safety analysis of aircraft systems in aviation, safety is defined as the absence of accidents and...
TRANSCRIPT
![Page 1: Safety analysis of aircraft systems In aviation, safety is defined as the absence of accidents and incidents. JAR 25 treats systems as a whole. Acceptable](https://reader034.vdocuments.mx/reader034/viewer/2022042821/56649c9c5503460f9495a3d6/html5/thumbnails/1.jpg)
Safety analysis of aircraft systems
• In aviation, safety is defined as the absence of accidents and incidents.
• JAR 25 treats systems as a whole.• Acceptable accident rates must be established,
100% safety can never be guaranteed.• A relationship must be established between
severity of effect and probability of occurrence.
![Page 2: Safety analysis of aircraft systems In aviation, safety is defined as the absence of accidents and incidents. JAR 25 treats systems as a whole. Acceptable](https://reader034.vdocuments.mx/reader034/viewer/2022042821/56649c9c5503460f9495a3d6/html5/thumbnails/2.jpg)
Probability versus severity of effect
![Page 3: Safety analysis of aircraft systems In aviation, safety is defined as the absence of accidents and incidents. JAR 25 treats systems as a whole. Acceptable](https://reader034.vdocuments.mx/reader034/viewer/2022042821/56649c9c5503460f9495a3d6/html5/thumbnails/3.jpg)
The principle of graceful degradation
• In any system the failure of a single element, component or connection should not prevent continued safe flight and landing.
• This single failure should also not lead to an unacceptable workload for the operating crew.
![Page 4: Safety analysis of aircraft systems In aviation, safety is defined as the absence of accidents and incidents. JAR 25 treats systems as a whole. Acceptable](https://reader034.vdocuments.mx/reader034/viewer/2022042821/56649c9c5503460f9495a3d6/html5/thumbnails/4.jpg)
Types of failure to be considered
• Single active failure
• Passive and undetected (dormant) failures
• Combinations of independent failures
• Common-mode failures
• Cascade failures
• Failures produced by the environment
![Page 5: Safety analysis of aircraft systems In aviation, safety is defined as the absence of accidents and incidents. JAR 25 treats systems as a whole. Acceptable](https://reader034.vdocuments.mx/reader034/viewer/2022042821/56649c9c5503460f9495a3d6/html5/thumbnails/5.jpg)
Errors
• Design errors
• Manufacturing errors
• Maintenance errors
• Pilot mismanagement
• Errors in manuals or checklists
![Page 6: Safety analysis of aircraft systems In aviation, safety is defined as the absence of accidents and incidents. JAR 25 treats systems as a whole. Acceptable](https://reader034.vdocuments.mx/reader034/viewer/2022042821/56649c9c5503460f9495a3d6/html5/thumbnails/6.jpg)
Dormant failure
• Reverser is deployed!• Lauda Air B767 , 26-
5-1991• Design errors in the
thrust reverser electric systems led to unobserved deterioration of the HIV valve
![Page 7: Safety analysis of aircraft systems In aviation, safety is defined as the absence of accidents and incidents. JAR 25 treats systems as a whole. Acceptable](https://reader034.vdocuments.mx/reader034/viewer/2022042821/56649c9c5503460f9495a3d6/html5/thumbnails/7.jpg)
Common-mode failure
• Whatever you do, keep us away from the city!”
• UA 232, 19-6-1989, Sioux City, Iowa.
• No. 2 engine fan disc disintegration severed all 3 hydraulic lines in the tail area.
• Exceptional flying by the crew led to a landing at Sioux airport
![Page 8: Safety analysis of aircraft systems In aviation, safety is defined as the absence of accidents and incidents. JAR 25 treats systems as a whole. Acceptable](https://reader034.vdocuments.mx/reader034/viewer/2022042821/56649c9c5503460f9495a3d6/html5/thumbnails/8.jpg)
Cascade failure
• THY 981, 3-7-1974, Paris
• Inadequately closed lower deck door opened, causing floor collapse
• This blocked the flying control runs under the floor, causing catastrophic failure
![Page 9: Safety analysis of aircraft systems In aviation, safety is defined as the absence of accidents and incidents. JAR 25 treats systems as a whole. Acceptable](https://reader034.vdocuments.mx/reader034/viewer/2022042821/56649c9c5503460f9495a3d6/html5/thumbnails/9.jpg)
Failure rates in light single engined aircraft
• Engine failure. A minimum demonstrated flying speed must be 61 kts or below, to enable a succesful off-airport landing.
• Instrument systems for IFR operations must be dual and independent. Vacuum pump MTBF 700 hrs.
• Prevention of flap asymmetry must be adequate
![Page 10: Safety analysis of aircraft systems In aviation, safety is defined as the absence of accidents and incidents. JAR 25 treats systems as a whole. Acceptable](https://reader034.vdocuments.mx/reader034/viewer/2022042821/56649c9c5503460f9495a3d6/html5/thumbnails/10.jpg)
A few examples
• Cessna 172. Seat rails, flap system, elevator control
• Piper PA 28 wing attachment
• Robinson R22 helicopter, mast bumping
![Page 11: Safety analysis of aircraft systems In aviation, safety is defined as the absence of accidents and incidents. JAR 25 treats systems as a whole. Acceptable](https://reader034.vdocuments.mx/reader034/viewer/2022042821/56649c9c5503460f9495a3d6/html5/thumbnails/11.jpg)
Current concerns for GA
• Inadequate training
• Inadequate currency
• Insufficient pilot ability
• Lack of familiarity with the full flight envelope
• Inadequate understanding of increasingly complex systems
![Page 12: Safety analysis of aircraft systems In aviation, safety is defined as the absence of accidents and incidents. JAR 25 treats systems as a whole. Acceptable](https://reader034.vdocuments.mx/reader034/viewer/2022042821/56649c9c5503460f9495a3d6/html5/thumbnails/12.jpg)