wanttaja
En-Route
As most of you are aware, I do a lot of Homebuilt accident statistical analyses, using the NTSB accident database. As part of that, I occasionally use the same processes to look at particular production-type aircraft.
The ongoing discussions re: Cirrus accidents got me curious. So I fired up my last-downloaded version of the NTSB database (December 2015) and ran my usual process against Cirrus SR20 and SR22 aircraft.
Let's compare them to two other groups: Those of Cessna 210 accidents (for 1998-2007), and for a combined set of Glasair and Lancair homebuilt aircraft (aka HPHB). All analyses include only accidents that occurred within the US...no foreign accidents are included.
This includes only accidents that occurred in the US, international accidents aren't included.
This includes only accidents that occurred in the US, international accidents aren't included.
The number of accidents were reasonably close:
Cirrus: 231
Cessna 210: 370
HPHB: 247
The second line on my results addresses fatal accidents, and computes the percentage of accidents that result in any fatalities.
Cirrus: 34.2%
Cessna 210: 23.2%
HPHB: 42.5%
Cirrus' 34.2% is about twice that of the overall GA fleet. But remember, the lethality of an an accident depends on how fast the airplane is going at impact...and a high-performance aircraft like the Cirrus, Cessna 210, and the high-powered homebuilts will have higher fatality rates.
Yes, the Cirrus rate is about 50% higher than the Cessna 210. But my previous analyses tend to show that high-wing aircraft have a lower fatality rate, probably due to better protection of the cabin.
Cirrus' 34.2% is about twice that of the overall GA fleet. But remember, the lethality of an an accident depends on how fast the airplane is going at impact...and a high-performance aircraft will have higher fatality rates:
Of the three groups, the pilots involved in Cirrus accidents have the lowest median total time:
Cirrus: 727 hours
Cessna 210: 1468 hours
HPHB: 1700 hours
This factors into the biggest category for my analysis process: "Pilot Miscontrol." This category addresses stick-and-rudder errors that lead to accidents.
Cirrus: 51.1% of accidents
Cessna 210: 35.1%
HPHB: 37.9%
The fact that the Cirrus pilots have lower total time probably is the main driver here. It's interesting to note that Pilot Miscontrol accounts for 55% of Cessna 172 accidents...even when training accidents are excluded. And, again, the pilot experience level is lower, about 500 hours total time, median.
When I looked at the in-depth data, one of the first things that struck me is how less often Cirrus engines quit running. The percentages below are the number of accidents where the engine quit for any reason. This includes mechanical failure as well pilot-induced issues
Cirrus: 13.0%
Cessna 210: 31.6%
HPHB: 30.4%
This factors into the survivability of engine failures, as well. 16.7% of Cirrus engine failures lead to at least one fatality or serious injury, vs. 39.3% for the Cessna 210 and 41.3% for the High Performance Homebuilts. Having the CAPS is probably a big factor, here.
The three groups see roughly the same percentage of engine mechanical issues. Other mechanical issues come up less for the Cirrus...their percentage is about a third of those of the Cessna 210 (and that doesn't include landing gear issues).
Continued VFR into IFR conditions occur at about the same rate for the three classes. 4.8% for Cirrus, 4.3% for Cessna 210, and 4.0% for the high-performance homebuilts (which, you'll recall, have the most experienced pilots).
One spot where the Cirrus' rate is much higher is accidents stemming from pilot disorientation:
Cirrus: 4.3%
Cessna 210: 0.5%
HPHB: 1.2%
Again, the Cirrus pilots have the least total time of the three groups.
Here's a summary of some of the main factors:
Ron Wanttaja
The ongoing discussions re: Cirrus accidents got me curious. So I fired up my last-downloaded version of the NTSB database (December 2015) and ran my usual process against Cirrus SR20 and SR22 aircraft.
Let's compare them to two other groups: Those of Cessna 210 accidents (for 1998-2007), and for a combined set of Glasair and Lancair homebuilt aircraft (aka HPHB). All analyses include only accidents that occurred within the US...no foreign accidents are included.
This includes only accidents that occurred in the US, international accidents aren't included.
This includes only accidents that occurred in the US, international accidents aren't included.
The number of accidents were reasonably close:
Cirrus: 231
Cessna 210: 370
HPHB: 247
The second line on my results addresses fatal accidents, and computes the percentage of accidents that result in any fatalities.
Cirrus: 34.2%
Cessna 210: 23.2%
HPHB: 42.5%
Cirrus' 34.2% is about twice that of the overall GA fleet. But remember, the lethality of an an accident depends on how fast the airplane is going at impact...and a high-performance aircraft like the Cirrus, Cessna 210, and the high-powered homebuilts will have higher fatality rates.
Yes, the Cirrus rate is about 50% higher than the Cessna 210. But my previous analyses tend to show that high-wing aircraft have a lower fatality rate, probably due to better protection of the cabin.
Cirrus' 34.2% is about twice that of the overall GA fleet. But remember, the lethality of an an accident depends on how fast the airplane is going at impact...and a high-performance aircraft will have higher fatality rates:
Of the three groups, the pilots involved in Cirrus accidents have the lowest median total time:
Cirrus: 727 hours
Cessna 210: 1468 hours
HPHB: 1700 hours
This factors into the biggest category for my analysis process: "Pilot Miscontrol." This category addresses stick-and-rudder errors that lead to accidents.
Cirrus: 51.1% of accidents
Cessna 210: 35.1%
HPHB: 37.9%
The fact that the Cirrus pilots have lower total time probably is the main driver here. It's interesting to note that Pilot Miscontrol accounts for 55% of Cessna 172 accidents...even when training accidents are excluded. And, again, the pilot experience level is lower, about 500 hours total time, median.
When I looked at the in-depth data, one of the first things that struck me is how less often Cirrus engines quit running. The percentages below are the number of accidents where the engine quit for any reason. This includes mechanical failure as well pilot-induced issues
Cirrus: 13.0%
Cessna 210: 31.6%
HPHB: 30.4%
This factors into the survivability of engine failures, as well. 16.7% of Cirrus engine failures lead to at least one fatality or serious injury, vs. 39.3% for the Cessna 210 and 41.3% for the High Performance Homebuilts. Having the CAPS is probably a big factor, here.
The three groups see roughly the same percentage of engine mechanical issues. Other mechanical issues come up less for the Cirrus...their percentage is about a third of those of the Cessna 210 (and that doesn't include landing gear issues).
Continued VFR into IFR conditions occur at about the same rate for the three classes. 4.8% for Cirrus, 4.3% for Cessna 210, and 4.0% for the high-performance homebuilts (which, you'll recall, have the most experienced pilots).
One spot where the Cirrus' rate is much higher is accidents stemming from pilot disorientation:
Cirrus: 4.3%
Cessna 210: 0.5%
HPHB: 1.2%
Again, the Cirrus pilots have the least total time of the three groups.
Here's a summary of some of the main factors:
Ron Wanttaja