Why don t airplanes have their own parachute?

The type rating is required in aircraft that need additional training. It is a safety of flight issue not a for hire issue.

I have never heard of that (although maybe you should suggest it to them). I am fairly active on COPA (Cirrus Owner and Pilot's Association), and I have never heard it mentioned.

I will tell you this - the parachute works. It's an emergency device, and the plane is rarely salvageable, and you *may* even get banged up - but the impact under canopy is almost always survivable. And that is far better than the outcome for most IMC loss of control or aircraft control failure situations in conventional aircraft.

Great book to read is "Wings On My Sleeve" by Eric Brown. Only pilot in the world to have flown most of the airplanes of WWII.
https://www.goodreads.com/book/show/1299333.Wings_on_My_Sleeve

Usually it is airspeed of the aircraft. Each aircraft has different airspeed requirements for operation the flaps or landing gear. Usually that speed is determined by the airframe manufacturers and the design of the flap system component. You could built it strong enough to handle any airspeed, but a plane can only carry so much weight. If you built everything to work without any limitations you might have an airplane too heavy to fly. Designing a plane is a balance between lifting capability and weight. Both of these are important design parameters.

here ya go...
http://www.explainthatstuff.com/jetengine.html
tis physics.

That would be the ground prox system on the aircraft it lets the flight crew know how far they are above the ground during an approach to the landing runway.

amid is Russian

Aircraft too heavy. Weight is extremely valuable/expensive and the weight of a parachute system would be too heavy and costly, sacrificing room for paying passengers.