Numerous media outlets are reporting on two Air New Zealand engine failure emergencies that happened on Sunday 8 May 2011. Fortunately both planes landed safely, although passengers were very shaken by their experience.

The first was an Air NZ Boing 737-300, Flight NZ-417 from Auckland to Wellington with 101 people on board source

The plane was was enroute near Hamilton (New Zealand) when the crew needed to shut the right hand engine (CFM56) down. The aircraft turned around and diverted to  Hamilton for a safe landing on Hamilton’s runway 36.

Passengers reported they heard a loud bang from the right hand engine, the aircraft yawed and rolled to the right before returning to straight wing level flight.

The airline reported the engine may have shut down as result of low oil pressure. source AV Herald

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More about the CFM56 engine from Wikipedia

Several fan blade failure incidents were experienced during the CFM56’s early service, including one failure that was noted as a cause of the Kegworth air disaster, while some variants of the engine experienced problems caused by flight through rain and hail. However, both these issues were resolved with engine modifications. By January 2010, the CFM56 had flown more than 470 million cumulative hours (the equivalent of more than 53,000 years)

Comments from the public were left on the AV Herald’s website about the flight, including these

By Jake (NZHN) on Sunday, May 8th 2011 22:18
“What is interesting is that acording to witnesses on board and few other sources the engine has seized after what looks like inflight explosion / flameout.

Yet most media is reporting that pilots shut the engine down as a precaution due to low oil pressure.

My feeling is that this was something more then a precautionary engine shtdown and that it basically seized it self prior to the pilots actually shutting it down. All I heard over the ATC was that they were having an engine problem and were returning to Auckland. Decision was then made to return to Hamilton as it is quieter strip but still has the necessary emergency services. I would imagine they did not want to risk shutting down countrys busiest airport and that Hamilton was still close enough to Auckland for the plane to land.

There are ample maintenance facilities in Hamilton to handle a 737 size a/c”

By JDA on Sunday, May 8th 2011 21:52
My Wife was aboard said aircraft. She was sitting above the right engine when a loud bang was heard a a brief flame and smoke issued from the rear of the engine, and a smell of smoke was sensed in the cabin. The aircraft lurched to the right and the bank angle to the right went to 45degrees, with a marked loss of altitude. This was immediately corrected and the bank angle went to the left and then stabilized.

The pilot was very professional in keeping the passengers in the loop.

However I found it most amazing that an Air New Zealand spokesman said the problem related to low oil pressure and the engine was shut down. Am I in correct in saying that if you are shutting down an engine under normal circumstances, the drag would be steadily compensated by a steady input of rudder control.

My opinion for what it is worth is that the engine seized very quickly and destabilized the flight path. Having said all that I have complete faith in Air New Zealand.

The second Air NZ flight to make an emergency landing yesterday was a  Beechcraft 1900D 19-seater. According to a NZ Herald report the aircraft was over Opotiki when the pilot announced there was a problem and was heading back to Gisborne.

“They were very calm at that stage,” said a man, who was aboard the with his 16-year-old son.

“We were pretending to be calm but really we were shitting ourselves. When you actually see the propeller stop, you get a bit worried. My son pointed to it and just shook his head.”

The passenger said a couple of people were crying, including a young girl on her first flight.

“The pilots did really, really well …. but the landing was sweet and the pilots were really calm.

“We gave them a clap after we touched down.

Most people on the flight got on to another flight to Auckland about an hour later.

Gisborne Airport staff are looking into the incident but could not comment this morning…more here on the NZ Herald’s site

On 28 November 1979 an Air New Zealand a McDonnell Douglas DC-10-30, Fight ZK-NZP, crashed on Mount Erebus in Antarctica, killing 257 people. This was the airline’s first fatal crash.

The disaster was subject to a controversial Royal Commission of Inquiry headed by the respected Justice Peter Mahon.

“…Mahon controversially claimed airline executives and senior (management) pilots engaged in a conspiracy to whitewash the inquiry, accusing them of “an orchestrated litany of lies” by covering up evidence and lying to investigators…” read more here

In 2008 an Air New Zealand Airbus A320, Flight 888T, leased to XL Airways, Germany, crashed into the sea in France. It was carrying five New Zealanders and two Germans who were killed when the twin-engine plane they were testing  stalled as it was coming in to land at Perpignan airport. source. 

French prosecutors decided not to prosecute and attributed the crash to pilot error and sensor faults. Read more here