I’m pretty sure most of these aircrafts are flown with 1-2 people most of the time, sometimes 3 or 4, irrespective of seating capacity. I don’t think correcting per capacity is that relevant.
Even on your family 210 I’m ready to bet most of the time is flown with 3 POB or less 
I’m not convinced that it makes sense to correct the fatality rate by number of seats. It’s some estimation, yes. But it would be more interesting to see the number of fatal accidents divided by accidents in total. I assume this information is not easy to obtain. Because the fatality rate of the PA24 does look ugly and I’m not convinced that it’s got to do anything with the type. And it doesn’t get better if I told you that by far the most Comanches only have 4 seats. It’s only the B and C Comanches that have 6 seats (around 900 of the nearly 5.000 Comanches).
The fatality rate of the DA40, on the other hand, looks actually very good, and that could in fact coincide with the efforts done in passive safety. However, what’s important when doing an off-field landing is the stall speed that decides at what minimum speed you’re going to hit a hard object. The Comanche simply won’t fly below say 65 knots, maybe 68-70 (depending on the load) where you can get the DA40 even below 50 knots. That’s a huge difference in terms of energy dissipation.
Fatal crashes per flying hour would be a good start, but in most cases you don’t know the annual hours.
One can find out the fleet size (e.g. about 2k for the TB aircraft). But annual hours will vary a lot. An awful lot of planes are hangar queens.
The Comanche simply won’t fly below say 65 knots, maybe 68-70 (depending on the load) where you can get the DA40 even below 50 knots. That’s a huge difference in terms of energy dissipation.
Any plane – even a 747 – will crash if you fly it at Vs x 0.8 OK; if you put a muppet into a DA40 and a muppet into an MEP with a Vs of 70kt, then more muppets will survive in the DA40. But I would expect fewer muppets flying the MEP… because there is more training, and a bit of pilot selection by aircraft type.
There are so many impossible factors. I would expect the PA38 Tomahawk to be the most deadly plane of all. At Vs it just drops a wing and dives straight down. That, reportedly is why masochistic FIs loved them. I have 20hrs in them and spent much of that dropping wings. And my first solo. A totally useless plane for going anywhere, so probably not that likely to get crashed.
Diamonds also have 2 doors. Nobody will be getting out of a Mooney (or a PA28) easily especially if it is on fire.
I have made up a proxy for utilization (total hours flown accounted for in stats) by using years since the middle of the total production run, and that is the bottom row.
How would that give you a measure of annual hours?
maxbc wrote:
I’m pretty sure most of these aircrafts are flown with 1-2 people most of the time, sometimes 3 or 4, irrespective of seating capacity. I don’t think correcting per capacity is that relevant.Even on your family 210 I’m ready to bet most of the time is flown with 3 POB or less
Yes, my bet is 4 seaters is flown on average 1.5POB and a 6 seater 2.2POB. THe point is six seaters are bound to have higher fatality solely due to higher average POB.
If you count by flight hours, our 210 averages about 2.5 POB, I’ll try and verify my impression with hard data think …we usually travel 3-4 POB, occasionally 5-6 POB. By number of flights it is a lower figure since I do short training flights solo or 2POB.
Peter wrote:
How would that give you a measure of annual hours?
It would not. It would only give a measure of total hours flown by the fleet (ie #of aircraft produced times years since middle of production run)
That is the point of the bottom figure: divide number of crashes by number of (aircraft x years). For a total identical number of aircraft produced, it is not fair to compare number of crashes for an aircraft type that has only been in service an average of 10 years vs another one which has been in service for 40 years. Assuming both are utilized the same average number of hours per year, and for the same accident rate per hour, the latter would have had four times as many accidents.
While I applaud your effort, @Antonio, without hard(ish) data on flight hours these comparisons are meaningless. The problem is, that there is precious little data about flight hours of the GA fleet available, let alone type of operation. Of course you could argue that by introducing the same error(s) across the board you arrive at some kind of valid comparison, but I still think there’s too much conjecture to come up with anything meaningful.
Yes I too appreciate the effort, Antonio, it’s an important topic to think about.
Does anyone know how the aviation consumer magazine got the flight hours of aircraft? I can’t find the article directly, seems to be behind a paywall, but several sources point to it.
https://www.avweb.com/news/aviation-consumer-cirrus-safety-record-just-average/
It’s telling 0.35/100.000 (deaths per flight hours) for the DA40 in comparison to 1.6/100.000 for the SR22.
They also present those numbers for several types that don’t log everything electronically, like a C172. And also have number of crashes per 100.000 flight hours. The article points out that while the average in GA is 6.3/100.000 (that is accidents and incidents) the SR22 has half of that (around 3) while the DA40 got 1/6 (around 1) of that.
They also point out that a DA40 has not a single fuel related incident, which is really remarkable – when taking into account that probably around 95% or more of engine failures are reasoned by missing or misplaced fuel (wrong tank).
Going back to the MCR4S which was the launching pad.for this recent part of the thread. Here we are talking of a non certified and kit built aircraft. IMHO not many would build a 4 seater unless they thought they would need at least 3 of those seats on a regular basis. Whereas people may buy a PA28 or C172 just because they are used to them or trained in one.
I too am surprised that the DA40 has not had a single fuel related accident.
IMHO not many would build a 4 seater unless they thought they would need at least 3 of those seats on a regular basis
I would because the space is extremely useful when going on a holiday etc.
I too am surprised that the DA40 has not had a single fuel related accident.
I wonder whether there is another factor in this: Diamond owners have their very own social media community, so information is better controlled. We’ve had examples of this already. IIRC, I posted some issue with the gelcoat, with photos, and some quite unhappy owner popped up and said this might devalue the fleet. This is an issue with any plane in current production because the mfg is active in “information management”; various previous threads on these factors.
What might explain this is 100% installation of a fuel totaliser and pilots knowing how to use it. Otherwise, the zero figure makes no sense.
Good point 👍
