A batch of Embraer E-Jets in operation at 10 airlines from around the world are the focus of a 10-year simultaneous study by the airframer to determine the effects of aging and environment on the high intensity radiated fields (HIRF) and lightning protection features of the aircraft.
The programme, which began last year and is expected to be concluded by 2017, involves inspections and regular checks on a sampling of ten aircraft - five E-170s and five E-190s, reveals Embraer.
Operating on five continents, the E-Jets represent the world fleet in terms of geographic distribution and environmental effects on the HIRF and lightning protection features. A sampling period of 12,000 flight hours has been considered for the inspection interval for the elected aircraft.
"In sequence, the results give the necessary feedback to determine the final maintenance plan inspection requirements and intervals and, if necessary, the corrective actions to improve the aircraft maintenance plan," Embraer VP engineering airline market Waldir Goncalves tells ATI.
"As a result, the developed programme shall show that the inherent level of HIRF and lightning protection along the life cycle of the Embraer aircraft fleet is assured."
Embraer has always been concerned about the direct and indirect effects of lightning bolts, which are common in all regions of the world, but more frequent in the tropics. "The direct effect of a lightning bolt usually results in lesser or greater damage to the airframe, while indirectly, but subtly, it could cause damage to the electronic-digital systems that are increasingly found on modern jets," says the Brazilian airframer in an article running in its Banderainte magazine.
This study is timely since the use of composite materials with low electrical conductivity is growing, "along with the digital electronics and automation that increase vulnerability to lightning", notes engineer Marcelo Tadeu Motta Ferreira in the article.
Embraer applied a similar programme to the ERJ-145 fleet beginning in 2002. The study, in which five airlines participated, is expected to end this year.
"The sample fleet inspections, thus far performed for the ERJ-145 fleet, have demonstrated that the aging and environmental effects upon the HIRF and lightning protection features are negligible and have defined that the presently stated maintenance procedures are adequate," says Goncalves.
"As a consequence, no additional maintenance procedures will need to be incorporated to the maintenance plan of this [ERJ-145] aircraft."