What happened
A comprehensive safety study conducted by the UAE Air Accident Investigation Sector (AAIS) analyzed aviation occurrences between 2010 and 2023 to evaluate the effectiveness of Emergency Locator Transmitters (ELTs). The research focused on the ability of these devices to alert the National Search and Rescue Center (NSRC) following accidents, particularly those occurring in remote locations. The study reviewed various incidents, including a Boeing 747-44F cargo plane crash caused by lithium battery fire and several helicopter incidents, to determine if distress signals were successfully transmitted.
The investigation
The AAIS examined a wide range of data, including accident reports from the UAE, Australia, and Canada, alongside interviews with GCAA and Search and Rescue specialists. The investigation looked into the mechanics of different ELT types, such as Automatic Fixed ELT (ELT AF), Automatic Portable ELT (ELT AP), and Survival ELT (ELT S). The researchers specifically scrutinized the 406 MHz and 121.5 MHz signal transmission processes via the Cospas-Sarsat satellite system and evaluated how well current equipment adheres to ICAO standards.
Findings
The study identified a concerning trend where ELTs often failed to facilitate prompt rescue responses. While some accidents, such as a Bell B212 crash near an oil rig, resulted in successful distress calls, many other incidents involved non-activation. Key reasons for these failures included impact damage destroying the unit, suboptimal installation, and maintenance lapses. In some cases, such as a helicopter ditching near Mubarras Island, the low rate of descent failed to trigger the G-sensor in an Automatic Deployable ELT, and the crew did not manually activate the device. Additionally, some aircraft, such as a Cessna 208B Grand Caravan, were found to be not equipped with the technology at all.
Safety action
The study highlights the potential for enhanced safety through the integration of the Global Aeronautical Distress and Safety System (GADSS) and new technologies like Distress Triggered ELTs (ELT DT). The findings suggest that addressing maintenance gaps and leveraging advancements in detection technology are essential to ensuring that distress signals are reliably received during critical emergencies.