Boeing Co (BA) shares drifted lower for a third seventh consecutive session Thursday, extending the stock's week-to-date decline past $30 billion, as investigators in France comb through details of the so-called 'Black Box' recorder from Sunday's fatal crash of Ethiopian Airlines Flight 302.

France's Bureau of Enquiry and Analysis for Civil Aviation Safety said Thursday it had received the information from Ethiopian authorities, but couldn't say how long it would take to analyse the voice and data information until it can determine the damage from the box itself. The U.S. Federal Aviation Administration said yesterday that "new evidence" collected at the crash site compelled it to ground all "Boeing 737 MAX aircraft operated by U.S. airlines or in U.S. territory", reversing an earlier statement on the plane's safety.

"The grounding will remain in effect pending further investigation, including examination of information from the aircraft's flight data recorders and cockpit voice recorders," the agency added. "An FAA team is in Ethiopia assisting the NTSB as parties to the investigation of the Flight 302 accident. The agency will continue to investigate."

Boeing shares were marked 0.8% lower by late morning trade Thursday to change hands at $374.10 each, a move that takes its week-to-date decline to around 11.2%.
 
Beyond the horrific human cost of both the ET302 tragedy and the early October crash of a Lion Air flight out of Indonesia, which collectively took the lives of nearly 350 passengers, investors in Boeing, as well as companies linked to the 737's production in Renton, Washington, are looking into the impact on both its $600 billion order backlog and first quarter earnings.
 
At present, however, analysts haven't priced-in changes to the group's single-A credit rating, with Moody's Investors Service saying Thursday that it plans no changes to the group's A2 grade, nor its stable outlook, "at this time".