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Dear Colleague,
Flight safety is a non-negotiable prerequisite for all aviation operations and this will be the central theme establishing the baseline for the monthly Flight Safety Newsletter. The content will include pertinent aviation safety reports, aviation safety articles and audit results relevant to pro-active accident prevention. These will be presented in abbreviated format with active links providing more in-depth information where appropriate.
Further additions will cover an analysis of the age-old decision making processes critical to the delicate balance between cost saving and aviation safety, with real life de-identified audit results demonstrating the pitfalls of this critical balancing act; all too often within the audit regime we identify failures in the Operator - Command & Control structures that have the potential to expose the organisation and travelling public; these will be highlighted without reservation in an attempt to enhance safety.
Helideck operations will be included as an integral component of aviation operations.
It is hoped that this Newsletter will precipitate a response, creating an interactive forum that will provide a free flow of information, confidential or otherwise, identifying aviation safety issues of concern for the benefit of all participants.
Sincerely,  Colin Weir, Managing Director Flight Safety Pty Ltd |
2nd Annual Flight Safety Seminar
7th - 9th September 2009
Flight Safety are gearing up for another informative seminar in September at the beautiful Hyatt Regency Resort at Coolum in Queensland. Delegates will include all Flight Safety personnel and associates, client representatives and CASA rotary wing flying operations inspectors.
The seminar will cover all aspects of the audit process and Safety and Quality Management. However the focus this year will be on helideck inspections, as the newly launched Flight Safety Helideck Certification Pty Ltd (sister company to Flight Safety Pty Ltd) takes on additional helideck inspections in the Asia Pacific region this year.
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Agusta Westland 139 Tail Boom Incident
A Gulf Helicopters AW-139 lost its tailboom during the taxi for take-off in Doha, Qatar on the 25th August 2009.
An extract of a relevant Airworthiness Directive issued by AW is as follows:
"Some operators of AB/AW139 helicopters have reported finding debonding of fuselage tail boom panels. This condition, if not detected and corrected, could lead to the structural collapse of the tail boom installation, resulting in loss of control of the helicopter.
For the reason described above, this AD requires repetitive inspections of the tail boom assembly and, in case signs of debonding are detected, the reporting of findings to the design approval (type certificate) holder of the helicopter, and the accomplishment of corrective actions."
Read on >>
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S-92 Accident Investigation
The Transportation Safety Board of Canada has issued an Investigation Update into the Sikorsky S-92A Helicopter Accident (A09A0016) that occurred on the 12th March 2009.
So far the investigation has determined that:
- There was no loss of main
rotor drive and that the main rotor blades were rotating at the time of
the impact;
- The tail
rotor drive gears had been severely damaged, resulting in a loss of
drive, causing it to stop producing thrust;
- The metallurgical examination of the titanium oil filter attachment
studs revealed fatigue cracking in the studs as well as evidence of
thread damage;
- Just before the recorder stopped, engine power was reduced, a
descent from 800 feet was initiated, and the speed of Flight 491 began
to decrease from 133 knots.
- The helicopter continued to descend and to
slow down in a controlled manner, until about 1225:44, at which time
driving power to the tail rotor was lost. At this time, Flight 491 was
heading 290° magnetic (M) at 85 knots and was descending through
approximately 500 feet.
- At 1225:47, a shut-down of both engines was initiated, which is consistent with a tail rotor drive failure emergency.
- Subsequently, the aircraft experienced a number of large and rapid
attitude changes;
- The helicopter struck the water at approximately 1226 in a slight right-banked, nose-high
attitude,
with moderate speed and a high rate of descent.
- The wreckage was found
at a depth of 165 metres on a bearing of 283° from the surface position.
- The Sikorsky S-92A flotation system activation switch was found in
the armed position after recovery.
- The helicopter experienced
significant forces during the impact with the water, and examination of
the inflation bottles indicates that they had not released their
compressed gas to inflate the flotation collars.
The investigation into root causes of all the above continues.
The full article is available from the TSB Canada website >>
See also the investigation photos >>
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Aircraft Maintenance Incident Analysis from CAA
 The Civil Aviation Authority UK has published an
analysis of an 11 year sample of maintenance related mandatory
occurrence reports (MORs) for fixed wing jet aircraft above 5700kg
MTOW, performed for CAA by DHAC-Avia Ltd. The study comprised a
literature review, the development of a maintenance incident taxonomy
and the analysis of 3982 maintenance related MORs covering the period
January 1996 to December 2006.
The paper can be downloaded in PDF format from the CAA website >>
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Ground Resonance in Helicopter Operations
 Ground Resonance has damaged or destroyed helicopters and killed pilots, passengers, and bystanders. The US National Transportation Safety Board records 34 incidents in the United States since 1990, not including military helicopters or incidents that did not injure people or destroy the helicopter. Not all types of helicopters are susceptible to ground resonance - some two-blade helicopters are exempt because their "teetering" rotors are a single rigid structure, like a see-saw. The only rotors that can produce ground resonance are those with three or more blades. The International Association of Drilling Contractors (IADC) has recently issued a Safety Alert that aims to warn operators of the causes and preventive/corrective measures relating to Ground Resonance. It includes a case study of an incident that occurred on a helideck in which, fortunately, all present escape injury, but were shaken by the near miss. The cause of this incident was ground resonance. When the aircraft landed one of its skids rested on one of the helicopter lash down points on the helideck, resulting in the helicopter laying at a slight angle which led to the rotor oscillating. Had this been allowed to continue there was a risk of the aircraft rolling over on the deck. If ground resonance begins, the pilot's best option is to get the helicopter into the air. Once the tires or skids are no longer touching the ground, the vibration fades. If the rotors do not have sufficient speed for flight the next best remedy is to eliminate lift by reducing blade pitch; shut down the engine; and hope for the best while waiting for the rotor to slow. The IADC website contains an excellent archive of issued Safety Alerts gong back to 1998, including the one on Ground Resonance, at IADC Safety Alerts >>
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North Sea Super-Puma Accident April 2009 Investigation Update
Bulletin Special S5/2009
This Special Bulletin from the AAIB (Air Accidents Investigations Branch - UK) details the progress made towards identifying the initiating factor(s) and failure sequence of the epicyclic gearbox module, and follows the publication of two initial reports which contained four Safety Recommendations. This Special Bulletin contains two further Safety Recommendations.
The main recommendation arising from the investigation to date is as follows:
"It is recommended that the European Aviation Safety Agency, in conjunction with Eurocopter, urgently review the design, operational life and inspection processes of the planet gears used in the epicyclic module of the Main Rotor Gearbox installed in AS332L2 and EC225LP helicopters, with the intention of minimising the potential of any cracks progressing to failure during the service life of the gears."
The detailed 14 page report (PDF) can be downloaded from the AAIB website >>
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Recent changes to General Aviation Aerodrome Procedures (GAAP)
CASA
On the 21st of July 2009 CASA issued instrument 329/09 and 330/09 with regard to changes in procedures at the following GAAP aerodromes.
- Archerfield
- Bankstown
- Camden
- Jandakot
- Moorabbin
- Parafield
The changes in procedure follow a detailed review of existing GAAP procedures.
A full summary of the review and the changes in procedure can be viewed on the CASA website >>
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