The aircraft departed Griffith for a chemical spraying operation in the Hillston area. A considerable amount of fog and low cloud was encountered enroute, however, the pilot said he had been assured by the farmer at Hillston that the area was clear.

Nearing Hillston the pilot was unable to find a break in the cloud cover, so he elected to track to the east to find an opening but was unsuccessful. Shortly after commencing a return to Griffith the pilot said, he found a large cloud break. He notified his base of his intentions and descended below the cloud base. After passing over a low range of hills he descended to about 300 feet above ground level to continue to remain clear of cloud, but shortly after he was unable to prevent the aircraft from entering lower cloud.

The pilot commenced a slow turn, still able to see the ground immediately below the aircraft. However, he was unable to outclimb rising terrain, despite attempting to dump the chemical load. The aircraft consequently struck the ground and was destroyed, however, the pilot was able to vacate the aircraft without injury.

The pilot reported that when on short final for runway 14, a golf ball passed from left to right, in front of, and higher than the nose of the aircraft.

SAFETY ACTION

The Federal Airports Corporation (FAC) was informed, and the Airport General Manager discussed the occurrence with the local Council. A public park located beneath the approach path to runway 14 was frequently used for golf practice. The Council reacted promptly by prohibiting golf practice in the park and signs were placed to warn the public. FAC Duty Safety Officers were requested to increase patrols of the area to warn off anyone seen playing golf in the area. Subsequently, a golf practice area was established in an area nearby which is clear of the approach path to the runway and meets Civil Aviation Safety Authority regulatory requirements.

VH-ANJ was tracking from over Canberra to Sydney at flight level 150. VH-WGW was tracking outbound from Sydney via Pager, Shelleys and over Canberra, climbing to flight level 140. VH-ANJ was turned right onto a heading of 050, for positioning on a 15-mile final approach for runway 34 at Sydney and cleared to descend to flight level 130. This heading change put the two aircraft on opposing tracks.

To maintain separation, VH-WGW was turned to the right 20 degrees. At that time the two aircraft were nose to nose and 15 miles apart with a closing speed of 450 knots. VH-ANJ was then turned a further 10 degrees to the right, however separation reduced to 3.5 miles laterally and 700 feet vertically as the two aircraft passed.

The minimum separation required was five miles horizontal or 1000 feet vertical.

Significant Factors

The following factors were considered relevant to the development of the incident: 

1. The controller did not take the appropriate action to ensure adequate separation was maintained.

The helicopter was being landed at the completion of a training exercise. The weather was reported as being fine and clear, with little or no wind. During the landing, shortly after making a normal touchdown, the helicopter commenced to shake violently. The transition from normal operation was very rapid and did not allow the instructor time to take any remedial action before control of the helicopter was lost.

The most probable reason for the loss of the aircraft resulted from the rapid onset of ground resonance. This problem is associated with fully articulated rotor systems and is the result of geometric imbalance of the main rotor system. This imbalance of the rotor causes an oscillation which is transmitted throughout the entire helicopter, giving movement from side to side, as well as fore and aft. This action can become violent enough to cause the helicopter to roll over or incur major structural damage. Although not determined in this investigation, the onset of ground resonance can be aggravated by a number of factors, including incorrect landing gear strut inflation pressures, and incorrectly adjusted friction type blade dampers.

The pilot stated that he departed Lismore at approximately 1030 hours for a flight to Evans Head. He carried out two touch and go landings at Evans Head before departing for the return flight to Lismore. At about 1115 when the aircraft was cruising at 1500 feet, the engine lost power and began surging. The pilot said he selected full rich mixture, applied full carburettor heat and gave two strokes on the fuel wobble pump at which time complete engine failure occurred. During this time the aircraft had descended to 1000 feet and the pilot selected a paddock and began an approach at 70 knots.

After flaring slightly to clear 20 metre high trees at the paddock boundary a soft touchdown was made at about 50 knots. The pilot said he had deviated slightly from his chosen path between scattered trees as forward visibility in the aircraft when on the ground is almost nil. Approximately 40 metres after touchdown the right upper wing clipped a tree spinning the aircraft clockwise. The right lower wing and aileron contacted the ground during the rotation. After vacating the aircraft, the pilot noticed flames in the rear of the engine and under the fuselage. The flames were extinguished with water from a nearby cattle trough.

Examination of the engine revealed that the gascolator bowl retaining clip had partially separated allowing the glass sleeve to become dislodged, and this had caused fuel starvation.

The student had returned from the training area, after a solo consolidation exercise, and entered the circuit for runway 24R. He made a normal approach but allowed all three wheels to touchdown together causing the aircraft to bounce back into the air. The pilot applied some power, in an attempt to rectify the situation, and landed the aircraft a second time. The landing was heavy, resulting in structural damage to the nosewheel and causing the propeller to strike the runway. The aircraft finally came to rest with the nosewheel completely separated from the nose undercarriage strut.

It is probable the student's inexperience was the major factor in his misjudgement of the initial approach and in the failure of his recovery action to prevent the heavy landing.

During climb the Boeing B737 crew noticed an un-commanded stabiliser movement. The stabiliser would continue to run on after a command had ceased. The aircraft returned to Melbourne where a normal landing was carried out.

Maintenance investigation determined that the fault was in the stabiliser clutch. The clutch was found to be sticking confirming the crew's observations.

Clutch sticking had previously been recognised by the manufacturer as a problem in B737-400 and 500 aircraft. The manufacturer devised a modification to prevent clutch sticking and an instruction to modify all actuators was notified to the industry via Alert Service Bulletin 737-27A1191 Rev 1 dated 3 November 1994.

On 10 February 1995, the operator acted on the manufacturer's advice, raising an internal engineering instruction EI-737-27-26 to expedite incorporation of the modification into its fleet. The actuator fitted to the incident aircraft was not one of those that had been modified.

The Civil Aviation Authority (now CASA) raised Airworthiness Directive AD/B737/88 on 12 June 1995. The AD was published in CAO Part 105 Amendment 8/95 (August 1995). The AD referenced the manufacturers Alert Service Bulletin and required that all affected actuators fitted to Australian registered aircraft be modified prior to 12 June 1996.

The operator has since amended the EI to conform with the requirements of the AD.

Significant factors

The following factors were considered relevant to the development of the incident:

1. The stabiliser actuator clutch contained a known fault that allowed the clutch to remain engaged.

2. The clutch had not been modified to eradicate the fault.

3. The clutch stayed engaged after a command was removed.

Safety actions

The following safety actions were taken:

1. The manufacturer raised an Alert Service Bulletin to notify the need to modify the actuators.

2. The operator raised an Engineering Instruction to expedite the incorporation of the modification into its fleet.

3. CASA raised an AD to require all Australian registered B737-400 and 500 aircraft to be modified before 26 June 1996.

FACTUAL INFORMATION

At approximately 1300 CST, 7 June 1995, a military aircraft suffered a landing gear failure during the landing roll on runway 11 at Darwin. The aircraft ground looped through 180 degrees, coming to rest on the northern (left) side of the runway between taxiways B2 and E2, with about 0.4 m of its left wingtip overhanging the runway.

Not long after that occurrence, the crew of VH-TJV, which was on descent to Darwin, was advised by Air Traffic Control (ATC) of the accident. They were given the location of the disabled aircraft and informed that runway 11/29 would be closed for an estimated period of 1-2 hours. The crew considered using runway 36 but calculations showed that it would be unacceptable. After calculating the aircraft's endurance, the crew decided to divert to Tindal. Both pilots subsequently reported that at the time of the diversion they believed that the accident aircraft was at about the midway point of runway 11/29.

When the aircraft arrived at Tindal the surface movement controller passed a message to the crew from RAAF Darwin, advising that runway 11 now had an available length of 5,500 ft, but with a landing over a displaced threshold and the accident aircraft. Runway 29 was also available with a 15kt downwind component.

RAAF Darwin ATC had advised RAAF Tindal ATC that runway 11 had a landing distance available (LDA) of 1,936 m and a take-off run available (TORA) of 2,036 m. This message was to be passed to the crew of VH-TJV after its arrival at Tindal. The RAAF flight planning officer, who received the message, wrote the LDA and TORA down on a piece of notepad paper and personally delivered it to the aircraft, handing it to the pilot in command. He believed he had advised the pilot in command of the displaced threshold and that the landing would be over the disabled aircraft. The pilot in command remembered being given the handwritten message but stated that he had not been given any information other than the LDA and TORA.

After arranging for the aircraft refuelling and passenger requirements, the pilot in command contacted the company's Operations Department by telephone to report arrival at Tindal, and to arrange for another flight plan to be issued for the Tindal - Darwin sector. A short time later he called Operations again and was transferred to a dispatcher who arranged the flight plan issue. The pilot in command advised that he did not require another copy of the weather as the information he had was still valid. The dispatcher assumed that since the pilot in command was in the area, and aware of the problem in Darwin, there was no need to send the NOTAM concerning the displaced threshold as this would mean transmitting all the Darwin NOTAM pages, therefore only the flight plan was sent.

VH-TJV departed Tindal for Darwin at approximately 1550 CST.

During approach to Darwin the co-pilot obtained the following landing information from the Automatic Terminal

Information Service (ATIS): "Information Juliet, runway 11, displaced threshold, 36, wind 060/10-15, QNH 1009, 29.80, temperature 32, CAVOK, runway 11 LDA 1,936 m, TORA 2,036 m, pedestrians and vehicles operating in the undershoot". The co-pilot annotated the relevant information onto the landing data card, then showed it to the pilot in command who had also been monitoring the ATIS while communicating with ATC. The pilot in command acknowledged but did not confirm the information as required by company policy. Neither pilot could recall noticing the information concerning the displaced threshold.

When the aircraft was on final for runway 11, ATC again advised of the displaced threshold and instructed the crew to report sighting the displaced threshold markers. Then, after a pause of several seconds, the controller advised that the visual approach slope indicator system (VASI) was turned off. The crew subsequently reported that they did not hear the reference to the requirement to sight the markers although they did note that the VASI was not available. ATC did not prompt the crew when they had not reported sighting the displaced threshold markers.

As a precautionary measure when aircraft were landing, all vehicles and personnel were removed from the undershoot area. Only personnel working on the disabled aircraft remained in position.

Although the weather was fine and clear, the crew reported that from the air there was a certain amount of haze and sun glare which made objects on the ground appear to blend into their surroundings  They advised that during the approach they were concentrating on maintaining the correct speed and profile to arrive as close as possible to the threshold in order to utilise all of the available runway length, and did not see the white runway unserviceable crosses located in the undershoot area.

The controllers reported that when they noticed the aircraft on short final, about 150-200 ft above ground level (AGL), it appeared about to land in the undershoot area. The controllers believed that RAAF policy precluded turbo-jet aircraft from going around below 200 ft AGL due to slow engine response time, and therefore considered it safer to allow the aircraft to continue. The crew's first awareness of landing in the undershoot area was when the aircraft passed over one of the white crosses.

The information supplied to the crew by ATC prior to their diversion to Tindal concerning the location of the disabled aircraft, and the available runway length situation, appeared to have allowed both pilots to develop a mindset that the western end of runway 11, that is the normal threshold, was the serviceable area.

The airport operator, who had arranged the displaced threshold, advised that all markings were in accordance with the Rules and Practices for Aerodromes (RPA) standards. The temporarily displaced threshold was marked with Vee-Bars, and the white crosses in the undershoot area were twice the standard size, i.e. 12 m x 0.9 m. RPAs also require runway threshold identification lights (RTIL) to be in place, marking a displaced threshold at aerodromes serving international regular public transport jet aircraft, e.g. Darwin. These lights were not available.

Prior to the occurrence the pilot in command had been rostered for two days on reserve duty, preceded by one day off, and the co-pilot had been off duty for three days. They had completed a 10-hour tour of duty, having flown four sectors including the diversion.

Since 1981 there have been 25 reported occurrences of pilots failing to see runway displaced threshold or unserviceable markings, six occurring since 1990. Anecdotal evidence suggests that this figure may be much higher. In many cases poor contrast of the markings with the surrounding surface may have been the problem.

SIGNIFICANT FACTORS

1. Information flow available for the crew at the Tindal diversion point was inadequate.
2. Information provided to the crew by RAAF Tindal was inadequate.
3. The company flight dispatcher failed to provide a hard copy of the NOTAM to the crew.
4. The Darwin ATIS was misleading; however, enough information was available for the crew to seek clarification.
5. The co-pilot did not take note of the ATIS comments about the displaced threshold, and the pilot in command, contrary to company policy, did not confirm the ATIS information.
6. The crew developed a mindset regarding the serviceable runway and the disabled aircraft location, and did not clarify information available to them.
7. ATC did not verify that the crew understood the instruction to sight the displaced threshold markers.
8. ATC did not issue go-around instructions.
9. Light conditions may have made the runway displaced threshold markings difficult to see.

SAFETY ACTION

The Bureau of Air Safety Investigation issued interim recommendation IR950176 to the Civil Aviation Safety Authority.

"The Bureau of Air Safety Investigation recommends that the Civil Aviation Safety Authority:

"(i) review "runway displaced threshold" and "runway unserviceable" markings to improve the visibility to pilots under all conditions. This review should consider the use of different colours, shapes and backgrounds to increase the contrast and distinguishability of such runway markings; and

"(ii) ensure that airport owners and operators have the correct portable runway lighting available for identifying unserviceable areas of the runway where required."

The following response was received from the Civil Aviation Safety Authority on 17 October 1995:

"I refer to Interim Recommendation IR950176 concerning the displaced threshold incident involving a Boeing 737, VH-TJV, at Darwin on 7 June 1995.

"Summary

"(i) The Authority has no plans to review the standards for runway displaced threshold and runway unserviceable.

"(ii) Work is currently being undertaken on the production of a Civil Aviation Order on Aerodrome Lighting. "Background to Response

"Displaced Threshold and Unserviceability markings depicted in Rules and Practices for Aerodromes, Chapters 11 and 20, are consistent with ICAO standards and recommended practices. The Authority has no plans to review these standards.

"Work is currently being undertaken on the production of a CAO on Aerodrome Lighting which will include the standards for displaced threshold lighting and temporary runway end lighting. It is considered that, in the interim, the requirements of the lighting section of the Rules and Practices for Aerodromes is an adequate and acceptable standard. It is not anticipated that these requirements will be changed significantly with the making of the CAO."

Response status: CLOSED NOT ACCEPTED.

The pilot of VH-LHF was on an instrument flight rules (IFR) flight in instrument meteorological conditions and was conducting an NDB/DME instrument approach procedure for the descent and approach into Moorabbin. When the aircraft was about eight kilometres from the airfield and on the inbound leg of the approach, the Melbourne Radar Advisory Service (RAS) controller observed a radar return from an opposite direction aircraft about four kilometres ahead.

Both aircraft were in uncontrolled airspace. VH-LHF was descending through 1,200 ft and the altitude readout for the other aircraft indicated it was at 1,000 ft. The RAS controller passed traffic information on the unidentified aircraft to the pilot of VH-LHF, who altered heading to turn away from the other aircraft.

The other aircraft was operating under visual flight rules (VFR) procedures and was tracking outbound from Moorabbin, just below the cloud base. There is no instruction to require VFR aircraft to remain clear of the instrument approach track for the Moorabbin NDB approach.  However, written instructions for departures (both VFR and IFR) into uncontrolled airspace include a statement to track clear of VFR approach points.  IFR approach procedures allow appropriately qualified pilots to safely descend in non-visual conditions, and, on occasions, such approaches are used in visual conditions.

Since January 1992 there have been six reported occurrences of VFR aircraft conflicting with regular public transport aircraft making IFR approaches. The problem of possible confliction between IFR aircraft on instrument approaches and VFR aircraft exists at many locations where instrument approach procedures are used outside controlled airspace.

The situation is compounded by the fact that most VFR pilots are not familiar with instrument approach procedures, do not have access to instrument approach charts and are, therefore, usually unaware of the location of instrument approach flight paths.

The existing publications for VFR pilots do not provide information on the locations, directions and altitudes of instrument approach tracks. Overseas, VFR charts show the tracks of IFR approaches. The inbound final instrument approach tracks to Australian aerodromes could be included in a publication to which all VFR pilots have access.

SIGNIFICANT FACTORS

1. There was no information provided to VFR pilots as to the position of instrument approach tracks.
2. There was no statement to require VFR pilots to remain clear of instrument approach flight paths.

SAFETY ACTION

As a result of the investigation, the following interim recommendation was issued to the Civil Aviation Safety Authority (CASA) and Air Services Australia:

IR950206

The Bureau of Air Safety Investigation recommends that the Civil Aviation Safety Authority:

1. publish details of final inbound instrument approach paths at aerodromes in a format to assist VFR pilots in avoiding these areas; and,
2. highlight to VFR pilots the need for caution and vigilance when operating in the vicinity of the final instrument approach legs at aerodromes containing a published instrument approach.

The following response was received from the Civil Aviation Safety Authority on 11 September 1996:

"I refer to your interim recommendation IR950206 concerning the incident involving PA31-350, VH-LHF, and PA34-200, VH-PCP at Moorabbin on 3 June 1995. The following comments are forwarded for your consideration.

To be practically utilised in flight by VFR pilots, details of the final track of instrument approaches need to be depicted on a navigational chart. Current navigation charts are either not able to accommodate the inclusion of this information or, in the case of VTC, there is insufficient coverage. However, as part of the Airservices/Defence joint charting program, work is progressing in evaluating the production of a 1:500,000 visual navigation chart (VNC) which could be a suitable chart for provision of the information."

The following response was received from Air Services Australia on 29 August 1996:

"With regard to the publication of instrument approaches on charts to assist VFR pilots, as discussed in IR950206, I understand that CASA is in the process of reviewing this recommendation. In addition, publication of instrument approaches on charts is currently under discussion in the Airspace 2000 proposals on pages 36 and 68 of the document titled "Airspace 2000 - A Plan for the Future of Australian Airspace"."

Response Status - OPEN

The pilot reported that, on approaching top of descent, the flight attendants noticed smoke coming from the rear toilet.

Investigation revealed a small fire in the rear toilet waste bin. The fire was extinguished by crew using water and BCF fire extinguishers. A normal approach and landing was carried out at Maroochydore.

Passengers were subsequently interviewed by Queensland Police but neither the cause of the fire nor the person responsible could not be identified.

The burnt material appeared to be a small quantity of rolled up tissue paper.