Most commercial flights, however, fly at 38,000 feet above the Class B maximum height and there is not a specific speed limit imposed. BA Captain Dave Thomas stated why they fly at this height: 'This sort of altitude is a good compromise between engine efficiency and aerodynamic efficiency for jet aircraft.
The most common cause of de Quervainâs tenosynovitis is chronic overuse of the wrist. Repetitive movements day after day cause irritation and pain. One common movement that causes it is lifting a child into a car seat. Another is lifting heavy grocery bags by the handles.
Causes of Tourette Syndrome. Tourette Syndrome (TS) is a complex, neurological condition and it is not yet known what causes it. The condition is hereditary and a person with TS has, roughly, a 50 per cent chance of passing on the gene to their children. This doesnât mean, though, that the child will inherit an identical form of TS.