Airworthiness Directive · Amendment 39-15802 · Equipment/furnishings
Learjet Model 55, 55B, and 55C Airplanes
This AD applies to Learjet Model 55, 55B, and 55C airplanes, certificated in any category; serial numbers 002 through 147 inclusive.
We are adopting a new airworthiness directive (AD) for certain Learjet Model 55, 55B, and 55C airplanes. This AD requires inspecting the installation of the forward light assembly in the aft lavatory to determine the location of the terminal connector; inspecting for damage of the light assembly terminals, wires, and oxygen lines; inspecting to determine if the cable nipple is installed over the light assembly terminal; and doing corrective actions if necessary. This AD also requires installing a clamp to the forward side of the frame to maintain a positive distance between the light assembly and oxygen line. This AD results from a report of a cabin fire in the left-hand upper cabin fuselage above the aft cabin window at frame 23. We are issuing this AD to detect and correct improper installation of the lavatory light assembly, which could result in contact between the electrical terminals of the light assembly and an adjacent oxygen supply line, and consequent short circuit or fire hazard.
Comply with this AD within the compliance times specified, unless already done.
Within 30 days or 25 flight hours after the effective date of this AD, whichever occurs first, do the actions specified in paragraphs (g)(1) and (g)(2) of this AD. Do the actions in accordance with the Accomplishment Instructions of Bombardier Alert Service Bulletin A55-25-7, dated December 17, 2008.
(1) Do a general visual inspection of the installation of the forward light assembly in the aft lavatory to determine the location of the terminal connector; do a general visual inspection for damage of the light assembly terminals, wires, and oxygen lines; do a general visual inspection to determine if the cable nipple is installed over the light assembly terminal; and do all applicable corrective actions. Do all applicable corrective actions before further flight.
Note 1: For the purposes of this AD, a general visual inspection is: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to ensure visual access to all surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”
(2) Install a clamp and hardware to the forward side of the frame to maintain the distance specified in Bombardier Alert Service Bulletin A55-25-7, dated December 17, 2008, between the light assembly and oxygen line.
Although Bombardier Alert Service Bulletin A55-25-7, dated December 17, 2008, specifies to submit certain information to the manufacturer, this AD does not include that requirement.
