{"id":"F2006B03983","name":"AD/BEECH 55/35 - Internally Lighted Altimeter","slug":"ad-beech-55-35-internally-lighted-altimeter","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"repealed","isInForce":false,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":43592,"registerId":"commonwealth-F2006B03983-current","compilationNumber":null,"startDate":"2026-04-02","status":"Repealed","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"AD/BEECH 55/35 - Internally Lighted Altimeter","content":"COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 \\- 105 CIVIL AVIATION SAFETY AUTHORITY\n\nSCHEDULE OF AIRWORTHINESS DIRECTIVES\n\n![](image.001.png)  \nBeechcraft 55, 58 and 95-55 (Baron) Series Aeroplanes\n\nAD/BEECH 55/35 Internally Lighted Altimeter 4/75\n\nApplicability: All models with internally lighted altimeters supplied as spares ex Beech Wichita between 1 September 1972 and 1 August 1973, and all models with S/Nos. TH-269 to TH-366, TE-884 to TE-934, and TC-1490 to TC-1592.\n\nRequirement: 1. Prior to next flight visually inspect the internally lighted altimeters. If the locking stud screw is located above and to the left of the barometric scale adjustment knob, no further inspection or replacement is necessary.\n\n2. If the locking stud screw is located below, and to the right of the barometric adjustment knob, replace the instrument within 50 hours’ time in service after\n\n17 October 1973. Until replacement is accomplished check the altimeter prior to each flight as follows:\n\nRotate barometric scale adjustment knob while applying outward finger pressure to ensure the elevation hands do not disengage from the barometric scale.\n\nDisengagement will be readily recognised by the knob snapping outward and the elevation hands will not move when the barometric scale is rotated. If disengagement occurs, replace the altimeter with a 58-380045-3 millibars scale 35,000 feet altimeter, or an equivalent. All future altimeters will have locking stud screws above and to the left of the adjusting knob as in 1 above.\n\nNote: Until replacement altimeters are installed forward pressure should be exerted on the knob whenever changing barometric settings.\n\nCompliance: As detailed in the Requirement.","sortOrder":0}],"analysis":{"kimi_summary":{"_metrics":{"model":"kimi-k2.5","source":"moonshot-batch","completionTokens":2733},"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"The directive maintains its original narrow scope addressing the specific manufacturing defect in internally lighted altimeters. It has not expanded to cover other instrument types or aircraft models beyond the identified Beechcraft Baron series."},"complexity_factors":["Multiple applicability criteria requiring cross-referencing of aircraft serial numbers against manufacturer date ranges","Technical aviation terminology requiring specialised knowledge (e.g., 'time in service', 'elevation hands', 'barometric scale')","Bifurcated compliance pathway depending on physical location of a locking stud screw","Specific manufacturer's part number mandated for replacement instruments","Interim operational requirements (pre-flight functional checks) pending mandatory component replacement"],"plain_english_summary":"This directive requires owners/operators of Beechcraft 55, 58, and 95-55 Barons with certain spare altimeters (Sept 1972–Aug 1973) or specific serial-number ranges to visually inspect the altimeter locking-stud position because a mislocated stud can let the altitude hands disengage, making height indications unreliable.\n\nIf the stud is in the wrong place, you must replace the altimeter within 50 flight hours and check it before every flight; meanwhile pilots should push the knob forward when changing barometric settings."}},"importantCases":[],"_links":{"self":"/api/acts/ad-beech-55-35-internally-lighted-altimeter","history":"/api/acts/ad-beech-55-35-internally-lighted-altimeter/history","analysis":"/api/acts/ad-beech-55-35-internally-lighted-altimeter/analysis","conflicts":"/api/acts/ad-beech-55-35-internally-lighted-altimeter/conflicts","importantCases":"/api/acts/ad-beech-55-35-internally-lighted-altimeter/important-cases","documents":"/api/acts/ad-beech-55-35-internally-lighted-altimeter/documents"}}