Most modern commercial air travel is actually slightly slower on average than it was in the 1960s. Cruising speeds for today's airlines are about 500 knots (575 miles per hour). However, 525 knots (600 miles per hour) was the specified cruising speed for the Boeing 707, which was the first commercially successful jetliner.
Modern aircraft are not designed to go much faster than this because an increase of speed burns too much expensive fuel. Additionally, at 667 knots (770 miles per hour) an airplane would hit supersonic speed, resulting in a sonic boom. While there have been commercial flights which deliberately breached supersonic speeds, many countries have restricted the use of this in their airspace, making it impractical for the majority of airlines.
More about air travel:
- The Boeing 707 had a capacity of about 190 passengers (depending on the model). The Boeing 747 can hold up to 660 passengers, while the Airbus A380 can seat up to about 850.
- NASA is currently working on designing aircraft which will make a less disruptive sonic boom when breaching the sound barrier.
- The Concorde was a supersonic passenger airliner which operated from 1976 to 2003. Its top speed was over 1,350 miles per hour and it could fly from London to New York in two hours.