QFA10, VH-OJI, departed Melbourne on radar vectors on climb in stages to 5,000 ft. At the same time VH-UJL was on track Essendon - Owens maintaining 6,000 ft. The radar controller observed QFA10 climb through 5,400 ft and turned the aircraft onto a new heading to avoid conflict with VH-UJL. Separation reduced to 500 ft vertically and 1.5 miles laterally.

Between 3,000 ft and 4,500 ft the first officer and second officer changed seats to enable the second officer to climb the aircraft. The captain had been flying manually until handing over to the second officer at about the time the aircraft was cleared from 4,500 to 5,000 ft. The second officer continued to manually fly the aircraft. 5,000 ft had been dialled up on the altitude selector, but altitude hold had not been selected because the pilots were anticipating a further climb clearance. The flaps were fully retracted normally approaching 5,000 ft. However, once the flaps retracted the flight management computer (FMC) automatically increased thrust to accelerate the aircraft to climb speed of 320 kts. With the sudden thrust increase, the rate of climb increased, and the aircraft overshot 5,000 ft. By about 5,460 ft thrust was manually retarded and the aircraft was descended back to 5,000 ft.

At the time of the incident the traffic alert and collision avoidance system (TCAS) on QFA10 showed conflicting traffic at approximately the 10 o'clock position, two miles ahead and 500 ft higher. No traffic advisory (TA) or resolution advisory (RA) indication occurred because the breakdown in separation was not severe enough.

Significant Factors

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

1. Altitude hold had not been selected so the FMC did not level off the aircraft at 5,000.

2. Aircrew had changed seats not long before the aircraft reached 5,000 ft.

3. The second officer did not anticipate the FMC induced increase in thrust/ rate of climb as the flaps fully retracted approaching 5000 ft.

4. The captain was not properly monitoring the situation.

SAFETY ACTION

QANTAS advised that the company would review when pilots would be permitted to change seats.

As the passengers were boarding, a sudden power surge was indicated by way of relay lights and instrument flags flashing on and off. A flight attendant indicated there was smoke coming from the rear galley area. The crew immediately turned off the galley power switch and all aircraft power and advised all passengers to disembark in an orderly fashion. The first officer then proceeded to the rear of the aircraft with a fire extinguisher, however it was not required.

Later examination found that both the rear galley circuit breakers had popped. The cause for the smoke was traced to a fault in the main three phase coupling plug. A section of the female to male coupling plug had short circuited and burnt. The coupling was replaced and the aircraft returned to service.

The flight was to be the first after the aircraft had recently completed a scheduled 100 hourly maintenance inspection. Soon after departure from Canberra the pilot reported a gear unsafe warning to Air Traffic Control and requested that a visual check of the landing gear be carried out. ATC reported that all landing gear doors appeared to be closed. The pilot continued the flight to Goulburn and completed aerial work in accordance with the flight plan. The aircraft did not land at Goulburn. After departing the Goulburn circuit area the pilot carried out a normal extension and retraction of the landing gear to test the system. Normal indications were received. During a practice ILS approach at Canberra the pilot again selected the landing gear down. The gear unsafe light and warning horn were activated and the nose landing gear "down" light had not illuminated.

A check of the mirror on the aircraft, which is situated to enable the pilot to determine if the nose landing gear is down, confirmed that it had not extended. The pilot requested a missed approach and a further circuit. During this period, attempts were made to lower the nose landing gear using the standard emergency extension method. The pilot then requested a departure from the circuit area so that further attempts could be made to rectify the problem. The aircraft was yawed vigorously and a number of abrupt 'pull up' manoeuvres were carried out to assist the extension of the nose landing gear. Throughout this time the pilot continued attempting to lower the nose landing gear by the emergency method, without success. The aircraft returned to the circuit area and the pilot requested that the safety officer report on the current position of the nose landing gear. The safety officer indicated to the pilot that the nose landing gear doors were partially 'cracked'. The officer also reported that he could not see the nosewheel. The pilot requested emergency services and an inspection of the grass strip parallel to runway 30 in preparation for an emergency landing. While this was being carried out the aircraft departed the circuit area to enable the pilot to carry out a further attempt to extend the nose landing gear, after which it returned to the airfield for a landing. Soon after the main wheels touched down the nose of the aircraft settled and slid along the grass for a short distance. Emergency shutdown procedures were completed. The pilot and passenger subsequently evacuated the aircraft without injury. Examination of the aircraft revealed minor damage to the nose area and to both propellers.

The aircraft nose was raised in preparation for relocation of the aircraft to a maintenance facility. The nose landing gear then extended immediately and locked down. Examination of the nose landing gear revealed that a bolt in the centering spring assembly had been incorrectly re-installed after the aircraft had undergone recent maintenance. The bolt had been installed with the bolt head uppermost as is the case with all other Piper models with the same landing gear system. However, in the PA-34-200 Seneca and PA-34-200T Seneca II, this bolt is to be installed with the head down and the nut uppermost to prevent fouling on the nose gear door actuation aft tube assembly during retraction and extension. The engineer concerned also stated that he had added an extra washer under the bolt head which further reduced the bolt's clearance from the aft tube assembly. After re-assembly, the landing gear operation was tested with the aircraft on jacks, but the error was not revealed during this test. Once airborne, however, the air loads affected the track of the nose landing gear sufficiently for the bolt to come into contact with the aft tube assembly and thus affect the extension cycle.

On 11 October 1988 the Piper Aircraft Corporation issued Service Bulletin, Number 893, to ensure installation of the correct type of bolt into position with the head down. The Service Bulletin also stated that a placard warning against incorrect installation must be placed on the nose landing gear leg where it would be seen. In October 1992 the Australian Civil Aviation Authority issued an Airworthiness Directive - AD/PA-34/41. The AD refers to the Service Bulletin and explains that when the bolt is installed incorrectly, there is a significant risk of the nose landing gear failing to extend. The aircraft maintenance logbook indicated compliance with this Airworthiness Directive. On 2 February 1995 the CAA issued an Airworthiness Advisory Circular alerting operators to the risk of incorrect bolt installation and reminding all maintenance staff to refer and strictly adhere to the maintenance manual procedures and to ensure that the correct type of bolt was used and correctly fitted. The familiarity with the bolt in a particular position in all other similar Piper aircraft may have led to a skill-based error on the part of the engineer concerned. The engineer stated that the bolt had been incorrectly installed before the recent maintenance work. The placement of the bolt with the head down is not in accordance with 'general engineering practice' that is taught to maintenance staff.

It was most likely that, due to this learned behaviour, the re-assembly had been carried out without close reference to the aircraft maintenance manual and the engineer replaced the bolt in the position in which he had found it. The placard, stating that the bolt must be installed with the head down, had not been placed in the correct position on the landing gear leg. The placard had been placed on the inside of one of the nose gear doors. The engineer who had last assembled the centering spring assembly stated that he did not see the incorrectly located placard.

Findings

1. The nose landing gear of the aircraft failed to extend.

2. The pilot carried out an emergency landing with the nose landing gear in the retracted position.

3. A bolt in the nose landing gear centering spring assembly had been re-installed in the incorrect position during recent maintenance.

4. The engineer had placed an extra washer under the bolt head which further reduced the bolt's clearance from the aft tube assembly.

5. The bolt had been installed incorrectly before recent maintenance work. The engineer re-installed the bolt in the position in which he had found it.

6. Post-maintenance ground tests of the landing gear operation indicated that it was functioning correctly.

7. A Service Bulletin, Airworthiness Directive and Airworthiness Advisory Circular had been issued alerting maintenance personnel to the potential problem.

8. A placard advising maintenance personnel to install the bolt with the head down and nut uppermost was installed in the incorrect position. The engineer did not see this placard.

9. The aircraft maintenance logbook indicated compliance with the Airworthiness Directive.

10. The aircraft maintenance manual contained correct installation instructions for the bolt.

11. The incorrect installation of the bolt resulted in the centering spring mechanism coming into contact with the nose gear door actuation aft tube assembly during flight, thus preventing full extension of the nose landing gear.

Factors

• The engineer did not comply with the instructions in the Aircraft Maintenance Manual and Airworthiness Directive in reference to the installation of the bolt in the centring spring assembly.
• The engineer failed to see the placard which warns maintenance personnel to fit the bolt with the head down.

The pilot reported that he had completed two touch-and-go landings on runway 22 left and had been cleared for a touch-and-go on runway 22 right which had a displaced threshold. The approach, which was being flown with 20 degrees flap and about 1500 rpm engine power, was shallower than the earlier approaches. The pilot said that, about two metres above the ground, as he was about to increase power slightly to ensure that the aircraft did not touch down before the displaced threshold, the nose dropped. The nosewheel struck the ground firmly and the aircraft nosed over. The pilot could not recall hearing the stall warning sound during the approach, although it had tested serviceable before the flight.

The pilot reported that the landing was being conducted directly towards the setting sun. This affected his ability to see the strip and the aircraft touched down on the clearway beside the strip proper. During the landing roll, the nose wheel entered a depression which crossed the clearway and collapsed. Damage was also caused to both propellers and the forward underside of the fuselage.

The aircraft was engaged in crop spraying operations. The spray runs were being conducted in a north-south pattern across the area which was intersected by a three-strand power line running east to west.

The pilot advised that due to the crosswind conditions, it was necessary to fly close to the power line on each pass to adequately control the spray pattern. On the sixth spray run, the main wheels struck the uppermost strand of wire, causing the aircraft to descend into the crop. The pilot was not injured in the impact and was able to exit the aircraft safely.

The pilot stated that on the last spray run he either misjudged the height of the wires, or the aircraft encountered a down draft in the lee of tall timber growing along the paddock boundary.

The student pilot reported that during the landing at Kingaroy the aircraft became airborne again after touchdown. The right wing dropped and contacted the ground causing damage to the aileron and wingtip.

The pilot advised that shortly after the aircraft entered the first of what was to be a series of aerobatic manouvers, the aircraft's left rudder cable failed. After establishing what degree of flight control was still available, the pilot was able to make an uneventful landing.

Later examination found that the rudder cable had pulled through the rear swage fitting at the rudder horn end. The investigation found that both the left and right rudder cables were replaced at the last periodic maintenance inspection only three flight hours prior to the incident.

An examination of the manufacturers cable making processes revealed that the clamping tool used in the manufacture of the failed cable was not adjusted correctly. It was also found that there were significant wall thickness variations for the type of swage sleeves being used. All cables previously manufactured by the particular method used for the failed cable were identified and withdrawn from service. The manufactures cable making process for the failure type are currently under review by the CASA.

Two Cessna 150s, VH-MHD and VH-KMC, were conducting visual flights from Canberra at the same time. 

VH-MHD was commencing circuits on runway 30 and VH-KMC was departing on a city joy flight from runway 35.  At 1533 (all times are EST) VH-MHD was cleared for take-off from runway 30 with a requirement to maintain runway heading.  At 1535.20 VH-KMC was cleared for take-off from runway 35 and cleared for a left turn after take-off.

At 0535.55 VH-MHD was instructed to make a right circuit, early turn onto crosswind and downwind, traffic to sight is a Cessna heading for the racecourse, airborne off 35 over the old farmhouse.  At 0536.30 VH-MHD was instructed to continue the right turn to the tower and asked do you have that traffic now, it’ll be coming up in your 10 o’clock position. The pilot of VH-MHD responded uh MHD looking, do you want us to turn right now.  VH-MHD was then instructed continue the right turn to track to the tower, that will put you well inside the traffic

At 0536.55 VH-MHD was again asked if the traffic was sighted.  The pilot replied MHD negative.  VH-MHD was then instructed to......tighten the turn thanks, it’s in your 12 o’clock position half a mile continue the right turn now thanks straight to the tower.  At 0536 VH-MHD was advised ... you are clear of that traffic now continue downwind........

Meanwhile, after becoming airborne from runway 35, the pilot of VH-KMC contacted Canberra Departures Control at 1536.42 and advised .......KMC in a left turn on climb to 4000 left 2500.  VH-KMC had not been given any traffic advice by Canberra Tower on VH-MHD and there had been no coordination with Canberra Departures Control to pass any traffic advice.

At 1537.08 the pilot of VH-KMC advised departures we seem to have an aeroplane in the circuit area still heading towards us, do you have anything on it.  Departures advised VH-KMC of traffic in his 12 o’clock position and to maintain separation with that traffic.  VH-KMC then advised he’s just passed over me at about a 100ft.

When the aerodrome controller instructed VH-MHD to make a right circuit off runway 30 this put the aircraft in the same quadrant of airspace as VH-KMC making a left turn off runway 35.  The controller thought that instructing VH-MHD to tighten the right turn would resolve any potential conflict.  However, VH-KMC turned left earlier than expected whereas VH-MHD turned right later than expected.  The controller continued to give traffic to VH-MHD and instructed the pilot to track towards the tower but at no time passed traffic to VH-KMC nor instructed VH-KMC to remain on tower frequency.  The pilot of VH-MHD never sighted VH-KMC.

The traffic information passed to VH-MHD may not have been sufficient for the pilot to sight VH-KMC as it pre-supposed that the pilot was familiar with local landmarks and no relative height was passed. Additionally, the controller did not think it was significant that the pilot of VH-MHD may have had difficulty seeing VH-KMC in that he was flying a high wing aircraft, in a right turn, with the traffic approaching from his four to five o’clock position.

When it became apparent that VH-MHD could not sight VH-KMC and was not tracking towards the tower, the controller failed to issue a positive control instruction to VH-MHD, such as turn right immediately, to ensure that separation was maintained between the two aircraft.

An examination of the recorded radar data for Canberra terminal area indicated no apparent traffic reason why VH-MHD was instructed to make a right circuit.  The controller advised that he thought there was inbound traffic which may have conflicted if VH-MHD flew a left circuit.  At the time of the occurrence the aerodrome controller was under a moderate workload.  There were two aircraft operating in the circuit, VH-KMC departing on a scenic flight and a BA146 on final for runway 35.

Significant Factors

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

1. The aerodrome controller placed two VFR aircraft in the same small quadrant of airspace and on different radiofrequencies, when an alternative was available.
2. The aerodrome controller did not pass mutual, timely and effective traffic information.
3. The aerodrome controller did not take positive steps to ensure separation.
4. The pilot of VH-MHD was slow in complying with an instruction to make a right turn.
5. The pilot of VH-KMC made an earlier than expected left turn.

The pilot submitted a plan for a flight from Moorabbin to Corowa via Melbourne and Mangalore. When the aircraft was approaching Melbourne, air traffic control (ATC) issued a clearance to track direct to Corowa. About 15 minutes later the pilot reported that he entered intermittent instrument meteorological conditions (IMC). The aircraft was cruising at 7000 feet and no icing was present. Shortly afterwards, the aircraft entered continuous IMC and a short time after that ice started to form on the windscreen.

The pilot requested descent. Before ATC responded to his request, he adjusted the directional gyro (DG) to correspond with the magnetic compass. The autopilot had been engaged for some time before the DG adjustment was made. The pilot made the adjustment by pressing in on the heading bug knob while he pressed and turned the DG adjusting knob. This procedure was intended to prevent the aircraft from turning while the DG was adjusted.

The pilot said that immediately after the two knobs were released, the aircraft turned sharply to the right. He attempted to correct this manoeuvre, principally with rudder, but the aircraft persisted with the turn and began a rapid descent. From that point the pilot probably became disorientated. He made a mayday call and advised that the aircraft was inverted and that he had lost control. ATC assisted by providing advice on aircraft present position, lowest safe altitude, ground elevation and cloud base.

ATC then asked the pilot if the aircraft was autopilot equipped. This prompted the pilot to disengage the autopilot and shortly afterwards he regained control. Until that point, he had unwittingly been trying to override the autopilot. The aircraft was close to 4000 feet when control was regained. Recorded radar data and communications showed that the aircraft had executed a series of left turns and descended from 7000 feet to 4200 feet in about two minutes. Three and a half minutes after the mayday call the pilot advised that control had been regained. Altitude varied up and down during that time.

The pilot then elected to proceed to his destination, initially accepting ATC vectors via Mangalore. When the aircraft was later inspected by its home base maintenance organisation, no fault could be found with the autopilot. The aircraft had not been overstressed during the incident.

Factors

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

• Control of the aircraft was lost in IMC for undetermined reasons.
• The autopilot was engaged when control was lost and the pilot neglected to disengage the autopilot, until prompted by ATC, while trying to regain control.