Is Your Aircraft Talking to You? Listen!

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Cathy Gagne, AS-70

General Aviation (GA) Safety

• About 1,500 accidents, 475 people killed annually

• GA on NTSB Most Wanted List

• Personal flying sector of GA: greatest activity, proportion of accidents

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Top Occurrence Categories

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Fatal accidents in GA personal flying sector, 2000-2011

Discussion of Accident Cases

• Completed cases: common causes, factors, and scenarios

• Used as educational tools• Not intended to admonish accident

pilots

• Intended to help other pilots learn

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Scenario 1: Beech 36

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Accident Synopsis

• Pilot/owner planned personal round-trip night IFR flight

• Complete engine power loss on return leg

• Forced landing, pilot fatal

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Pilot

• Sole owner/operator

• About 2,300 total flight hours

• Flight instructor, with multi-engine and instrument ratings

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Airplane History

• Engine:10 hours since overhaul at time of pilot’s purchase

• Pilot added about 50 hours prior to accident

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Airplane History

• Engine oil pressure problem several weeks before accident

• Mechanic: Overhaul issue

• 1 week later, pilot said engine “seemed OK”

• No evidence of corrective actions

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Accident Flight

• No outbound leg problem reports

• Midnight taxi out, return to FBO

• Pilot requested mechanic (unavailable until morning)

• Pilot then opted to depart, IFR

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Accident Flight

• Complete loss of power 9 miles from destination

• Night IMC forced landing

• Engine examination: crankshaft fracture

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Bearing, Crankshaft Damage

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Missed Opportunities

• Actively address problem • Maintenance troubleshooting

• Do not fly until resolved

• Take conservative approach• Take all indications seriously

• Ground airplane until problem identified and resolved

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What Pilots Can Learn

• Resist external pressures to fly

• Identify, assess all risks

• Maintenance: Don’t talk self into believing what you want to hear

• Problem indications not always obvious

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What Pilots Can Learn

• Conservative approach can be inconvenient, costly (but is safer!)

• To avoid inappropriate choices:• Consider options and outcomes

• Prevent outside factors from adversely influencing decisions

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What Pilots Can Learn

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Scenario 2 – Vans RV-6

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Accident Flight

• Vans RV-6

• Departed 20 minutes before accident

• Private pilot was fatally injured

• Maintenance test flight

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Airplane History

• Oil leak discovered 6 weeks earlier

• Source of leak: propeller governor high pressure oil line

• Weld “repair” was made

• Pilot departed for test flight, but chose to conduct cross-country flight

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Accident Site

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Wreckage Examination

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Missed Opportunities

• Stick to maintenance test plan

• Review service bulletins, airworthiness directive

• Be prepared to execute emergency procedures

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What Pilots Can Learn

• If signs of problem persist, be prepared to discontinue flight

• Review, practice emergency procedures

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Scenario 3 – Beech G35

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Photo from sales advertisement

Scenario 3 – Beech G35

• 1956 Beech Bonanza (G model)

• Recent purchase by two pilots

• Lost engine at destination

• Owner/pilot: 40 hours in BE35

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Airplane History

• 3,350 hours total time airframe

• 80 hours since major overhaul on Continental E-225 powerplant

• Owners: Multiple mechanics troubleshooting oil leaks

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Airplane History

• Mechanics found, fixed some leaks; troubleshooting others

• Owners monitored; mechanics rechecked daily

• Oil temperature, oil pressure normal, no contamination

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Photo from sales advertisement

Flight History

• Owner/pilot (low time BE35) flew RYY to CHS (235 nm) day VFR

• At CHS: remark about oil leak

• Checked oil level, departed on return flight to RYY

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Flight History

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Flight History – Outcome?

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Flight History – Outcome

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Findings

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• Engine teardown: No evidence of case fretting or bearing damage

• Wrong type of case thread (not silk) used at overhaul

• Eventual consequences had it continued to fly? Depends …

What Pilots Can Learn

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• Troubleshooting may take time

• Even trusted sources may provide conflicting information

• Decisions: not easy, not cheap, not always obvious what is right

In Conclusion

• This issue, others covered in SAs

• Hot links (or short urls) to find reports, dockets, other resources

• www.ntsb.gov

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Thank You!

Questions? Discussion?

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