Correct Answer : 6
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.
Correct Answer : Navigation
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.
Correct Answer : Positioning
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.
Correct Answer : AHRS
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.
Correct Answer : Celestial navigation
Explanation : 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 Answer : Doppler shift
Explanation : The aircraft’s velocity is measured from the Doppler shift of the transmission or from a sequence of position measurements. Since the aircraft is continuously moving, each interrogation pulse when it is received will have different phase shift which corresponds to the aircraft’s velocity.
Correct Answer : 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 Answer : Radio altimeter
Explanation : 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.
Correct Answer : Decision height
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 : Terminal phase
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.
Correct Answer : Stall speed
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 : Airborne distance
Explanation : 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.
Correct Answer : 50ft
Explanation : 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.
Correct Answer : Minimum control speed on the ground
Explanation : 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 : Sonar
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.
Correct Answer : Geodetic latitude
Explanation : 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.
Correct Answer : Newton’s laws are not valid
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 Answer : Earth centered, Earth fixed
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 Answer : Time Dilution of position
Explanation : TDOP is the Time Dilution of position. It is the contribution of clock error to the error in pseudorange.
Correct Answer : 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.
Correct Answer : Bearing
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.
Correct Answer : Dead reckoning
Explanation : 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.
