Inside the Navy
37 aircraft in question
V-22 FIRE PROMPTS NAVY TO ORDER FLIGHT RESTRICTION ON TILTROTORS
Date: December 10, 2007

A November fire on a V-22 Osprey in North Carolina has prompted the
Navy to order modification kits for 37 tiltrotors due to the
preliminary results of an investigation that suggested an engine
component was at fault, a Naval Air Systems Command spokesman told
Inside the Navy Dec. 6. The fire occurred Nov. 6 on a V-22 during a
flight near Cherry Point, NC, according to a statement released by
Marine Corps Air Station Cherry Point. The aircraft "had a nacelle
fire during a training mission and was forced to land," after which
the crew was evacuated and local fire departments were called to the
scene, the statement reads. The Navy suspects that both this fire and
a similar V-22 fire earlier this year were caused by the aircraft's
engine air particle separator (EAPS), which cleans the air that comes
from the engine intake in order to extend engine life, said James
Darcy, a spokesman for NAVAIR's V-22 program. "It's a hydraulically
driven part," he said, "and ultimately what was happening was this
bearing was seizing up and causing the hydraulic back-pressures to
kind of burst the line and cause a leak, and then the leak had
resulted in past incidents of fire." The Navy's solution was to issue
a restriction dictating that EAPS must be shut off during flight. The
aircraft would be safe to fly, but by not using the system, the wear
and tear on the engine would be increased, Darcy said. The
modification kits, which will come from V-22 manufacturer Bell-Boeing,
will solve the problem, he said. Darcy stressed that the investigation
was not finished, but said "there's enough initial evidence" to make
this move. The problem will not affect 14 tiltrotors in the United
States and the 10 aircraft that have already been deployed to Iraq
because they already have the modification kits, he said. "Bell-Boeing
is under contract to deliver these kits, but what we're doing now is
pursuing an acceleration," he said. He described the problem as a
"known issue with a known mitigation," but said the fires have
prompted the Navy to reassess how quickly the kits would be needed.
The modifications will be made to the remaining 37 aircraft, which
will continue to operate, but without the EAPS system functioning, he
said. The cost for the modifications will be $87,492.25 per aircraft,
he said. "Right now, what we're hoping for is to really start getting
[the kits] in bulk in February '08," Darcy said. "So we're looking at
a period of operations without EAPS potentially between anywhere from
two to four months." The modifications will preclude a permanent
change to the design of the aircraft's EAPS system down the road, he
said. He added that the new modifications could have the added benefit
of making the EAPS more resistant to hydraulic leakage while the
aircraft was under enemy fire. The November fire caused damage in
excess of a $1 million, which is the threshold for the Navy's most
severe damage classification, class A. "No one would quibble with you
if you used the word 'extensive,'" Darcy said. However, he added that
the threshold hasn't changed for decades, and thus isn't as hard to
cross as it was in earlier years. "It doesn't take that much to reach
the $1 million threshold on a modern aircraft," he said. The V-22 has
had a troubled history plagued by cost run-ups and fatal accidents. In
2000, two fatal V-22 mishaps nearly ended the program. Despite
improvements to the aircraft in recent years, the V-22 still has many
critics who have voiced concerns about the aircraft's reliability and
safety. A squadron of 10 V-22s left for Iraq in September for a seven-
month deployment, where they are being used to ferry Marines and
supplies. The Navy also has been searching for a weapon solution for
the aircraft, which today has only a .30-caliber, 7.62 mm M240 gun
mounted in the rear. The Navy wants an all-quadrant gun system that
can provide greater coverage