Hayden Mark S, Shanahan Dennis F, Chen Li-Hui, Baker Susan P
Medical Services Corp, U.S. Army, Injury Analysis, Carlsbad, CA 92009-3020, USA.
Aviat Space Environ Med. 2005 Aug;76(8):782-5.
Crash-resistant fuel systems (CRFS) have demonstrated close to 100% effectiveness in survivable crashes of Army helicopters, but the technology has been slow to transfer into the civil helicopter arena. Federal standards for civil helicopter CRFS are less stringent than those for military helicopters. A reduction in standards for CRFS in military helicopters is being considered.
The goal of this study was to determine whether crashes of civil helicopters with CRFS are less likely to result in post-crash fire than crashes of those without.
Crashes of civil helicopters during 1982-2004 were analyzed, comparing Bell 206 helicopters manufactured with CRFS with Aerospatial 350 helicopters manufactured during the same period (post-1981), but lacking CRFS. Bell 206 helicopters with CRFS were also compared with earlier models without CRFS.
The highest proportion of crashes with post-crash fires (11.3%) was in AS-350s manufactured after 1981 (non-CRFS), and the lowest (3.7%) was in Bell 206s (with CRFS) [unadjusted risk ratio (RR) = 3.3, 95% confidence interval (CI) = 1.04, 10.50; adjusted for light and weather, RR = 2.81, Cl = 0.82, 9.69]. Earlier models of Bell 206s without CRFS had higher risk of post-crash fire than post-1981 models with CRFS (7.4% vs. 3.7%; adjusted RR = 2.11, Cl = 0.82, 5.45).
The results of this study suggest a better performance, in terms of post-crash fire prevention, of CRFS-equipped civil helicopters as compared with those without CRFS. It is possible that CRFS in civil helicopters have not achieved the same degree of effectiveness as CRFS in military helicopters. CRFS should be used more widely in civil helicopters. The more stringent CRFS requirements for military helicopters should not be reduced without further research.
防撞燃油系统（CRFS）在陆军直升机可 survivable 坠毁事故中已显示出接近 100%的有效性，但该技术向民用直升机领域的转移一直较为缓慢。民用直升机 CRFS 的联邦标准不如军用直升机的严格。目前正在考虑降低军用直升机 CRFS 的标准。
本研究的目的是确定配备 CRFS 的民用直升机坠毁后起火的可能性是否低于未配备的。
分析了 1982 年至 2004 年期间民用直升机的坠毁情况，将配备 CRFS 的贝尔 206 直升机与同期（1981 年以后）制造但未配备 CRFS 的宇航 350 直升机进行比较。还将配备 CRFS 的贝尔 206 直升机与早期未配备 CRFS 的型号进行了比较。
坠毁后起火比例最高的（11.3%）是 1981 年以后制造的 AS - 350（未配备 CRFS），最低的（3.7%）是贝尔 206（配备 CRFS）[未调整风险比（RR）= 3.3，95%置信区间（CI）= 1.04，10.50；经光照和天气调整后，RR = 2.81，CI = 0.82，9.69]。早期未配备 CRFS 的贝尔 206 型号坠毁后起火风险高于 1981 年以后配备 CRFS 的型号（7.4%对 3.7%；调整后 RR = 2.11，CI = 0.82，5.45）。
本研究结果表明，与未配备 CRFS 的民用直升机相比，配备 CRFS 的民用直升机在坠毁后防火方面表现更好。民用直升机中的 CRFS 可能未达到与军用直升机中 CRFS 相同程度的有效性。CRFS 应在民用直升机中更广泛地使用。在没有进一步研究的情况下，不应降低对军用直升机更严格的 CRFS 要求。
