The aircraft maker constructs the cowlings.
A seltzer maker's cost varies by brand and the number of features/materials used in a seltzer maker. A seltzer maker can go for at least $79-99 (SodaStream Jet Starter Kit.)
There are thousands of makers of aircraft around the world.
Being a Website Maker
Cadillac division of General Motors is NOT an aircraft maker.
Skyfox Aviation Ltd. based out of Australia is the manufacturer.
Because to do so would require a much higher pressure differential (the difference between the pressure outside the aircraft and the pressure inside) this would need a much stronger aircraft (smaller widows & heaving materials) which would increase the weight of the aircraft unnecessarily. People all around the world live at altitudes where the pressure is greater than sea level so its not required.
Soda water makers are becoming more popular and can be found in more and more stores. Sodastream is one of the main manufacturers of soda water makers and you can find them at Bed Bath & Beyond, Amazon, and Canadian Tire.
Pratt & Whitney . Its actually GE, Pratt and Whitney are 3rd with Rolls Royce second..I believe.
Boeing has been making aircraft since the early 1900s. They are definitely the largest manufacturer. I believe the statistic is, "A Boeing aircraft takes off somewhere around the world every five seconds."
It is not possible till now for a aircraft/airplane to go hypersonic since the thrust produced by the aircraft is supported by the air present around it. However, the engine maker Rolls Royce is experimenting a new way to bring the speed of airplanes closer to the speed of sound.
normally yes unless the maker was asked to take the air bag out