The DC-10 1979 Grounding – What Happened?

The full accident report can be found here;

https://www.ntsb.gov/investigations/AccidentReports/Reports/AAR7917.pdf

The National Transportation Safety Board determines that the probable cause of this accident was the asymmetrical stall and the ensuing roll of the aircraft because of the uncommanded retraction of the left wing outboard leading edge slats and the loss of stall warning and slat disagreement indication systems resulting from maintenance-induced damage leading to the separation of the No. 1 engine and pylon assembly at a critical point during takeoff. The separation resulted from damage by improper maintenance procedures which led to failure of the pylon structure.​

It was a very spectacular crash. A lot of people witnessed it. The media was wild.
The FAA had the spotlight on them so they did what all Government agencies do under pressure---look for someone to blame.
That is not to say that the people who were performing unauthorized (McDac) maintenance proceedures were innocent. There was PLENTY of blame to go around.

It did not help that a lot of lawsuits left over from the TK crash in the spring of '74 were just being settled with spectacular payouts. Never mind what was uncovered during discovery. Also the lawyers were able to [prove that the pax. on TK knew they were going to die and thus had horrible mental anguish up until impact.
The same would be proven for the pax. of Flt.191,

It was a mess. The ripple-effect was huge on the airlines ops the -10's.

I was living in TPA at the time. NA and NW were big -10 users. After the grounding It seemed strange when the -10's suddenly disappeared. The media kept the turmoil on the front page for weeks. It was one of those "dark times" in commercial aviation.
All the airlines that ops L-1011's made a big fuss about their "Tri-Stars" and "Lockheed" aircraft, they were so panicked that the public might associate the "10" in "1011" as being a "DC-10"!
(They are going to do the same thing with the 737-Max, you watch!)
It was so bad McDac knew they would never sell another "DC" anything, so they made the switch to "MD".

When the grounding was lifted it took a while for the public to get used to the -10's again.
NW was competing (like everybody else) and trying to run Air Florida out of business in the State of Florida. NW had an afternoon DC-10 flight out of MIA to ORD that stopped in TPA. You could buy a ticket between MIA and TPA for about $18.00 at that time and find the airplane nearly empty.
The take-off performance of a DC-10 lightly loaded can be compared to a take-off on the Space Shuttle.

One of the public perception responses McDonnell Douglas undertook was full-page ads in newspapers advocating the inherent goodness of the -10 airframe, and an opportunity for the public to write to McD for a booklet on the DC-10's attributes. My twelve-year old self took up the offer, wrote to McD for the booklet, and several weeks later, the booklet arrived. I still have it... I need to dig through my parents' attic to find it.