21. However, investigators stated that even if a mid-air engine failure occurred, the pilots still could have returned to the airport safely. 22. Air engines have been used since the 19th century to power mine locomotives, pumps, drills and trams, via centralized, city-level, distribution.23. He invented a hot air engine known as the " Surge Turbine " for which he was granted a US patent. 24. It is technically challenging to design air engines to maintain high efficiency and sufficient power over a wide range of pressures. 25. Tata has moved onto phase 2, " completing detailed development of the compressed air engine into specific vehicle and stationary applications ". 26. Examples include steam in a steam engine, air in a hot air engine and hydraulic fluid in a hydraulic motor or hydraulic cylinder. 27. This innovation improved the efficiency of Stirling's engine and should be present in any air engine that is properly called a Stirling engine. 28. Each door was controlled by an air engine , consisting of a large and a small cylinder, which were supplied with compressed air at. 29. It was revealed that if an aircraft had a mid air engine failure in one of its engine, the plane still could fly. 30. Electric door motors were used for the first time, replacing the standard compressed air engines which had served on much of the older equipment.
