During the climb, at about 5,000ft, the crew became aware that the aircraft cabin was not pressurising. Alternate selections were tried without success. The captain then decided to proceed to the destination at FL130 after briefing the cabin crew to be alert for any passenger distress and to administer oxygen from portable bottles if necessary. In accordance with safety requirements, the captain and first officer both donned oxygen masks for the flight above 10,000ft.

After reaching cruise level, several passengers and one member of the cabin crew reported headaches and light headedness. The captain descended the aircraft to FL120, and later to 10,000ft when fuel reserves permitted. The flight continued and landed without further incident. None of the affected passengers required medical attention. The aircraft had suffered a pressurisation system failure three days earlier on a flight from Canberra to Sydney.

After rectification at Sydney, it flew without incident until this flight. Investigation revealed that the Cabin Outflow Valve and the Equipment Cooling Auto Flow Control Valve were out of adjustment. The Panel Pressurisation Control Mode Selector Switch was also faulty with an intermittent continuity failure. The pilots did not contravene any regulation or company procedure by continuing the flight unpressurised. However, no consideration had been given to any medical problems that any of the passengers may have had, or that could affect their well-being at higher cabin altitudes.

Safety Action

As a result of the incident, the company has issued instructions that an aircraft that fails to pressurise after take-off and does not respond to early corrective action should return to the departure port or divert to the closest suitable airport.

The pilot had calculated he would arrive at his destination five minutes before last light. Ten minutes before last light he realised the light was fading, so decided to land at a property airstrip he could see below. During the landing roll the left wing of the aircraft struck the star pickets of a barbed wire fence. The aircraft yawed to the left and the right main gear collapsed. The pilot had not seen the fence until it was struck by the left wing.

VH-ELZ departed Brisbane for Toowoomba and was given an initial heading of 270 degrees. Two minutes later, VH-SGQ departed, also for Toowoomba, and was given a departure heading of 240 degrees. At about the same time, Approach instructed VH-ELZ to turn on to 240 degrees. The aircraft came within 3 miles of one another without vertical separation existing. Approach was occupied by a trainee under the supervision of a training officer at the time of the occurrence.

The trainee had recently transferred from another centre where Tower did not depart aircraft less than three minutes apart. This was to ensure that five miles separation existed when the aircraft contacted Approach. In this instance, the trainee was surprised when VH-SGQ departed less than three minutes after VH-ELZ. The training officer said that he misjudged the level of expertise of the trainee. This probably affected how closely he monitored the trainee, allowing the loss of separation to develop.

The following factors contributed to the development of this occurrence:

1. The Approach position was occupied by a trainee controller under the supervision of a training officer.

2. The trainee expected the second aircraft to be further separated from the first than was the case.

3. The training officer misjudged the level of expertise of the trainee.

Both aircraft were inbound to Sydney on different but converging routes, cruising at the same level. The Sydney Flow Controller requested that VH-TJL be positioned 15NM behind VH-TJD to facilitate their arrival. The controller responsible for the aircraft instructed VH-TJD to turn right (to place it on the same track as VH-TJL) and to descend. As VH-TJD converged on the track flown by VH-TJL the required lateral separation of 5NM was lost before the required vertical separation was achieved.

The helicopter was being used for feral animal culling with the pilot and a shooter on board. Weather conditions at the time were hot, and the helicopter was operating close to its maximum all up weight. While flying downwind the helicopter began to sink and the pilot overpitched the main rotor system while attempting to recover. The resultant loss of rotor RPM caused the helicopter to descend rapidly and strike a tree. Both occupants escaped with minor injuries, but the helicopter was destroyed.

On arrival in the circuit area at Wedderburn, the pilot was unable to extend the landing gear by the normal method. The failure of the gear to extend was accompanied by a very loud high-pitched noise in the headset and speaker systems. His attempts to lower the landing gear by the manual emergency system were also unsuccessful.

As a result, the pilot elected to return to Bankstown. However, on arrival in the circuit, he was unable to communicate by radio to the Tower or other aircraft. Air traffic control staff recognised the pilot was experiencing difficulties with the landing gear and called out the emergency services. When the services were in place the aerodrome was closed and the pilot advised by signal light that he was cleared to land.

The aircraft subsequently landed on runway 11 with the landing gear retracted. An investigation revealed a fault in the alternator field circuit which prevented the battery from being charged. The landing gear failed to extend by the normal means due to low battery voltage. The pilot was unable to lower the gear by the manual system because he could not gain access to the emergency gear extension handle due to an incorrectly fitted piece of interior trim. It was not determined how the trim came to be incorrectly fitted.

VH-FCU was enroute Gladstone-Brisbane and was being radar vectored for a left base for runway 01. VH-CZM had departed Brisbane on a standard instrument departure off runway 01. This involves the aircraft intercepting and tracking the 360 degree radial from Brisbane and, at 10 DME Brisbane, turning left and tracking for Kilcoy. Both aircraft were under the control of Brisbane Approach. At the time of the occurrence, the Approach position was occupied by a trainee controller under the supervision of a training officer.

The training officer alerted the trainee to the potential confliction between the two aircraft as VH-CZM turned left for Kilcoy. However, as the trainee was about to instruct VH-FCU to turn, a number of radio transmissions prevented him transmitting the instruction until a loss of separation was unavoidable. The aircraft came within four miles of one another while vertical separation did not exist. The trainee was an experienced approach controller from another centre and had only recently begun training in Brisbane. The training officer was aware of the trainee's experience level and delayed his intervention on this basis.

The following factors were considered relevant to this occurrence:

1. The Approach position was occupied by a trainee controller under the supervision of a training officer.

2. The training officer delayed his intervention in the process because of the trainee's previous experience.

3. Other radio traffic delayed the trainee issuing instructions to the aircraft which would have ensured separation.

The pilot was mustering sheep on his property and had handed off two mobs to ground handlers. He was on his fourth pass and was in a 45-degree left turn, descending from 100 to 50 ft at about 70 kts when he realised that he was too close to the sheep and applied left rudder to slip the aircraft away from the sheep. He then attempted to bring the wings level with aileron and arrest the descent without releasing the left rudder pressure. As the aircraft approached 50 ft, the pilot realised he could not recover and closed the throttle. The aircraft struck the ground with the left wing. The propeller then contacted the ground and the aircraft cartwheeled, coming to rest in a distance of about 40 m facing 180 degrees from the direction of flight.

9V-STT was en-route from Perth to Singapore and tracking via air routes B469 then R586 after Carnarvon, cruising at flight level (FL) 350. VH-EAL was also Perth for Singapore but tracking via air route G337 at FL350. The routes flown by the two aircraft are initially laterally separated but, because the cross-track tolerance changed as the aircraft proceeded north, it was necessary to apply separation to ensure that the standards were not infringed. This action was not completed by the air traffic controller responsible for the aircraft by the required point along the routes, and the standards were infringed.

About 30 minutes prior to the incident there was a change of controller on the sector responsible for the aircraft. The controller commencing duty thought that he had confirmed that correct separation existed. The handing over controller believed the other controller had referred to two different aircraft when they discussed the adequacy of the separation during the handover. The controller assuming responsibility for the aircraft had recently returned from a period in the Perth Control Tower and may have forgotten, because of a lack of recent experience, that the cross-track tolerances of the two routes vary.

The handing over controller was recently rated in the position and assumed that the more experienced controller was aware of the lack of separation between the routes. Safety Action: The Civil Aviation Authority is redesigning the route structure, and this should remove the potential for separation reductions in this area of airspace.

FACTUAL INFORMATION

On final approach to Launceston, maximum nose-up stabiliser trim was insufficient to trim out the nose-heavy force. After landing it was found that 60 golf bags weighing approximately 1,300 kg had not been included on the aircraft load trim sheet. The golf bags belonged to a tour group of 60 people who were to travel some days after this occurrence. They were bulk delivered to the baggage handling area at Melbourne Airport to be forwarded to Launceston on a space available basis to meet a requirement that they be available when the group arrived.

The load controller and the baggage loaders were aware that the golf bags were to be moved on a space available basis. The operator's Ramp Manual requires that a load plan must be prepared for each flight. It states that a load plan is an instructional document which specifies where cargo, special load items, livestock, mail, and baggage are to be loaded on an aircraft. The document is produced by the load control section and distributed to members of the loading team so they can perform their duties in the correct loading of the aircraft.

It is necessary to follow the load plan to ensure that the load is correctly segregated and all weight and balance requirements are met. When the loading of an aircraft differs from the load plan, the load controller is to be consulted. On this occasion the loading supervisor informed the load controller that the aircraft was full but did not tell him that the 60 golf bags were on board. The load controller was aware that low density cargo was on board. He had not considered it possible to load the golf bags as well and they were not included in the load plan.

At the time of the occurrence, the load plan declaration stated:

This aircraft has been loaded in accordance with these instructions except for the deviations recorded. The load has been secured in accordance with company regulations. The loading supervisor did not sign the declaration, nor did the load controller seek such certification prior to completing the load and trim sheet. Two load conditions are shown in the following list.

The first column is the load displayed on the load plan accepted by the crew. The second column is the estimated load with the extra 60 golf bags.

Load displayed on the load plan accepted by the crew	Estimated load with the extra 60 golf bags
Bay 1 (most fwd) 26 kg	350 kg
Bay 2 26 kg	472 kg
Bay 3 260 kg	468 kg
Bay 4 212 kg	212 kg
Bay 5 325 kg	500 kg
Bay 6 (most aft) 325 kg	500 kg

Bays 1 to 4 are in the forward fuselage and received most of the extra load, thereby adding to the forward centre of gravity.

The horizontal stabilizer trim setting listed on the load trim sheet was 1.3 units nose up. The crew did not notice any extra nose-down moment during takeoff. It only became evident during the approach and landing. The investigation team recalculated the trim, taking into account the most probable baggage loading condition. It was concluded that the aircraft was still just within the forward limit of the centre of gravity envelope at take-off. The required take-off horizontal stabilizer trim setting would have been 2 units nose up on a 3-unit scale. VH-FKO was the most nose-heavy F28 in this operator's fleet.

The load controller stated that to compensate for this he had blanked out the front row of four seats. However, the computer-generated load trim sheet showed that the aircraft was "trimmed by seat row" and, using the code "BLKD 0", showed that no seats were blocked. The requirement for the front row of four seats to remain unoccupied because of balance considerations was not brought to the attention of the cockpit and cabin crews. The aircraft had a fuel load of 4,400 kg in the wing tanks. No fuel was carried in the centre tanks.

The centre of gravity moved rearwards with fuel burn. There were 65 passengers including 4 infants who occupied 61 out of 74 seats. The investigation did not determine if passengers were redistributed in the cabin after takeoff, resulting in some or all of the four front seats being occupied. When combined with the nose-down force generated by the weight of the 60 golf bags, any forward movement of passengers would have moved the centre of gravity up to or just outside the forward limit, depending on how many of the front row seats were occupied.

The operator uses a system of standard passenger and baggage weights rather than actual weights when compiling a load trim sheet. Accordingly, the actual weights on this flight could not be determined.

ANALYSIS

Most passenger jet aircraft have a large centre of gravity range and variations from a load plan may be permissible provided the aircraft is loaded within the centre of gravity limits. The F28 aircraft type has only a small tolerance to variations from a load plan which conforms to the manufacturer's specifications. The loading supervisor did not certify that the aircraft had been loaded in accordance with the operator's instructions. Certification is part of the operator's quality assurance safety net.

On this occasion the safety net failed. The reason the documentation was not signed could not be clearly established. The operator stated that the reason the loading supervisor did not sign the load plan was an industrial issue rather than a safety issue. The reason maximum nose-up stabiliser trim was insufficient to trim out the nose-heavy force during the approach and landing was not determined.

Findings

1. The cargo and baggage were not loaded in accordance with the load plan.

2. The 60 golf bags were not included in the weight and balance calculation on the load trim sheet.

3. Some passengers may not have been seated in accordance with the load plan during the approach and landing.

4. Maximum nose-up stabiliser trim was insufficient to trim out the nose-heavy force during the approach and landing.

Significant factors

1. The loading supervisor did not certify for the accuracy of the loading and did not ensure that the load controller was aware of the difference between the load plan and the actual loading.

2. The load controller did not advise the cockpit and cabin crews that the front row of four seats was not to be occupied due to balance considerations.

SAFETY ACTION

The Bureau of Air Safety Investigation issues safety advisory notice SAN 960031 to the Civil Aviation Safety Authority. The Bureau of Air Safety Investigation informs the Civil Aviation Safety Authority that it is possible, unless adequate notification is given to cockpit and cabin crew, that the movement and reseating of passengers can inadvertently cause an out of balance situation of certain aircraft under certain loading conditions. Furthermore, as a result of this occurrence, the operator advised that it had initiated the following

Safety actions

1. Established an aircraft load management group. This group compromises company personnel dedicated to establishing operating procedures to ensure aircraft are loaded in accordance with regulatory and company requirements. The group is also required to conduct audits of all operator ports to ensure all requirements are being met in the field and to develop a training syllabus for all staff involved with the loading of aircraft.

2. Initiated an aircraft load management training course. This course is designed for state managers, operations managers, ramp supervisors, load controllers, senior clerks, senior freight clerks and leading hand loaders. The course syllabus covers all aspects of aircraft loading, weight and balance and the legal requirements of the Civil Aviation Regulations and Civil Aviation Orders.

3. Developed an aircraft abnormal loading alert form to provide staff with a method of reporting any incidents or events which may compromise company procedures or matters of safety with regard to the loading of aircraft.

4. Introduced a requirement for the leading hand who loaded the aircraft, to sign a declaration on the load sheet. The declaration states: "I certify that: - loading staff have been instructed to load this aircraft in accordance with the load plan - all deviations from the load plan have been reported - all ULDS [container] and bulk cargo have been loaded and secured in accordance with company procedures".

5. Appointed a national ramp manager to co-ordinate ramp and loading procedures across the network of ports used by the operator.

6. Introduced a system of examination and certification of the load controllers within handling companies on the international network. A similar scheme is being introduced for the domestic network.

7. Introduced an enhanced computerised weight and balance system. This system provides more automation to the loading process and will be introduced to enhance the documentation for the ramp staff.

8. Provided improved communications between the load controller and leading hand loaders with the introduction of two-way radios at the major stations.