It was the afternoon of July 19, 1989 in Denver, and the weather was fair - a broken cloud layer at 4,000 feet, 15 miles of visibility, and a northerly wind at 14 knots. The flight departed Stapleton Airport normally at 2:09 PM and climbed to its cruising altitude of 37,000 feet, where the flight was routine until 3:16 PM. At that time, there was a loud bang towards the rear of the aircraft, and the aircraft began to shudder. The middle engine had failed and pieces of shrapnel shot out from it.

Engine failures aren't terribly uncommon, and pilots are well trained to respond accordingly. When running the engine restart checklist, the crew of Flight 232 noticed that the hydraulic pressure was zero, which was very unusual. None of the backup hydraulic pumps worked, either. Quickly, it became evident that it wasn't just an issue with the instruments, as the aircraft's flight controls were no longer working (they were actuated by the hydraulic system on the DC-10).

Unfortunately, the inboard ailerons of the aircraft were stuck in a deflected position, and thus, the aircraft had a right-banking tendency. There was a check airman on board the flight (an airline flight instructor) who decided to change the thrust levels in the two remaining engines to control the aircraft. This was the only option that really existed, and later analysis showed that this choice helped save the flight. The aircraft was only capable of making right turns because of the ailerons.

A memorial to Flight 232 in Sioux City, Iowa. Public Domain.

Unbeknownst to the crew, the shrapnel that shot out from the engine failure had punctured all three hydraulic lines. There was an area near the tail of the aircraft where all of the hydraulic lines passed through, and the puncturing led to the complete hydraulic failure. The quick reference handbook produced by the manufacturer had no instructions on what to do in this situation, as they considered it an impossibility that it would even happen.

The crew also figured out that there was significant structural damage to the horizontal stabilizers of the aircraft - that, combined with the inability to control the elevators, caused the aircraft to experience a phenomenon known as phugoid oscillation. The aircraft would lose airspeed, which would cause the nose to drop and the aircraft to descend. However, as the aircraft loses potential energy, it gains kinetic energy in the form of airspeed. The increase in airspeed also increases the lift produced by the wings, which causes the nose to pitch up again, and the airspeed to decrease. This continued all the way to the ground.

Turkish Airlines flight 981 wasn't as lucky. They also had the cargo door open during flight, causing rapid decompression. However, it was more severe this time, and a large portion of the rear of the aircraft was completely separated, causing six passengers to immediately fall out of the aircraft. As the aircraft sustained significant structural damage, the flight controls were no longer effective, and the middle engine had also failed. The aircraft crashed and all 346 occupants died.

In 1979, the DC-10 was grounded after American Airlines flight 191 crashed, killing 273 people (including two people on the ground). This accident wasn't McDonnell Douglas's fault, though, as maintenance personnel had improperly installed the number 1 engine onto the aircraft after servicing it. The engine fell off the aircraft during the takeoff roll, causing the pilots to lose control of the aircraft.

After McDonnell Douglas fixed the issues with the aircraft, it returned to the skies and continued flying passengers and cargo for the next few decades. Even though much of the general public was aware of the many issues the aircraft had, they still kept flying on it!

This situation parallels the issues the Boeing 737 MAX had - it gained a worldwide reputation for being a dangerous aircraft, and people were genuinely concerned about its safety. However, after it was recertified by the FAA and airlines started flying it again, people seem not to care anymore. So was the corporation really able to re-earn the trust of the public? Most people don't actually know which aircraft they are flying on when they fly, so do they not know? Would people go out of their way to cancel or rebook their flights if they found out?

Regardless of the answers, the point seems to be that it's not as difficult as it seems to regain the trust of the public when it comes to aviation. However, it is still up to the aircraft manufacturer to do the best they can when designing an aircraft, and not take any safety shortcuts.