Bell Helicopter Textron [TXT] said on Jan. 26 that its plant in Amarillo, Texas has completed the first nacelle improvements on a U.S. Air Force CV-22 special operations helicopter by a Bell/Boeing [BA] team.

The upgrade is “to improve the wiring components within the nacelles and to change the structure in order to improve maintainability,” Bell said.

After receiving the improved nacelles, the CV-22 returned to the 20th Special Operations Squadron at Cannon AFB, N.M., last month, on Dec. 13, and nacelle improvement work on the second CV-22 is underway, Bell said.

The first CV-22 slated to receive the improved nacelles arrived at Bell’s Amarillo plant last Sept. 21 (Defense Daily, Sept. 24, 2021).

“Bell completed the modifications at the Amarillo Assembly Center (AAC), which actively produces new V-22s for the Department of Defense,” the company said on Jan. 26. “The AAC employs more than 500 employees to manufacture new and modify existing military aircraft. Completing nacelle improvements at the AAC utilizes Bell artisans with the most experience removing and replacing nacelles.”

In December 2020 Naval Air Systems Command (NAVAIR) awarded Bell and Boeing an $81 million contract for nacelle improvements for nine CV-22s. NAVAIR has an option period to cover fabrication and installation through 2025 for the 50 CV-22s in the Air Force fleet.

Air Force Special Operations Command (AFSOC) has said that its highest priority for the CV-22 has been modifying the engine nacelles to improve engine reliability and reduce the amount of required touch maintenance and the amount of sand, dust, and other particles ingested by the engines.

AFSOC Commander Lt. Gen. James Slife  told reporters on Sept. 20 last year at the Air Force Association Air, Space & Cyber conference that the command is “singularly focused right now on sustainability improvements in the CV-22 fleet” and that “the initial results of the nacelle improvement program tests have been very, very favorable, and we’re looking forward to pushing all our airplanes through a nacelle improvement modification in the coming years” (Defense Daily, Sept. 20).

In 2019, mission readiness for the Marine Corps MV-22 and the AFSOC CV-22s fell below 60 percent.
Bell and Boeing have sought to increase V-22 mission readiness rates by 10 to 12 percent through removing 8 of the 10 wiring interface boxes on the aircraft’s nacelles, changing wiring types, and through nacelle structural upgrades, such as latch changes.

“Approximately 60 percent of [CV-22] maintenance man hours are spent in the nacelles,” per the companies. “Bell Boeing successfully engineered more than 1,300 new V-22 part numbers to help improve reliability and maintainability of the nacelles while also reducing repair time. The improvements are predicted to increase aircraft availability and reduce maintenance time.”

The companies said that NAVAIR completed the first flight with nacelle improvements on a Marine Corps MV-22 test aircraft on April 23 last year–testing that was to inform the CV-22 nacelle modifications in Amarillo and Fort Worth.

The MV-22 shares the same nacelle structure as the CV-22.