A helicopter pilot’s prompt response to a rattling noise in a Robinson R22 helicopter avoided a potentially serious accident.

A helicopter pilot’s prompt response to a rattling noise in a Robinson R22 helicopter avoided a potentially serious accident.

On 12 October 2011, the pilot was performing aerial work near Saxby Downs, Queensland when he heard the rattling noise. He opened the clutch actuator circuit breaker and, at the same time, noticed a burning rubber smell. He immediately made a precautionary landing and shut down the helicopter.

The ATSB’s investigation into this incident, traced the problem to the clutch assembly where a group of locking nuts had cracked and fractured. This cracking had stemmed from the likely embrittling effect of residual hydrogen generated during the cadmium electroplating process applied during manufacture. The nut failures led to a series of mating part failures and a breakdown of the clutch assembly, producing the symptoms experienced by the pilot, which led to the landing.

The prompt actions of the pilot who followed emergency procedure requirements by landing immediately avoided a potentially serious accident.

At the time of this occurrence the brittle failure of MS21042L-series nuts was an emerging airworthiness issue and several safety actions had already been implemented. Two months before this occurrence, the helicopter manufacturer issued service letters alerting owners and maintenance personnel to the potential for cracking and requiring the replacement of any cracked nuts on inspection.

On the same day as this occurrence, the Civil Aviation Safety Authority (CASA) issued an Airworthiness Bulletin alerting pilots and maintenance personnel of the need to closely monitor the condition of high-strength steel hardware (such as these nuts) with a view to identifying any failures that may have resulted from hydrogen-induced cracking.     

In April 2012, the manufacturer of the nuts issued a Technical Quality Notice Bulletin addressing, in detail, many procedural improvements that were being introduced to reduce the potential for hydrogen-related failure of this nut type.

The prompt actions of the pilot who followed emergency procedure requirements by landing immediately avoided a potentially serious accident. This occurrence highlights the importance of being vigilant when conducting pre-flight and maintenance inspections. It also reveals the importance of pilots and maintenance personnel remaining attentive to the release of new information about new or emerging airworthiness issues that may affect their operations.

Read the final report: Embrittled nut and related failures Robinson R22 Beta, VH-JNP, 22 km north of Saxby Downs, Queensland, on 12 October 2011

A collision between two aircraft has shown the dangers that exist at Australia’s many non-controlled aerodromes.

A collision between two aircraft has shown the dangers that exist at Australia’s many non-controlled aerodromes.

On 10 November 2013, a flight instructor and a student pilot were flying circuits in a Cessna 152 at Tyabb aerodrome, Victoria. Deciding to conduct a practice glide approach and a touch-and-go landing, the pilot commenced the approach from closer to the runway than for a normal circuit. As they commenced a continuous turn towards runway 17, he broadcast his intentions.

 At the same time, the pilot of a Jabiru J160 with one passenger on board was at the holding point, preparing to take off from the same runway. He heard the Cessna’s broadcast, but when he looked for it in the normal circuit position, he could not see it. He assumed that it was sufficiently distant that he would have time to leave the holding area and take off. He broadcast that he was lining up and rolling on runway 17, and then he commenced the take-off run.

This accident has demonstrated the need for pilots to maintain good communication and a good lookout, especially when operating at non-controlled aerodromes, and doubly so when conducting non-standard or modified circuits.

In fact, the Cessna was much closer than he thought, coming in behind him on a high, close final approach. The pilot of the Cessna had seen the Jabiru waiting at the holding point, and broadcast that he was coming into the runway. He assumed that the Jabiru would continue to hold until the Cessna had landed.

Neither pilot, however, heard the other’s broadcast and they may have transmitted their calls simultaneously.

The student pilot of the Cessna continued the glide approach, aiming to touch down about halfway along the runway. The Jabiru, however, had commenced take-off and, as his aircraft became airborne, the pilot saw the underside of the Cessna appear from above and fill the windscreen. The Cessna appeared to be overtaking the Jabiru very slowly and still descending.

The two aircraft collided, with the elevator trim tab of the Cessna contacting the fin of the Jabiru. The pilot of the Jabiru would later recall that the wheels of the Cessna appeared to be either side of his cockpit, with the front wheel just clear of the Jabiru’s propeller blades.

The pilot of the Jabiru forced the aircraft onto the ground and it skidded along the runway.

The pilot of the Cessna heard a loud bang behind him, but did not see the Jabiru. He took control of the aircraft from the student and commenced a go-around.

The Jabiru was substantially damaged, and the Cessna sustained damage to the right elevator and trim tab. No one was injured.

This accident has demonstrated the need for pilots to maintain good communication and a good lookout, especially when operating at non-controlled aerodromes, and doubly so when conducting non-standard or modified circuits.

The issue of safety around non-controlled aerodromes is one of the ATSB’s top safety concerns. ATSB research has found that, between 2003 and 2008, there were 709 airspace-related events at, or in the vicinity of non-towered aerodromes. This included 60 serious incidents and six accidents (mid-air and ground collisions). Most of the 60 serious incidents were near mid-air collisions.

The ATSB’s SafetyWatch initiative and report on safety in the vicinity of non-towered aerodromes, provides useful advice and strategies for pilots.  

Read the final report: Mid-air collision involving a Cessna 152, VH-TNV and a Jabiru J160, 19-4430, Tyabb Airport, Victoria, on 10 November 2013

The ATSB found that a proper lookout was not being kept on either vessel in the time leading up to the collision.

The collision between the bulk carrier Furness Melbourne and the yacht Riga II on 26 May 2012 near Bowen, Queensland emphasises the need for those navigating vessels of all types and sizes to keep a proper lookout and take early and appropriate action to avoid a collision.

Riga II was dismasted and its hull was damaged, but no one was seriously injured. The yacht was towed to Bowen by a volunteer marine rescue vessel. Furness Melbourne was not damaged and after rendering assistance, continued its voyage.

The ATSB found that a proper lookout was not being kept on either vessel in the time leading up to the collision. Furness Melbourne’s lookout had sighted Riga II’s starboard sidelight prior to the collision, however, the officer of the watch made a series of assumptions based on limited information and concluded that the light was from a distant navigation buoy rather than a vessel that represented a risk of collision.

The ATSB found that a proper lookout was not being kept on either vessel in the time leading up to the collision.

Riga II’s watchkeeper did not visually identify Furness Melbourne’s navigation lights in time to make an effective appraisal of the situation, did not set the yacht’s automatic identification system (AIS) unit on a range scale that would provide adequate warning of approaching vessels, and when alerted of the approaching ship, misinterpreted the information.  

The ATSB has investigated 39 of the reported 60 collisions that have involved ships and small vessels over the past 25 years. The findings of these investigations invariably include the failure of watchkeepers to keep a proper lookout.

Read the final report: Collision between the bulk carrier Furness Melbourne and the private yacht Riga II, north of Bowen, Queensland, on 26 May 2012

The ATSB has just released a new aviation bulletin containing 10 investigation reports. The Aviation Short Investigation Bulletin Issue 25 covers short, office-based investigations.

The ATSB has just released a new aviation bulletin containing 10 investigation reports. The Aviation Short Investigation Bulletin Issue 25 covers short, office-based investigations.

The bulletin covers incidents, serious incidents and accidents involving turboprop aircraft, piston aircraft and helicopters. In some of the occurrences, people suffered minor injuries while some of the aircraft were substantially damaged.

Short investigations cover incidents and accidents where the associated factors are usually well-understood and do not require more detailed investigations. Nonetheless, each investigation has the potential to produce important Safety Messages for pilots, operators and others in the aviation industry. The investigations also help the ATSB identify statistics and trends in air safety.

The incidents covered in the report include:

• Runway event involving a Beech 1900C, VH-­VNV
• Runway incursion between a Fairchild SA227, VH-­UZP and a Bell 47G, VH-­UTF
• Pilot incapacitation event involving a Cessna 210, VH-JMG
• Aircraft proximity event between a Cessna 172, VH-­NUU and a Beech F33A, VH­-ZBZ
• Wheels-up landing involving a Beech 95­B55, VH­-TLP
• Runway undershoot involving a Cessna 404, VH­-HAZ
• Loss of control involving a Cessna 172, VH-IGS
• Mid-air collision involving a Cessna 152, VH-­TNV and a Jabiru J160, 19­4430
• /publications/investigation_reports/2013/aair/ao-2013-203
• Total power loss involving a Robinson R22, VH-­STK

Read the ATSB’s Aviation Short Investigation Bulletin – Issue 25

A warning to pilots on the dangers of flying visually at night following a number of fatal accidents that occurred in dark-night conditions.

The ATSB today released a report warning pilots on the dangers of flying visually at night following a number of fatal accidents that occurred in dark-night conditions.

The report comes shortly after the release of the ATSB’s investigation into the fatal helicopter crash at Lake Eyre where the pilot likely became spatially disoriented during a visual flight at night.

ATSB Chief Commissioner, Mr Martin Dolan, said accidents involving visual flight at night are becoming an increasing safety concern in Australian aviation.

Even when undertaken by appropriately qualified pilots, night flight clearly presents an added level of complexity.

“Over the past 20 years, the ATSB has investigated 36 accidents as a result of visual flight at night. Of these accidents, 27 had fatal outcomes which tragically led to 58 fatalities,” Mr Dolan said.

“Even when undertaken by appropriately qualified pilots, night flight clearly presents an added level of complexity.

“But accidents of this nature are avoidable and can be managed by pilots maintaining their proficiency, knowing their own personal limitations and only flying in environments that do not exceed their capabilities.”

The report, which features case studies on several night-flight accidents, helps pilots better understand and manage the dangers of flying at night.

Visual flight at night accidents: What you can’t see can still hurt you

This accident highlights the importance of following procedures and diligently completing checklists.

On 22 January 2013 the pilot of a Cessna U206F amphibious aircraft was conducting a joy flight over Corio Bay in Victoria with two passengers on board. During the flight the pilot landed to refuel at Barwon Heads Airport, requiring the use of the landing wheels.  When departing from Barwon Heads the pilot became distracted and did not retract the landing wheels during the after take-off checks.

On the return trip the pilot diverted for sightseeing before heading back to Corio Bay for a water landing. Under perceived time pressure, the pilot did not complete the normal downwind and short final checks, and failed to notice that the wheels were still extended. On touchdown the aircraft pitched over and came to rest upside down. The pilot assisted the passengers to safely evacuate the aircraft before rescue vessels arrived. No one was injured in the accident.

This accident highlights the importance of following procedures and diligently completing checklists.

This accident is a reminder that human error can occur at any time and highlights the importance of managing operational pressures and avoiding distractions. It also highlights the importance of following procedures and diligently completing checklists. Effective application of threat and error and distraction management principles can reduce risk. The ATSB noted that the operator’s requirement for the passengers to wear life jackets throughout the flight enhanced the survivability of the passengers.

Read the final report: Wheels-down water landing involving Cessna U206F floatplane, VH-UBI, Corio Bay, Victoria, on 22 January 2013

The risks associated with the handling of an approach to land have been highlighted by the ATSB after a Dash 8’s approach set off its warning system.

The risks associated with the handling of an approach to land have been highlighted by the ATSB after a Dash 8’s approach set off its warning system.

The incident occurred on 17 May 2012, when the flight crew of the Dash 8 was conducting a circling approach to Laverton Aerodrome in Western Australia. It departed from Perth as a passenger charter flight, with a flight crew composed of a captain and a first officer. As the crew commenced descent into Laverton, they observed that the weather in the area was mostly clear but there were bands of fog and low stratus cloud in the general vicinity of the aerodrome.

Because of the low cloud, the crew positioned the aircraft to maintain their visual reference with the runway threshold and conducted a circling approach. The resulting final approach, however, required such a high rate of descent that it triggered the aircraft’s Enhanced Ground Proximity Warning System (EGPWS). The crew heard some alerts from the EGPWS and knew they had a high rate of descent, but they did not identify an unstable approach.

...the flight crew did not have an adequate understanding of the aircraft’s EGPWS or the operator’s standard operating procedures in regard to mandatory go-arounds.

The stability of an aircraft’s final approach is an extremely important safety element. As they draw nearer to the runway, pilots need to ensure that their approach fulfils various requirements to achieve a stabilised approach. That includes being on the correct flight path to the runway touchdown point at the correct speed and with the aircraft in the landing configuration. The power setting needs to be appropriate for the aircraft configuration and the rate of descent less than 1,000 ft/min.

“If any of these requirements are not met,” says Dr Stuart Godley, head of the ATSB’s research section, “it constitutes an ‘unstable approach.’ Pilots in that situation should undertake a go-around, and try the approach again. The consequences of not doing so can be severe.” The Flight Safety Foundation cites a lack of go-arounds from unstable approaches as the number one risk factor in approach and landing accidents and the primary cause of runway excursions.

Despite the activation of the EGPWS, the flight crew of the Dash 8 continued their approach and landed safely.

The ATSB investigation found that at the time of the occurrence, the flight crew did not have an adequate understanding of the aircraft’s EGPWS or the operator’s standard operating procedures in regard to mandatory go-arounds.

In response to this occurrence, the operator refined their stabilised approach criteria and formulated a method of incorporating realistic EGPWS warning events in the Dash 8 simulator training program. This incident highlights the importance of crews adhering to standard operating procedures and correctly responding to cockpit warnings.

The issue of handling approaches to land is one of the ATSB’s safety priorities, and it forms part of the SafetyWatch web initiative.

Read the final report: Unstable approach involving de Havilland Canada Dash 8, VH-XFZ, Laverton Aerodrome, Western Australia, on 17 May 2012

The Aviation Short Investigation Bulletin Issue 24 contains 15 investigation reports.

The Aviation Short Investigation Bulletin covers a range of the ATSB’s short investigations and highlights valuable safety lessons for pilots, operators and safety managers.

Released periodically, the Bulletin provides a summary of the less-complex factual investigation reports conducted by the ATSB. The results, based on information supplied by organisations or individuals involved in the occurrence, detail the facts behind the event, as well as any safety actions undertaken. The Bulletin also highlights important Safety Messages for the broader aviation community, drawing on earlier ATSB investigations and research.

Issue 24 of the Bulletin features 15 safety investigations:

Jet aircraft

• Runway event involving a Fokker F28, VH-JFB
• Ground proximity event between a Boeing 737, VH-VZA and a security vehicle

Turboprop aircraft

• Wheels up landing involving a Cessna 441, VH-SMO
• Airspace related event involving a Saab 340B, VH-ZLJ and parachutists
• Wirestrike involving an Air Tractor AT 502, VH-CJY

Piston aircraft

• Landing on a closed runway involving a Cessna 404, VH-HVR
• Fuel starvation event involving a Beech BE58, VH-ECL
• Loss of control involving a Piper PA 28R-200, VH-MMU
• Engine fire involving a Beech A36, VH-FFY
• Runway incursion involving a De Havilland DH 82, VH-BJE and a Piper PA 34, VH-SEN
• Runway incursion between a Cessna 206, VH -LHX and a Cessna 210, VH-HGZ
• Total power loss involving a Piper PA 28 140, VH-RVJ

Helicopters

• Partial power loss involving a Bell 47G, VH-RTO
• Aircraft proximity event between a Cessna 172, VH-RQZ and an Agusta AW139, VH-ESZ
• Aircraft configuration event involving a Robinson R22, VH-ONT

Read the ATSB’s Aviation Short Investigation Bulletin – Issue 24

The fatal accident involving a Piper PA-28-180 Cherokee highlights the risks of flying at night under the visual flight rules (VFR).

The fatal accident involving a Piper PA-28-180 Cherokee highlights the risks of flying at night under the visual flight rules (VFR).

On 15 August 2011, the pilot was conducting a private flight transporting two passengers from Essendon to Nhill in Victoria under the VFR. The flight was arranged by the Angel Flight charity to return the passengers to their home after medical treatment in Melbourne.

Global Positioning System data recovered from the aircraft indicated that when about 52 km from Nhill, the aircraft conducted a series of manoeuvres followed by a descending right turn. The aircraft subsequently impacted the ground at 1820 Eastern Standard Time, fatally injuring the pilot and one of the passengers. The second passenger later died in hospital as a result of complications from the injuries sustained in the accident.

A VFR flight in dark night conditions should only be conducted by pilots with high instrument flying proficiency as there is a significant risk of losing control if attempting to fly visually in such conditions.

The ATSB found that the pilot had landed at Bendigo and accessed a weather forecast before continuing towards Nhill. After recommencing the flight, the pilot probably encountered reduced visibility conditions approaching Nhill due to low cloud, rain and diminishing daylight. That likely led to disorientation, loss of control and impact with terrain. One of the passengers was probably not wearing a seatbelt at the time.

The ATSB also established that flights are permitted under the visual flight rules at night in conditions where there are no external visual cues for pilots. In addition, pilots conducting such operations are not required to maintain or periodically demonstrate their ability to maintain aircraft control with reference solely to flight instruments.

As a result of previous ATSB investigations the Civil Aviation Safety Authority (CASA) has drafted new legislation, effective 4 December 2013, requiring a biennial review for night VFR‑rated pilots. CASA has also indicated that it will clarify what is meant by the term ‘visibility’ in dark night conditions, provide enhanced guidance on night VFR planning and other aspects of night VFR operations.

This tragic accident serves as a reminder for operators and pilots considering night VFR flights to assess the likelihood of dark night conditions by reviewing weather conditions, celestial illumination and available terrain lighting. A VFR flight in dark night conditions should only be conducted by pilots with high instrument flying proficiency as there is a significant risk of losing control if attempting to fly visually in such conditions.

The ATSB will soon release an educational booklet in its Avoidable Accidents series related to visual flight at night. The booklet will highlight risks associated with night VFR flight and discuss strategies for their management.

Read the final report: VFR flight into dark night conditions and loss of control involving Piper PA-28-180, VH-POJ, 31 km north of Horsham Airport, Victoria, on 15 August 2011

On 23 July 2013, a Bell 47G2A helicopter flying on a local photography flight from Lake Manchester, Qld sustained a total power loss.

On 23 July 2013, a Bell 47G2A helicopter flying on a local photography flight from Lake Manchester, Queensland sustained a total power loss. The pilot conducted an auto-rotation which resulted in a heavy landing, causing substantial damage to the helicopter.

The pilot had taken off from Lake Manchester with the carburettor heat on, as was required for the climb. The pilot also adjusted the carburettor heat as required according to the gauge. At the time of the accident the temperature was 13.5 ˚C and the dew point was 9.1 ˚C. According to the carburettor icing probability chart, these conditions were conducive to carburettor icing.   

When the insurance assessor arrived following the accident, the helicopter was started and performed without fault. No fuel contamination was found and the helicopter was found to have been well maintained and in excellent condition. The insurance assessor considered that the weather conditions may have caused icing of the carburettor. The pilot reported that he would have expected the engine to run roughly if icing was present.

All pilots of aircraft fitted with a carburettor are advised to check weather forecast conditions and know the risk of carburettor icing before each flight. The

is available from the CASA website. The report contains details of other helpful publications on carburettor icing.

Read the final report: Total power loss involving a Bell 47G2A, VH-KHJ, 11 km east of Amberley Airport, Queensland, on 23 July 2013