# SAIB NM-16-20: Scheduled Maintenance Checks - Type: Special airworthiness information bulletin (advisory, not mandatory) - Status: Current - Revision: 0 - Issued: August 3, 2016 - Products: Transport Category All - Product type: Aircraft, Large Airplane - PDF: https://openairdocs.org/files/sha256/38/86/3886c3ef25757e3e1911052bbe781701ca5b1cf0ee5d171d793daa8a780b3cde - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/D015A345B5502656862580040066FD4E.0001 - DRS record last changed: January 26, 2017 - Page: https://openairdocs.org/saib/NM-16-20 ## Text FAA Aviation Safety **SPECIAL AIRWORTHINESS** INFORMATION BULLETIN SUBJ: Scheduled Maintenance Checks SAIB: NM-16-20 Date: August 3, 2016 This is information only. Recommendations aren’t mandatory. Introduction This Special Airworthiness Information Bulletin (SAIB) advises registered owners, operators and maintenance personnel of all Transport Category airplanes of incidents on certain airplanes that were returned to service after incomplete scheduled maintenance tasks. At this time, the airworthiness concern is not an unsafe condition that would warrant airworthiness directive (AD) action under Title 14 of the Code of Federal Regulations (14 CFR) part 39. Background We have received reports of cases where maintenance personnel did not complete required post-maintenance inspections, checks, and tests that would have prevented accidents or incidents. In one case, the maintenance crew only had time to adjust the tension of one elevator control cable and did not complete the elevator control system re-rigging. The crew then decided to do only a portion of the system post-maintenance inspections, checks, and tests. The system post-maintenance inspections, checks, and tests selected by the crew did not reveal that the airplane elevator control system was rigged incorrectly. Subsequently, when that airplane returned to service, the misrigged elevator control cable resulted in an accident. The National Transportation Safety Board (NTSB) review of this accident found that the maintenance crew did not perform all the appropriate post-maintenance inspections, checks, or tests necessary to detect the condition, which resulted in the accident (NTSB Report No. AAR-04-01). The NTSB review found that “. . . because the Raytheon Aerospace quality assurance inspector and the Structural Modifications and Repair Technicians mechanic did not diligently follow the elevator control system rigging procedure as written, they missed a critical step that would have likely detected the misrigging and thus prevented the accident”. We have released Policy No. PS-ANM-25-18, instructing applicants for part 25 type certificates to have a process in place to specify appropriate inspections, tests and checks after full, partial, or limited maintenance tasks. However, this policy will only apply to future part 25 airplanes, and not to existing type certificated part 25 airplanes, or those pending certification. Therefore, we want to emphasize that maintenance personnel do not have the discretion to conduct only portions of maintenance inspections, checks and tests even after doing very small sub-tasks. Recommendation We recommend that airline maintenance organizations and independent contract maintenance facilities of the affected airplanes do the following: Reinforce that if maintenance personnel perform full, partial, or limited maintenance tasks, they must conduct all post-maintenance inspections, checks and tests for that system. If a partial or limited maintenance task for a system does not list a specific set of post-maintenance inspections, checks, and tests, all system inspections, checks, and tests should be completed. This ensures that even if the 2 mechanic performs full, partial, or limited maintenance tasks, the airplane is adequately evaluated to be returned to service per 14 CFR 43.13(a) and (b). If there are questions about which inspections, checks, and tests apply for a specific maintenance task or subtask, maintenance personnel should contact their principal inspector or local Flight Standards District Office, as appropriate, for clarification. For Further Information Contact Robert Jones, Aerospace Engineer, Propulsion/Mechanical Systems Branch, ANM-112, FAA, 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone: 425-227-1234; fax: 425-227-1149; e-mail: robert.c.jones@faa.gov. --- 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.