Originally Posted by jbcarioca

Technically thrust reversers on transport category aircraft will not deploy without an actual landing, that is weight on the extended landing gear. There have been a tiny number of incidents where that happened, notably a 1991 crash of a Lauda Air Boeing 767 with a loss of all on board, which resulted in disabling all 767 thrust reversers while that was fixed. The DC8 once could have thrust reversers deployed in flight and some B737-200 models were modified to permit it. Despite those it is a certification requirement for all aircraft equipped with thrust reversers that they cannot be deployed in flight. No MD11 ever had such an incident on record. Some turboprops can have their propellers reversed in flight (the ATR 42-72 being notable) but most of thsoe not incorporate the "squat" switch also that precludes reverse deployment without weight on the landing gear. There is colorful history on this subject, mostly involving incorrect rigging and inadequate preflight inspections. That said, don't worry about it, it is almost 100% certain that such a thing will never happen to you.

As for turbulence, turbulence can and has caused inflight breakups. No commercial use aircraft can withstand unlimited weather. There is a speed, called "turbulent air penetration speed" that is the maximum speed permitted in turbulent air. That speed is the one below which the aircraft will 'stall' before structural damage can happen. Without discussing load limits and 'stall' definitions, this means that a well maintained and piloted aircraft can endure some very frightening weather. I've been in such weather as both a pilot and as a passenger. The passenger side is probably less of a strain... anyway accidents in turbulence are indeed very, very rare.

There are quite a few FTers who are type rated on jet aircraft, including me, so if you want more pilot perspective on any of this kind of thing just ask, and they'll emerge to venture informed opinions, and will correct me quickly if I hjave made any errors in my comments.