Cessna 210 Accident Mt ISA

[anxiao]

Digging a bit deeper into the SL and the documents that it references. I am working on the C177 figures but as far as we see the C210 is the same, as it has essentially the same carry through spar structure.

The documents for reference includes Temporary Revision number 8 dated 1 December 2011 (for the C177) which defined Severe usage and Severe environments. Severe Usage is defined below, and for Australia all the coastline and inland for about 500km is considered as severe environment. (It is difficult to see the scale on the corrosion maps but it looks about 500km to a non Oz)

The SL goes on to say that:

For airplanes flown in SEVERE Usage as defined in Section 2A-10-00:

• Airplanes that have more than 2,500 flight hours must accomplish this document within 10 flight hours.
  
• Airplanes that have less than 2,500 flight hours must accomplish this document within 10 flight hours upon reaching 2,500 flight hours.
  
• It is acceptable to accomplish this service document before 2,500 hours to align with a scheduled maintenance event or inspection.

2. Inspection Requirements

A. Two types of inspection requirements are available based on operating usage and two additional types of inspections are available based on operating environment.
(1) Operating Usage

1. (a) Severe Usage Environment
   1. 1 If the average flight length is less than 30 minutes, then you must use the SEVERE inspection time limits.
      
   2. 2 If the airplane has been engaged in operations at low altitudes such as pipeline patrol, fish or game spotting, aerial applications, police patrol, sightseeing, livestock management, etc. more than 30% of its life you must use the SEVERE inspection time limits.
      
2. (b) Typical Usage Environment
   1 If neither 2(A)(1)(a)(1) or 2(A)(1)(a)(2) above applies, the TYPICAL usage environment applies.

(2) Operating Environment

(a) Severe Corrosion Environment

1 If the airplane is operating more than 30% of the time in a zone shown as severe on the corrosion severity maps in Section 2A-30-01, then the SEVERE CORROSION environment time limits apply.

(b) Mild or Moderate Corrosion Environment

1 If 2(A)(2)(a)(1) does not apply, then the MILD/MODERATE CORROSION environment time limits apply.

So your low level aircraft around the coast of Australia come under the Severe Usage 2500 hour limit as above.

For airplanes flown in TYPICAL Usage as defined in Section 2A-10-00: (ie not Severe usage)

• Airplanes that have more than 15,000 flight hours must accomplish this document within 10 flight hours.
  
• Airplanes that have less than 15,000 flight hours must accomplish this document within 10 flight hours upon reaching 15,000 flight hours.
  
• It is acceptable to accomplish this service document before 15,000 flight hours to align with a scheduled maintenance event or inspection.
  

So if you have a 14,900 hour C210/C177 in the middle of Australia that has had an easy life, relax, you've got another 100 hours before you need to do the SL.

That is if CASA even follows the American SL/SB system, which as a non Oz I do not know.

FWIW