APNG Crash Report Highlights Defects

By PORENI UMAU

THE preliminary report on the Airlines PNG plane crash in Madang last month was released by the Accident Investigation Commission (AIC) last week.

The nine page report was released in the presence of Civil Aviation Minister Puri Ruing and the media by AIC acting chief executive officer Syd O’Toole, deputy chairman Minson Peni and commissioner Nahau Rooney.

The report stated that on October 13, 2011, the flight crew of the Airlines PNG P2-MCJ Bombardier DHC-8-103 lodged a Regular Public Transport flight plan at Jacksons International Aerodrome Briefing Office for the CG1600 flight to Nadzab and to Madang.

The plane landed at Nadzab, refueled and left for Madang at 1647 tracking 264 degrees with a flight level 160 during its climb. Estimated arrival time in Madang was 1717. The fight progressed normally and was shifted to Madang Air Traffic Control (ATC) at 1710 with descent into Madang. The profile was steep with closeness of the Finisterre Ranges to Madang and the pilot in command was hand-flying the aircraft because the autopilot was unserviceable.

He controlled the plane visually to avoid cloud and thunderstorms. In response to a request from Madang tower at 1712, the crew reported the aircraft was 24 nm from Madang, leaving 13 000 feet on descent. At 1715, the plane’s overspeed warning sounded and shortly, both propellers oversped and exceeded their maximum permitted revolutions per minute by in excess of 60 per cent.

Witnesses on the ground reported hearing a loud bang as this occurred and the crew shut down both engines. By 1717, the crew made a “Mayday” call to the ATC to report an in-flight emergency and both engines had stopped. Madang Tower declared a “Distress Sar Phase”. The aircraft landed 33 km south of Madang town at a sparsely wooded flat and rocky terrain near a dry river bed leaving a wreckage trail about 300 metres long. It was severely damaged on impact, colliding with trees and the ground and an intense fuel-fed fire began.

At the crash site, villagers found the fuselage severely disrupted and engulfed in flames. They helped the four survivors to the nearest aid post. Investigators found the outboard section of the left wing at the start of the wreckage trail, followed by other elements of the left wing structure and its components. The left engine separated in two sections during the impact and the tail section separated from the fuselage and was found next to the main fuselage section. The rest of the aircraft including the main fuselage, right wing and right engine were at the end of the trail. Thermal damage to the aircraft parts showed that a post-impact fuel-fed fire began when the plane was about halfway along the wreckage trail and the fire intensified and consumed most of the aircraft when it came to rest.

Examination at the site showed that the plane was configured with the flaps and landing gear in the fully retracted position. The left engine was isolated from the left wing and was broken into two sections. The propeller hub was still attached to the reduction gearbox, however, three of the four propeller blades had separated from the hub on impact. The left propeller actuator was in the feathered position, indicated the propeller blade angles at the time of the crash. The right engine was still attached to the right wing and the reduction gearbox outer case was completely ruined. The right propeller blades were in the fully feathered position.

The pilot was 64 years old at the time with about 18 200 hours flying experience, 500 hours were in the DHC-8. He had a valid PNG Airline Transport Pilot Licence (PNG ATPL) issued on July 4, 2011 and a Class 1 Aviation Medical Certificate (AMC) valid until December 2, 2011 and issued with the condition that he wear correcting lenses while flying.

The first officer was 40 years old with 2750 hours flying experience and 410 hours were in the DHC with a valid PNG ATPL issued in May 30, 2011 with a Class 1 AMC valid until March 29, 2012.

The flight attendant was 28 years old with a valid PNG certificate of achievement, issued on March 28, 2009 with about 2500 hours flying experience as a flight attendant with the operator. The weather was calm with visibility greater than 10 km with smoke within the aerodrome area in Madang.

The aircraft was fitted with a cockpit voice recorder (CVR) and a separate flight data recorder (FDR). Both were found in the plane’s tail section and were not damaged. They were flown to Port Moresby and then to Canberra for full examination and data download. The CRV was downloaded and showed that audio from the accident was successfully recorded. The 30 minute recording covered the start of the climb after takeoff at Nadzab until power was disrupted at the force landing. Recovered data from the FDR contained 53 hours of aircraft operation covering the accident flight and 33 previous flights.

Analysis of the CVR and FDR data is ongoing and will include detailed analysis of all the recorded parameters of the accident flight, comparison with FRD data recorded during previous flights and a sound frequency analysis of the CVR audio particularly relating to the propeller and engine operation. The ongoing investigation would also analyse engine and propeller assemblies, recorded information and maintenance documentation and procedures. It would also include operations documentation.

Source: Post-Courier Online - Original post by Albert Tagua on Monday, 7 November 2011 at 13:21 (for ease of reading post reformatted by forum author).