matblack
7th May 2007, 22:49
Why is it after all of this time since the suspected rudder issues were identified with the 737 that AD's are still issued as recently as a few weeks ago regarding failure of the pcu even on the 800 & 900 series? I always thought that Boeing retrofitted a revised pcu on older 737's and one would assume built 800/900 series with a more effective pcu.
matblack
8th May 2007, 20:49
[Docket No. FAA-2006-26323; Directorate Identifier 2006-NM-150-AD; Amendment 39-14918;
AD 2007-03-07]
RIN 2120-AA64
brief snippet:
Therefore, we have determined that, for certain Model 737-600, -700, -700C, -800, and -900
series airplanes on which the suspect input control rod of the standby rudder PCU was installed
during production, the compliance times for the following actions in the NPRM will not detect and
correct failure of the input control rod of the standby rudder PCU in a timely manner:
The initial compliance time and repetitive intervals for the operational tests specified in
paragraph (g)(1), and
The threshold for the replacement of the input control rod of the standby rudder PCU specified
in paragraph (g)(3).
Failure of one of the two input control rods of main rudder PCU, under certain conditions, could
result in reduced controllability of the airplane; and failure of any combination of two input control
rods of the main rudder PCU and/or standby rudder PCU could cause an uncommanded rudder
hardover event and result in loss of control of the airplane.