Hawk T Fatal Accident 13 Feb 1996

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Hawk T Fatal Accident 13 Feb 1996

• Weather check sortie Pilot was QFI
• Uncontrollable roll to right on take off -
  40º/sec
• Pilot unable to arrest roll (reached 70º/sec)
• 150ft AGL, 110º AOB - pilot ejected into ground
  and was killed
• Aircraft continued rolling, impacted the ground
  and was destroyed

Note Not the accident aircraft
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Incident Details FDR Output

• During pilot checks rudder and tailplane were
  fully deflected but ailerons did not move
• During take-off roll left aileron position was 1º
  down, right 1º up
• Once airborne deflection increased
• 8 seconds after take-off deflection was 18º (full
  deflection)

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Determination of Cause

• Examination of wreckage found aileron control rod
  disconnected aft of the spring feel unit
• Due to point of disconnect, aileron control felt
  normal (thus not discovered in pre-flight checks)

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Maintenance Prior to Accident

• Aircraft underwent SI/Hawk/96B
• (NDT inspection of fuselage airframe)
• Aileron control rod removed for access
• Control rod not reconnected on
• completion of task

Figure from NDT inspection procedure
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Aileron Control Rod
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Key Events Leading to Accident

• TechA tasked to prepare aircraft for inspection
  IAW publications
• Publications allowed some discretion in equipment
  to be removed for inspection
• Technician removed all components to allow NDT
  inspector best access, including disconnection of
  the aileron control rod
• Tech A called away and briefed Tech B on the
  work completed
• Tech A did not document any maintenance he had
  completed
• On completion of NDT task, Tech B re-fitted all
  components to aircraft based on verbal handover
  from Tech A and signed for his work
• Tech A returned and retrospectively signed for
  removal of components, but did not document
  disconnection of the aileron control rod

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Key Events Leading to Accident

• Supervisor reviewed documentation no
  independent inspection required due to the depth
  of work conducted (unaware that aileron rod was
  disconnected)
• Supervisor conducted appropriate checks on work
  certified by Tech B to ensure it was competed
• Aircraft delivered to flight line with ailerons
  disconnected
• Pilots checks failed to recognise problem
  location of disconnection resulted in controls
  feeling normal
• Pilot did not notice that ailerons were not
  moving when commanded

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Contributing Factors
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Lessons Available

• Always document maintenance conducted
• Mandatory inspections - clearly identify any
  requirements arising during the task
• Inadequate procedures - be on the lookout and do
  not put up with them - have them fixed
• Provide adequate supervision it is our primary
  safety barrier!

Think AMIP!
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Improving Our Handovers
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