CIRCUMSTANCES: "During a routine maintenance inspection on 2 March 1988 numerous creases were found in the surfaces of both wings. In addition, spar cap rivets were found to be damaged by shear load. The damage was indicative of the aircraft having been subjected to excessive positive `G' loading in flight. The circumstances leading to permanent deformation of the wings were not determined."

Circumstances:

"A Boeing 747 (B747) operating a scheduled regular public transport flight from Singapore to Melbourne and a Boeing 767 (B767) operating a scheduled regular public transport flight from Perth to Auckland were involved in an alleged close proximity incident near Narrandera NSW. Due to staff shortages in the Melbourne Area Approach Control Centre (AACC) the Melbourne Sector 4 airspace was declared to be deactivated by the issue of a Notice To Airmen (NOTAM) 1523. Whilst this airspace was deactivated transiting aircraft were required to comply with Traffic Information Broadcast Area (TIBA) procedures specified by NOTAM 1522.

The B767 flight path would transit this airspace during the period of deactivation. The B747 was offered route shortening at a non-standard level of Flight Level 37 000 feet (FL370) within Sydney controlled airspace under the jurisdiction of the Sydney Area Approach Control Centre Sector 6. The non-standard level was assigned due to other international traffic inbound to Sydney operating below the B747. No positive information update had been provided to the Sector 6 controller about the progress of the B767. Flight paths of both aircraft were within radar surveillance range and jurisdiction of the Sydney Sector 6 controller for some time prior to the incident.

The shortened route would place the B747 on a track which would cross that of the B767 at the same level and approximate time near Narrandera unless some separation action was taken. The B767 subsequently entered Sydney Sector 6 airspace three minutes earlier than flight planned estimates indicated. As soon as that aircraft contacted Sector 6 it was instructed to descend from FL370 to non-standard level FL350 to provide vertical separation with the crossing B747. The aircraft queried the instruction which was verified by Sector 6. However, communications with the aircraft were then lost and no readback of the assigned level was received.

Because of this the Sector 6 controller then instructed the B747 to change heading intended to maintain separation and to eventually pass behind the B767. ZK-NBE (B767) The B767 flight plan was submitted at Perth at 1438 Coordinated Universal Time (UTC) for a flight from Perth to Auckland via waypoints overhead Adelaide and Sydney. The flight would transit deactivated airspace promulgated in Melbourne NOTAM 1523 at 0848UTC. This airspace was normally under the jurisdiction of Melbourne AACC Sector 4. The B767 would then enter airspace under the jurisdiction of Sydney AACC Sector 6 at Narrandera.

The flight plan Estimated Time of Departure (ETD) was 1530UTC with the associated Estimated Time Intervals (ETI) and Estimated Times of Arrival (ETA) providing en-route timings for the following coded waypoints ETI to MALIM 02.51 - ETA 18.21UTC NYA 02.58 - 18.28 ASSS 03.05 - 18.35 NAR 03.17 - 18.47 RUG 03.31 - 19.01 Once the departure message was received from Perth notifying the actual departure time as 1542UTC (12 minutes later than flight planned) the above estimates could then have been updated as follows ETI to MALIM 02.51 - ETA 18.33UTC NYA 02.58 - 18.40 ASSS 03.05 - 18.47 NAR 03.17 - 18.59 RUG 03.31 - 19.13.

This could have given Sydney Sector 6 some expectation that the B767 would enter the deactivated airspace at 1828UTC (prior to MALIM waypoint) and exit deactivated airspace at NAR at 1859UTC. Because of the deactivation of Melbourne airspace, the normal step-by-step co-ordination exchanges between the Adelaide Melbourne and Sydney controllers were not completed and the Narrandera strip and estimate could therefore not be accurately updated by the Sector 6 controller. The last actual reported position of the B767 was to Adelaide control at 1748UTC when the aircraft reported over waypoint T6B 1747UTC FL370 estimating MALIM waypoint at 1830UTC, i.e. three minutes earlier than could have been expected by the Sydney Sector 6 controller.

VH-EBU (B747) The B747 flight plan was submitted in Singapore at 1132UTC for a flight from Singapore to Melbourne via waypoints overhead Derby Parkes Bindook (near Katoomba) Shellys (near Goulburn) and Eildon Weir. This circuitous route was planned to keep the aircraft within controlled airspace and clear of the Melbourne deactivated airspace which had been notified at 0856UTC (Melbourne NOTAM 1523). The aircraft had planned to descend from FL370 to the standard level of FL350 after passing Bindook and tracking towards Shellys and onwards to Melbourne. The aircraft departed within a few minutes of the notified ETD of 1215UTC and proceeded as planned.

Subsequently at 1808UTC Adelaide control instructed the B747 to contact Sydney control on Very High Frequency (VHF) 128.2 Megahertz (MHz) at the next waypoint T34A. (At 1812UTC Adelaide control instructed another international aircraft also to contact Sydney control on 128.2 MHz as primary frequency but offered 118.5 MHz as a secondary (alternative) frequency). The B747 contacted Sydney control on 128.2 MHz at 1813UTC and reported passing waypoint T34A maintaining FL370 and estimating Parkes at 1849UTC. At 1836UTC Sydney control Sector 6 advised Melbourne control Sector 2 of the B747 inbound via Parkes and requested if a shorter track from Parkes to Wagga and Melbourne would be available in the Melbourne airspace.

Melbourne control analysed the situation and concurred that the B747 could be given amended clearance to track Parkes Wagga Albury Eildon Weir Kinglake and Epping. At 1838UTC Sydney Sector 6 passed this amended clearance to the B747. Then the B747 was given a frequency change from 128.2 MHz to 118.5 MHz to maintain continuous communications for the amended route. Investigation Summary Investigations indicated that the crew of the B767 were given the Melbourne NOTAMs 1522 and 1523 on the flight deck just prior to departure from Perth. They did not consider that there had been a breakdown of separation resulting from the incident.

The B767 crew considered that the incident had been resolved as a Sydney control supervisor had spent some time discussing the matter on air with them. They acknowledged that they had the appropriate NOTAMs but had not fully understood the significance of Para.7 of NOTAM 1522. The B767 crew believed that their clearance from Perth via planned route was valid through all Australian airspace and that the wording of Para 7 ""SHOULD"" was not a mandatory requirement even though they had been advised of the frequency by Adelaide as 128.2 MHz. It should be noted that the VHF site for the 128.2 MHz facility is at Mt Oxley approximately 260 nautical miles north of Narrandera near Bourke.

As VHF communications are restricted to line-of-sight propagation characteristics the use of this frequency placed the B767 at the limit for communications over this distance at FL370 and out of communications at FL350. The crew of the B767 were using Jeppesen charts which similar to the Australian documentation carried ambiguous frequency data indicating that the choice of frequencies to be used in the Trans Continental Control Area (TCTA) and Western Routes (from Sydney) were 128.2 MHz or 118.5 Mhz when beyond 150 nautical miles Sydney. Whereas the latter frequency was the correct frequency to be used in the Southern portion of Sector 6 airspace.

The 118.5 MHz VHF facility site is located at Mt Canobolas near Orange almost on the direct track and only 130 nautical miles from Narrandera. The B767 crew had made all the required broadcasts on the TIBA frequency 128.95 MHz whilst within deactivated airspace. They first became aware that the event had been reported as an incident when they heard it from the media after arrival at Auckland. Investigation of the incident indicated the following. the Sector 6 controller had no co-ordination update provided for the Narrandera waypoint. the flight progress strip ETA Narrandera was correctly based on ATD.

The Sector 6 controller was unable to descend the B747 due to other crossing traffic. an SSR return was observed in the vicinity of Narrandera indicating FL370 which was believed to be the B767. the Sector 6 controller could not determine the frequency used by the B767 on first contact because of the placement and operation of the VHF control and presentation facilities on controller workstations. the B767 did not respond to the level change instruction and the level readout display was slow to indicate a descent had been initiated. the Sector 6 controller was not permitted to use the Mode C level readout for separation purposes.

The Sector 6 controller discussed the situation with more senior controllers and elected to turn the B747 right of track to avoid crossing the flight path of the B767. radar separation standards were maintained at all times. the aircraft had vertical separation of 2000 feet at the time of passing. the B767 had not called 15 minutes prior to entering Sydney airspace for clearance in accordance with TIBA NOTAM procedures. The investigation concluded that there was no breakdown of the prescribed separation standards and that although both aircraft had not been formally identified on radar there was sufficient information for the Sydney Sector 6 controller to anticipate that the aircraft painting over Narrandera at FL370 was the B767.

The off-airway route shortening of the B747 initiated by air traffic control added complexity to the prevailing traffic airspace management and co-ordination requirements. The investigation noted that at the time that the B767 first made contact with Sydney Sector 6 on 128.2 MHz the VHF transmission was very broken. This can be indicative of an aircraft either with transmitter problems or on the extreme range of VHF communications. On the first communication Sector 6 instructed the B767 to descend to non-standard level FL350. This was intended to maintain vertical separation between the B767 and the crossing B747.

The VHF reception of Sector 6 by the B767 was also most probably broken for the same reason (i.e. equipment problems or out of range) and the B767 aircrew queried that instruction. Sydney Sector 6 verified the instruction and added that the aircraft was required to report reaching FL350. There was no response to this instruction or readback of the new assigned level by the B767. This was most probably because it was then out of range of the Mt Oxley VHF facility even at FL370. Loss of communications with the B767 left the Sydney Sector 6 controller with minimal options to maintain separation between the B747 and the B767.

The chosen action was to vector the B747 away from the flight path of the B767. Sydney Sector 6 contacted the B747 thirty seconds later and instructed that aircraft to turn right onto a magnetic compass heading of 270 degrees for separation purposes. Sector 6 continued to call the B767. When no contact could be established the B747 was given traffic information with the relative bearing (2 o'clock) and distance (30nm) from the B767 with the advice that the aircraft was out of communications at that time. The B747 reported sighting the B767 traffic. Subsequently at the time of passing (1900.30UTC by radar plot) the aircraft were separated by 10.5nm horizontally travelling in opposite directions and achieving 2000ft vertical separation.

Sydney Sector 6 continued to call the B767 until communications were established on 118.5 MHz at 1901.40UTC some 4 minutes 20 seconds after contact was lost at 1857.20UTC. The B767 then reported maintaining FL350. At that time, the aircraft was 2000 feet below and 17 nm from the B747 and increasing the horizontal separation. The investigation also revealed that the crew of the B767 and the Air Traffic Service staff did not fully understand the intentions and procedures expressed in the appropriate Melbourne NOTAMs. This is not a reflection of the comprehension skills of the personnel but an indictment of the complexity and ambiguity of the NOTAMs and the procedures."

Recommendations:

"It is requested that the Civil Aviation Authority give consideration to the following recommendations to ensure that air traffic control personnel.

1. Use consistent phraseology when initiating frequency change instructions.

2. Issue the correct frequency change instruction for the area in which an aircraft is or will be operating.

3. Are reminded of the necessity to accomplish frequency changes before an aircraft is out of VHF range from the previous VHF outlet.

4. Are provided with documentary evidence of the VHF coverages available from the outlets under their control.

5. Are provided with training in VHF communications characteristics of the CAA radio telephony systems.

6. Have the control and presentation of the VHF/UHF frequency call lights modified so that controllers can immediately determine the frequency on which an aircraft is calling.

7. Have procedures prescribed to indicate the frequency coded, if necessary, on which an aircraft is communicating and all subsequent frequencies recorded on the flight progress strip applicable to a particular controller where more than one frequency is terminated at that workstation.

8. Be advised of this incident as an example of where the offering of track shortening and non-standard levels can result not only in increased communications control workloads and co-ordination but may suddenly and unexpectedly result in reduced safety standards."

CIRCUMSTANCES: "The pilot reported that during the takeoff roll the aircraft was slow to accelerate. At about 50 knots the aircraft became airborne in a nose-high attitude, and the pilot experienced difficulty in lowering the nose. Shortly afterwards the aircraft stalled, the left wing dropped and the aircraft turned through about 120 degrees before impacting the ground. It was determined that the takeoff had been conducted with the flaps in the fully extended position. The pilot had not previously flown this particular aircraft, and was not aware that a flap position indicator was fitted. He had judged the takeoff setting by watching the flaps extend, and had then released the selector, expecting it to be spring-loaded to the neutral position. However, the centering spring was broken and the flaps continued to full extension. The aircraft was found to be about 57 kilograms above the maximum permitted all-up-weight, and the centre of gravity was close to the rear limit. It was evident that the pilot was surprised by the aircraft attitude and the unusually high control column forces required after takeoff, and was unable to react to the situation in time to avoid losing control of the aircraft."

This accident was not subject to an on scene investigation. CIRCUMSTANCES: During a maintenance inspection substantial damage was found to the wing structure in the vicinity of the left main landing gear. It was considered that the damage was consistent with a heavy landing. The aircraft had been flown on several occasions in the previous month by different pilots. No reports had been made of any occurrence likely to cause the damage found to the aircraft. The damage should have been readily noticeable during pre-flight inspections.

CIRCUMSTANCES: "VH-TAB was eastbound from Perth to Melbourne. VH-TAD was westbound Melbourne to Perth. The eastbound aircraft was initially flying air route T6/T10 at Flight Level 330 (Fl 330) and the westbound aircraft on an air route further to the south, T15 at Fl 310. When the eastbound aircraft passed position T6E the Adelaide Sector One controller contacted Perth Sector with a request that the eastbound aircraft be asked if it would accept clearance to track direct from position T6D to Mr William on track T10. (See attached chart) T6D direct Mt William represents a short cut compared with the standard route T6T10. The eastbound aircraft accepted the revised track at 1925. At the time of the track change the Adelaide Sector was being operated by a 'controller-under-training' and the rated training controller for the sector was away from his position taking a meal break. However, before going for the meal break the controllers had discussed ""track shortening"" for both aircraft. Track shortening was not offered to the Westbound aircraft because problems may result with radio communications if aircraft are given routes to the South of T15. The short cut took the eastbound aircraft further to the south than the standard route and eliminated the lateral separation between the tracks of the two aircraft. When the rated controller returned to duty from his meal break the trainee 'handed over' the Sector and went to dinner. A short time later, at 2006 hours, the westbound aircraft reported at position T15B and requested climb to FL 330. This report was relayed to the Adelaide Sector One controller who then cleared the aircraft to FL 330. Each aircraft was on a different radio frequency and each was unaware of the position and altitude of the other. At about 2032 hours, the pilot of the eastbound aircraft observed an aircraft approaching and turned on more of his lights. The pilot of the westbound aircraft responded in a similar manner. The crews report the aircraft appeared to pass at about the same level and within two kilometres laterally. The trainee controller who offered the 'track shortening' for the eastbound aircraft was aware that he was giving away the lateral separation existing between the normal eastbound and westbound routes, and he was conscious that the vertical separation, which existed, had to be maintained. One of the functions of ATC is that of expediting the flow of air traffic. Controllers at Adelaide believed that track shortening saved the airlines considerable sums of money. However the 'T' route structure across the Great Australian Bight is designed to provide the most direct routes possible while laterally separating eastbound and westbound traffic. Short-cuts on these routes will result in insignificant savings in flight time. Furthermore, the loss of lateral separation can preclude the use of optimum cruise levels. The saving, in flight time, for the eastbound aircraft involved in this incident would have been about one minute. When the rated controller returned from his meal break the traffic situation was explained to him and he was made aware that the eastbound aircraft had been given track shortening. This information was also displayed on the flight progress board. Nevertheless, when the westbound aircraft requested FL 330 the controller cleared the aircraft at that amended level in the belief that the required lateral separation would exist at the time the aircraft passed each other. Following the investigation, safety recommendations have been made. These have led to a review of training, checking and supervision procedures for controllers and to track shortening being prohibited on 'T' routes outside of radar cover, except when requested by aircraft for operational-safety reasons."

CIRCUMSTANCES: "On 16 July 1983, the pilot/owner of the aircraft, Mr Elsing, flew it from Griffith, its home base, to Hobart with Mr and Mrs Twilley as passengers. The purpose of the trip was an overnight visit to Hobart, with a return to Griffith on 17 July. Mrs Twilley suffered earache and airsickness on the flight to Hobart and decided to return on an airline flight. Initially her husband was to accompany her but finally decided to return on VH-WJC. Prior to departing from Hobart the pilot supervised the refuelling of the aircraft and had 344 litres added to the fuel tanks. After the refuelling he personally checked the security of the fuel tank caps. The pilot submitted a flight plan to the Hobart Briefing Office for a private category flight from Hobart to Moorabbin, tracking via Launceston and Wonthaggi. The plan indicated that the flight would be conducted under Instrument Flight Rules (IFR) at Flight Level 120 (12000 feet on standard atmospheric pressure of 1013.2 millibars), with two persons on board. The flight plan showed that the aircraft had a fuel endurance of 220 minutes, and carried an Emergency Locator Beacon (ELB) and life jackets. There was no indication that a life raft was carried. The aircraft departed Hobart at 1352 hours and the flight apparently progressed normally until 1452 hours when the pilot advised Launceston Air Traffic Control, ""Er Whiskey Juliet Charlie we seem to have been in trouble with er fuel here the red er warning light comes and the gauge is down .."". At 1454 hours the pilot transmitted a Mayday call, indicating that he was descending from Flight Level 120 to track to Bass (a position reporting point); present position was 85 nautical miles (nm) from Launceston and he would be making a controlled ditching. Launceston Control suggested a diversion to Devonport but the pilot did not respond to the suggestion. At 1455 The pilot reported, ""We have lost an endurance of more than two two zero in flying time of seven zero minutes and when the warning light goes on this aircraft we have got three zero minutes flying left ....."". At 1456 the pilot advised that he intended to remain on track and make an emergency descent at 2000 feet per minute ""in case the pressurisation gets lost"". At that time the pilot reported his position as 92 miles from Launceston and indicated that he would stay on track and fly low ""in case we cut out"". At 1457 he asked if there was any advice available from Aero Commander experts on how to ditch the aircraft, however no information on the matter was immediately available. At 1459 Launceston Control established that the pilot intended descending to 500 feet to ""observe the situation"". The pilot also advised that the aircraft was ""DME Wonthaggi nine five"", i.e. the aircraft was 95 nm from the Wonthaggi Distance Measuring Equipment (navigation aid). In response to further enquiries, the pilot reported that the aircraft had left 4000 feet on descent and the remaining flying time was ""none whatsoever theoretically"". The last recorded transmission from the aircraft was at 1501 45 when the pilot confirmed that there were two persons on board. There was no indication from the pilot, at any time, that the fuel supply had been exhausted or that either engine had failed. It was estimated that the aircraft ditched at about 1505 hours, at an approximate position of 81 nm from Wonthaggi on the planned track. Searching aircraft subsequently sighted a fuel slick and a survivor in the water, however, contact with this person was lost before rescue helicopters and ships reached the area. No trace has since been found of the aircraft or its occupants. Subsequent investigation indicated the loss of fuel reported by the pilot was probably the result of a malfunction in the fuel system, rather than a spurious indication of fuel remaining. In the absence of the wreckage the precise reason for the fuel loss cannot be determined. Calculations relating to aircraft performance revealed that had the pilot elected to remain at the planned cruising level, the aircraft could have glided for about 35 nm after fuel expiry, with both propellers feathered. It was considered that had the pilot elected to turn back when he realised the nature of the problem and maintained altitude until the remaining fuel was exhausted, the aircraft could have reached the northern Tasmanian coast. There is no known hazard associated with a potential loss of cabin pressurisation that would have required an emergency descent from FL 120. The pilot's reason for conducting such a descent could not be established, however the effect of the decision was that the aircraft was ditched at an earlier time, and further from the Victorian coast, than was necessary. This factor increased the difficulties encountered during the subsequent search and rescue operation."

CIRCUMSTANCES: "The aircraft was planned to conduct a regular freight service to Brisbane and Cairns. After an evidently normal take-off from Runway 16 the crew contacted DEPARTUREs Radar, advised that the aircraft was climbing to Flight Level 370 and requested the direct track to Brisbane. Approximately two minutes later the crew did not respond to calls from the radar controller, and the aircraft faded from the radar screen. Witnesses subsequently reported that the aircraft was seen diving steeply towards the water. The evidence obtained from eye witnesses, recorded radar information and the Flight Data Recorder indicated that the aircraft entered a rapid turn to the right and rolled, probably to a nose-down inverted position, before entering a steep descent. The pilot in command intended to use the flight to assess the performance of the co-pilot, who was being considered for up-grading to command status. He was known to simulate emergency instrument flight conditions while checking company pilots. These simulations took the form of failures to the Flight Attitude Indicators on the left instrument panel, and the masking of the indicator on the right by covering or the removal of instrument lighting. It was likely that on this occasion that the simulated failures referred to above were given shortly before the aircraft commenced a planned turn to the left to take up the track towards Brisbane at a height of about 5000 feet. At this time the pilot in command had no external reference by which to monitor the attitude of the aircraft in relation to the horizon. The pilots did not recover control of the aircraft before impact with the water. NOTE A full report on this accident has been prepared and is available from the Australian Government Publishing Service in each Capital city."

PLT NON-NVMC RATED BECAME UNSURE OF POSN IN POOR WX CONDITIONS IN REMOTE AREA.ACFT BROKE APART AS ARESULT OF OVERLOAD FORCES IN A STEEP DIVE.PLT'S OF SEARCHING ACFT REP WX CONDITIONS IN AREA WERE IMC

The pilot was completing an air test following work on one propeller. During the base leg for runway 21 at Perth the aircraft appeared to stall and the pilot did not regain control. It crashed in the back yard of a house in Bassendean causing some roof damage. The out-of-control descent was described as a "falling leaf" indicating the aircraft had little forward speed. Also there was no wreckage trail. The aircraft caught fire on impact. The reason for the loss of control was not determined however, the post-mortem examination of the pilot indicated a possibility of incapacitation resulting from heart failure.

MERCY FLT.ON ARR KALGOORLIE CCT,PLT ENCOUNTED SEVERE STORM CELLS,INTENSE WIND GUSTS & TURBULANCE.ONFINAL AFTER A NUMBER OF SUDDEN ATTITUDE CHANGES A/C COLLIDED WITH A MINE POPPET HEAD.L WING TORN OFF