Chasing gremlins

Photo By 1st Lt. Richard Longoria | Peter Vandamme, Senior Technician (Avionics), adjusts a radio altimeter receiver-transmitter.  

GEILENKIRCHEN, NW, GERMANY

05.22.2015

Courtesy Story

NATO E-3A Component

By Senior Master Sgt. Michael Swahn

GEILENKIRCHEN, Germany - The Electronics Maintenance Squadron (EMS) consists of five aircraft maintenance specialties with the mission to deliver precise, proactive, and responsive mission system and flight essential maintenance on the E-3A fleet. During the efforts to maintain the electronics aircraft systems the shops often face tremendous challenges that go beyond the scope of normal duties yet the specialists of EMS continually prove they can tackle any challenge and find technical solutions that have led to the Component’s mission success. This article provides examples of challenges and is sometimes described as “chasing gremlins” since electronic failures can be very elusive, yet our experts at EMS continually find the technical solutions.

The Avionics division was dispatched to a priority maintenance tasking prior to flight, where the Global Positioning System (GPS) showed a constant NO-GO indication. The aircraft was accepted with the deficiency, and performed satisfactorily in flight. However, prior to the next flight, the problem reappeared. A defective GPS antenna was suspected and replaced and the aircraft was towed to spot 9 where the system operational checks tested satisfactory. Following a successful flight, the aircraft returned to spot 1A and the problem reappeared. The aircraft was towed to several other spots on the flight line which led to the discovery that the GPS system only failed on spots 1A – 3. The issue was isolated to a couple possible sources of interference that could involve the new Internet server tests occurring on the flight line or the new air conditioning fans that were recently fitted onto the roof of Hangar 2. A spectrum analyser was used to identify radio frequency signals on the flight line and some abnormal unknown interference was recorded. Accordingly, ‘The Bundesnetzagentur' holds the authority to monitor radio frequency use within Germany and were brought in to utilize their 'detector' vehicle for investigation. This led to the discovery of a GSM mobile phone antenna that was mounted on the heating plant chimney and was creating harmonic interference. The relevant authority in Cologne remotely lowered the output power of the transmitter and raised the angle of the antenna. The event was monitored real-time by the detector vehicle, and after further testing the system interference disappeared.

The Communications division is directly involved in many vitally important projects that directly impact the mission capabilities of the E-3A. They maintain a satellite simulator lab that is utilized for the Internet Protocol Communication modification (IP-COMM). The lab provides data and voice satellite transmission capabilities between the aircraft SATCOM/DAMA system. The shop is developing a setup procedure for the aircraft satellite system utilizing the satellite simulator as a backup when a live satellite channel is not available during the IP-COMM modification of the fleet. This test procedure will also provide convenience for future testing and troubleshooting of aircraft satellite systems when missions require IP-COMM with the NATO frequency table. The hands-on satellite training course experience has ensured shop expertise for these important testing capabilities. Additionally, the shop is responsible for the maintenance and installation of the Aircraft Instant Messaging System (AIMS Chat) and Automatic Identification System (AIS) providing the capability to receive vessel IFF details transmitted live via Iridium Satellite and instant message communication to aircraft, vessels and Combined Air Operations Centers. There is an incredible demand from the operations aircrew community for these systems and technicians remain extremely busy supporting these capabilities. They have become experts in resolving crew reported discrepancies during aircraft launches and repairing broken cables for the operator’s carry-on laptops.

The Radar division is responsible for the maintenance of the surveillance Radar and the Identification Friend or Foe interrogator system. Periodically, the aircraft is sent for depot maintenance where they perform extensive corrosion treatment that requires the entire Radar transmitter removal prior to leaving the MOB. In some cases when the aircraft returns the Radar technicians encounter unusual failures with the Radar system. In recent history, an aircraft returned from this depot maintenance and the Radar shop was tasked to re-install the transmitter. Once the system was installed, the standard practice of servicing the system with Sulfur hexafluoride (SF6) gas was conducted. During the servicing, the technicians encountered an issue while attempting to fill the antenna waveguide and a leak was suspected. The technicians began troubleshooting and could not find this leak leading them to the conclusion that the relieve valve could be stuck but again the service test for the valve passed testing. The technicians proceeded with full operational checks that included Radar ground testing and during this test RF energy was detected. The technicians opened the waveguide and discovered an unusual smell similar to that of burned shavings. They began further waveguide disassembly on the connection from the Rotodome to strut where it was discovered that a piece of green tape was still covering one end of the waveguide and was partially burned. Quality Assurance launched an investigation and the waveguide was cleaned prior to re-installation. The technicians performed another ground test and all tests were successfully completed with no issues. The results of the investigation found that the Rotodome was removed from the aircraft during the depot maintenance and part of their procedure is to tape off the waveguides to prevent debris from entering. The depot technicians had simply forgotten to remove the tape prior to the waveguide re-installation process. The waveguide pressurization issues were caused by a hole being blown into the tape as a result of the gas pressure.

The Computer System maintenance section developed unique system software procedures to facilitate Situation Display Console and Mission Data recorder operating system loading in the event of corruption. The new procedure eliminates unnecessary supply procedures, maintenance downtime, and can be utilized at remote locations. The software procedure development was far beyond the scope of normal maintenance activities for the workcenter. Additionally, the shop led the implementation of the AWACS Maintenance Test Bench that led to ease of use benefits and greatly enhanced overall system reliability. For example, the wrong settings in the Single Board Computer firmware will cause system restarts and this test bench provided the capability to ensure proper configuration prior to installation on the E-3A. This vitally important configuration issue was first identified by a Computer shop technician using the test bench and as a result established routine testing procedures. Furthermore, the Computer shop identified the Mission System Interface Computer failed to come online due to an issue with the hard-drive. The defective status was never identified by the engineering group but through advanced analysis and testing the faulty hard drive was isolated by the computer shop. Additionally, they discovered the failing hard drive had resulted in numerous mission delays.

The Electronic Support Measures (ESM) shop undertook a major modification project to prepare the entire fleet with the Large Aircraft Infra-Red Countermeasures (LAIRCM) system. The LAIRCM system provides an active countermeasure and ESM a detection system providing the capability for all aircraft under the control of the E-3A to fly safely into hazardous environments since the aircrew can locate the least dangerous routes for the fighter aircraft under their control. The LAIRCM upgrade became imperative in order to fly the Afghanistan missions since the system provided missile avoidance capabilities over hostile zones. The system was absolutely critical for the E-3A to participate as they did during the ISAF missions since without the added capability our fleet could not have been located to operate from Mazar-e-Sharif. The ESM shop has conducted several upgrades to the system since the original modification that has increased system performance and the most recent upgrade has increased system reporting by twenty-five percent. The ESM technicians are a vital part of the modification process assisting engineers and providing valuable data collected through routine and non-routine maintenance. Additionally, the ESM shop developed a database that provides the capability to track LAIRCM system performance trends and ensure the system components remain fully mission capable to the greatest extent. Maintaining this system to the maximum level requires the ESM technicians to interpret highly complex data during troubleshooting and they consistently demonstrate capabilities to ensure successful system operation.

The Electronics Maintenance Squadron will be undergoing numerous significant changes in the foreseeable future as we transition from a squadron into a flight under the Maintenance Production Squadron and will be renamed the Aircraft Electronics Systems Branch. Additionally, the Electronic Support Measures (ESM) shop will combine with the Computer shop and begin the noteworthy task of qualification training for the assigned workcenter personnel on both systems. The squadron technicians will also receive additional general maintenance task qualifications normally performed by Crew Chief Specialists to alleviate their reduction in manning power. The EMS technicians are meticulous with every discrepancy making every effort to thoroughly test out the system and in an attempt to duplicate the issue on the ground. Due to the nature of electronics there are situations when a failure is very elusive and intermittent, yet the technicians continue to devote hours or sometimes days of system testing to isolate these types of discrepancies and keep the mission systems operating for the fleet. The squadron is prepared to take on the many challenges ahead as the E-3A Component adapts to the largest structural change since activated in 1982.

• Date Taken: 05.22.2015
• Date Posted: 05.22.2015 04:32
• Story ID: 164234
• Location: GEILENKIRCHEN, NW, DE