# AD 68-23-06: Internal Portion of Beech Center Section Wing Truss Assembly - Type: Airworthiness directive - Status: Current - Products: Textron C-45G, C-45H, D18C, D18S, E18S, E18S-9700, G18S, H18, JRB-6, TC-45G, TC-45H and TC-45J - Effective: December 19, 1968 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Small airplane - Amendment: 39-684 - Registered aircraft: 230 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/23F4F2B5526C141986256A08006C49D6.0001 - DRS record last changed: January 21, 2026 - Page: https://openairdocs.org/ad/68-23-06 ## The airworthiness directive 68-23-06 BEECH: Amendment 39-684. Applies to Models D18C, D18S, E18S, E18S- 9700, G18S, H18, C45G, TC45G, C45H, TC45H, TC-45J (SNB-5), and JRB-6 with Volpar Tri- Gears, Serial Numbers 1 through 368, installed in accordance with STC SA111-WE or SA4- 1531. Compliance is required within the next six calendar months after the effective date of this AD, unless already accomplished. Repetition thereafter is not necessary. To determine the possible presence of corrosion and to provide a moisture barrier for the internal portion of the Beech center section wing truss assembly, accomplish the following: (a) Remove two bolts at each attachment point where the Volpar truss in each nacelle is secured to the center section wing truss as shown in Figure Nos. 1 and 2 of Volpar Service Bulletin no. 14. Dry and seal tubes from which bolts were removed in accordance with paragraphs 1 and 2 of Volpar Service Bulletin No. 14 or later FAA approved revision. (b) Remove the bolt which passes through the lower sparcap just inboard of each outer wing attach point as shown in Figure 3 of Volpar Service Bulletin No. 14. Inspect the bolts for corrosion and pitting, and the edges of the bolt hole through the elliptical spar tube for indications of moisture and/or corrosion. If pitting of the bolts exceeds .005 inches in depth or if evidence of moisture or corrosion exists, further inspections outlined under (c), below, must be accomplished. Otherwise dry and seal the lower spar cap in accordance with paragraphs 1 and 2 of Volpar Service Bulletin No. 14, or later FAA approved revision. (c) Conduct an x-ray inspection of the elliptical lower spar cap outboard of the wing to fuselage intersection for evidence of internal corrosion in accordance with Volpar Service Bulletin No. 14 and Report No. 34 or latter FAA approved revisions. If corrosion is indicated by this inspection, before further flight, the part must be replaced or the extent of corrosion and the corrective action to be taken must be evaluated by Volpar, Inc., and concurred in by the Chief, Aircraft Engineering Division, FAA Western Region. (d) Upon satisfactory completion of (c), dry and seal the lower spar cap as specified in (b), above. (e) Modify the Volpar Part No. 299-2 drag strut by cutting off the lug for the bolt in accordance with Figure 3 of Volpar Service Bulletin No. 14. Install Volpar Part No. 873 strap installation and Volpar Part No. 873-2 strap or an equivalent approved by the Chief Aircraft Engineering Division, FAA Western Region. (f) Aircraft with corrosion found pursuant to (c) of this AD may be flown in accordance with FAR 21.197 to a base where further evaluation or repair may be accomplished. This amendment becomes effective December 19, 1968. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A-765](https://openairdocs.org/tcds/A-765): Textron Aviation Inc.; names 12 of 17 models: E18S-9700, TC-45J, TC-45G, C-45H, C-45G, G18S, E18S, TC-45H… ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 230 (230 by airframe model, 0 by engine model) - Makers: Beech 230 Models with the most aircraft: - [Beech D18S](https://openairdocs.org/model/beech-d18s): 55 aircraft (airframe model) - [Beech E18S](https://openairdocs.org/model/beech-e18s): 51 aircraft (airframe model) - [Beech C-45H](https://openairdocs.org/model/beech-c-45h): 50 aircraft (airframe model) - [Beech H-18](https://openairdocs.org/model/beech-h-18): 28 aircraft (airframe model) - [Beech G18S](https://openairdocs.org/model/beech-g18s): 23 aircraft (airframe model) - [Beech C-45G](https://openairdocs.org/model/beech-c-45g): 9 aircraft (airframe model) - [Beech E18S-9700](https://openairdocs.org/model/beech-e18s-9700): 7 aircraft (airframe model) - [Beech TC-45J](https://openairdocs.org/model/beech-tc-45j): 5 aircraft (airframe model) - [Beech TC-45G](https://openairdocs.org/model/beech-tc-45g): 2 aircraft (airframe model) All 11 models: https://openairdocs.org/ad/68-23-06/models.md Every aircraft: https://openairdocs.org/ad/68-23-06/aircraft.md Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.