Two US police aviation units have completed the field demonstration of a US Air Force-developed jet fuel additive which reduces maintenance caused by coking in engines and fuel systems. The USAF is briefing other law enforcement and civil helicopter operators.
Florida's Tampa Police Department and Hillsborough County Sheriff's Office conducted a joint 10-month evaluation of the +100 additive in the Jet A fuel used in their Allison T63-powered helicopters. The additive was developed by the USAF to allow its JP-8 jet fuel to be heated by a further 38íC without increasing its propensity to form coke.
The trial, involving more than 900 flight hours, demonstrated reduced coke deposits and sooting in the T63s. The fuel nozzle cleaning interval was increased tenfold, to between 70h and 200h.
Use of the additive increased fuel cost by 15-18 cents/litre, or about $800 a year between the two police aviation units.
Source: Flight International
