Sign-up to receive weekly Defense email updates with news, commentary, photos, videos and more!
Focusing on the critical interplay of programs, policy, funding and operations to provide integrated intelligence and global perspective to defense and government leaders worldwide.
Aerospace Daily & Defense Report is relied upon for the latest, critical intelligence on programs, budgets and policies in defense, as well as military and civil space.
Unmanned Horizons is a dedicated section of AviationWeek.com's defense coverage of unmanned systems.
Access news, blog posts, videos, photos and other exclusive unmanned systems-related defense content.
Aviation Week is proud to announce its new Innovation Special Topic page supported by Booz Allen Hamilton.
Check out articles, white papers, interactive features and more related to aviation, aerospace and defense innovation.
The Marine Corps still has some issues to deal with regarding the V-22 Osprey. Although the Corps is big on how well the aircraft is operating in combat, aircraft in-theater are still burning out engines at a startling rate. It took a couple of question cycles on Boeing's pre-Paris media tour in Philadelphia on Monday to get a number out of Navair program manager Col Greg Masiello, but he says that engine time-on-wing in theater is averaging "between 100 and 200 hours".That's a worse number than was cited three years ago, when we reported here that the Navy was threatening to seek a new engine supplier - not a realistic threat but a ploy to get the contractor's attention. At the time, we reported that engines were lasting 300+ hours. (V-22 engines in more benign environments are lasting for 560+ hours, Masiello says. Other helicopter engines aim at four-digit time-on-wing numbers.)The problem is dust and sand, which gets sucked into the engine and erodes blades and seals. The result is that the Rolls-Royce engines start to lose power and have to be returned to the US for overhaul. It's not a unique issue to the V-22 but it is particularly acute: the tilt-rotor can't use the barrier-type filters on other rotorcraft because they degrade performance in high speed forward flight, and while single-rotor aircraft tend to blow dust away from the helicopter, the V-22's side-by-side rotors throw dust at one another.This is not good for engines (Marine Corps photo)A number of measures to reduce the problem are being tried. Every engine returned from overhaul since March 2011 has incorporated "four specific changes" to increase time-on-wing, Masiello says. Other modifications could be fielded as soon as the end of the year. A proof-of-concept version of a modified engine air particle suppressor (EAPS) has been fielded for trials, and Maseillo hopes that the engine could be made robust enough to eliminate the EAPS -- which was never designed to tolerate the tornado of crud that the engines encounter in Afghanistan. A further package of modifications is about to be presented to the customer.
ar99, v-22, marines
Copyright © 2013, Aviation Week, a division of McGraw Hill Financial.