What it does
This Civil Aviation Safety Authority (CASA) Airworthiness Directive (AD/BEECH 35/73, 10/2008) requires replacement of specified circuit breaker toggle switches in certain Beechcraft Bonanza series aeroplanes and prohibits re‑installation of the affected old part numbers as initial fit or replacement spares. The Directive’s Applicability block identifies aeroplanes listed in Table 1 that "have any circuit breaker toggle switch with a part number (P/N) 35‑380132‑1 through 35‑380132‑53 installed." Table 1, as it appears in the Directive, lists model V35B, serial numbers D‑9069 through D‑10403. Requirement 1 mandates, "Unless previously accomplished, replace all circuit breaker toggle switches P/N 35‑380132‑1 through 35‑380132‑53 with an improved circuit breaker toggle switch, P/N 35‑380132‑61 through 35‑380132‑113, as applicable, as specified in Raytheon Aircraft Company (RAC) Recommended Service Bulletin SB 24‑3735, Issued: August 2005." Requirement 2 states that the older P/Ns "may not be installed on any aeroplane as an initial fit or as a replacement spare."
The Directive also establishes compliance times. Under the Compliance heading it prescribes: for Requirement 1, "Within the next 24 months after the effective date of this Directive." The documented effective date is 25 September 2008, therefore the specific compliance window set by this Directive extended to 25 September 2010. For Requirement 2 it prescribes: "Before further flight after the circuit breaker toggle switch has been replaced in accordance with Requirement 1." The Directive further records that "Later revisions of the above SB, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2008‑13‑17, are considered acceptable for compliance with the equivalent Requirements of this Directive." The Directive includes a Background paragraph describing FAA reports of overheating and potential for smoke in the cockpit and inability to turn off the switch, and it notes that a draft was posted for public comment on 9 July 2008 with no comments received. The Directive is signed (James Coyne, Delegate of CASA) with signature date 8 August 2008.