Maybe they were heavy, maybe it was too hot, humid, whatever. By the way, anyone have the METAR at the time of the accident?
In any case, I've spent enough time trying to squeeze maximum power out of internal combustion engines to say this:
Just because an engine is rated at a given power output, and it checks out that all systems are functioning normally.... that means absolutely nothing regarding how much power you are actually making. ESPECIALLY with carbureted equipped engines. Even MORE so with large-bore engines with high combustion chamber volume. That's probably the least efficient configuration possible. All performance numbers are predicated on power output, and it is most certainly a variable. It's variable due to density altitude, sure. But it's variable just on it's own for a whole host of factors.
If you've ever spent time tuning all available parameters on a car or motorcycle engine, you'll realize quickly that the few engine controls a piston airplane is equipped with are more antiquated and less precise than trying to sync carburetors by holding a piece of cardboard over the butterfly valves.
I'd be doubly suspicious of a rental vehicle of any kind.
In any case... what a sad situation. Every time something like this happens I'm reminded of all the dumb-ass mistakes I've made, how badly it could have gone, and how lucky I am to be here.
