ATSB INVESTIGATION REPORT: LSA collision with ferris wheel in NSW

The Australian Transport Safety Bureau has released its preliminary investigation report into an unusual incident that saw a Cheetah Sierra 200 LSA collide with a Ferris wheel last month.
 
On October 1 2011, at about 1000 Eastern Standard Time a Cheetah Sierra 200 (Sierra) registered 24-7634 was attempting to land at the Old Bar Airstrip after a private VFR flight from Taree, NSW. On board were a pilot and a passenger. The purpose of the flight was to position the aircraft at the airstrip for a static display held in conjunction with a beach festival in the area surrounding the airstrip.

The flight was originally cancelled due to weather conditions that made VFR flight difficult, but about 20 minutes later the weather conditions improved and the pilot resumed preparing for the flight. Another aircraft, a Super Diamond Twister (Diamond) registered 19-7344, was to accompany the Sierra during its flight to Old Bar.

Upon arrival at Old Bar, the Diamond entered the circuit for, and was observed to land on, Runway 35. When the Sierra arrived at Old Bar, the pilot overflew the airstrip and elected to join the circuit for Runway 17. The pilot reported flying a normal left circuit and touching down about 20ft (6m) into the runway from the threshold markings. He then performed a touch-and-go followed by another circuit for Runway 17.

The Sierra pilot decided that, following the second circuit, he would conduct a full stop landing. The pilot reported that the second circuit was normal, of similar dimensions to the first, and with a touchdown point also in a similar position. The pilot stated that, after touching down, he became aware that he may not be able to stop the aircraft before the end of the airstrip, and elected to conduct a go-around. After applying power and raising the flaps, the aircraft became airborne toward the end of the runway.

Witnesses described the aircraft’s airspeed as being relatively slow and indicated that it was climbing slowly. The aircraft was reported to have continued to climb; however, it impacted a ferris wheel that was located to the south of the airstrip.

Sierra pilot recollection
In a statement to the NSW Police, the pilot reported arriving at the Old Bar Airstrip and conducting a touch-and-go landing to assess the condition of the airstrip and the local conditions. He indicated to the police that he approached at about 60kts, which he felt was too fast, and touched down too far into the airstrip as compared to the previous approach. Electing to conduct a go-around, the pilot recalled that when applying power, the nose of the aircraft pitched up and to the left. He reported realising that he was low but that it was ‘within an acceptable range according to aviation standards’. The pilot advised that at no time during the flight had he seen the ferris wheel.

Pre-flight preparation
The pilot advised the investigation that before leaving Taree Airport, he had consulted the Country Airstrip Guide entry for the Old Bar Airstrip and determined that there were no obstacles in the area around the airstrip and that the runway length was sufficient for the flight. He also indicated that he had checked the NOTAMS and determined that there were no problems in conducting the flight. The pilot did not report accessing any weather information prior to leaving home, and did not contact the caretaker of the airstrip to obtain an assessment of the local conditions or for permission to use the strip.

The pilot reported that the aircraft owner indicated that about 80L of fuel was on board the aircraft. After loading his passenger, the pilot started the aircraft and taxied to the run-up bay where he carried out his checks with no abnormalities noted.

Arrival at Old Bar
The pilot reported overflying the Old Bar Airstrip and, after checking the windsock and assessing that there was no wind, electing to enter the downwind leg of the circuit for what he described as ‘the southern runway’. When questioned further, the pilot could not identify the strip directions at Old Bar, explaining that it was appropriate to use the terms ‘from the north or south’ when making circuit entry radio calls. He stated that he was using the southern airstrip as this was the one that he had used when operating from Old Bar about two weeks previously.

The pilot indicated that on his second approach airspeed on final was between 50 and 60kts and that he extended the flaps to the three-quarter down position. The pilot reported touching down ‘in about the same spot as before’, and then applying the brakes for about half of the strip length to slow the aircraft. The brakes operated normally, with no sign of abnormal braking or locking of the brakes as the aircraft slowed down. The pilot described increasing concern while braking about the high ground speed and that he would not be able to stop the aircraft before the end of the strip. He elected to conduct a go-around and applied full power and raised the flaps before becoming airborne ‘a little bit past three-quarters down the runway’.

As the aircraft climbed away, the pilot realised that he was low but was unconcerned as the aircraft was climbing. The pilot reported maintaining the climb attitude and 60kts until, as he was about to increase the airspeed to 70kts, ‘everything stopped’. It took some time for the pilot to realise that he had collided with the ferris wheel. The pilot reported that he did not sight the ferris wheel during the overfly and circuit entry, the first circuit and touch-and-go landing, or the second circuit and go-around.

Witnesses recollection
As a result of the beach festival, there were numerous witnesses located in the area around the airstrip, a number of whom were experienced aviators. The witnesses reported that all of the other aircraft that had arrived at Old Bar that morning had used Runway 35 for landing. Witnesses on the western side of the airstrip indicated that the Sierra appeared to touch down well into the airstrip, some distance from the landing threshold. Two witnesses reported that the aircraft touched down about halfway down the airstrip.

One of the witnesses indicated ‘alarm’ at the actions of the pilot when the engine power increased during the go-around. Another reported ‘grave concerns’ about the aircraft’s performance and the actions of the pilot, and giving the aircraft his full attention. Both of these witnesses had considerable aviation experience. All of the witnesses reported that the Sierra became airborne almost coincident with the threshold markers at the departure end of runway 17. They also reported that it cleared the wire fence at the end of the airstrip by no more than about 1.5m and that the aircraft appeared to be travelling very slowly.

None of the witnesses reported hearing any abnormal engine sounds from the aircraft; rather, they all reported that the engine sounded normal. Witnesses commented on the aircraft’s continued slow climb in a nose-high attitude and that it missed a number of trees before flying in a straight line into the ferris wheel. A review of a video that was taken by persons who were on the ferris wheel at the time of the impact, confirmed the lift off point of the Sierra. In addition, the aircraft’s recorded flightpath was consistent with that reported by the witnesses.

CAPTION: The location of the ferris wheel in relation to the runway.

Injuries to persons
The passenger in the Sierra reported a minor injury as a result of the impact. There were no reported injuries from the pilot or any of the four occupants of the ferris wheel.
The NSW Police received one report of a minor injury from a member of the public as a result of falling debris.

Pilot information
The pilot had 79.5 hours total flight time, of which 51.5 hours were logged in recreational aircraft. Of that time in recreational aircraft, 28.6 hours was dual and 22.9 hours solo. The remaining flight hours were obtained in VH-registered aircraft some 24 years previously.
The pilot was issued with his recreational aviation pilot certificate on May 16, 2011.
 
Aircraft information
The Cheetah Sierra 200 was a factory–built, two-seat, single engine aircraft. The aircraft’s registration certificate expired on September 24, 2011. Information from RA-Aus indicated that the aircraft’s registration was renewed on September 30, 2011. The serial number on the registration certificate did not match the serial number on the aircraft’s data plate.

An examination of the aircraft following the accident revealed no pre-existing airframe or engine defects that would have precluded normal operations. However, the following manufacturing-related items were noted that had the potential to impact on future operations:

• The use of electrical cable ties to secure fuel lines and connectors within the aircraft. A post-impact fuel leak was identified that resulted from the disconnection of a fuel line at the main tank drain. Electrical cable was routed alongside and connected to a number of fuel lines.
• The single flight control column showed numerous holes and repairs at the single attachment point to the flight control attachment bracket. There was no evidence of a bushing around the attaching bolt.
• A number of hydraulic brake lines were routed through holes that were drilled in the bottom of the fuselage, with no evidence of grommets being employed to prevent chafing; and
• A number of tailplane ribs were not aligned with rivet lines

Meteorological information
The closest automatic weather station (AWS) to Old Bar Airstrip was at Taree Airport.
Data from the Taree AWS for 1000 that day recorded the wind as being from the north-north-west at 3kts with gusts of 4kts. Cloud was reported in the area and rain had been recorded as falling in the previous hour. The aerodrome forecast (TAF) for Taree forecast a wind from 340° at 10kts. Witnesses at Old Bar reported that the wind at the airstrip during the morning and at the time of the accident was blowing from the north-west and that there were occasional gusts. They also reported that a rain shower had passed through the area about an hour before the accident.
 
Old Bar Airstrip
The Old Bar Airstrip is a heritage-listed airstrip located about six nautical miles to the south-south-east of Taree. It is orientated in a broadly north-south direction, with runway strip designations of 17/35. Each runway was 540m long and the surface grass. There was a windsock on the western side of the airstrip and both runway thresholds were marked with gable and cone markers. Photographs of the airstrip that were taken on the day of the accident did not reveal any wheel ruts, skid marks or other phenomena that could be associated with the Sierra’s landing roll. Following the accident the airstrip was closed by the caretaker.

The local council reported that the airstrip has never been formally surveyed for obstructions. However, a number of trees to the south of the airstrip that were under the approach path and to the south-eastern side of the airstrip exhibited evidence of pollarding to ensure that they did not pose a hazard to aircraft operations. The airstrip is not a public airstrip and prior permission for its use is required from the Old Bar Heritage Airstrip Committee. The caretaker of the strip indicated that the pilot of the Sierra had not sought permission to use the airstrip that day.

(ATSB)

Ferris wheel examination
The ferris wheel was of a portable design; its base was a large flat-bed trailer, with the support structures being incorporated into the base of the trailer. When erected, the height of the ferris wheel (structure and wheel) was reported by the operator as being 20m. The centre of the ferris wheel was located 34m to the east of the runway centreline, 161m from the end of the runway. Examination of the area between the end of the airstrip and the ferris wheel did not reveal any evidence that the aircraft had contacted any structure or tree prior to impacting the ferris wheel.

The ferris wheel remained upright following the collision. The aircraft impacted the upper right side of the wheel as viewed from the direction of flight. At the time of impact, the occupants in the ferris wheel were located in two carriages, one below and one to the left of the aircraft impact. The aircraft became entangled in the wheel structure and took considerable effort to remove. The aircraft was reportedly leaking fuel following the impact and firefighting foam was deployed by emergency services to minimise the risk of fire. The impact moved the base of the ferris wheel about 75cm. The operator of the wheel reported that nearly all of the wheel’s structure was damaged or bent by the collision.

Further investigation
The investigation is continuing and will include the:
• examination and assessment of the conduct of the pilot’s training and issue of the pilot’s certificate;
• assessment of the ergonomics of the Sierra cockpit, including the control locations and indicators as they might have contributed to the development of the accident;
• analysis of witness statements and conduct of further interviews;
• assessment of the festival activities and supporting risk assessments;
• assessment of the council approval processes for the festival; and
• examination of the aviation activities associated with the festival.

Readers note: The information contained in this preliminary factual report is derived from the initial investigation of the occurrence. Readers are cautioned that new evidence will become available that may alter the circumstances as depicted in this preliminary report. As such, no analysis or findings are included in this report.