59-12-08 de HAVILLAND: Applies to All Model 104 "Dove" Aircraft.
Compliance required not later than July 20, 1959.
A case has been reported where a powerplant fire extinguisher spray pipe P/N 4M-99ND had been installed without having the spray holes drilled in it.
(1) Spray pipe P/N 4M99ND must be inspected to ascertain whether it has the spray holes drilled in it as follows:
(a) Open the engine cowlings and inspect the spray pipe running from the distributor unit round the blower casing.
(b) If the pipe has not had the spray holes drilled in it remove the pipe and replace with a serviceable item; or
(c) The unserviceable pipe may be rendered serviceable by working to the details shown in de Havilland Technical News Sheet CT (104) No. 163.
(2) The above inspection, and replacement or rework action where necessary, must be accomplished on all spare powerplants and spares stock before installation in aircraft.
The British Air RegistrationBoard considers this mandatory.
(de Havilland TNS CT (104) No. 163 covers the same subject.)