Textron Aviation (Beechcraft) 55, 58 and 95-55 (Baron) Series Aeroplanes

AD/BEECH 55/79 Amdt 7

Wing Bolt, Nut and Fitting

12/2025

Applicability:

All models of Textron Aviation (Beechcraft) 55, 58 and 95-55 series aircraft.

Requirement:

1. Remove inspection covers from wing attach fitting recesses and inspect for corrosion or loss of inhibitor. Also inspect drain holes for any blockage that would cause water or debris to accumulate.

Note 1:  It may be necessary to use a bright light and mirror/magnifying glass to see hard to view areas of the bolt or fittings for signs of corrosion on accessible areas of the bolt. Non accessible areas like the bolt thread encapsulated by the nut will be inhibited, so it is highly unlikely they will experience corrosion unless the general surrounding area is corroded.

2. Remove and inspect wing bolts, washers, nuts and fittings in accordance with:

• Beechcraft Baron Maintenance Manual 55-590000-13 Revision H2 Revision date May 29, 2024, Section 57‑10-00, for model 55 and 58 series; or
• Baron Maintenance Manual 102‑590000-5 Revision A25, Revision date June 01, 2002, Section 57-00-00, for model 58P and TC series;

both as in force on the date of commencement of this AD.

Note 2:  The bolt torque should be checked before removal for inspection or replacement to confirm the bolt has been torqued to correct value. If the torque value is incorrect, other maintenance action may be required.

3. Retire wing bolts, washers and nuts from service and replace with new hardware in accordance with:

• Beechcraft Baron Maintenance Manual 55-590000-13 Revision H2 Revision date May 29, 2024, Section 57‑10-00, for model 55 and 58 series; or
• Baron Maintenance Manual 102‑590000-5 Revision A25, Revision date June 01, 2002, Section 57-00-00, for model 58P and TC series;

both as in force on the date of commencement of this AD. Render unserviceable all hardware retired.

Alternatively for Model 55 and 58 series aircraft only, the bolts may be maintained on condition IAW Table 201, Beechcraft Baron Maintenance Manual 55-590000-13 Revision H2 Revision date May 29, 2024, Section 57‑10-00, as in force on the date of commencement of this AD.

Compliance:

For Requirement 1:

Every 12 calendar months for all aircraft. If visible corrosion is found within the recess or on visible portion of the bolt or nuts, washers or fittings, then Requirement 2 must be accomplished before further flight.

For Requirement 2:

a. For aircraft operating only in private operations:

i. unless the inspection has already been accomplished in accordance with either the Beechcraft Baron Maintenance Manual 55-590000-13 Revision H2 dated May 29, 2024 or the Baron Maintenance Manual 102‑590000-5 Revision A25 dated June 1, 2002, each as in force at the commencement of this AD (the requirement documents) within 10 years from the initial installation of the wing bolts — inspect within 100 hours’ time in service (TIS) or 12 months from the commencement date of this AD, whichever occurs first.

Note 4:  Installation of the wing bolts includes where they are removed for inspection purposes and re-installed.

ii. re-inspect at intervals not to exceed 10 years from the previous inspection.

b. For all other operational categories:

i. unless the inspection has already been accomplished in accordance with either of the requirement documents within 5 years from the installation of the wing bolts — inspect within 100 hours’ TIS or 12 months from the commencement date of this AD, whichever occurs first.

Note 5:  Installation of the wing bolts includes where they are removed for inspection purposes and re-installed.

ii. re-inspect at intervals not to exceed 5 years from the previous inspection.

For Requirement 3:

1.        For models 55 and 58 series aeroplanes - Before 20 years TIS after the first installation of new zero time wing bolts.

b. For models 58P and 58TC series aeroplanes - Before 15 years TIS after the first installation of new zero time wing bolts.

Alternatively for Model 55 and 58 series aircraft only, the bolts may be maintained on condition IAW Table 201, Beechcraft Baron Maintenance Manual 55-590000-13 Revision H2 Revision date May 29, 2024, Section 57‑10-00, as in force on the date of commencement of this AD.

Note 6: Always replace wing attach nuts with new items when removing the wing attach bolts for inspection.

Mandatory reporting requirements:

Both NIL findings of defects and confirmed defects for Requirement 2 inspection must be reported via CASA’s Defect Reporting Service, either through the online portal at:

https://www.casa.gov.au/resources-and-education/our-systems/defect-report-service

or by using Form 404 available from:

https://www.casa.gov.au/defect-report

Commencement date:

This AD commences on 13 July 2025.

Background:

The initial issue of this Airworthiness Directive became effective on 1 February 1996 and made mandatory the inspection and replacement periods for the wing attachment hardware as detailed in the requirement document.

Amendment 1 of this AD updated the revision status of the Beech 55 Shop Manual.

Amendment 2 of this AD added the Note to Requirement 2 and added the fittings as an item to be inspected when the wing bolts, washers and nuts are removed and inspected.

Amendment 3 of this AD removed the alternative means of compliance that had been issued to allow in-situ inspection of the wing attachment bolts and nuts rather than conduct the manufacturer’s required MPI.

Amendment 4 of this AD was issued to extend the compliance time for Requirement 1 by two months whilst the proposed airworthiness directive process was conducted for AD/BEECH 55/79 Amdt 5.

Amendment 5 of this AD allowed for aircraft used in private operations to be visually inspected for corrosion in the exposed areas of the wing attach bolts and wing fitting recess with the inspection interval increased from 5 to 10 years, in lieu of using the manufacturer’s maintenance instructions. For all other types of operations, the inspection requirements remained unchanged, requiring inspection of the wing attach hardware and fitting recess per the manufacturer’s maintenance data.

Amendment 6 of this AD was issued following a change to the Instructions for Continued Airworthiness (ICA) by the type certificate holder, increasing the life limit of the wing bolts to 20 years and only requiring a removal and visual inspection at the five-year interval. This change was only applicable to the models 55 and 58 series aircraft and not models 58P and 58TC aircraft.

Amendment 7 of this AD follows the amendment of Beechcraft Maintenance Manual 55-590000-13 Revision H2 allowing for the wing attach bolts to be maintained on condition following their 20 year in service life as an option to replacing the bolts.