# AD 78-07-05: Wheelwell Frame Fittings - Type: Airworthiness directive - Status: Current - Products: Boeing DC-9-11, DC-9-12, DC-9-13, DC-9-14, DC-9-15, DC-9-15F, DC-9-21, DC-9-31, DC-9-32, DC-9-32 (VC-9C), DC-9-32F, DC-9-32F (C-9A) and 10 more - Effective: May 18, 1979 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Large airplane - Amendment: 39-3467 - Registered aircraft: 99 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/00E0391AC7FFCCB786256E0C00738F8F.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/78-07-05 ## The airworthiness directive 78-07-05 MCDONNELL DOUGLAS: Amendment 39-3176 as amended by amendment 39-3467. Applies to Model DC-9 and C-9 series airplanes, certificated in all categories, which correspond to the factory serial numbers as listed below. 45695 thru 45749 47389 thru 47397 45770 thru 45799 47399 thru 47482 45825 thru 45847 47484 thru 47514 45863 thru 45876 47516 thru 47557 47000 thru 47386 47559 thru 47764 47769 47771 Compliance required as indicated, unless already accomplished: To prevent possible failure of the over-wheelwell fuselage frame(s) lower fittings manufactured with 7075-T6 aluminum alloy material, accomplish the following: a. For airplanes with 12,000 or more hours time in service on the effective date of this AD, which have not had new frames installed, within the next 3400 hours time in service or 12 calendar months, whichever occurs earlier, and thereafter at intervals not to exceed 8000 hours time in service or 37 calendar months, whichever occurs earlier, comply with the program of inspections established in Paragraph (c), below. b. For airplanes with less than 12,000 hours time in service as of the effective date of this AD, comply with Paragraph (c), below, prior to the accumulation of 15,400 hours time in service or 50 calendar months, whichever occurs earlier, and thereafter at intervals not to exceed 8000 hours time in service or 37 calendar months, whichever occurs earlier. c. Visually inspect for evidence of cracking, using optical inspection aids with a minimum of 2X magnification, the fore and aft webs, flanges and radii, in the areas of the frame lower fitting, as shown in Sketch No. 2765 of McDonnell Douglas Service Bulletin 53-131 dated February 24, 1978 or later FAA approved revision, (hereinafter referred to as SB 53-131). d. If no cracks are found: (1) Clean and spray the pocket and adjacent areas of the frame fitting with corrosion inhibiting compound, per DAC SRM, Chapter 51-10-3, and perform repetitive inspections and corrosion inhibiting treatment at intervals not to exceed 8,000 hours time in service or 37 calendar months, whichever occurs earlier; or (2) Repair per Option 1 of SB 53-131 and conduct repetitive inspection at intervals not to exceed 16,000 hours time in service or 54 calendar months whichever occurs earlier; or (3) Replace with new part(s) per Paragraphs f.2 or f.3 and comply with the applicable program of repetitive inspections and/or corrective actions per this AD. e. If cracks are found which are within the limits of Figure 1 of SB 53-131, aircraft may be continued in service provided that (1) Repetitive inspections are conducted at intervals not to exceed 3,400 hours time in service if an adjacent frame does not have cracks in pocket area or has been repaired per Option 1 of SB 53-131; or (2) Repetitive inspections are conducted at intervals not to exceed 1,700 hours time in service if adjacent frame(s) hasunrepaired flange cracks within limits as outlined on Figure 1 of SB 53-131. f. If cracks are found, which are beyond the limits of Figure 1, but within the limits of Figure 2 of SB 53-131, before further flight. (1) Repair per Option 1 of SB 53-131 and conduct repetitive inspections at intervals not to exceed 8,000 hours time in service or 27 calendar months, whichever occurs earlier; or (2) Replace with a new part(s) of the same design made from 7075-T6 aluminum material; or (3) Replace with a new part(s) of the same design made from 7075-T73 aluminum alloy material. g. If cracks are found which are beyond the limits of Figure 2 of SB 53-131, before further flight: (1) Replace with a new part(s) of the same design made from 7075-T6 aluminum alloy material; or (2) Replace with a new part(s) of the same design made from 7075-T73 aluminum alloy material. h. The requirements per this AD may be terminated for that frame(s) only, when both theright and left hand fittings, made from 7075-T73 aluminum alloy material, have been installed. i. If new parts have been installed per f(2) or g(1) for the stations specified, the requirements of this AD may be discontinued for that part(s) only, until the new part(s) has accumulated 15,400 hours time in service or within 50 calendar months after the part(s) has been replaced, whichever occurs earlier, at which time reinstate the program of repetitive inspections and/or corrective action per this AD. j. Equivalent inspection procedures and repairs may be used when approved by the Chief, Aircraft Engineering Division, FAA, Western Region. k. Special flight permits may be issued in accordance with FAR's 21.197 and 21.199 to operate airplanes to a base for the accomplishment of inspections and/or maintenance required by this AD. l. Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Aircraft Engineering Division, FAA Western Region may adjust the initial and repetitive inspection intervals specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for that operator. This supersedes Amendment 39-3149 (43 FR 9587), AD 78-05-03. Amendment 39-3176 became effective April 6, 1978. This amendment 39-3467 becomes effective May 18, 1979. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A6WE](https://openairdocs.org/tcds/A6WE): The Boeing Company; names 19 of 25 models: DC-9-12, DC-9-15F, DC-9-41, DC-9-13, DC-9-34F, DC-9-81 (MD-81), DC-9-33F, DC-9-83 (MD-83)… ## 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: 99 (99 by airframe model, 0 by engine model) - Makers: Mcdonnell Douglas 93, Douglas 6 Models with the most aircraft: - [Mcdonnell Douglas DC-9-83(MD-83)](https://openairdocs.org/model/mcdonnell-douglas-dc-9-83-md-83): 49 aircraft (airframe model) - [Mcdonnell Douglas DC-9-82(MD-82)](https://openairdocs.org/model/mcdonnell-douglas-dc-9-82-md-82): 22 aircraft (airframe model) - [Mcdonnell Douglas DC-9-87](https://openairdocs.org/model/mcdonnell-douglas-dc-9-87): 13 aircraft (airframe model) - [Mcdonnell Douglas DC-9-15F](https://openairdocs.org/model/mcdonnell-douglas-dc-9-15f): 3 aircraft (airframe model) - [Mcdonnell Douglas DC-9-33F](https://openairdocs.org/model/mcdonnell-douglas-dc-9-33f): 3 aircraft (airframe model) - [Douglas DC-9-83](https://openairdocs.org/model/douglas-dc-9-83): 1 aircraft (airframe model) - [Douglas DC9-15](https://openairdocs.org/model/douglas-dc9-15): 1 aircraft (airframe model) - [Douglas DC-9-15F](https://openairdocs.org/model/douglas-dc-9-15f): 1 aircraft (airframe model) - [Douglas DC-9-21](https://openairdocs.org/model/douglas-dc-9-21): 1 aircraft (airframe model) - [Douglas DC-9-32F](https://openairdocs.org/model/douglas-dc-9-32f): 1 aircraft (airframe model) - [Mcdonnell Douglas DC-9-32](https://openairdocs.org/model/mcdonnell-douglas-dc-9-32): 1 aircraft (airframe model) - [Mcdonnell Douglas DC-9-32F](https://openairdocs.org/model/mcdonnell-douglas-dc-9-32f): 1 aircraft (airframe model) - [Douglas DC-9-33F](https://openairdocs.org/model/douglas-dc-9-33f): 1 aircraft (airframe model) - [Mcdonnell Douglas DC-9-87 (MD-87)](https://openairdocs.org/model/mcdonnell-douglas-dc-9-87-md-87): 1 aircraft (airframe model) All 14 models: https://openairdocs.org/ad/78-07-05/models.md Every aircraft: https://openairdocs.org/ad/78-07-05/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.