Recommendation

Cessna Aircraft Company responded to this proposed safety
recommendation (draft recommendation F) in the ATSB draft report by
stating:

Cessna continues to support our previous stance on this subject.
A chip detector annunciation can identify a minor to a major
problem. This is the reason Cessna has elected to leave the
checklist somewhat up to the pilot's discretion. The pilot is the
only one in a position to assess whether he has a minor or major
problem and the potential effects. It would be equally bad to lead
the pilot into a premature off airport landing when a minor problem
would have allowed the engine to run normally to a safe airport
landing.

Prior to this occurrence, Cessna and APC records show that there
has never been an electrical discharge damage (EDD) failure on an
APC starter generator installed on 208 aircraft. A review of the
Lucas starter generator maintenance history, that Cessna had access
to, reveals no incidents of any EDD or electrical short problems on
Lucas units during the past five years. (Five years is as far as
the easily accessible records go back.) Based on the above
information, Cessna does not believe a change to the emergency
procedures is warranted.

ATSB comment:

The ATSB does not accept Cessna's comment in relation to the
information contained in the pilot's emergency procedures. 
While acknowledging that the pilot is best placed to evaluate any
abnormal situation, the emergency procedures statement "if engine
gauges are normal, proceed to destination..." can be misleading if
the number-1 engine bearing is becoming distressed.  This
investigation has shown that this process can take only a few
minutes from chip detector light illumination to complete engine
failure. 

It is the ATSB's view that the Cessna emergency procedures
should consider this scenario and include a statement such as "land
at the nearest suitable location" irrespective of engine gauge
readings. This does not mean the pilot should carry out an off
airport landing as stated in the Cessna response.  As such,
the ATSB now formally issues safety recommendation R20070018.