"Airplane" is a vague and broad term.<quoted text>
Again you are establishing a singular intent where more terms and intents apply. Can you say the same about airplanes when the first sale of an airplane was to the Army who had a military intent.
So since the military has used the airplane since its conception to kill people you have to define airplane=weapon.
Islamist use commercial airplanes as weapons .
Airplanes were designed to be weapons.
Some airplanes are meant to be used as weapons. Some are meant for transportation. Whether or not something is a weapon depends on its design. Guns, at least the ones which I (and many others) want restrictions on, are very obviously weapons. Some guns are not weapons (for example - a flare gun or a gun designed for competitions), however, most are designed with an intent to do as much damage as possible.