Boeing Co. (NYSE: BA) must fix electrical wiring issues inside its grounded 737 MAX planes before they are cleared to fly by the FAA.What Happened In another setback for Boeing, the Federal Aviation Administration (FAA) concluded that the wiring layout of the 737 Max violates wiring-safety standards aimed at preventing short-circuits, according to The Wall Street Journal. The aviation regulator decided that "under extreme circumstances," the failure of the wiring could lead the 737 MAX flight control systems to point the plane's nose sharply downwards in the same manner as the two MAX Jets that crashed in the past and killed 346 people.Official confirmation has not been made by FAA Administrator Steve Dickson, but the regulator's safety and certification officials have been told by technical experts at the FAA that changes are required in the wiring locations. Why It Matters In late February, Boeing had discovered foreign object debris in some of the grounded MAX's fuel tanks.Wiring changes could delay 737 MAX's returns to the skies by several weeks reported the Journal citing sources. Boeing had planned to return the 737 Max back to service by mid-June.This is a test of new Boeing CEO Dave Calhoun's ability to steer the company out of the crisis caused by the fatal crashes that led to the grounding of these aircraft. Calhoun has taken a more conciliatory stand with respect to the FAA.What Else Is There In a boost for Boeing last month, Japanese airline group ANA Holdings Inc. announced the purchase of 20 additional 787 Dreamliners valued at more than $5 billion at list prices.Price ActionBoeing shares traded 1.27% lower at $259 in the after-hours session on Friday. The shares had closed the regular session 0.75% higher at $262.33.See more from Benzinga * Bill Gates Foundation To Fund Coronavirus Testing Kits In Seattle, Aims At Checking Spread Of Disease In The Region * Lipper Award Winners Pick Healthcare and Technology Stocks Amidst Coronavirus Downturn * Bitcoin Mining Equipment Company Canaan Sued By Investor Alleging Securities Law Violations(C) 2020 Benzinga.com. Benzinga does not provide investment advice. All rights reserved.