Editing Diesel fuel (section)

=== Aircraft ===
[[file:Packard DR-980 USAF.jpg|thumb|Packard DR-980 9-cylinder diesel aircraft engine, used in the first diesel-engine airplane]]

In general, diesel engines are not well-suited for planes and helicopters. This is because of the diesel engine's comparatively low [[power-to-weight ratio|power-to-mass ratio]], meaning that diesel engines are typically rather heavy, which is a disadvantage in aircraft. Therefore, there is little need for using diesel fuel in aircraft, and diesel fuel is not commercially used as aviation fuel. Instead, petrol ([[Avgas]]), and [[jet fuel]] (e. g. Jet A-1) are used. However, especially in the 1920s and 1930s, numerous series-production aircraft diesel engines that ran on fuel oils were made, because they had several advantages: their fuel consumption was low, they were reliable, not prone to catching fire, and required minimal maintenance. The introduction of petrol direct injection in the 1930s outweighed these advantages, and aircraft diesel engines quickly fell out of use.<ref>Konrad Reif: ''Dieselmotor-Management – Systeme, Komponenten, Steuerung und Regelung'', 5th edition, Springer, Wiesbaden 2012, {{ISBN|978-3-8348-1715-0}}, p. 103</ref> With improvements in power-to-mass ratios of diesel engines, several on-road diesel engines have been converted to and certified for aircraft use since the early 21st century. These engines typically run on [[Jet A-1]] aircraft fuel (but can also run on diesel fuel). Jet A-1 has ignition characteristics similar to diesel fuel, and is thus suited for certain (but not all) diesel engines.<ref>Cord-Christian Rossow, Klaus Wolf, Peter Horst: ''Handbuch der Luftfahrzeugtechnik'', Carl Hanser Verlag, 2014, {{ISBN|9783446436046}}, p. 519</ref>