.1 Define the following acronyms:  

A. RADAR - RADIO DETECTION AND RANGING

P-3C either equipped with either APS-115 or APS 137(V3)-SAR (V5)- ISAR. RADAR. Some CDU (counter drug Upgrade) aircraft are equipped with the APG- 66 RADAR.

*note (V3) SAR, only on update III (V5) ISAR, only on AIP

B. IFF - Identification Friend of Foe.

A typical IFF system consists of an (APX-76) interrogator unit, a synchronizer unit and a receiver unit which make up the challenging station as well as a(APX-72) transponder unit which makes up the responding station. Ships, airplanes and ground stations may issue IFF challenges but aircraft and ships are usually the only responders.

There are five IFF modes: Modes 1 & 2 are used exclusively by the military for identification. Mode 3/A is used by both civil and military air traffic control stations, Mode 3C is used to report the aircraft's altitude to an air traffic control station and Mode 4 is a military encrypted code which is classified.

C. ADF - Automatic Direction Finder

The ARN-83 low frequency ADF is used for routine point-to-point radio navigation. The ADF operates on AM signals in the 190 to 1750 KHz frequency range. The receiver converts ground radio beacons or commercial broadcasts into bearings for the HSI (Horizontal Situation Indicator) displays.

Air navigation charts list show ground stations which are labeled with their radio frequency. By tuning into this beacons, the pilots or navigator can get a "point" or direction to that station. By this means they can navigate "point-to-point" using ADF. ADF is can also be used in Search and Rescue to get a point to an emergency beacon from survivors in the water or a ship in distress.

D. TACAN - Tactical Air Navigation

The TACAN set is an airborne receiver - transponder designed to operate in conjunction with surface stations for navigation purposes. The airborne and surface equipment form a radio navigation system that enables aircraft to obtain range and bearing from the selected beacon up to 390 NM away. There is also an air-to-air mode that allows range and bearing information from another aircraft with the same capability only if the channel difference is 63 channel separation. The X-TACAN system has 99 channels, with 126 channels on the X-Mod and 126 on the Y-Mod for a total of 256 channels. Ground TACAN stations are normally co-located with a VOR (VHF omni directional Range) radio beacon used with the ADF.

E. IRDS - Infrared Detection System

The IRDS system converts infrared radiation emanating from a heat source and converts it to a black and white television like image at the SS-3 station.

On the P-3, the IRDS turret retracts into the nose of the aircraft below the radome. When lowered, a joystick at the SS3 station controls the turret. Be aware that there are other names used for IR systems such as FLIR (Forward Looking Infrared) but that all these are IR systems using the same type of technology.

F. MAD - Magnetic Anomaly Detection

The ASQ-81 Mad system employs a helium magnetometer that detects submarines by measuring changes (anomalies) in the earth's magnetic field caused by the submarine. The detected anomalies are registered on a paper recorder (RO -32 ) located at the SS3 station.

The large boom extending from the rear of the aircraft is the MAD boom that houses the magnetometers. This sensor is usually used to "pinpoint" the sub location and is often the preferred indication for when to drop the weapon on a submarine.  

G. ESM - Electronic Support Measures

The ESM set detects and analyzes low and high band radar signals and measures the RF, PRF, pulse width and relative bearing of the intercepted radar signal. The parametric data of the processed signal is displayed at the SS3 station and bearing lines to the source can be displayed on the SS3 and TACCO MPD's. ESM is a totally passive system meaning that it does not emit any signal that can be detected by the enemy.

Due to configuration some planes use either the ALQ-78 ESM set while others or the ALR-66. Based on the parameters of the intercepted radar signal, the Electronic Warfare Operator (the SS3) can identify the category of radar (search, fire control, navigation, etc) and in many instances, the specific type of radar . Based on the type of radar the operator can often times identify the class of ship or aircraft emitting the radar signal.  

H. ISAR - Inverse Synthetic Aperture Radar { APS-137( V5) }.

The ISAR is a radar processing system that generates true, recognizable, two- dimensional images of any selected ship target. These two-dimensional views aid the radar operator in recognizing and classifying target images.

The ISAR is a more highly sophisticated radar system than the APS-115 with which most P-3C's are still equipped.  

I. SAR -Synthetic Aperture Radar { APS-137 (V3) .}

An airborne system which utilizes the flight path of the aircraft to simulate an extremely large antenna or aperture electronically. SAR radar is partnered by what is termed ISAR technology which is broadest terms, utilizes the movement of the target rather than the emitter to create synthetic aperture.  

.2 Discuss the importance of the Aircraft Static Dissipation System.

Static dischargers are used on P-3 aircraft to allow continuous satisfactory operation of onboard navigation and radio communication systems during adverse charging conditions by limiting static potential buildup on the aircraft and by controlling interference generated by the corona.

Static dischargers are not lightning arresters. They are attached to numerous points on the aircraft and are fabricated with a wick or wire to provide a high resistance discharge path between the aircraft and the air.  

.3 State the purpose of the P-3 Electrical Power Supply system as stated in the NATOPS Flight Manual.

The electrical power supply system provides the necessary AC and DC power for aircraft requirements. Aircraft AC power is furnished by three engine driven generators and one additional generator driven by the APU. DC power is supplied by three Transformer Rectifiers, which convert AC power to DC power.