Jet oils are specialized synthetic oils used in high-performance jet engines. They have an appreciable hazard due to toxic ingredients, but are safe in use provided that maintenance personnel follow appropriate safety precautions and the oil stays in the engine. Aircraft engines that leak oil may expose others to the oils through uncontrolled exposure. Airplanes that use engines as a source of ...

An understanding of jet noise source mechanisms can facilitate targeted noise reduction efforts. This understanding has been enhanced with acoustic imaging technologies, such as near-field acoustical holography (NAH). In this study, multisource statistically optimized NAH (M-SONAH) was used to image the sound field near a tethered F-35 aircraft at multiple frequencies. A linear microphone array...

Near-field acoustical holography methods are used to predict sound radiation from an engine installed on a high-performance military fighter aircraft. Cylindrical holography techniques are an efficient approach to measure the large and complex sound fields produced by full-scale jets. It is shown that a ground-based, one-dimensional array of microphones can be used in conjunction with a cylindr...

A multi-organizational effort led by the Air Force Research Laboratory conducted acoustic emissions measurements on the F-35A and F-35B aircraft at Edwards Air Force Base, California in September 2013. These measurements followed American National Standards Institute/Acoustical Society of America S12.75-2012 to collect noise data to support community noise modeling and ground personnel noise ex...

Propulsion airframe integration design and analysis has many challenges as we move into the 21 century. Along with the conventional challenges of integrating a propulsion system on an aircraft, new technologies and new business drivers dictate innovative approaches to the design process be developed and applied. On the technical side, new innovations in jet noise suppression and new aircraft co...

A consultation was undertaken to investigate the views and concerns of stakeholders in the aircraft industry about the possible harmful effects on personal health, comfort and safety of aircraft cabin environments. Stakeholders were identified from a variety of sources including Government agencies, the Internet, House of Lords inquiry, and suggestions of interviewees. They represented: aircraf...

Emissions of nitrogen oxides (NOx) from aircraft cause air quality degradation and climate change. Use ultra-low sulfur fuel along with post-combustion emissions control results in a net benefit 304 USD per metric tonne jet burned.