPUTED by measuring the elevation and azimuth of celestial bodies relative to the navigational coordinate frame at precisely known TIMES. Since it is a completely passive system, it is considered to be stealthy and is used in special purpose high altitude aircraft in conjunction with an INERTIAL navigator.

Correct option is (C) AHRS

The BEST explanation: There are three TYPES of positioning systems radio systems, celestial systems and mapping navigation systems. AHRS or Attitude Heading Reference System use accelerometer and gyroscope and hence FALL under the DEAD reckoning navigation system.

The correct answer is (B) Positioning

Easiest explanation: Navigation systems can be categorized as positioning or DEAD reckoning. Positioning systems measure the state VECTOR WITHOUT regard to the path travelled by the vehicle in the PAST.

Right answer is (a) NAVIGATION

For EXPLANATION: When the STATE VECTOR is measured and calculated on board, the process is called navigation. When it is calculated OUTSIDE the vehicle, the process is called surveillance or position location.

Right OPTION is (a) 6

The explanation: The three COMPONENTS of position and the three components of velocity MAKE up a six component state vector that fully describes the TRANSLATIONAL MOTION of the vehicle.