Did you ever wonder what would happen to a helicopter should its engine fail? After all, an airplane is carried by its wings so it can still glide even after an engine failure. But a helicopter’s lift is generated by the spinning rotor which is rotated by the engine.

Have no fear, Autorotation is here. Simply put, autorotation means that the pilot can disengage the engine from the rotors, allowing them to spin freely so that he can safely land the helicopter, gliding to the ground.

Those who are considering purchasing their first power wheelchair are sometimes concerned what would happen should the power mechanism fail. Although today’s wheelchairs are extremely reliable, there is always a remote possibility that something can go wrong. More common is battery failure. Batteries are consumables. They do not last forever and eventually have to be replaced. However, they generally don’t stop working from one minute to the next. Rather, they gradually lose their ability to hold a charge and slowly begin to last less and less between charges. So this too shouldn’t be of much concern.

But it is possible for a wheelchair user to misjudge the distance he or she needs to travel and believe that they have enough power when they do not. Also, it is possible for one to forget to charge the wheelchair and not pay attention to the battery indicator, just as motorists sometimes run out of fuel.

Manufacturers have not overlooked this issue. Many power wheelchairs have a mechanism for disengaging the motor to allow the chair to be pushed manually by another person. This does not mean that the power wheelchair can do double duty as a manual chair. In fact, even when disengaged, the chair is meant to be pushed by someone else, not by the actual rider. What a motor disengagement mechanism does provide is the assurance that should something fail, the wheelchair user won’t be stranded in a chair that is difficult to move