Helios Airways Flight 522

Helios Airways Flight 522 (HCY 522 or ZU522) was a Helios Airways Boeing 737-31s flight that crashed on 14 August 2005 at 12:04 EEST into a mountain north of Marathon , Greece. Rescue teams located wreckage near the community of Grammatiko 40 km (25 miles) from Athens. All 121 on board were killed. Hans-Jürgen Merten, who was a German contract pilot hired by Helios for the holiday flights, served as the captain. Pampos Charalambous, a Cypriot who flew for Helios, served as the first officer. 32-year old Louisa Vouteri, a Greek national living in Cyprus who served as a chief purser, replaced a sick colleague.
The flight, which left Larnaca, Cyprus at 06:07 local time, was en route to Athens, and was scheduled to continue to Prague. Before take-off the crew failed to set the pressurisation system to "Auto," which is contrary to standard Boeing procedures. Minutes after take-off the cabin altitude horn activated as a result of pressurization. It was, however, misidentified by the crew as a take-off configuration warning, which signals the plane is not ready for take-off, and can only sound on the ground. The horn can be silenced by the crew with a switch on the overhead panel.
Above 14,000 ft (4,267 m) cabin altitude, the oxygen masks in the cabin automatically deployed. An Oxy ON warning light on the overhead panel in the cabin illuminates when this happens. At this point, the crew contacted the ground engineers. Minutes later a master caution warning light activated, indicating an abnormal situation in a system. This was misinterpreted by the crew that systems were overheating.

Space Shuttle Challenger disaster

The Space Shuttle Challenger disaster occurred on January 28, 1986, when Space Shuttle Challenger broke apart 73 seconds into its flight, leading to the deaths of its seven crew members. The spacecraft disintegrated over the Atlantic Ocean, off the coast of central Florida, United States. Disintegration of the entire vehicle began after an O-Ring seal in its right solid rocket booster (SRB) failed at liftoff. The O-ring failure caused a breach in the SRB joint, allowing pressurized hot gas from within the solid rocket motor to reach the outside and impinge upon the adjacent SRB attachment hardware and external fuel tank. This led to the separation of the right-hand SRB's aft attachment and the structural failure of the external tank. Aerodynamic forces promptly broke up the orbiter.
The crew compartment and many other vehicle fragments were eventually recovered from the ocean floor after a lengthy search and recovery operation. Although the exact timing of the death of the crew is unknown, several crew members are known to have survived the initial breakup of the spacecraft. However the shuttle had no escape system and the astronauts did not survive the impact of the crew compartment with the ocean surface.

The Hindenburg disaster

The Hindenburg disaster took place on Thursday 6 May 1937 as the Lz129 Hindenburg caught fire and was destroyed within one minute while attempting to dock at the Lakehurst Naval Air Station. Of the 97 passengers on board, 35 died in addition to one fatality on the ground. The disaster was the subject of spectacular newsreel coverage and photographs. The actual cause of the fire remains unknown, although a variety of theories have been put forward for both the cause of ignition and the initial fuel for the ensuing fire.
The accident served to shatter public confidence, and marked the end of the giant, passenger carrying rigid airships.