R22 accident figures
From Pilot magazine, January 2002:
The claim that the Robinson R22 helicopter is less safe than other models is put into perspective in a new accident analysis from aviation consultants PLH Associates.
A 'level playing field' comparison of accidents against numbers of hours flown over a five-year period shows that the R22’s fatal accident rate is markedly lower than that of the Schweizer 300/Hughes 269 or the Bell 206. The perception that the R22 suffers more accidents seems to arise from the fact that almost half of all single-engine helicopter hours in the UK are now flown on the machine.
PLH arrived at their conclusions after analysing 15 years of CAA data following a request from a client who wanted to know whether the R22 was less safe than other machines. “The answer is no,” says PLH director Neil Lunam. “The R22 is guilty of having driven an enormous growth in the number of helicopter hours flown, but not of causing an inconsistent growth in accident rates.”
The statistics come with the usual health warning. While accident figures are fairly accurate, the number of hours flown (put at 99,393 in 1995 and 197,576 in 2000) has been extrapolated from C of A maintenance records returned to the CAA. Furthermore, apart from the R22, R44, 300/269, 206 and AS350, few types flew enough hours to make their inclusion meaningful.
The number of fatal accidents is small – 15 over the five years – making one fatal accident equivalent to 6.7 per cent of the total and rendering it especially difficult to use percentages meaningfully for that parameter. But certainly at the high-hours end, the PLH figures are a useful indicator.
They show that 46.5 percent of the total hours flown by all single-engined helicopters in the UK were on the R22. The R22 was involved in about one third (35.66 percent) of all reportable accidents, and one fifth (20 percent) of fatal accidents (three in total). The R22 had one reportable accident for every 7,515 hours’ flying, and one fatal accident for every 115,213 hours.
The other main ab initio trainer, the Schweizer 300/Hughes 269, flew fewer than one tenth as many hours as the R22 (4.2 percent of the total) but was involved in ten per cent of reportable accidents, and 6.7 percent of fatal accidents (one). It suffered one reportable accident for every 2,380 hours’ flying, and one fatal accident for 30,939 hours – about three times worse than the R22 on both counts.
The figures for the Bell 206 show that while the machine had fewer reportable accidents, the chances of an accident being fatal were higher – perhaps indicating that greater weight and speed counterbalances docile handling and peerless autorotational behaviour. Apart from the R22, the 206 is the only helicopter with a big slice of the total hours, at 26.4 percent. It recorded one in ten (10.9 percent) of the accidents, but one in three (33.3 percent) of the fatal accidents (accidents, not persons killed). It had one reportable accident for every 14,047 hours’ flying – twice as good as the R22 – but one fatal accident every 39,903 hours – three times worse than the R22.
The AS350 Single Squirrel flew 8.4 percent of the total hours, had 3.1 percent of the reportable accidents and one fatal accident. This runs out at one accident for every 15,685 hours, and one fatal accident for 62,741 hours. The R44, which only began coming onto the UK market in appreciable numbers at the beginning of this reporting period, flew five percent of the total hours, had 3.9 percent of reportable accidents and 20 percent of fatal accidents. Its reportable accident rate, at one for every 7,488 hours is almost identical to that of the R22, but its fatal accident rate, at one for every 12,480 hours, is ten times worse.
Of the other machines only the MD500 series topped two percent of total hours, and then only just at 2.01 percent. The Enstrom 28, 280 and 480 series, the Bell 47, and the Gazelle all recorded around one percent, while the Brantly and the late-coming EC120 failed to make the scoresheet. The homebuilt RotorWay Exec stands out as having flown 0.55 percent of total hours while having had one fatal accident – a rate of one fatal accident for 4,068 hours airborne.
On these figures it’s impossible to conclude that any helicopter has a 'worse' accident record than any other, but it is clear that the R22 is a safer machine than is generally thought, and undeserving of the rap is so frequently takes. Pat Malone