Stanley514 said:
The airships have no large wings. Are they unstable?
Airships rely on an entirely different concept for flight. They are lighter-than-air vehicles, and thus use buoyancy to stay aloft and don't require large amounts of thrust to stay afloat. Planes, on the other hand, are heavier-than-air vehicles and require forward motion to stay aloft.
An airship remains stable simply due to the fact that the buoyancy force is acting at a point above the center of mass of the whole vehicle, so if it were to tip one way or the other, there is a natural restorative torque that would tend to rotate it back to its upright position. If you had just a cylinder relying on lift, orientation doesn't matter, much like a rocket, and you would need to have some kind of control surfaces to maintain stability. Presently, those control surfaces are integrated into the wings and tail. This is one of several reasons that wingless designs are not just tubes.
Stanley514 said:
There would be no chances that wing will simply fall out as it sometimes happens, a plane will not crush in other plane or building on airstrip or in the air and not scratch anything with a wing. Imagine a plane on airstrip without wings. It would have many more space to move around without fear to scratch some object.
In what modern instance have the wings just fallen off of a plane? Regarding clipping objects with wings, that rarely happens and is always a result of human error. You can solve that problem by procedurally rather than structurally.
There's a reason you don't see wingless flying animals. It isn't an efficient means of flight and requires a large amount of thrust per weight to achieve compared to winged flight, so natural selection simply wouldn't allow it to evolve that way, as any organism would be simply be outcompeted by winged animals.
Also consider that the solar planes that are built these days and the planes built for long-duration flight both must be very efficient in generating lift (have a lot of lift per unit weight and thrust) in order to achieve their flight goals, and the solution there is always to make bigger wings. The stubbier the wings (or removing them entirely) is simply extraordinarily inefficient compared to winged vehicles.