Actually the 6000 Cirrus SR2x was about right ;-) COPA used that number this year.
USFlyer wrote:
There are about 4,500 Pipers flying in the USA, 6,000 Cirrus.
USFlyer wrote:
Total number of Cirrus are 4,600
Total number of Piper are 45,000
So not only were the number of Pipers off by a factor of 10, but also you had about 30% too many Cirrus a/c?
USFlyer wrote:
Given the age of the Piper fleet assume 25% are not flying that leaves about 34,000 assumed to be flying somewhat regularly.
Even given this assumption, your original figure was off by a factor 7-8.
Using the FAA registry: http://registry.faa.gov/aircraftinquiry/AcftRef_Inquiry.aspx
Total number of Cirrus are 4,600
Total number of Piper are 45,000
Given the age of the Piper fleet assume 25% are not flying that leaves about 34,000 assumed to be flying somewhat regularly.
All the Cirrus are new enough to be flying regularly.
NTSB for 2015:
18 Cirrus crashes, 5 fatal.
206 Piper crashes, 52 fatal.
The ratio holds for number flying, number crashing and number fatal. The Cirrus is no more crash-prone than any other aircraft…and the parachute reduces fatalities.
There’s more than 10.000 Super Cubs built, almost 5000 Warriors, more than 5000 Senecas … and that’s only 3 types Piper made/makes. . … other examples: 5000 Aztecs were built, 20.000 J3 Cubs… So “4.500” is of course completely wrong
The numbers I know from COPA are: Cirrus fatal accident rate for the past 36 months: 0.63 for 100.000 hours of flying. (In the past 36 months, there have been 17 fatal accidents and approximately 2,700,000 flying hours for a rate of 0.63 fatal accident per 100,000 hours of flying time).
Numbers for the GA fleet: 1.05 overall, and 2.38 for Personal & Business flying
RobertL18C wrote:
mh, would have to trawl through all the Piper types, but the PA18 production run alone was 7,500, the PA28 was 32,000, the PA23 over 5,000, you have from the J2 through the PA46, so possibly around 100,000 produced in all the types? what the active fleet might be is difficult to estimate, 60,000?
Thanks, that’s what I expected and why I didn’t believe USFlyers “facts” for a moment.
@USFlyer: Why?
USFlyer wrote:
There are about 4,500 Pipers flying in the USA
Here we go again… @USFlyer, could you please be more careful with your claims.
In the last ten years there have been 92 Cirrus fatal accidents in the NTSB database, out of a total of 215. A fatal rate of around 30% to 40% per accident does not seem to out of line given the type of operations and kinetic energy of this GA aircraft (it was 33% in 2015), and as LeSving points out the CAPS may have less statistical influence on the fatal accident rate, when compared to similar aircraft without CAPS, than we might think a priori. The 33% rate seems a fair estimate, at the lower end of the historical average.
A statistician then might calculate what is the Poisson probability that the Cirrus fleet accident rate stays at the 2015 rate of 15 accidents in the year, compared to a historical average of 20 plus, before concluding that it is the safest of its type.
In any event this is hair splitting. Compared to Part 121 operations, GA has such a higher accident probability (in the order of 50 to 100 times higher), that whether a GA type experiences 1 or 3 fatals per 100,000 hours is not that relevant. Survivability, and this is linked to type of operation and aircraft type, is a factor, and here I would champion the PA28 or DA40 or C172 as superior.
mh, would have to trawl through all the Piper types, but the PA18 production run alone was 7,500, the PA28 was 32,000, the PA23 over 5,000, you have from the J2 through the PA46, so possibly around 100,000 produced in all the types? what the active fleet might be is difficult to estimate, 60,000? They are relatively un complicated with limited ADs, and for example around 2,000 PA18s active in Alaska where they don’t lead a sheltered existence with a relatively high accident rate reflecting the hostile weather and off airport operations.
I don’t know if the Piper fleet flies ten times the hours of the Cirrus fleet, but it might. To ‘control’ the statistics, you might compare the Cirrus to the Saratoga or the PA46, but they are still different vintages/types (Saratoga mainly produced in the 1980’s, the PA46 a high altitude, more complex aircraft), and I expect these Pipers to be average, or above average on the fatal rate, with the rate creeping up as the fleet gets older. Controlling for a specific year of production and type of operation would yield too small a set of data to be meaningful.
I would give the Cirrus the benefit of the doubt that it is probably one of the safer cross country high performance SEPs ever built, even though not so long ago (up to 2012) the report card was average to worse than average. The poissonic nature of the accident curve means the last three years may not yet be meaningful, statistically.
Which reminds me of Zhou-en-lai responding drily at the Korean peace talks in Paris, what did he think of the French Revolution: ‘too early to tell’. I like the quote as this period prompted the US to ship several thousand PA18s to Europe to help re build the Western European air forces from the bottom up, including little old L18C 51-1555 sent to the French ALAT.
USFlyer wrote:
By contrast there were 206 Piper crashes, 52 fatal.
The “death rate” in a Cirrus is 28% and it’s 25% in a Piper. Statistically speaking the chute doesn’t help much.
USFlyer wrote:
There are about 4,500 Pipers flying in the USA, 6,000 Cirrus. Yet 10x more Piper crashes in 2015.
That can’t be right.
