1. Air Canada Flight 143
Ken Duenwald

2. Overview The Incident The Causes Summary Damaged Fuel Gauge Processor
Crew Assumptions
Unit Conversion Error
Summary
Lessons Learned

3. The Incident 23 July 1983 New Boeing 767
Scheduled Montreal to Edmonton Flight
Fuel exhausted mid-flight
Diverted to Gimli, Manitoba

4. Damaged Fuel Gauge Processor
Dual Channel System
Faulty inductor coil in one channel, gauges blank
Damaged channel disabled, gauges restored
Damaged channel later reactivated

5. Crew Assumptions Malfunction and blank gauges noted
Manual Fuel Measurement
Flight crew assumptions vs. Minimum Equipment List

6. Source: Flight Safety Australia
Unit Conversion Error
Volume vs. Weight
22,300 kg. of fuel required
7,682 liters measured before refuel
Metric System new in Canada
Incorrect mass to volume conversion (lb vs. kg)
Fuel Quantity
Correct value
Calculated Value
Conversion Factor
0.803 kg/liter
1.77 lb/liter
Weight before refuel
6,169 kg
13,597 lb
Weight required to refuel
16,131 kg
8,703 lb
Volume required to refuel
20,088 liters
4,916 liters
Total Fuel
22,300 kg
22,300 lb (10,116 kg)
Source: Flight Safety Australia

7. Summary Fuel Exhaustion Mid-flight Causes Lessons Learned
Mechanical Flaws
Human Error
Lessons Learned

8. How the plane was landed
No fuel, power, hydraulics, or electronics
Ram air turbine provided basic systems
Side-slip (Crab) Configuration
Increased descent without increased speed

9. Damaged Processor Details
Design Faults
Cold Solder Joint
Dual Channel Flaw
Malfunction Log Error

10. Why volume vs. weight Ground crew only considers how much fuel to add
Volume easier to measure
Pilots consider weight for various factors
Take-off
Cruise Speed
Landing
Adequate amount without excess weight

11. Aftermath Plane repaired and resumed service
Government Recommendations
Metric conversion training
More spare parts
Improved training with new aircraft
Aircraft design improvements
Ethical Improvements
Possibly remove