Operators of Boeing 737 Maxes affected by an electrical grounding problem that effectively removed more than 100 of the narrowbody airliners from service have begun to apply remedies following the FAA’s approval on Wednesday of two related Service Bulletins.

On April 30 the FAA issued an Airworthiness Directive prompted by manufacturing design changes to certain metallic support panel assemblies installed in the flight deck that resulted in insufficient electrical bonding of the panels and, therefore, deficient electrical grounding of installed equipment. The AD requires modification of the electrical bonding of the assemblies.

On April 8, Boeing advised 16 customers to temporarily ground 109 Maxes due to the new production problem. During the company’s April 28 earnings call, Boeing CEO David Calhoun said it would take “a matter of days” to repair each airplane. Boeing delivered just four Maxes during the month of April after halting shipments to address the problem in airplanes still in inventory.

Meanwhile, the FAA confirmed it continues an audit of Boeing’s methods for making minor design changes across its product line to identify areas where the company can improve its processes. “These initiatives are part of our commitment to continually evaluating and improving our oversight of all aspects of aviation safety, recognizing that catching errors at the earliest possible point enhances what is already the world’s safest form of transportation,” said the FAA in a statement.