RTL Flyer makes a very good point. I think that the aerodynamics of the 152 vs the 150M (aside from flaps beyond 30, and powerplant) are effectively identical. The wings are the same on all models. The obvious statistical difference is probably not attributable to the aircraft model itself, but more who, and how it is being flown. The 150's were probably older, and to put it bluntly, less cared for (pilot horsing around, 'cause he's flying a junk heap anyway). 152's are more prized, simply because they are newer. It's like saying older cars are more likely to be in a collision than newer ones. Its' not the car, it's how it's driven.
40 flaps should not factor in to departure stall spin accidents. If you took off or went around, and that much flap were still out, you would not climb high enough to fall far enough to hurt yourself! Stall/spin during foolish low flying, or landing, much more likely. The plane is just so comfortable to the end during this kind of manuevering, that it does not scare you until it's too late. Other types (Tomahawk, which I like, but flies differently) tend to be less assured in slow or abusive flight, and scare the pilot back to reason before all is lost.
It is my opinion that stall/spin/slow flight may not always be taught well enough. I've had instructors tell other pilots that "[me] was flying my plane around below stall speed". At least one was asked "how come it did not stall then?" STOL kit.
The rudder stop issue, and another erroneously issued AD for STOL kit wing fence height, are in my considered opinion unworthy non-starters.
In the case of the rudder stops, look at a 150 rudder. The bellcrank would have to be soooo far bent or falling off for this to be possible, that it was already quite damaged, and this should be evident on a walkaround. In the Canadian accident of this nature, I suspect that it was possible that the rudder over the stop happened after contact with the ice, and it was just a completely mis-managed manuever, or the rudder was predamaged, and not noticed. If the stops were installed incorrectly, that's a maintenance issue/design allows mis-installation. The revised stop kit solved a problem which was not there in the first place, and was a cheap resolution to a liability open end. 22000 150's in 40+ years, and two accidents, one with mis-installation of parts as the cause, not statistically worthy of AD action in my opinion.
The STOL kit wing fence height AD suggests that the aircraft is somehow sensitive to this characteristic. NOT AT ALL!. I spoke with the FAA inspector who issued this AD, and he did not test fly any combination of STOL kit on a 150 before issuing the AD. He just assumed that because the wrong fences were there, that was the problem. My 150M has the same wrong fences, and there is no negative characteristic as a result. If there were I would have found it by now. I've put over 2000 hours on this particular plane in the last 20 years I have owned it. The aircraft generally cannot be held into a spin (hence the removal of spin approval - no prohibition though, so don't start on me). The STOL kitted 150 can no longer demonstrate the requirement to hold in for 6 turns, and recover after 4 more - it just will not stay in. The spin becomes a spiral dive, which requires a much different recovery technique.
I do not believe that it was the FAA who limited the 152 flap travel, it was Cessna's choice for many of their models. Any competent 152 pilot will have no problem with 40 degree flaps in a 150. It is only in the manual flap 150's that you can go from 40 to zero instantly where a hazard could exist, but in that case, you startle yourself, and put the flap part way back down just as quickly.
Were any of the 150's 150 or 180 HP mods? Those do fly differently to their underpowered sister ships, and that is worthy of consideration. The torque affect of a departure stall in one of these would encourage a spin.
The task of improving safety in the fleet is worthy, and close to my heart, but I find that there is a large enough proportion of accidents (and I've helped investigate a few) which were just pure stupidity, that looking for a problem with the plane is just not where the problem is to be found.
Pilot DAR