Pintle exotic metal alloys. For World War II aircraft with sideways-retracting main gear units, carefully set-up "pintle angles" for such axes of rotation during retraction and extension allowed the maingear struts to be raked forward while fully extended for touchdown and better ground handling, while permitting retraction into rearwards-angled landing gear wells in their wings to usually clear the forward wing spar for stowing while in flight. Pintle A pintle is a pin or bolt, usually inserted into a gudgeon, which is used as part of a pivot or hinge. Other applications include pintle and lunette ring for towing, and pintle
Squeaky hinge Squeaky hinge Squeaky hinges produce a squeaking or rasping noise when they are moved. Sounds can differ when opened or closed. Lubrication fixes this. Suitable lubricants include plumber's grease and silicone spray. Oil is not so suitable as it can drip off when in excess. Graphite is also unsuitable as it spreads to other surfaces and makes a mess. To give complete coverage of lubricant, the hinge pin is removed to be covered in the lubricant, and then reinserted. Oiling a squeaky hinge is considered a masculine behaviour. Some hinges are designed not to squeak. Chinese hinges may be designed