Source: https://www.federalregister.gov/documents/2001/12/12/01-30193/airworthiness-directives-mcdonnell-douglas-model-dc-9-10--20--30--40-and--50-series-airplanes-c-9
Timestamp: 2018-07-22 23:12:40
Document Index: 112617853

Matched Legal Cases: ['art 39', 'art 39', 'art 39', 'art 39', 'art 39', 'art 51']

66 FR 64129
Amendment 39-12534
AD 2001-24-17
01-30193
https://www.federalregister.gov/d/01-30193 https://www.federalregister.gov/d/01-30193
This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9-10, -20, -30, -40, Start Printed Page 64130and -50 series airplanes; C-9 airplanes; and Model DC-9-81, -82, and -83 series airplanes. This AD requires modification of the light switch for the cargo compartment(s). This action is necessary to prevent generation of smoke and fire in a cargo compartment due to an illuminated light with a missing cover contacting cargo contents for an extended period of time. This action is intended to address the identified unsafe condition.
A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 series airplanes; C-9 airplanes; and Model DC-9-81, -82, and -83 series airplanes; was published in the Federal Register on July 23, 2001 (66 FR 38178). That action proposed to require modification of the light switch of the applicable cargo compartments.
The Air Transport Association (ATA), on behalf of its members, recommends that the FAA withdraw the proposed AD. The commenter states that the proposed AD does not increase the level of safety, because it does not address the root cause of the incident (i.e., the missing cover from the cargo compartment light). The commenter suggests that, instead of the proposed modification, the FAA should mandate scheduled maintenance action. In an attached comment, one ATA member recommends repetitive inspections to verify that the light cover is installed, as well as rewiring of the cargo door switch to the cargo light switch, so the cargo light cannot stay on. In another attached comment, another ATA member recommends changes to the Master Minimum Equipment List (MMEL) to prohibit operation of the airplane with a missing light cover, unless the exposed bulb is removed or the lighting system for the cargo compartment(s) is deactivated. The ATA and one of its members also point out that all airplanes that would be subject to the proposed AD are required by Federal Aviation Regulations to have a smoke and fire detection and suppression system installed in the cargo compartment(s) of the airplane.
The FAA does not concur with the request to withdraw the proposed AD. In the “Identification of Unsafe Condition” section of the proposed AD, we explain that the identified unsafe condition related not only to the cover missing from the cargo compartment light, but also the fact that the light did not automatically shut off when the cargo compartment was closed. Thus, we have determined that the action required by this AD (i.e., modification of the light switch in the cargo compartment) is adequate to address the identified unsafe condition. Under paragraph (b) of this AD, we may consider a request for approval of an alternative means of compliance (AMOC) with this AD, provided that data are submitted that show that the means of compliance provides an acceptable level of safety.
With regard to the commenters' suggestions to mandate scheduled maintenance action or revise the MMEL, the mechanism that exists to rectify an FAA finding that an unsafe condition exists is an amendment to part 39 of the Federal Aviation Regulations (14 CFR part 39). In addition, under existing bilateral airworthiness agreements, we are obligated to advise foreign airworthiness authorities of unsafe conditions relating to products produced in the United States, and the means of doing this is an amendment to part 39.
One commenter requests that, if the FAA does not agree to withdraw the proposed AD, it revise the applicability of the proposed AD to exclude airplanes equipped with a certain smoke and fire detection and suppression system installed in the cargo compartment(s) by a certain supplemental type certificate (STC). The commenter points out that the unsafe condition addressed by the proposed AD requires three events to occur: a missing cover on the cargo compartment light, cargo stacked against that light, and the light being illuminated for the entire flight. The commenter states that the STC for installing the referenced smoke and fire detection and suppression system specifies a restriction against stacking cargo within two inches of the ceiling of the cargo compartment. Thus, there would be no contact with the cargo compartment light located in the ceiling, and the unsafe condition addressed by the proposed AD would not occur.
We do not concur with the request to revise the applicability of this AD. Note 1 of this AD specifies that, if an airplane has been modified in such a manner that the service information referenced in this AD does not apply, the owner/operator must request approval of an AMOC in accordance with paragraph (b) of this AD. For us to approve such a request, the owner/operator must provide data that show that an acceptable level of safety is achieved through installation of the smoke and fire detection and suppression system and the procedural changes to which the commenter refers. No change to the final rule is necessary in this regard.
One commenter requests that the FAA require repetitive inspections following the proposed modification of the light switch for the cargo compartment(s). The inspections would ensure that the guard is still installed over the light switch. The commenter suggests that these inspections could be added to the maintenance program. The commenter's request is based on maintenance reports from its fleet of airplanes, which have been modified per the service bulletin referred to in the proposed AD. The maintenance reports show that the guard over the light switch breaks frequently because of chafing between the guard and the door structure during the numerous opening and closing Start Printed Page 64131cycles of the cargo compartment door during daily ground handling.
We acknowledge the concerns of the commenter, but do not concur with its request. We have received information indicating that breakage of the guard over the light switch, such as that noted by the commenter, may occur if cargo handlers rely upon the guard to extinguish the light in the cargo compartment, rather than MANUALLY extinguishing the cargo compartment light and closing the switch guard before closing the cargo door. We also have received information that the cargo loading document for the airplanes subject to this AD will be revised in the near future to specifically state that the cargo compartment light must be manually extinguished before closing the door. No change to the final rule is necessary in this regard.
There are approximately 1,068 Model DC-9-10, -20, -30, -40, and -50 series airplanes; C-9 airplanes; and Model DC-9-81, -82, and -83 series airplanes; of the affected designs in the worldwide fleet. The FAA estimates that 525 airplanes of U.S. registry will be affected by this AD, that it will take approximately 1 work hour per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will cost between $1,147 and $2,332 per airplane depending on the airplane configuration. Based on these figures, the cost impact of this AD on U.S. operators is estimated to be between $633,675 and $1,255,800, or $1,207 and $2,392 per airplane, depending on the airplane configuration.
2001-24-17 McDonnell Douglas: Amendment 39-12534. Docket 99-NM-295-AD.
(a) Within 1 year after the effective date of this AD, modify the light switch for the cargo compartment(s) per McDonnell Douglas Alert Service Bulletin DC9-33A081, Revision 01, dated November 8, 1999.
(d) The actions shall be done in accordance with McDonnell Douglas Alert Service Bulletin DC9-33A081, Revision 01, dated November 8, 1999. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Boeing Commercial Aircraft Group, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data and Service Management, Dept. C1-L5A (D800-0024). Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; at the FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. Start Printed Page 64132
[FR Doc. 01-30193 Filed 12-11-01; 8:45 am]