Opaerator Message from Bombardier
The following message is being sent to all Bombardier Aerospace Regional Aircraft Q400 Operators and Bombardier Aerospace Regional Aircraft Field Service Representatives.
DISCUSSION:
As a result of the information contained in the preliminary report, attached below, Operators are advised that should a Solenoid Sequence Valve (SSV) or Mechanical Sequence Valve (MSV) be replaced, care should be taken to ensure that FOD is not collected and transferred during the replacement of serviceable unit/s.
Although highly improbable that the transfer of such FOD would have a major impact on the hydraulic system, under special circumstances the migration of such FOD could cause the landing gear system to malfunction.
Operators are encouraged to ensure that only official documentation is used when changing components, that unions and fixtures on the SSV and MSV are not swapped out with alternative components without thorough care and cleaning, and only if following approved, documented procedures.
Under normal circumstances, FOD will be captured by the existing filters and valves but unapproved procedures without care can bypass these safeguards.