I agree that those are the two likely possibilities. Given that the pilot was pretty experienced, and was a multi-engine instructor, I'd say that disorientation is less likely.
On a cold day at sea level, the 310 should be able to get at least 200fpm. The book number is about 300fpm. However, they may not have been going fast enough to get book performance, and a plane that old usually can't make nearly the book numbers. They hit at about .3nm from the end of the runway, significantly left of the extended centerline, and at an altitude of about 100 feet. That would be consistent with a climb rate of about 150-200fpm.
My guess is that the left engine failed. The left engine is the critical engine, and so the plane would have very strongly wanted to turn left. It would have been slow having just taken off, and so the pilot probably had to turn to keep his speed up and maintain a positive climb rate. He probably either forgot about the power lines, or was just hoping to clear them since he couldn't see them.
Sadly, this is probably just another instance of the second engine being just enough to get you to the scene of the crash.
Yes, they do. The supposed advantage of a twin engine plane is that you can fly if one quits. The FAA makes you demonstrate that you can handle the plane on one engine before they turn you loose with a twin-engined plane, but the unfortunate reality is that the fatal accident rate for twin engined (small, piston) planes is worse than singles. The problem is that the probability of an engine failure is twice as high in a twin as in a single. In a single, if the engine quits, you're a glider, and the plane is fairly straightforward to handle. As long as you don't hit anything too solid, you'll be OK if you keep the plane under control through the landing. In a twin though, you have to do everything just right, or you can end up out of control and hit the ground nose down and die.
In most light twin planes, both props turn the same direction, and so the plane has a natural left-turning tendency when climbing. If the left engine goes out, you're in a very bad situation, because now the plane really wants to go to the left. If you indulge it, you don't get to go where you want. If you don't, you may get a worse climb rate (which is already very bad.)
My impression (with ~20h single-engine, so not exactly an authority) is that while they train single-engine operations, they don't really do it at takeoff exactly because you're close to Vmc, the speed where you don't have enough rudder authority with one engine to keep the plane from going out of control, which would have consequences similar to what happened here.
On a cold day at sea level, the 310 should be able to get at least 200fpm. The book number is about 300fpm. However, they may not have been going fast enough to get book performance, and a plane that old usually can't make nearly the book numbers. They hit at about .3nm from the end of the runway, significantly left of the extended centerline, and at an altitude of about 100 feet. That would be consistent with a climb rate of about 150-200fpm.
My guess is that the left engine failed. The left engine is the critical engine, and so the plane would have very strongly wanted to turn left. It would have been slow having just taken off, and so the pilot probably had to turn to keep his speed up and maintain a positive climb rate. He probably either forgot about the power lines, or was just hoping to clear them since he couldn't see them.
Sadly, this is probably just another instance of the second engine being just enough to get you to the scene of the crash.