A CMV-22B Osprey, from the “Sunhawks” of Fleet Logistics Multi-Mission Squadron (VRM) 50, rests after landing on the flight deck of the aircraft carrier USS Nimitz (CVN 68). Nimitz is underway conducting routine operations. (U.S. Navy/David Rowe)

WASHINGTON — While the Defense Department’s various V-22 fleets may all have returned to some form of service following a safety-related grounding, they will continue to operate under a “limited envelope” for the foreseeable future, top acquisition officials said today.

Nickolas Guertin, the Navy’s senior acquisition official, told Senate appropriators that his service has established a “crawl-walk-run” approach to slowly bring the V-22 fleet up to full speed, but did not give a timeline for when that might be.

The US grounded its V-22 fleets on Dec. 6, following a Nov. 29 mishap during which eight airmen were killed when their Osprey crashed off the coast of Japan. Flight operations formally resumed March 6, although clearly not at full-strength.

“We rigorously investigated” the cause of the crash, Guertin said today. “We looked at what — we actually brought that craft back up out of the water, we investigated what was going on, did a detailed analysis. And we better understand what happened in that particular failure mode.”

The V-22 fleets are “now in a limited envelope. But we’re characterizing and collecting data so that we can better understand where we are, and be able to safely get back to the full flight envelope for that aircraft.”

While Guertin did not explain what that “limited envelope” means, the recently released draft National Defense Authorization Act contains language that sheds some light on the issue, as first reported by Aviation Week.

“The committee understands that current CMV-22 operations are limited to flights and missions that stay within 30 minutes of a suitable divert airfield,” the language from the subcommittee on seapower and projection forces reads.

According to Aviation Week, that 30 minute restriction currently applies to all V-22 variants, not just the CVM-22 — although, as the HASC notes, that variant is supposed to do carrier operations, and effectively cannot do that mission as long as the restrictions are in place.

The December grounding represented just the most recent issue for the Osprey. In August 2022, Breaking Defense first reported that the Air Force was grounding its CV-22 fleet over safety concerns with the clutch of the aircraft. At the time, the Marine Corps did not follow suit, instead insisting their pilots could compensate for the issue and had been doing so for some time. While the Air Force returned to flight weeks later, the issue re-emerged and a Pentagon-wide grounding across a “subset” of the Navy, Air Force and Marine V-22 models was instituted in February 2023. The Pentagon has not said what it believes caused the November 2023 crash.

The Osprey variants include the Air Force’s CV-22, the Marine Corps’ MV-22 and the Navy’s CMV-22B. Geurtin appeared alongside his Army counterpart Doug Bush, Air Force counterpart Andrew Hunter, and William LaPlante, the undersecretary for acquisition and sustainment. The Navy is the lead on V-22, though Hunter noted that they are working closely with Air Force Special Operations Command, which operates over 50 aircraft of the CV-22 variant and was the command responsible for the V-22 that crashed in November 2023.

“As Secretary Guertin indicated, with a crawl-walk-run approach, we have definitely taken great care,” Hunter said. “And I know AFSOC has taken great care to ensure that as we return, as we get on the path to return to flight operations, every step of an echelon of the operating units, and the support functions that support them are ready to go to the next stage to resume flight operations.”

Ashley Roque contributed to this report.