Jesus nut
Jesus nut ( German Jesus mother ) is a slang term for the retaining or shaft nut that fixes the main rotor on the rotor shaft of some helicopter types. The related slang -term "Jesus pin" (Jesus-pin) refers to the Backup splint , which is used for securing the retaining nut. In general, the two terms “Jesus nut” and “Jesus pin” are used to refer to a component that represents a single point of failure , the malfunction of which has catastrophic consequences, so that the crew “only to Jesus pray ”.
origin
The term "Jesus nut" was probably coined by US soldiers during the Vietnam War . In this conflict, a large number of soldiers (mainly infantry ), who did not belong to the classic (flight-experienced) paratrooper troops, were brought to their locations by air (by helicopter) for the first time.
Should the “Jesus nut” fail, break or get lost in flight, the main rotor would come loose from the helicopter. Therefore: "Tighten did damn Jesus nut down good cause I is not in the mood to see him today." (Pull this fucking Jesus nut, because I'm not in the mood to see him today) .
There are few documented examples of the failure of Jesus nuts / pins. However, the nut and cotter pin must before every flight at the check be checked.
In 2000, a main rotor retaining nut was removed for rework and was not professionally checked prior to the test flight. The helicopter crashed less than ten minutes after take-off. Two people were killed. Some newer helicopter systems do not have a "Jesus nut".
The term could also go back to the amphibious aircraft Consolidated PBY , in which two "Jesus screws" held the wings in the fuselage.
Extended context
More recently, the term has been used more broadly throughout engineering to include any individual component the failure of which would result in catastrophic failure of the entire system.
Another use of the term can be found in the English-speaking world in climbing and refers to the first intermediate securing, which is often done by means of clamping wedges , which are also called "nuts" in English. The first intermediate protection - the "Jesus Nut" - reduces the potential fall distance and the fall factor . It relieves the load on the anchorage point at the rope team's stand in the event of the person climbing ahead falling.
The term "Jesus Nut" became popular in literature through the novel Chickenhawk by Robert Mason, a story about his experiences as a pilot of a "Huey" ( Bell UH-1 Iroquois ) in the Vietnam War.
In the English-speaking world, so-called circlips ( retaining rings ) and axle nails are also often referred to colloquially as "Jesus Nut".
miscellaneous
- There is a sung security notice as a video for the preflight check on this subject.
Individual evidence
- ↑ huey.co.uk
- ↑ United States Army Aviation Digest . US Government Printing Office, 1969 ( google.com [accessed April 5, 2021]).
- ^ Gordon L. Rottman: Grunt Slang in Vietnam: Words of the War . Open Road Media, 2020, ISBN 978-1-5040-6170-4 ( google.de [accessed April 5, 2021]).
- ↑ apps.dtic.mil
- ↑ Urban Dictionary: Jesus nut. Retrieved April 6, 2021 (American English).
- ^ Transportation Safety Board of Canada Government of Canada: Aviation Investigation Report A00Q0046. December 18, 2001, accessed April 5, 2021 .
- ↑ Aviation Safety Maintainer 1/2002 - Transport Canada. May 17, 2013, accessed April 5, 2021 .
- ↑ Stephen Joiner: Legends of an Ocean-Crossing Seaplane. Retrieved April 5, 2021 .
- ^ David Coley: High - Advanced Multi Pitch Climbing . Akreative, 2013, p. Section 408 of 5150.
- ↑ John Long, Bob Gaines: Climbing Anchors. 2nd Edition. Falcon Press, London 2006, ISBN 0-7627-2326-2 .
- ^ Robert Mason: Chickenhawk . Penguin Publishing Group, 2014, ISBN 978-1-101-17515-6 , p. 84.
- ↑ Lennard Zinn: Mountain Bike Performance Handbook . Velo Press, Osceola 1998, ISBN 0-933201-95-8 .
- ↑ The Jesus Nut. YouTube, accessed April 6, 2021 .
