After departing Port Moresby, Papua New Guinea, at 0406 Universal time, coordinated on 31 December 2007, the flight crew of a Boeing 737-229 aircraft, registered VH-OZX, operating a scheduled flight from Port Moresby to Brisbane, experienced severe vibration through the aircraft's airframe, resulting in the crew declaring a MAYDAY and returning to Port Moresby.

A subsequent examination found a section of the right elevator balance tab had detached and was missing. Examination of the remaining sections of the balance tab revealed that two attachment screws from one of the elevator balance tab hinge blocks had unwound, which led to the tab failure.

The investigation found that airframe vibration had been reported by the flight crew the day prior to the accident. On that occasion, a level I - General Inspection of the aircraft was conducted by a licensed aircraft maintenance engineer after the aircraft landed, with no defects found.

The aircraft manufacturer was aware that other operators had experienced in-flight vibration as a result of excessive wear in the elevator balance tab hinge and control linkages, and had issued a number of service bulletins (SBs) to address the issues. These SBs included SB737-55A1070, which directed operators to carry out detailed inspection of the elevator balance tabs, including checks for free-play, control rod wear and loose hinge screws.

As a result of this accident, the aircraft operator implemented a 'fleet campaign directive' requiring the immediate accomplishment of SB 737-55A1070 on all of its aircraft.

Following completion of a scenic charter flight, at about 1905 Eastern Daylight-saving Time on 29 December 2007, a Robinson Helicopter Company R44 Raven 1, registered VH-MEB, departed the Pier 35 private helipad, located adjacent to the Yarra River, Melbourne, Vic. on a private flight to return to the operator's base, with two pilots on board. Witnesses located at a nearby marina, reported that shortly after the helicopter's take-off in a north-north-westerly direction, it banked left and turned to the south-west, passing a marina while at a height of about 30 to 35 ft above mean sea level (AMSL). Witnesses reported that during the accident flight take-off, the helicopter passed to the west of a channel marker in the river adjacent to the pad. During the departure from the pad on previous flights the helicopter had passed to the east of the channel marker.

The helicopter's forward airspeed decreased and it 'rocked or wobbled in the air' then pitched nose up, rolled to the left, descended and impacted the water. The handling pilot exited the helicopter via the right side, where he was seated, and was recovered by the crew of a nearby boat. The other pilot, who was the chief pilot of the operator, did not exit the helicopter and was fatally injured.

The investigation found that the helicopter did not gain altitude, departed controlled flight, descended and struck the water. During this event, the main rotor revolutions per minute (RPM) were at a lower-than-normal value to sustain controlled flight. The investigation could not identify any problems with the helicopter, its systems or engine, which would have led to the low main rotor RPM as witnessed. The investigation determined that environmental factors in combination with pilot handling technique probably resulted in the low main rotor RPM event.

Following the accident, the helipad operator ceased all helicopter operations at Pier 35 and any on-going use of that pad by any person.

VH-MEB response to the Coroner

The ATSB notes that the Victorian Coroner, Mr J Olle, having conducted an investigation into a 2007 fatal Robinson R44 helicopter accident at Pier 35, Melbourne Victoria, has recently released a finding into the death without holding an inquest. The ATSB made submissions to assist the coronial investigation. The Coroner’s findings largely adopt the findings made by the ATSB in its report published on 8 May 2009. 

Circumstances of the accident

Following completion of a scenic charter flight, the helicopter departed the Pier 35 private helipad that was located adjacent to the Yarra River in Melbourne, Victoria, with two pilots on board.

The helicopter's forward airspeed decreased and it 'rocked or wobbled in the air' then pitched nose up, rolled to the left, descended and impacted the water. One pilot was fatally injured

ATSB findings

The investigation found that the helicopter did not gain altitude, departed controlled flight, descended and struck the water. During this event, the main rotor revolutions per minute (RPM) were at a lower-than-normal value to sustain controlled flight. The investigation could not identify any problems with the helicopter, its systems or engine, which would have led to the low main rotor RPM. The investigation determined that environmental factors in combination with pilot handling technique probably resulted in the low main rotor RPM event.

Towering take-off

One of the matters for consideration was whether a ‘towering take-off’ could be safely used over buildings surrounding the helipad, rather than going over the water. The ATSB noted that there were risks involved in conducting such a take-off, but that it was an option to clear the objects to the south of the helipad and avoid the potentially higher risks of a take-off with a tailwind over the water.

The Coroner accepted that a towering take-off was possible but noted it should only be used in circumstances where pertinent information on the use of the Pier 35 helipad were known to the pilot (see the Coroner’s recommendation below).

ATSB safety issue and the Coroner’s recommendation

The ATSB identified a safety issue that ‘there was not readily available information for pilots planning to use the helipad on the pad’s unique characteristics, including constraints on operations and, in particular, the fact that the windsock may provide erroneous wind indications in some weather conditions.’ It was considered likely that the then position of the windsock resulted in erroneous indications of the wind direction on the day of the accident.

Pier 35 is under management of a new operator who has relocated the windsock. This operator has also published a policy on the use of the helipad that is available at http://melbourneheli.com/landing_policy.html.

As a result, the inquest, the Coroner issued the following recommendation to the new operator:

1.      Place signage at Pier 35 helipad in relation to its unique characteristics. For example, the sign could warn that wind from the south-south-west may be deflected over the Pier 35 boat storage shed. This signage may assist in heightening awareness as to the possibility of turbulence or eddies existing on the opposite of the boat shed so that pilots can complete a risk analysis and adopt procedures to assist the performance of the helicopter in those conditions.

Other matters in the Coroner’s findings

The ATSB focussed on factors that contributed to the development of the accident or that increased safety risk. The Coronial investigation looked at these factors but also noted that the new operator of the helipad had made changes to improve safety at the Pier 35 helipad. Readers should refer to the Coroner’s findings to ensure they are understood in their own context.

ATSB investigations and coronial investigations

Coronial investigations are separate to ATSB investigations. In this matter the respective authorities are in accord as to the factors that contributed to the development of the accident.

The ATSB's report can be downloaded by clicking on the link: ATSB Report.

The Coroner's report can be obtained from the Coroner's Court of Victoria. Contact details are available at: http://www.coronerscourt.vic.gov.au/home/. Queries regarding the Coroner's findings should be directed to the Coroner's Court of Victoria.

On 1 December 2007, a Cessna 172 aircraft and an Avid Flyer collided in midair while conducting circuit operations at Latrobe Valley Aerodrome, Victoria. The Cessna was being flown by a student pilot who was conducting a series of solo circuits and the Avid was being flown by an experienced pilot. The Cessna collided with the Avid from above and behind after both aircraft had turned onto the final leg of the circuit. The Avid descended uncontrolled and impacted the ground. The pilot was fatally injured. Although the Cessna sustained damage from the collision, the student pilot was able to land the aircraft.

The investigation revealed that the student pilot was unaware of the Avid's presence before turning onto final, even though both aircraft had been in the circuit for some time prior to the collision. Whereas there was no evidence that the common traffic advisory frequency procedures at the aerodrome were a factor in the occurrence, a radio broadcast that was made prior to the collision possibly contributed to the student becoming unaware of the position of the Avid.

The investigation also identified a safety issue in regard to the guidance contained in the flying school's operations manual. The flying school reported that, as a result of this accident, it has amended its operations manual to include guidance on competency-based training and risk management strategies for application to solo student flight operations. In addition, the flying school has implemented an electronic, competency-based training system and provided training on its use to the school instructors and students.

On 7 December 2007, the pilot of an Air Tractor Inc. AT-802 aircraft, registered VH-LIS, was conducting a test flight at Lake Liddell, NSW. The purpose of the flight was to test an experimental in-flight water collection system using skis attached to the aircraft's main landing gear.

At about 0910 Eastern Daylight-saving Time, the pilot was conducting the second test run of the day. After the aircraft skis had been in contact with the surface of the lake for 36 seconds, witnesses observed the aircraft pitching nose down, about its right main landing gear while rotating to the right. The aircraft then overturned and sank. The aircraft was substantially damaged and the pilot was fatally injured.

The investigation concluded that the right experimental ski breached the surface of the water which caused a substantial amount of drag to act on the right side of the aircraft, as a consequence, the aircraft became uncontrollable. The circumstances of this accident highlight the need for due diligence and detailed risk assessments to be performed as part of experimental test programs.

As a result of this incident, the Civil Aviation Safety Authority (CASA) has proposed amendments to Advisory Circular 21-10 - Experimental Certificates to provide:

• updated guidance information to persons applying for the issue of experimental certificates
• advice on risk management for test pilots during experimental flight testing.

In addition, the Australian Transport Safety Bureau (ATSB) issued a safety recommendation to CASA in respect of the need to consider the safety of third parties, including on the ground or water, before issuing a Special Certificate of Airworthiness.