Historically, when are midair collisions most likely to occur?

Midair collisions are most likely to occur in busy airspace. This is primarily due to the increased density of aircraft in a concentrated area, which raises the chances of multiple aircraft being in close proximity to one another at similar altitudes. In busy airspace, factors such as traffic volume, altitude, and flight paths can create challenging situations for pilots, even when visibility is good.

Good weather conditions can sometimes lead to an increase in flying activity, as more pilots are likely to take advantage of clear skies. This can exacerbate the risks associated with congested areas where many aircraft might be operating at the same time. Thus, while one might think that good weather would reduce the risk of collisions, it can actually have the opposite effect if it encourages many pilots to fly simultaneously in the same airspace.

Night flying and heavy rain generally present more challenges in terms of visibility and can often lead to lower traffic volume and less likelihood of midair collisions, as fewer pilots may choose to operate under those conditions.