55-15-01 BOEING: Applies to All Boeing 377 Series Aircraft with Hamilton Standard Propellers.
Compliance required by first scheduled engine change after November 1, 1955, but not later than November 1, 1956.
To increase the fire resistance integrity of the propeller feathering system against damage by a powerplant fire, all flexible hose components of propeller feathering lines forward of the firewall in zone 2 must be replaced with lines and fittings which will meet current fire resistance requirements. The following hose assemblies are considered acceptable for this applications:
(a) Aeroquip 680-10S hose assemblies with Aeroquip 304 protective sleeves over end fittings (Aeroquip assembly P/N 304000).
(b) Resistoflex SSFR-3800-10 hose assemblies.
(c) Aeroquip 309009-10S hose assemblies.