AD/PR/38 Propeller Electronic Controller (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.001(1) of CASR 1998.  The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.

Propellers - Variable Pitch - Dowty Rotol

AD/PR/38 Propeller Electronic Controller 3/2008 TX

Applicability:

Propeller Electronic Controller Part No. 699018002 with the following serial numbers:- 1488,1489, 1490, 1494, 1495, 1496, 1498, 1499, 1500, 1501, 1502, 1503, 1504, 1505, 1506, 1508, 1509, 1510, 1511, 1512, 1513, 1514, 1515, 1516, 1517, 1518, 1519, 1520, 1521, 1522, 1527, 1528, 1529, 1530, 1531, 1532, 1537, 1538, 1541, 1542, 1543, 1544, 1549, 1550, 1567, 1569, 1570, 1571, 1572, 1573, 1574 and 1581

Requirement:

1.    If two affected units, listed in the applicability, are installed on one aircraft, remove one unit from service.

2.    Remove all units identified above from service.

3.    Replace with a serviceable unit, Part no 699018002, in accordance with the relevant Aircraft Maintenance Manual.

4.    Once removed, do not refit affected units until the input/output circuit board has been replaced by an organisation approved for the task, in accordance with Alert Service Bulletin D8400-61-A77 dated 14 January 2008.

Note 1:  These units are known to be fitted to, but not limited to, Bombardier DHC 8-400 aircraft.

Note 2:  UK CAA AD G-2008-003 refers.

Compliance

For Requirement 1.      Within 7 days of the effective date of this AD.

For Requirement 2.      Within 1200 flight hours or 6 months of the effective date of this AD, whichever limit is reached first.

For Requirement 3       From the effective date of this Directive.

For Requirement 4       From the effective date of this Directive.

This Airworthiness Directive becomes effective on 21 January 2008.

Background: The TC holder has identified that, due to a production problem, there is an increased potential for failure of input/output circuit boards fitted to Propeller Electronic Controllers with the above unit serial numbers. Failure could lead to uncommanded propeller speed changes or loss of the autofeather function.

Charles Lenarcic
Delegate of the Civil Aviation Safety Authority

18 January 2008