Jet aircraft

A jet aircraft (or simply jet) is an aircraft (nearly always a fixed-wing aircraft) propelled by jet engines (jet propulsion).

Whereas the engines in propeller-powered aircraft generally achieve their maximum efficiency at much lower speeds and altitudes, jet engines and aircraft achieve maximum efficiency (see specific impulse) at speeds close to or even well above the speed of sound. Jet aircraft generally cruise at faster than about M 0.8 (609 mph, 981 km/h or 273 m/s) at altitudes around 10,000–15,000 metres (33,000–49,000 ft) or more.

Frank Whittle, an English inventor and RAF officer, developed the concept of the jet engine in 1928,Hans von Ohain in Germany, a decade later developed the concept independently at the end of the 1930s. He wrote in February 1936 to Ernst Heinkel, telling him of the design and its possibilities. However, it can be argued that the English engineer A. A. Griffith, who published a paper in July 1926 on compressors and turbines, also deserves credit.

Julia Stone

Julia Natasha Stone (born 13 April 1984) is an Australian folk-blues singer-songwriter and multi-instrumentalist. She is the sister half of Angus & Julia Stone and is also a solo musician. Her debut solo album, The Memory Machine, was issued in 2010. Her second solo album, By the Horns, appeared in May 2012, which peaked at No. 11 on the ARIA Albums Chart.

Biography

Julia Natasha Stone was born on 13 April 1984 and grew up in Sydney. Her parents, Kim and John Stone, were both folk musicians. John was a builder and later became a music teacher, who also performs in a covers band, Backbeat. Kim has an Honours degree in Science, worked as a marine biologist, high school teacher and singer, spent 20 years as Head of E-marketing, Marketing and Investor Communications in institutional funds management until commencing a career as a Non-Executive Director. Stone's older sister is Catherine (born ca. 1982) and her younger brother is Angus Stone (born 27 April 1986). Stone attended Newport Primary School and Barrenjoey High School. At primary school she joined the school band with her father teaching and her siblings accompanying. At family gatherings when the children performed, Stone played trumpet, Catherine on saxophone and Angus on trombone with Kim singing and John on keyboard or guitar. At about the age of 16 years her parents separated and she had a turbulent personal relationship with her boyfriend which broke up after a year.