Curiosities – rather than comments.
The first cab off the rank is an acknowledgement of the ‘tin-kickers’ good work. It must have been a hellish of a job sorting out as much data and ‘fact’ as they did. In fact, when you take a long hard look at the crash site, you have to admire all those involved, ambulance, fire, police etc. A terrible job very well done once again by our ‘services’. Thank you all.
I’m not sure the same praise can be lavished on those who polish and refine the ‘final’, sanitized version of the investigators analysis; however, it is up to us to complete our own analysis and form an opinion. Mind you, it is quite a thing, stand alone, that ATSB reports are always treated with suspicion these days. Sad indictment. No matter. I always like to read through the entire thing anyway, note down those items which cause irritation of the curiosity bump, then pick ‘em out for further consideration. That, I regret is as far as I have gotten so far. FWIW (and it ain’t that much) the following stand out passages tug at the subconscious, needing further head scratching.
Bulla Road Precinct obstacle limitation surface exceedances.
ZCR collided with a building constructed on the south-eastern corner of Essendon Airport (Figure 8). This building was one of four, collectively known as the Bulla Road Precinct – Retail Outlet Centre (outlet centre), proposed by the airport lessee in 2003, approved by the Federal Government in 2004, and completed in 2005.
The ERSA, a component of the Aeronautical Information Publication, publishes information about an airport’s infrastructure and, in particular, runway data and airspace obstructions that may affect operations at the airport. The airport data for Essendon included seven obstacles that breached the airport’s obstacle limitation surfaces (OLS). Four of those obstacles infringed the runway 26 transitional surface component of the OLS and were associated with two buildings within the outlet centre that were not struck by the aircraft. CASA accepted the breaches in 2015 after the airport operator applied lighting and colour to the obstacles to mitigate their risk to aircraft operations.
The OLS are a series of surfaces that set the height limits of objects around an airport. The transitional surface is a component of the OLS that is immediately adjacent to the runway area. The runway area includes the runway itself and an adjacent area that is required to be graded and clear of all obstacles. The intent of the OLS is to provide airspace around an airport that is kept as free as possible from obstacles so as to permit the intended aircraft operations at the airport to be conducted safely, as well as to prevent the airport from becoming unusable as a result of growth of obstacles around it. The airport operator is responsible for establishing an applicable OLS. The surfaces of the OLS are based on a complex set of criteria that include whether the runway is used for departures and/or landings, and the types of approaches attached to that runway.
At the request of the investigation, the airport operator produced an OLS based on runway 17/35 only, and mapped the outlet centre obstacles in relation to this particular OLS. That data identified that the listed obstacles did not penetrate the OLS for runway 17/35. The airport operator also identified a further three obstacles that were not listed in the ERSA as breaching the OLS. They were not listed as they were considered minor breaches of the OLS. These obstacles related to light poles in the area of the outlet centre. The aircraft did not collide with any of the obstacles that breached the OLS.
ZCR was fitted with a Fairchild model A100S CVR in June 1996, at about the time the aircraft entered service. The fire-damaged CVR was removed from the wreckage and transported to the ATSB’s technical facilities in Canberra for examination. The CVR was successfully downloaded, however, no audio from the accident flight was recorded. The recovered audio related to a previous flight on 3 January 2017. This recording began at the expected time prior to engine start. The recording stopped, however, at about the time the aircraft landed at the arrival aerodrome.
The post-landing taxi and engine shutdowns were not recorded. It was likely that the ‘impact switch’ was activated during the landing and power was removed from the CVR.
P.40. - Due to fire damage to ZCR, the ATSB could not determine which checklist was in the aircraft. The aircraft manufacturer provided a copy of the checklist referenced in the operations manual, a copy of the correct checklist by serial number for ZCR, 101-590010-309F, and a copy of a POH applicable to ZCR. The manufacturer advised that the checklists were unlikely to contain checks related to modifications to the aircraft such as the CVR. The three checklist sources were compared and it was found that, in regard to the rudder trim and weight and balance items, the checklists were identical. None of the checklists contained CVR checks.
Rudder trim.
The left rudder trim cable had failed at a position towards the rear of the fuselage. Inspection of the cable fracture revealed necking-type failure of individual strands within the cable. That, and the way the cable was splayed, were indicative of an overstress fracture, likely as a result of the collision (Figure 30).
Elevator trim.
Both the left and right elevator trim actuators were found in a position that equated to a full nose-up trim position. Witnesses, CCTV and ADS-B evidence either opposed or did not support ZCR having full nose-up trim at take-off. It is possible that the elevator trim was moved to this position by the pilot in an attempt to control the aircraft’s flight path or the trim may have moved as a result of impact forces. The ATSB determined however, that it was unlikely that the elevator trim was in the full nose-up position at take-off and etc.
Flap system.
The left inboard and outboard flap control surfaces were destroyed by fire. The right inboard and outboard flaps had separated from the aircraft and broken into numerous sections during the impact sequence.
All four flap actuators were identified in the wreckage. The left inboard and outboard actuator outer bodies had been fire-damaged, however, their internal shafts and attachment points were present. Initial on-site examination of the aircraft wreckage indicated the flaps were extended approximately 10°. More detailed analysis of the left inboard and outboard actuators, however found they were likely in the fully retracted, UP position, when the aircraft collided with the building. An accurate assessment of the right wing flap positions was not possible due to impact and fire damage.
Yaw damper and rudder boost operation.
The ATSB was unable to determine whether the yaw damper was engaged on the accident flight or when the pilot normally engaged the yaw damper (refer to section titled Aircraft wreckage – Cockpit instruments and switches). There was no evidence found to support a rudder boost malfunction (refer to section titled Aircraft wreckage – Rudder boost system inspection). Both systems could be disconnected by the pilot and the aircraft manufacturer advised that the pilot should have easily been able to overcome forces generated by the rudder boost and yaw damper systems.
P 57. - Ground roll, flight path and aircraft attitude
Automatic Dependent Surveillance Broadcast (ADS-B) data and closed-circuit television (CCTV) footage revealed ZCR reached the required rotation speed of 94 kt when about 730 meters from the threshold of runway 17. The aircraft then remained on the ground for an additional 285 meters and rotated at 111 kt. The data also showed that, at some point between 470m and 920 m from the threshold, ZCR’s ground track began to veer left from the runway centreline. At rotation, a witness familiar with the aircraft type observed a yaw to the left followed by a relatively shallow climb. The ATSB’s analysis of ZCR’s flight path profile and the impact sequence found that, the aircraft had minimal sideslip for the initial climb followed by substantial sideslip for the later part of the flight and at impact. The analysis also found there was minimal left roll, not exceeding 10° for the duration of the flight.
That’s about it for now, I shall confer with my peers and betters to see if a better conclusion can be reached than all ‘pilot error’. Little doubt there was some pilot error, but it is a matter of how much of the blame for the total disaster can be laid at the feet of a dead man.
One thing is for certain sure; the pilot had sweet bugger all to do with the buildings being where they are; that, standing alone, is worthy of serious investigation. That will be fun, won’t it?
Toot – toot..
The first cab off the rank is an acknowledgement of the ‘tin-kickers’ good work. It must have been a hellish of a job sorting out as much data and ‘fact’ as they did. In fact, when you take a long hard look at the crash site, you have to admire all those involved, ambulance, fire, police etc. A terrible job very well done once again by our ‘services’. Thank you all.
I’m not sure the same praise can be lavished on those who polish and refine the ‘final’, sanitized version of the investigators analysis; however, it is up to us to complete our own analysis and form an opinion. Mind you, it is quite a thing, stand alone, that ATSB reports are always treated with suspicion these days. Sad indictment. No matter. I always like to read through the entire thing anyway, note down those items which cause irritation of the curiosity bump, then pick ‘em out for further consideration. That, I regret is as far as I have gotten so far. FWIW (and it ain’t that much) the following stand out passages tug at the subconscious, needing further head scratching.
Bulla Road Precinct obstacle limitation surface exceedances.
ZCR collided with a building constructed on the south-eastern corner of Essendon Airport (Figure 8). This building was one of four, collectively known as the Bulla Road Precinct – Retail Outlet Centre (outlet centre), proposed by the airport lessee in 2003, approved by the Federal Government in 2004, and completed in 2005.
The ERSA, a component of the Aeronautical Information Publication, publishes information about an airport’s infrastructure and, in particular, runway data and airspace obstructions that may affect operations at the airport. The airport data for Essendon included seven obstacles that breached the airport’s obstacle limitation surfaces (OLS). Four of those obstacles infringed the runway 26 transitional surface component of the OLS and were associated with two buildings within the outlet centre that were not struck by the aircraft. CASA accepted the breaches in 2015 after the airport operator applied lighting and colour to the obstacles to mitigate their risk to aircraft operations.
The OLS are a series of surfaces that set the height limits of objects around an airport. The transitional surface is a component of the OLS that is immediately adjacent to the runway area. The runway area includes the runway itself and an adjacent area that is required to be graded and clear of all obstacles. The intent of the OLS is to provide airspace around an airport that is kept as free as possible from obstacles so as to permit the intended aircraft operations at the airport to be conducted safely, as well as to prevent the airport from becoming unusable as a result of growth of obstacles around it. The airport operator is responsible for establishing an applicable OLS. The surfaces of the OLS are based on a complex set of criteria that include whether the runway is used for departures and/or landings, and the types of approaches attached to that runway.
At the request of the investigation, the airport operator produced an OLS based on runway 17/35 only, and mapped the outlet centre obstacles in relation to this particular OLS. That data identified that the listed obstacles did not penetrate the OLS for runway 17/35. The airport operator also identified a further three obstacles that were not listed in the ERSA as breaching the OLS. They were not listed as they were considered minor breaches of the OLS. These obstacles related to light poles in the area of the outlet centre. The aircraft did not collide with any of the obstacles that breached the OLS.
ZCR was fitted with a Fairchild model A100S CVR in June 1996, at about the time the aircraft entered service. The fire-damaged CVR was removed from the wreckage and transported to the ATSB’s technical facilities in Canberra for examination. The CVR was successfully downloaded, however, no audio from the accident flight was recorded. The recovered audio related to a previous flight on 3 January 2017. This recording began at the expected time prior to engine start. The recording stopped, however, at about the time the aircraft landed at the arrival aerodrome.
The post-landing taxi and engine shutdowns were not recorded. It was likely that the ‘impact switch’ was activated during the landing and power was removed from the CVR.
P.40. - Due to fire damage to ZCR, the ATSB could not determine which checklist was in the aircraft. The aircraft manufacturer provided a copy of the checklist referenced in the operations manual, a copy of the correct checklist by serial number for ZCR, 101-590010-309F, and a copy of a POH applicable to ZCR. The manufacturer advised that the checklists were unlikely to contain checks related to modifications to the aircraft such as the CVR. The three checklist sources were compared and it was found that, in regard to the rudder trim and weight and balance items, the checklists were identical. None of the checklists contained CVR checks.
Rudder trim.
The left rudder trim cable had failed at a position towards the rear of the fuselage. Inspection of the cable fracture revealed necking-type failure of individual strands within the cable. That, and the way the cable was splayed, were indicative of an overstress fracture, likely as a result of the collision (Figure 30).
Elevator trim.
Both the left and right elevator trim actuators were found in a position that equated to a full nose-up trim position. Witnesses, CCTV and ADS-B evidence either opposed or did not support ZCR having full nose-up trim at take-off. It is possible that the elevator trim was moved to this position by the pilot in an attempt to control the aircraft’s flight path or the trim may have moved as a result of impact forces. The ATSB determined however, that it was unlikely that the elevator trim was in the full nose-up position at take-off and etc.
Flap system.
The left inboard and outboard flap control surfaces were destroyed by fire. The right inboard and outboard flaps had separated from the aircraft and broken into numerous sections during the impact sequence.
All four flap actuators were identified in the wreckage. The left inboard and outboard actuator outer bodies had been fire-damaged, however, their internal shafts and attachment points were present. Initial on-site examination of the aircraft wreckage indicated the flaps were extended approximately 10°. More detailed analysis of the left inboard and outboard actuators, however found they were likely in the fully retracted, UP position, when the aircraft collided with the building. An accurate assessment of the right wing flap positions was not possible due to impact and fire damage.
Yaw damper and rudder boost operation.
The ATSB was unable to determine whether the yaw damper was engaged on the accident flight or when the pilot normally engaged the yaw damper (refer to section titled Aircraft wreckage – Cockpit instruments and switches). There was no evidence found to support a rudder boost malfunction (refer to section titled Aircraft wreckage – Rudder boost system inspection). Both systems could be disconnected by the pilot and the aircraft manufacturer advised that the pilot should have easily been able to overcome forces generated by the rudder boost and yaw damper systems.
P 57. - Ground roll, flight path and aircraft attitude
Automatic Dependent Surveillance Broadcast (ADS-B) data and closed-circuit television (CCTV) footage revealed ZCR reached the required rotation speed of 94 kt when about 730 meters from the threshold of runway 17. The aircraft then remained on the ground for an additional 285 meters and rotated at 111 kt. The data also showed that, at some point between 470m and 920 m from the threshold, ZCR’s ground track began to veer left from the runway centreline. At rotation, a witness familiar with the aircraft type observed a yaw to the left followed by a relatively shallow climb. The ATSB’s analysis of ZCR’s flight path profile and the impact sequence found that, the aircraft had minimal sideslip for the initial climb followed by substantial sideslip for the later part of the flight and at impact. The analysis also found there was minimal left roll, not exceeding 10° for the duration of the flight.
That’s about it for now, I shall confer with my peers and betters to see if a better conclusion can be reached than all ‘pilot error’. Little doubt there was some pilot error, but it is a matter of how much of the blame for the total disaster can be laid at the feet of a dead man.
One thing is for certain sure; the pilot had sweet bugger all to do with the buildings being where they are; that, standing alone, is worthy of serious investigation. That will be fun, won’t it?
Toot – toot..