Due to the large number of questions that i have had regarding the meaning of AE,AD,AM, etc. I have decided to include this page as an explanation for those outside the Navy world.

Aviation electronics technicians (ATs) repair some of the most advanced electronics systems in the world. Repair jobs can range from flight deck trouble-shooting of the electronic weapons system on an F-14 Tomcat aircraft to changing computer circuit cards in an air-conditioned shop. ATs also have the opportunity to fly in what they fix and get paid extra while they're doing it. Naval aircrew volunteers can fly in various types of naval aircraft from helicopters to jets

What They Do:

Aviation electronics technicians troubleshoot and repair a number of complex electronics systems. Employing all the latest test equipment and procedures, ATs put that training to use repairing systems such as: communications navigation infrared detection radar laser electronics fiber optics digital computers or installing field changes, alterations and modifications to avionics systems.

Aviation Electrician's Mates (AE) are aircraft electricians. They maintain a wide range of electrical and navigational equipment in aircraft including power generators, power distribution systems, lighting systems, flight instrument and fuel systems, temperature and pressure indicating systems. AEs are also trained in computers to support this state-of-the-art equipment. Aircrew volunteers perform various in-flight duties in turbojet and propeller aircraft and helicopters. Aircrew volunteers should volunteer under the Aircrew Recruiting Program.

What They Do:

Duties performed by AEs include: testing, installing and maintaining a wide range of aircraft instruments and electrical equipment including generators, motors and lighting systems; reading electrical system diagrams; maintaining aircraft compass systems; performing electrical troubleshooting operations; using a variety of electrical measuring equipment; performing micro-mini module repair; maintaining automatic flight control systems; maintaining inertial navigation systems; performing as aircrew on various aircraft.

General Info: Aviation maintenance administrationmen perform a variety of clerical, administrative, and managerial duties necessary to keep aircraft maintenance activities running efficiently. The rating requires close communication with all other aviation maintenance ratings.

What They Do: The duties performed by AZs include, but aren't limited to: scheduling aircraft inspections; keeping charts that show trends in aircraft system reliability; organizing and operating libraries of technical publications, reports and related maintenance data; issuing aircraft inspection and work orders; performing a wide range of clerical and administrative duties related to aircraft maintenance, such as preparing reports and correspondence, filing and typing; performing data base and system analysis; maintaining aircraft and engine logbooks, and associated records.

Aviation Technicians are responsible for keeping naval aircraft powerplants and related systems, armament and ordnance systems, and aircraft ground support equipment in top operational condition. They may specialize in aircraft engines, reduction gear, helicopter rotor systems, ammunitions and aircraft weapons systems, gas turbine compressor systems, ground air conditioning, aircraft tow tractors, and automotive systems. Aircrew volunteers (AD and AO ratings) perform inflight duties in various types of naval aircraft and should apply via the Aircrew Recruiting Program.

What They Do:

The duties performed by ADs include: maintain and service aircraft engine, fuel, and lubrication systems. perform complete aircraft turboshaft, turbofan, and turboprop engine repair.

The Aviation Structural Mechanic - Hydraulics (AM), maintains all aircraft main and auxiliary hydraulic power systems, actuating subsystems and landing gear. Responsible for maintenance on the aircraft fuselage (mainframe) wings airfoils, and associated fixed and moveable surfaces and flight controls. Aircrew volunteers from this rating perform in-flight duties in various types of aircraft. These technicians may also volunteer to fly as Naval aircrew. Aircrew performs numerous in-flight duties and operates aircraft systems in turbojet, helicopter, or propeller aircraft. Aircrew earns additional pay for flying. (See the Aircrew Program for details.)

What They Do:

Remove, repair and replace hydraulic system pumps, auxiliary power systems and unit actuating subsystems; Maintain aircraft landing gear system, brakes and related pneumatic systems, reservoir pressurization, emergency actuating devices, pumps, valves, regulators, cylinders, lines and fittings; Service pressure accumulators, emergency air bottles, oleo struts, reservoirs and master brake cylinders; Inspect, removes and replace components of hydraulic systems; Replace gaskets, packing, and wipers in hydraulic components; Remove, repair and replace aircraft fuselage, wings, fixed and movable surfaces, airfoils, regular seats, wheels and tires, controls and mechanisms; Remove, install and rig aircraft flight control surfaces; Fabricate and assemble metal components and make minor repairs to aircraft skin; Install rivets and metal fasteners; Paint; Weld; Fabricate repairs for composite components; Perform non-destructive dye penetrant inspections (NDI), Perform daily, preflight, postflight and other periodic aircraft inspections.

This is not a comprehensive guide to all Naval Aviation ratings, simply a breakdown of the jobs found on a typical HSL detachment. 

The descriptions found on this page were taken taken from http://www.usmilitary.about.com