O-Strand (INS, AHRS, GPS, and IFF) Test Review

!! When referring to a gyroscope, what is rigidity?

!!the ability of a gyro to keep its axis fixed in space

!!What is the purpose of INS?

!!To keep track of position and not keep track of total distance traveled

!!The INS uses 3 accelerometers, one pointing north, one pointing east and one that is what?

!!vertical

!!The INU provides sensors to detect aircraft acceleration and altitude, what component (assembly) of you INU provides this?

!!Platform assembly

!!What IS related component provides means to input mega variation data to the INS? (The only component you can put data in)

!!EEC

!!What is the purpose of the ground alignment mode of operations

!!used by ground crews to establish the reference of the INS which computes the aircraft position

!!which major system provides pitch, roll, and azimuth signals to your AHRS system?

!!Displacement Gyroscope

!!which AHRS mode of operations is an emergency mode used when the displacement gyroscope is malfunctioning?

!!Compass Mode

!!What does ACLS provide the aircraft with?

!!aircraft with data link roll commands, pitch commands, and a warning if the ACLS becomes uncoupled.

!!Which mode in the ACLS system is fully automatic from entry point to touchdown?

!!Mode 1

!!What does the overall GPS system provide?

!!Passive Operation, All weather operations, real-time positioning, continuous operation, usability in hostile environments, and the number of uses.

!!The GPS provides 3D navigation accuracy to how many meters?

!!10 meters

!!The GPS provides highly accurate position, time data (any place in the world), and what?

!!velocity

!!what are benefits of GPS in military applications?

!!saves money, weapon accuracy, track forces, stream lining the route.

!!what component is the AN/ARN-151

!!The antenna

!!For your AN/ARN-151 what amplifies and converts your RF to IF?

!!the Antenna controller

!!In the IFF system which unit transmits back the proper reply code?

!!Transponder

!!which IFF subsystem unit transmits a reply when RF interrogation is received from an IFF interrogator?

!!transponder

!!which IFF subsystem unit has a 4-thumbwheel dial for mode 2 selection?

!!transponder

!!the information pulses representing the transponder reply code are contained between framing pulses

!!0.45 microseconds wide and spread 1.45 microseconds apart

!!how wide are IFF interrogation system pulses

!!0.8 (buffer) +/- 0.1 microseconds wide. (can be up to 0.9 microseconds wide)

!!procession will not occur unless a force is applies which tries to move what?

!!the rotor spin axis

!!what is the purpose of INS?

!!provides accurate position navigation

!!INS measurements are made by precision inertial devices mounted on a _____ stable element.

!!3-axis

!!what does your air data computer provide to the aircraft (INU)

!!barometric altitude, true airspeed and magnetic heading

!!what system or component preforms interfacing between the INS and other avionic subsystems?

!!Digital Data Computer (Mission Computer)

!!what correction factor is used in the alignment during the INS ground align mode?

!!Gyro bias

!!Which AHRS mode of operation is used at altitudes greater than 70 degrees?

!!Free Mode (FREE)

!!Bias sits in the direction of the earth's magnetic lines of flux, the compass transmitter develops and routes a magnetic heading signal to the compass compensator adaptor, what component will help develop and route that signal?

!!flux valve

!!what does the LCCS do?

!!tracks the aircraft and compares the aircraft position to the desired flight path

!!Where is the LCCS located?

!!On the ship

!!In what situations would the pilot need to take over the aircraft from Mode 1?

!!if the aircraft exceeds the control envelope boundaries, the COUPLE signal transmission ceases, and the aircraft autopilot disengages

!!3 principles that GPS uses?

!!Celestial Navigation, Radio Navigation, The Doppler Effect

GPS Safety Precaution?

The ARN-151 can provide false readings and/or dangerous potentials even though system power is off