This tragic story reveals shows why it's been so difficult to find MH370 in the Indian Ocean

South African Airways Flight 295 crashed planeWikimedia CommonsA South African Airways 747 crashed into the Indian Ocean in 1987, killing all 159 people on board.

More than a year after Malaysia Airlines flight MH370 disappeared during a flight from Kuala Lumpur to Beijing, China, there is renewed hope that the missing flight may have been found.

On Wednesday, aviation experts are debating whether or not debris found on Reunion Island in the Indian Ocean could be from MH370.

The search for MH370 may remind of another flight that ended tragically in the same waters.

On the evening of Nov. 27, 1987, the crew of South African Airways Flight 295 radioed air traffic control to alert them about smoke on the flight deck.

Flight 295, a Boeing 747-244B Combi, christened the Helderberg, was nine hours into a flight from Taipei to Johannesburg.

Just 19 minutes after the initial call, the aircraft plummeted into the dark waters of the Indian Ocean with 159 souls on board.

Nearly three decades after its demise, the challenges of the recovery and investigation of Flight 295 serve as a reminder of the difficulties facing those looking for Malaysia Flight 370. The search for the Boeing 777 -200 has been focused on a 7.3 million sq. mi. area in the southern Indian Ocean off the western coast of Australia.

The Indian Ocean features some of the greatest depths on earth. In the case of the Helderberg, the wreckage came to a rest at a depth of more that 15,000 feet, or about three miles below the surface.

The only way for investigators to reach the debris field was by using remotely operated vehicles (ROVs), and even that proved to be an ordeal. To keep the ROVs connected to surface ships, investigators had an especially long cable custom-built so that it would be long enough to reach the ocean floor.

South african airlines flight 295 wreckageFAAWreckage of South African Airways Flight 295 was found deep under the Indian Ocean.

So it’s no surprise a large portion of the aircraft’s wreckage, including the flight data recorder, was never recovered. It took two years to find the cockpit voice recorder, 16,100 feet down.

The report on the crash, commissioned by the South African government, didn’t offer an official cause, but suggested the aircraft either crashed into the ocean after the pilots became incapacitated by smoke, or that the tail of the plane collapsed because of structural failure caused by a fire.

Analysis of debris showed that a fire in the tail cargo compartment burned at more than 600 degrees Celsius (1,112 degrees Fahrenheit). The report did not give a specific cause of the fire, only suggesting an explosion cause by lithium batteries carried in the cargo compartment could not be ruled out.

According to a report by South African newspaper The Witness, Boeing investigator Fred Bereswill speculated that an oxidizer such as ammonium perchlorate — used in solid fuel rocket motors — was present.

In 1987, South Africa’s Apartheid government was subject to economic sanctions, including embargoes on military munitions.

Some have speculated the Helderberg was carrying a secret cargo of weapons for Armscor, the South African government’s weapons firm, despite that the official crash report found no Armscor cargo on the plane’s manifest.

We will never know what happened that night 27 years ago. If Malaysia Airlines Flight 370 did indeed crash into the Indian Ocean, then it too may well keep its secrets hidden in the depths.

Business Insider Emails & Alerts

Site highlights each day to your inbox.

Follow Business Insider Australia on Facebook, Twitter, LinkedIn, and Instagram.