cessna 441 life extension

1. 1 Cessna 441 Life Extension Graham Swannell / Kim White August 2010

2. Very popular aircraft in 80s and 90s for mining company charter and crew changes in WA It is fast and economical. 260 kts 500 pph (although smaller cabin volume than Kingair it is much more economical than the Kingair) Total 362 built and 30 in Australia (first delivery 1977 �out of production 1986)Very popular aircraft in 80s and 90s for mining company charter and crew changes in WA It is fast and economical. 260 kts 500 pph (although smaller cabin volume than Kingair it is much more economical than the Kingair) Total 362 built and 30 in Australia (first delivery 1977 �out of production 1986)

5. Feasibility / CASA agreement on cert plan / AEA & Tenix (TAE) STC HOLDER RESPONSIBILITIES Will act like the aircraft TC holder. Responsible for continuing airworthiness support of the entire aircraft for the remainder of the aircraft life. Feasibility / CASA agreement on cert plan / AEA & Tenix (TAE) STC HOLDER RESPONSIBILITIES Will act like the aircraft TC holder. Responsible for continuing airworthiness support of the entire aircraft for the remainder of the aircraft life.

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7. AEA database showed 175 structural repairs Reviewed Service Difficulty Reports (SDRs) We spoke with operators and did an operators survey Broke responses down into ATA chapters so we captured not only the structural aspects but also systems problems. AEA database showed 175 structural repairs Reviewed Service Difficulty Reports (SDRs) We spoke with operators and did an operators survey Broke responses down into ATA chapters so we captured not only the structural aspects but also systems problems.

8. Cessna SIDs inspections �based in F&DT , should be appropriate inspection intervals Cessna SIDs inspections �based in F&DT , should be appropriate inspection intervals

9. We verified from our analysis that the Cessna wing inspection intervals could be carried out to the new life Based on F&DT principlesWe verified from our analysis that the Cessna wing inspection intervals could be carried out to the new life Based on F&DT principles

11. Because there are so many components to the fuselage we needed to classify them And use standard methods of analysis for each classificationBecause there are so many components to the fuselage we needed to classify them And use standard methods of analysis for each classification

13. Tension cap are the areas of interest Inner cap at corners Outer cap fuselage sidesTension cap are the areas of interest Inner cap at corners Outer cap fuselage sides

14. Inner frame caps at the corners needed reinforcing to reduce stress levels Outer cap on fuselage side will talk about more shortlyInner frame caps at the corners needed reinforcing to reduce stress levels Outer cap on fuselage side will talk about more shortly

16. A failure of the outer skin and resulting frame outer cap failure would be significant Initially a pin joint would develop at this location as the internal structure stayed in tact but the bending moment re-distribution would cause a major structural failure. Cannot accept that type of failure hence the external straps. This was a major area of discussion with the engineering team and we decided on the external strap solution although there were other solutions.A failure of the outer skin and resulting frame outer cap failure would be significant Initially a pin joint would develop at this location as the internal structure stayed in tact but the bending moment re-distribution would cause a major structural failure. Cannot accept that type of failure hence the external straps. This was a major area of discussion with the engineering team and we decided on the external strap solution although there were other solutions.

17. 17 AEA uses elastic course mesh models for light gauge sheet metal structures Then do refined models as required and non-linear analysis if appropriateAEA uses elastic course mesh models for light gauge sheet metal structures Then do refined models as required and non-linear analysis if appropriate

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24. Location of strain gauges Note external straps Jack the aircraft to simulate wing deflection and any interaction with fuselage attachmentLocation of strain gauges Note external straps Jack the aircraft to simulate wing deflection and any interaction with fuselage attachment

25. Talk a bit about the damage tolerance analysis methodsTalk a bit about the damage tolerance analysis methods

27. Talk a bit about the damage tolerance analysis methodsTalk a bit about the damage tolerance analysis methods

30. 2 frames modelled and the skins Crack analysis with crack starting at the middle of the external strap. This crack will not be seen until it emerges from underneath the external strap. Need to see how well we can detect the crack and maintain residual strength Note that all fasteners were modelled as well with spring elements2 frames modelled and the skins Crack analysis with crack starting at the middle of the external strap. This crack will not be seen until it emerges from underneath the external strap. Need to see how well we can detect the crack and maintain residual strength Note that all fasteners were modelled as well with spring elements

31. Crack is visible once it appears from underneath the strap It becomes dangerous at 4.25� and we are easily able to find it from our inspections well before it becomes dangerousCrack is visible once it appears from underneath the strap It becomes dangerous at 4.25� and we are easily able to find it from our inspections well before it becomes dangerous

33. Flange cracking is the issue Very difficult to inspect, and in some areas impossible to inspect. This is one area of the Cessna SIDs program that does not work wellFlange cracking is the issue Very difficult to inspect, and in some areas impossible to inspect. This is one area of the Cessna SIDs program that does not work well