Photo courtesy of Airbus Helicopters
As devices become more affordable, flight data recorders (FDRs) and health and usage monitoring systems (HUMS) are gaining momentum in the helicopter industry, pushed by emerging regulations, OEMs and safety institutions.
Since the 1990s, most large airlines have adopted flight data monitoring (FDM) as an operational best practice. Following studies driven by big offshore companies, most oil and gas operators have embraced helicopter FDM programs.
In 2010, the International Helicopter Safety Team identified technologies like FDM and HUMS among areas of needed improvement to reduce accidents.
In many cases, those systems are not mandatory, though changes are coming. The FAA only requires FDRs for passenger-transporting heavy helicopters. But in 2014, it mandated that helicopter emergency medical services (HEMS) should have FDM systems by 2018. In Europe, helicopters above 3,175 kg for commercial transport must be equipped with a crash-protected cockpit voice and flight data recorder (CVFDR). But Europe is preparing a regulation that would require a “light recorder” on all helos weighing at least 2,250 kg for all civil operations, except for general aviation, starting in late 2018.
Since 2013, Airbus Helicopters has been making standard on all production helicopters except the H120 Appareo’s Vision 1000 flight data, audio and cockpit image recorder. Deployment will be complete by the end of this year.
The 300-g device was developed in collaboration with Airbus for low-cost application and simplified certification, making it affordable for light singles and twins. It collects inertial and positioning data as well as acoustic data and cockpit imagery at four frames per sec, stored on a crash-hardened memory module and a removable digital card. The data can be used for flight de-briefings as part of training sessions. It can also serve investigative purposes.
For medium and heavy helicopters like the Dauphin and Super Puma, this will come on top of a full CVFDR function. The added value is to understand what happened in the cockpit.
The Vision 1000 is also certificated as an option on the Leonardo AW139. The FAA has granted supplemental type certificates for the AW109, A119 and Bell Helicopter 206 series.
HUMS is becoming more powerful. Developed in the 1980s for the offshore community, “the system has been shared across the industry and is now a legal requirement on helicopters providing services in the North Sea and in other regions,” said HeliOffshore Operations Director François Lassale.
Studies have estimated that these systems were capable of detecting 70% of failure modes occurring on components that they were designed to monitor.
HUMS is a tool for maintenance, but is also recommended for safety. Its “health” component monitors vibrations of rotary parts, helping to detect failure or degradation. “Usage” monitors data from systems like engines, ensuring that parameters do not exceeded limits.
The U.S. military is using HUMS for condition-based maintenance, but that is not yet certificated.
High cost is still a hurdle against implementing HUMS on lighter machines, but developments tend to make lighter and more affordable devices.
Curtiss-Wright will demonstrate at Helitech its new crash-protected Fortress HUMS CVFDR. The company said it can be quickly and easily retrofitted on helicopters. Combining FDR and HUMS capabilities in a one box reduces installation weight from 70 lb to 13 lb (32 kg to 6 kg), the company said.
Airbus is seeking FAA certification of a HUMS and FDM for light helos. Weighing 7 lb, the system was developed in collaboration with Ultra Electronics-Flightline Systems and tested on a H145 gearbox.
The CAA in 2010 initiated the Advanced Anomaly Detection (AAD) program. It aims at synthesizing vibration indicators into aggregate signals (reducing from 300 to 45 for Airbus) to reduce false alarms and improve degradation detection thanks to correlation among indicators.
Real-time monitoring is another way forward.
Honeywell is combining satellite-based communications and HUMS to send real-time alerts of exceedances and maintenance issues to monitoring centers of the ground.
Rockwell Collins is working on a connectivity solution to send flight, video or HUMS data to the ground via WiFi, 4G or satellite means while uploading information like flight plans or weather.
What becomes of the data is another issue. The data feeding FDM programs go to the operators to be used to evaluate flight operations, address undesirable crew habits and improve training programs.
One of HeliOffshore’s highest priorities since its foundation in 2014 has been to establish an information and data sharing culture across its global industry. Members are already using the HeliOffshore Information Exchange to share events and lessons learned online, and the group is in the process of sharing FDM and HUMS information as well. The award for the procurement of a data management system is expected this month.