U.S. Marines from Maritime Medium Tiltrotor Squadron 166 execute routine maintenance on an MV-22 Osprey in Kuwait. Image – Lance Cpl. Andrew Skiver, U.S. Maritime Forces Central Command

The U.S. navy has cleared its fleet of V-22 Ospreys to fly once again, although officials say they still dont know why a essential portion unsuccessful.

The tiltrotor fleet wasgroundedon Dec. 6, a 7 days just after a materiel failure brought on an Air Drive CV-22 to crash off the coastline of Japan, killing 8 airmen.

Primarily based on engineering assessment we are assured that the mitigations set in spot with the protection controls allow us to resume flying though the [Joint Program Office] proceeds screening for added info to root lead to, an Air Drive Exclusive Functions Command spokesperson explained Friday.

Routine maintenance variations have been manufactured to deal with the failure and all a few solutions will have their own return-to-flight programs, in accordance to astatementfrom Naval Air Programs Command.

The Air Power is making use of a 3-phased strategy to return to flight and it will be a gradual ramp-up right before they resume entire operations, AFSOC said in astatement.

First, AFSOC will carry out ground and simulator education integrating planned flight controls, protection briefings, a assessment of routine maintenance data and refining by-squadron education ideas to put into action the new safety protocols. The next phase is a multi-month application for aircrew and maintainers to get back basic mission forex, in accordance to AFSOC. That will pave the way for the provider to resume total operations in the 3rd phase.

This phased approach affords AFSOC the time expected to maximize possibilities to understand as a lot as achievable from the Basic safety Investigation Board and Incident Investigation Board to mitigate danger to our aircrew, maintainers, and joint associates, AFSOC said.

Forward of the announcement, Rep. James Comer, R-Ky., chair of the Property Oversight Committee,criticized the Pentagon for lifting the grounding order with no providing responses about the protection of the aircraft.

The House Oversight Committee has nonetheless to receive satisfactory data requested from DOD as element of our ongoing investigation released months back into the basic safety and functionality of the Osprey aircraft. Really serious issues continue being this kind of as accountability actions put in position to protect against crashes, a common lack of transparency, how servicing and operational upkeep is prioritized, and how DOD assesses threats, Comer mentioned in the assertion.