By By Thierry Dubois | March 1, 2011
|Eurocopter EC120. The manufacturer led a study that showed using data monitoring on light helicopters brings safety benefits but draws a lot of human resources for data analysis. Eurocopter/Anthony Pecchi|
Eurocopter has examined the benefits of installing a helicopter flight data monitoring (HFDM) device on light helicopters for general aviation use, as a study has revealed this could prevent a significant proportion of accidents. During the December 2010 EASA Rotorcraft Symposium in Cologne, Germany, Eurocopter vice president for operational fleet safety, Gilles Bruniaux, presented the results of the 20-month study, which EASA commissioned and involved testing more than 1,000 flights with two partnering operators.
In December 2008, the European civil aviation authorities contracted the study to a consortium led by Eurocopter. Also in the consortium were two French operators: Jet Systems—which provides aerial work and public transport—and Helidax, a military pilot training organization. Aix-en-Provence, France-based ISEI was chosen as the supplier of the HFDM devices and included in the consortium as well. ISEI’s Safety Plane was selected thanks notably to the higher number of parameters it can record. Appareo, a competitor, is already also a Eurocopter supplier for similar devices. Weight was an important criteria. ISEI’s equipment, albeit not the lightest, is still just below one pound. Moreover, Safety Plane data can be downloaded in an automatic, wireless mode after each flight.
The consortium reviewed FAR Part 27 helicopter accidents from the EHEST database (the European helicopter safety team is part of an international effort to drastically cut rotorcraft accident rates). There were 205 accidents, 98 of them GA flights. For each crash, the four partners endeavored to answer the question: If the customer had an FDM program, would this accident have been avoided?” The answers could be “no,” “possible” or “very likely.” Results showed that 26 percent of the analyzed accidents had some probability of being avoided. Focusing on GA (including training), the potential for statistic improvement was 39 percent.
Then came the operational evaluation. Four helicopters—two EC120s and two AS350B3 Ecureuils (AStars)—were equipped with the FDM system.
Events reported were pre-defined “triggers.” The idea was to watch limitation exceedances—flight envelope or engine parameters. Operators also had expressed specific needs to detect pre-vortex ring state conditions and monitor autorotations. Even for those aircraft already fitted with engine monitoring displays, the partners found HFDM engine data brought some value, as data handling was reported to be easier. Out of the 1,069 flights conducted, 429 were for passenger transport, 223 for aerial work and 140 for training. Some major deviations were detected. Bruniaux mentioned several VNE exceedance events, some of them more than 20 knots over the speed limit. Another serious event, landing with low fuel, was detected several times. “In some cases, the event is the consequence of a defined operational practice in aerial work,” Bruniaux pointed out.
A “significant number” of pre-vortex occurrences were detected. They, too, can result from an operational practice in aerial work, Bruniaux noted. Therefore, he suggested standard operating procedures could be refined. This was the same with excessive pitch-down attitude. Bruniaux claimed to have demonstrated multiple benefits. First, partner operators said that HFDM improves flight incident analysis. “The system provides easy access to a set of flight data,” Bruniaux said. Moreover, compliance to standard operating procedures (SOPs) can be monitored and even prompt SOP adjustments. In maintenance, HFDM enables better detection of events requiring swift actions, such as hard landings. For the manufacturer, HFDM provides valuable fleet status knowledge. Estimated costs start with acquisition, installation and usage training—about $14,000 (approximately £11,000). Installation man-hours should be added. Operating the HFDM system will cost about $3,000 (£2,000) per year.
Bruniaux said there is room for improvement. He recommended that some capabilities should be added to the tested HFDM system. For example, the data sampling rate should be higher. Ideally, an HFDM system should combine the number of parameters monitored by ISEI’s device with Appareo’s cockpit audio and video recorders.
A major challenge is that small operators may not be able to allocate enough resources for regular data analysis. Bruniaux suggested that third-party data analysis services should be considered. This is all the more important as “HFDM could be envisaged as a meaningful component of a safety management system.” Finally, the evaluation showed that pilot acceptance was not an issue, once objectives are explained. (From March 2011 Rotorcraft Report)