Recommendation

FAA Enqine & Propeller Directorate Response



The BR700-715 engine has experienced four in-flight shutdowns
(IFSDs). The IFSDs result from the failure of the Engine Electronic
Control (EEC) in 2002. Since that time, the Engine & Propeller
Directorate Engine Certification Office (ECO) of the Federal
Aviation Administration (FAA) has been conducting an on-going
investigation of this airworthiness issue with Luftfahrt-Bundesamt
(LBA) and Rolls-Royce Deutschland Ltd and Co (RRD). On October 15,
2003, LBA issued AD-2003-235 to mandate Service Bulletin (SB)
SB-BR700-73-900334 Revision 1 and SB SB-BR700-73-900316 Revision 2.
However, the ECO disagrees with issuing an AD at this time for the
following reasons:



(1) Based on RRD's investigation, without taking any corrective
action, the risk of a dual engine IFSD rate is at 1.1x10-10, which
satisfies FAA airworthiness guidelines.



(2) RRD SB SB-BR700-73-900316 introduces a number of inspections
and modifications to isolate, remove, and replace certain
components to improve the EEC reliability. RRD has been conducting
an active EEC hardware campaign since March 2003 to remove the
units that have not met SB SB-BR700-73-900316 standard. More than
209 EECs have been campaigned to date. There has been no report of
an IFSD caused by the failure of an EEC since December 2002, which
could be attributed to the problem areas addressed by RRD SB
SB-BR700-73900316. During this time, the EEC mean time between
removals has increased by 95%. It is expected that the reliability
of the EEC will be further improved through the campaign on its
completion in September 2004.



The Engine & Propeller Directorate concludes the failure of the
BR700-715 EEC is an airworthiness issue and requires continued
monitoring. However, it is not a safety issue at this time.
Therefore, the Directorate does not plan to issue an AD to mandate
RRD SB SB-BR700-73-900316.