PA28 Flight Instructor described a landing gear failure that resulted in damage to the left wing. A strut mounting bolt had sheared off resulting in an initial unsafe gear indication and the strut punching through the wing during landing.

Narrative

During departure it was noticed that the left main gear light was not showing down and locked. An emergency was declared with Approach and a diversion was made to a nearby airport due to the availability of emergency response. Multiple low passes were accomplished in an attempt to ascertain the status of the left main gear. Tower; Airport Operations; and another pilot transmitted; 'gear appears to be down.' Another pilot even went so far as to ask if we had tried to switch out the bulbs (which is listed on the checklist). However; a left gear down and locked light was still not illuminated. After a final attempt and significant yawing of the aircraft; the left main gear light illuminated. We waited for emergency personnel to arrive on scene before attempting the landing. The landing was made without any further incident; except that on taxiing off the runway; it was noted that the left main strut was now exposed through the wing. Apparently; one of the gear mounting bolts had sheared off and caused the failure. It remains unclear as to the ultimate cause of the failure. We surmise that potential fatigue from a previous hard landing(s) had caused damage in the gear mount assembly; but we have no way to confirm this. Human Performance Considerations In aviation; there is a lot at stake; not the least of which includes operational; career; and also personal liability. I believe that because there is such a fear of potential liability that pilots cover up mistakes that can ultimately lead to problems for others. In my particular case; if there was a previous hard landing that could have damaged the gear; it is very easy to see how a pilot out of fear of consequence; could very easily have left the problem for the next pilot. This fear leads to a less safe operating environment in general. Yes; there needs to be accountability; but not to such an extent that fear of it ultimately leads to everyone looking out for themselves and a system that punishes honesty. The fear of liability is so prevalent that on discussion with other pilots after the incident; a few had even asked why I landed at that particular airport instead of the home airport; where the FSDO is known to be less 'strict.' I had not considered this at all in my decision making sequence; and I am glad that I had not. Imagine the degradation to safety of an operation that now starts to consider the implications of landing at an airport under the jurisdiction of a FSDO with a 'strict' reputation. Dealing with the issue at hand no longer becomes the issue; but rather the implications of the aftermath.