Structural Failure - Floor Beams Main Cargo Deck

Category - Airframe
Effective Date - 02/16/1999
Recurring - No
Supersedes - N/A
Superseded by - N/A
Amendment 39-10961. Docket 97-NM-09-AD.

Applicability:
Model 727 series airplanes that have been converted from a passenger to a cargo-carrying ("freighter") configuration in accordance with Supplemental Type Certificate (STC) SA1767SO, SA1768SO, or SA7447SW; certificated in any category.

Note 1:
This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (f) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance:
Required as indicated, unless accomplished previously.

Note 2:
The payload limitations specified in this AD are in addition to payload limitations that are otherwise applicable and do not allow for increases in payloads beyond those specified in such limitations. To prevent structural failure of the floor beams of the main cargo deck, which could lead to loss of the airplane, accomplish the following:
(a) Except as provided in paragraph (b) of this AD, within 90 days after the effective date of this AD, accomplish the requirements of paragraph (a)(1) or (a)(2) of this AD, as applicable.

(1) For airplanes that transport containers or pallets that have been manufactured in accordance with National Aerospace Standard (NAS) 3610 Size Codes "A," "B," "C," "D," "E," or the FedEx STC SA7447SW containers: Revise the Limitations Section of all FAA-approved Airplane Flight Manuals (AFM) and AFM Supplements, and the Limitations Section of all FAA-approved Airplane Weight and Balance Supplements to include the following information. This may be accomplished by inserting a copy of this AD in all AFM's, AFM Supplements, and Weight and Balance Supplements. "LIMITATIONS All containers with one door must be oriented with the door side of the container facing forward, except the door of the first container aft of the cargo barrier may face aft. The location of the horizontal center of gravity for the total payload within each container or pallet shall not vary more than 10 percent (8.8 inches) from the geometric center of the base of the container or pallet for the forward and aft direction, and 10 percent of the width from the geometric center of the base of the container or pallet for the left or right direction." "PAYLOAD LIMITATIONS For containers or pallets that have been manufactured in accordance with National Aerospace Standard (NAS) 3610 Size Code "A" (88 by 125 inches), "B" (88 by 108 inches), or "C" (88 by 118 inches): Do not exceed a total weight of 3,000 pounds per container or pallet on the main cargo deck, except in the area adjacent to the side cargo door. In the side cargo door area, for all containers or pallets completely or partially located between Body Station 440 and Body Station 660, those containers or pallets are restricted to a maximum payload of 2,700 pounds per container or pallet. The 3,000 and 2,700 pound payload limits include the payload in the lower lobe cargo compartments and any other load applied to the bottom of the floor beams of the main cargo deck for the same body station location as the container or pallet on the main cargo deck. For containers or pallets that have been manufactured in accordance with NAS 3610 Size Code "D" (88 by 54 inches) or "E" (88 by 53 inches), or FedEx STC SA7447SW containers (88 by 63 inches): Do not exceed a total weight of 1,500 pounds per container or pallet on the main cargo deck, except in the area adjacent to the side cargo door. In the side cargo door area, for all containers or pallets completely or partially located between Body Station 440 and Body Station 660, those containers or pallets are restricted to a  maximum payload of 1,350 pounds per container or pallet. The 1,500 and 1,350 pound payload limits include the payload in the lower lobe cargo compartments and any other load applied to the bottom of the floor beams of the main cargo deck for the same body station location as the container or pallet on the main cargo deck."

(2) For airplanes on which any other containers or pallets are transported: Revise the Limitations Section of all FAA-approved AFM's and AFM Supplements, and the Limitations Section of all FAA-approved Airplane Weight and Balance Supplements, in accordance with a method approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate.

Note 3:
The weight restrictions to be approved under paragraph (a)(2) will be consistent with the limitations specified in paragraph (a)(1) of this AD. (b) As an optional alternative to compliance with paragraph (a) of this AD, within 90 days after the effective date of this AD, accomplish the requirements of paragraph (b)(1) or (b)(2) of this AD, as applicable. This alternative may be used only during the period ending 28 months after the effective date of this AD.
(1) For airplanes on which containers complying with NAS 3610 Size Codes "A," "B," "C," "D," or "E," or STC SA7447SW, are transported: Revise the Limitations Section of all FAA-approved AFM's and AFM Supplements, and the Limitations Section of all FAA-approved Airplane Weight and Balance Supplements to include the following limitations. This may be accomplished by inserting a copy of this AD in all AFM's, AFM Supplements, and Weight and Balance Supplements. "LIMITATIONS Maximum Operating Airspeed of Vmo equals 350 knots indicated airspeed (KIAS), or Mode "B" 350 knots equivalent airspeed (KEAS). Minimum operating weight: 100,000 pounds. All containers with one door must be oriented with the door side of the container facing forward, except the door of the first container aft of the cargo barrier may face aft. The location of the horizontal center of gravity for the total payload within each container shall not vary more than 10 percent (8.8 inches) from the geometric center of the base of the container for the forward and aft direction and 10 percent of the width from the geometric center of the base of the container for the left or right direction." "PAYLOAD LIMITATIONS For airplanes that transport containers or pallets that have been manufactured in accordance with National Aerospace Standard (NAS) 3610 Size Code "A" (88 by 125 inches), "B" (88 by 108 inches), or "C" (88 by 118 inches): Except as provided below for Body Station 740 to Body Station 950, do not exceed a total weight of 9,600 pounds for any two adjacent containers or pallets and a total weight of 8,000 pounds for any single container or pallet. For those containers or pallets which are completely or partially located within Body Station 740 to Body Station 950 (the region of the wing box and main landing gear wheel well): Do not exceed a total weight of 12,000 pounds for any two adjacent containers or pallets and a total weight of 8,000 pounds for any single container or pallet. These container payload limits include the payload in the lower lobe cargo compartments and any other load applied to the bottom of the floor beams of the main cargo deck for the same body station location as the container or pallet on the main cargo deck; and For containers or pallets that have been manufactured in accordance with NAS 3610 Size Code "D" (88 by 54 inches) or "E" (88 by 53 inches), or FedEx STC SA7447SW containers (88 by 63 inches): Except as provided below for Body Station 740 to Body Station 950, do not exceed a total weight of 4,800 pounds for any two adjacent (in the forward and aft direction) containers or pallets and a total weight of 4,000 pounds for any single container or pallet. For those containers or pallets which are completely or partially contained within Body Station 740 to Body Station 950 (the region of the wing box and main landing gear wheel well): Do not exceed a total weight of 6,000 pounds for any two adjacent (in the forward and aft direction) containers or pallets and a total weight of 4,000 pounds for any single container or pallet. These payload limits include the payload in the lower lobe cargo compartments and any other load applied to the bottom of the floor beams of the main cargo deck for the same body station location as the container or pallet on the main cargo deck."

(2) For airplanes on which pallets or containers other than those specified in paragraph (b)(1) of this AD, are transported: Revise the Limitations Section of all FAA-approved AFM's and AFM Supplements, and the Limitations Section of all FAA-approved Airplane Weight and Balance Supplements, in accordance with a method approved by the Manager, Standardization Branch, ANM-113.

Note 4:
The weight restrictions to be approved under paragraph (b)(2) will be consistent with the limitations specified in paragraph (b)(1) of this AD.

(c) For airplanes complying with paragraph (b) of this AD, within 28 months after the effective date of this AD, accomplish the requirements of paragraph (a) of this AD.

(d) For airplanes that operate under the 350 KIAS limitations specified in paragraph (b) of this AD: A maximum operating airspeed limitation placard must be installed adjacent to the airspeed indicator and in full view of both pilots. This placard must state: "Limit Vmo to 350 KIAS."

(e) As an alternative to compliance with paragraphs (a), (b), (c), and (d) of this AD: An applicant may propose to modify the floor structure or propose differing payloads and other limits by submitting substantiating data and analyses to the Manager, Atlanta Aircraft Certification Office (ACO), FAA, Small Airplane Directorate, One Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia 30349. The Manager of the Atlanta ACO will coordinate the review of the submittal with the Manager of the Standardization Branch, ANM-113, in accordance with the procedures of paragraph (f) of this AD. If the FAA determines that the proposal is in compliance with the requirements of Civil Air Regulations (CAR) part 4b and is applicable to the specific airplane being analyzed and approves the proposed limits, prior to flight under these new limits, the operator must revise the Limitations Section of all FAA-approved AFM's and AFM Supplements, and the Limitations Section of all FAA-approved Airplane Weight and Balance Supplements, in accordance with a method approved by the Manager, Standardization Branch, ANM-113. Accomplishment of these revisions in accordance with the requirements of this paragraph constitutes terminating action for the requirements of this AD.

(f) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Standardization Branch, ANM-113. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Atlanta ACO, who will coordinate the approval with the Manager of the Standardization Branch, ANM-113.

Note 5:
Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.

(g) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

(h) This amendment becomes effective on February 16, 1999. Issued in Renton, Washington, on December 16, 1998. Ronald T. Wojnar, Manager, Transport Airplane Directorate, Aircraft Certification Service.