HICS

1

• HICS
• latent critical fuel scenarios

capt. raimund zopp flugwerkzeuge aviation software
2
HLF 3378 (Vienna, July 2000)

• Airbus 310, Charter flight from Chania/Greece to
  Hannover/Germany
• Landing gear retraction fault at takeoff in
  Chania
• Flight continuation to reach commercially
  favorable alternate
• fuel planning exclusively by FMS
• Repeated replanning to MUC and then to VIE after
  FMS fuel prediction deteriorates
• Early start of descent 90NM before optimum
• Fuel below original final reserve and fuel low
  level warning abeam ZAG, 133NM out of VIE
• Emergency declared 8 minutes later
• Both engine flame-out short before outer marker
• Crash landing on grass 500m before runway
• Only light injuries, aircraft written off

3

• Aircraft operated beyond range capability with
  landing gear down
• FMS fuel predictions used as sole means of fuel
  planning
• No ground support for fuel planning
• Subtle loss of situational awareness
• Violation of rules in final stageno diversion
  to ZAG or GRZ when fuel quantity dropped below
  final reserve
• official report should be available soon on
  http//versa.bmvit.gv.at

4
HLF 3378 (Vienna, July 2000)

• repeated replanning and shortcuts gave impression
  that FMS fuel prediction was still reliable
• documentation confusing and incomplete
• no other method for fuel planning considered

5
swiss cheese model of accident causation
according to j. reason
in the case of HLF3378, active inflight support
from dispatch would have been one of the defense
layers
6
HLF 3378 accident investigation

• one of several safety recommendation(free
  translation from German language, since official
  translation not yet available)
• ....
• application of support to cockpit crew by the
  flight dispatcher as required by ICAO Annex 6 and
  the quality manual of the operator
• ....
• remaining crucial questions
• is the dispatcher obliged to support the flight
  crew only on request ?
• does his support involve a fuel recalculation ?
• can (or shall) the dispatcher initiate an
  emergency ?
• how shall a dispatcher perform the neccessary
  calculations ?

7
HLF3378 - just a singular case?

• actual case gear-down diversion due to weather /
  hydraulic loss
• loss of hydraulic system early during flight
• continuation to destination with approaching
  frontal weather
• go-around due to weather
• gear retraction impossible
• diversion with gear down
• severe fuel situation / landing below final
  reserve
• loss of gear retraction capability was known for
  hours
• documentation gives no advice to adjust fuel
  planning
• potential case engine fail with locked rotor
• quiz how much does the fuel burn increase?

8
commercial pressure as a risk factor ?

• 2005/02/19 BA268
• with a failed engine from US west coast to UK
• uncritical weather
• good communication
• strong commercial motivation to continue
• professional ground support available, but not
  used
• late, but correct decision to abort initial goal
  (LHR)
• successful diversion to MAN
• how many lucky cases like this get away
  unnoticed?

• 2000/07/12 HFL3378
• prolonged gear down flight from Greece to Vienna
• uncritical weather
• good communication
• strong commercial motivation to continue
• insufficient ground support
• loss of situational awareness
• all engine flame-out
• crash

9
latent limitations of the 2-man cockpit

• some tasks of the flight engineer / navigator
  were actually never fully taken over by computers
• FMS / ECAM have severe limitations in abnormal
  operation
• no detailed documentation available onboard
• no training about latent limitations
• ICAO Annex 6 requires ground support from
  dispatch
• modern ground-based systems and high-quality
  communication channels are available worldwide

10
latent critical scenarios - handling

• prevent
• - additional fuel even for non-ETOPS enroute
  alternates
• - base diversion decisions on accurate
  calculations
• detect
• - use all available information to accurately
  predict potential scenarios
• - follow flight progress with all available
  means
• assist
• provide optimum tactical assistance in actual
  enroute diversions
• - based on precise aircraft performance data for
  the current configuration
• - based on up-to-date wind forecasts
• - select most suitable alternate
• - optimize flight profile
• - avoid terrain

11
latent critical scenarios - triggers

• change in destination / enroute alternate
  selection
• replanning without recalculation
• overburning / using up of contingency fuel
• rerouting / diversion
• change of wind / weather conditions
• change of aircraft status / configuration
• - engine fail
• - gear down
• - flight control problems
• - drag items
• - fuel leak

12
latent critical scenarios cost saving

• reduction of fuel reserves will bring us close to
  latent critical scenarios more often
• pilots instinctively uplift extra fuel for
  "safety reasons" sometimes counteracting
  reductions of reserves
• "instinctive" extra fuel is a significant cost
  factor with today's high fuel prices

credible in-flight support reduces this cost
factor and ensures a high safety level even when
operating under strong commercial pressure