Superior Air Parts XP-400 explained

The Superior Air Parts XP-400 is an aircraft engine, designed and produced by Superior Air Parts of Coppell, Texas, United States for use in homebuilt aircraft.^[1]

The company is owned by the Chinese company Superior Aviation Beijing, which is 60% owned by Chairman Cheng Shenzong and 40% owned by Beijing E-Town, an economic development agency of the municipal government of Beijing.

Design and development

The engine is a four-cylinder four-stroke, horizontally-opposed, 4000NaN0 displacement, fuel injected air-cooled, direct-drive, gasoline engine design. It produces 2150NaN0, with an 8.9:1 compression ratio.^{[1] [2]}

The engine is not type certified and is therefore intended for homebuilt aircraft.^[3]

In March 2019 the engine type was withdrawn from service and all customer engines were subject to a mandatory, immediate buy-back by the manufacturer to remove them from service. The company made this decision based on detonation problems found in some XP-400 engines that could not be resolved. Due to parts commonality, the decision was made to buy-back the Superior Air Parts XP-382 engines as well.^{[4] [5]}

In February 2020, Superior settled a lawsuit regarding the 2016 fatal crash of a Van's Aircraft RV-8A for US$5M. The crash was due to the failure of the crankshaft in the installed XP-400 engine. In the accident investigation the NTSB determined that the crankshaft failed due to metal fatigue. The crankshaft had 20 hours of flight time on it at the time of failure.^[6]

Notes and References

1. Tacke, Willi; Marino Boric; et al: World Directory of Light Aviation 2015-16, pages 262-263. Flying Pages Europe SARL, 2015.
2. Web site: Engine models. 17 April 2018. Superior Air Parts. superiorairparts.com . 2013. https://web.archive.org/web/20180405234700/http://www.superiorairparts.com/xp-series-engine/engine-models/. 5 April 2018.
3. Web site: FAQ. 17 April 2018. Superior Air Parts. superiorairparts.com . 2013. https://web.archive.org/web/20180316104030/http://www.superiorairparts.com/xp-series-engine/faq/. 16 March 2018.
4. Web site: Superior Grounds XP-382 And XP-400 Engines. 4 March 2019. O'Connor. Kate. AVweb. 1 March 2019. https://web.archive.org/web/20190410151427/http://flash.avweb.com/avwebflash/news/Superior-Grounds-XP-382-and-XP-400-Engines-232357-1.html. 10 April 2019.
5. Web site: Detonation Concerns Behind Superior's Buyback Of XP-400 And XP-382 Engines. 10 April 2019. Cook. Marc. AVweb. 1 March 2019. https://web.archive.org/web/20190409234254/http://flash.avweb.com/avwebflash/news/Detonation-Concerns-Superiors-Buyback-of-XP-400-and-XP-382-Engines-232603-1.html. 9 April 2019.
6. Web site: Superior Settles One XP-400 Lawsuit. 12 February 2020. Cook. Marc. AVweb . 11 February 2020. https://web.archive.org/web/20200212145044/https://www.avweb.com/aviation-news/superior-settles-one-xp-400-lawsuit/. 12 February 2020.