WASHINGTON, Oct 20 (Reuters) - The head of the Federal Aviation Administration will tell U.S. lawmakers on Thursday that the agency is taking a new stance in overseeing the safety efforts of airplane manufacturers like Boeing Co (BA.N). "Our approach to aircraft certification and safety oversight has changed. The FAA’s relationship with manufacturers is evolving," agency Administrator Steve Dickson says in prepared testimony for a hearing before a U.S. House of Representatives panel, which was seen by Reuters. "We are prioritizing oversight of manufacturers and working to focus that oversight on safety-critical areas. We are delegating fewer responsibilities and demanding more transparency from them, and evaluating key assumptions prior to delegating functions in certain areas." Congress in December approved legislation boosting FAA oversight of aircraft manufacturers, requiring disclosure of critical safety information and providing new whistleblower protections in the wake of two fatal Boeing 737 MAX crashes that killed 346 people and led to the plane"s 19-month U.S. grounding. Dickson is slated to testify before a Transportation Committee subcommittee at a hearing that comes nearly three years since Lion Air 610 crashed in Indonesia. Dickson noted that the new law includes over 100 unique requirements for the FAA to implement. The work "is still in the early stages, and we are carrying it out with the urgency that it requires," his testimony says. An FAA survey released in August 2020 found some safety employees reported facing "strong" external pressure from industry and raised alarms the agency does not always prioritize air safety. House Transportation Chairman Peter DeFazio said in prepare remarks released Wednesday the MAX crashes "were the culmination of a series of failures" at Boeing "as well as dangerous inadequacies in the FAA’s process for certifying new airplanes. It is clear that Boeing needed thorough regulation and strict oversight, but its regulator could not provide enough of either." DeFazio added "the FAA is making progress in implementing" reforms mandated by Congress but urged Dickson "to place particular emphasis on this work, because Boeing’s next aircraft—the 777X—is already in flight tests."