The failure scenario was known before the MAX entered service in 2017: it had been assessed in a safety analysis when the plane was certified. Boeing had concluded that pilots could perform a procedure to shut off the motor driving the stabilizer to overcome the nose-down movement.[141] The scenario also affects 737NG aircraft, though it presents less risk than on the MAX; on the NG, moving the yoke counters any uncommanded stabilizer input, but this function is bypassed on the MAX to avoid negating the purpose of MCAS.[142] Boeing also said that it agreed with additional requirements that the FAA required it to fulfill, and added that it was working toward resolving the safety risk. It will not offer the MAX for certification until all requirements have been satisfied.[3]