Airworthiness Directive · Amendment 39-14627 · Boeing Model 747-100B, 747-200B, 747-200F, 747-300, 747-400, 747-400F, and 747SP Series Airplanes
Boeing Model 747-100B, 747-200B, 747-200F, 747-300, 747-400, 747-400F, and 747SP Series Airplanes
This AD applies to Boeing Model 747-100B, 747-200B, 747-200F, 747-300, 747-400, 747-400F, and 747SP series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 747-54A2225, dated February 16, 2006.
The FAA is adopting a new airworthiness directive (AD) for certain 747-100B, 747-200B, 747-200F, 747-300, 747-400, 747-400F, and 747SP series airplanes. This AD requires doing inspections of the midpivot bolt and midpivot bolt access door of the spring beam of the inboard side of the outboard struts for discrepancies, installing a placard on the midpivot bolt access door, and applicable corrective actions if necessary. This AD results from reports indicating that the midpivot bolt and midpivot bolt access door of the spring beam of the inboard side of the outboard struts were installed in the incorrect position. We are issuing this AD to ensure that the subject midpivot bolts and midpivot bolt access doors are installed in the correct position. If not installed in the correct position, a midpivot bolt could be overloaded and crack or fracture, which could result in the loss of the spring load path and consequent separation of the associated outboard strut and engine from the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.
Do the inspections specified in Table 1 of this AD at the applicable compliance time listed in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 747-54A2225, dated February 16, 2006; except, where the service bulletin specifies a compliance time from the release date of the service bulletin, this AD requires compliance within the specified compliance time after the effective date of this AD. Do the inspections in accordance with the Accomplishment Instructions of the service bulletin.
| Do— | Of— | For— |
|---|---|---|
| (1) A general visual inspection | The midpivot bolt access doors | The correct part number, damage (i.e., wear, nicks, gouges, elongated fastener holes, or cracks), or the correct position of its anti-rotation tabs. |
| (2) A general visual inspection | The anti-rotation tabs of the midpivot bolt access doors | Damage (i.e., wear, nicks, gouges, or cracks) or any missing tab. |
| (3) A general visual inspection | The midpivot bolts | Correct position or damage (i.e., nicks, gouges, or cracks). |
| (4) An ultrasonic inspection | The midpivot bolts | Cracks. |
Note 1: There is a discrepancy in Step 2 of Figure 13, Sheet 2, of Boeing Alert Service Bulletin 747-54A2225, dated February 16, 2006. The “MORE DATA” column of the table incorrectly describes the anti-rotation slot installation as being “horizontal and are perpendicular to the strut skin aft edge.” The correct description is “vertical and are parallel to the strut skin aft edge.”
Before further flight after doing the inspections required by paragraph (f) of this AD, do the applicable actions specified in Table 2 of this AD in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-54A2225, dated February 16, 2006.
| If— | And if— | Then— |
|---|---|---|
| (1) Any midpivot bolt access door has the correct part number and no damage | Its anti-rotation tabs are present, are in the correct position, and have no damage | Install a placard on the midpivot access door. |
| (2) Any midpivot bolt access door has the incorrect part number and no damage | Its anti-rotation tabs are present, are in the incorrect position, and have no damage | Change the midpivot access door or replace it with a new or serviceable access door, and install a placard on the midpivot access door. |
| (3) Any midpivot bolt access door has the incorrect part number, any damage, or any damaged or missing anti-rotation tab | None | Replace the midpivot access door with a new or serviceable door and install a placard on the door. |
| (4) Any midpivot bolt is in the correct position | It has no damage | No further action is required by this paragraph. |
| (5) Any midpivot bolt is in the incorrect position | It has no damage | Correct the midpivot bolt position. |
| Any midpivot bolt has any damage | None | Replace the midpivot bolt with a new bolt. |
If any condition in paragraph (h)(1) or (h)(2) of this AD is found on any outboard strut, within 24 months after doing the inspections required by paragraph (f) of this AD, replace the midpivot bolt of the spring beam of the inboard side of that outboard strut with a new midpivot bolt, in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-54A2225, dated February 16, 2006.
(1) If any midpivot bolt access door of the spring beam of the inboard side of the outboard struts is found in the incorrect position (i.e., the midpivot bolt access door has the incorrect part number or its anti-rotation tabs are in the incorrect position) and if no damage is found on that bolt during any inspection required by paragraph (f) of this AD.
(2) If any midpivot bolt of the spring beam of the inboard side of the outboard struts is found in the incorrect position and if no damage is found on that bolt during any inspection required by paragraph (f) of this AD.
(i) As of the effective date of this AD, no person may install, on any airplane, a midpivot access door, part number 65B89670-339, 65B89670-340, 654U6624-356, or 654U6624-357, unless it has been inspected in accordance with paragraphs (f)(1) and (f)(2) of this AD and found to have the correct part number for the door location, no damage, and no damaged or missing anti-rotation tab.
Although the service bulletin referenced in this AD specifies to submit certain information to the manufacturer, this AD does not include that requirement.
