# AD 99-12-06: Navigation Receivers - Type: Airworthiness directive - Status: Current - Products: AlliedSignal Navigation Receivers, ATP, F27 Mark 050 and 31A - Effective: July 23, 1999 - Published: June 11, 1999, 64 FR 31490–31491 - Issued as: Final rule - Superseded by: Nothing supersedes this AD - Product type: Appliance - Amendment: 39-11190 - Docket: 95-CE-91-AD - Registered aircraft: 104 may be affected, by airframe or engine model (OpenAirDocs) - Official PDF: https://openairdocs.org/files/sha256/fe/34/fe348fc88552741af8c7344dd048af703eee6a8c7eef2cac7a1f1d9e222295c8 (from https://www.govinfo.gov/content/pkg/FR-1999-06-11/pdf/99-14537.pdf) - Federal Register: https://www.federalregister.gov/documents/1999/06/11/99-14537/airworthiness-directives-alliedsignal-inc-vn-411b-very-high-frequency-vhf-navigation-receivers - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/78B243F00F23E05B86256A400051BC96.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/99-12-06 ## Summary This amendment adopts a new airworthiness directive (AD) that requires replacing certain AlliedSignal Inc. VN 411B VHF navigation receivers installed on aircraft if the receivers do not have Modification 21 incorporated. This AD is the result of a report of navigation receiver interference during landing operations. The actions specified by this AD are intended to prevent VHF navigation receiver interference from frequency modulation (FM) radio station broadcasts, which could cause distortion of the navigation audio and deflection of the desired flight path of the airplane during landing operations with possible loss of control of the airplane. ## The airworthiness directive 99-12-06 ALLIEDSIGNAL INC.: Amendment 39-11190; Docket No. 95-CE-91-AD. Applicability: The following very high frequency (VHF) navigation receivers that are installed on, but not limited to, Learjet Model 31A, Fokker Model F27-50, and British Aerospace Model ATP airplanes: - VN 411B, BPN 3614004-4101, all serial numbers, that are currently at Modification Status 18, 19, or 20; - VN 411B, BPN/KPN 3614004-4101/066-1101-00, all serial numbers, that are currently at Modification Status 18, 19, or 20; - VN 411B, P/N 066-1101-00, serial numbers up to and including 4229, that are currently at Modification Status 18, 19, or 20; and - VN 411B, P/N 066-1101-/31/40/50, serial numbers up to and including 10799, that are currently at Modification Status 19 or 20. NOTE 1: This AD applies to each airplane in which a VHF navigation receiver identified in the preceding applicability provision has been installed, regardless of whether it has been 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 (d) 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 in the body of this AD, unless already accomplished. To prevent VHF navigation receiver interference from frequency modulation (FM) radio station broadcast frequencies, which could cause distortion of the navigation audio and deflection of the desired flight path of the airplane during landing operations with possible loss of control of the airplane, accomplish the following: (a) Within the next 90 calendar days after the effective date of this AD or upon replacement or repair of any affected AlliedSignal VHF navigation receiver, whichever occurs first, remove the navigation receiver and install one where an AlliedSignal Bendix/King service center has incorporated Modification 21, in accordance with AlliedSignal Bendix/King Service Bulletin VN 411B-21, dated November 1996. (b) As of the effective date of this AD, no person may install, on any airplane, one of the affected VHF navigation receivers that does not have Modification 21 incorporated in accordance with AlliedSignal Bendix/King Service Bulletin VN 411B-21, dated November 1996. (c) 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. (d) An alternative method of compliance or adjustment ofthe compliance time that provides an equivalent level of safety may be approved by the Manager, Wichita Aircraft Certification Office (ACO), 1801 Airport Road, Room 100, Wichita, Kansas 67209. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Wichita ACO. NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Wichita ACO. (e) The removal and installation required by this AD shall be done in accordance with AlliedSignal Bendix/King Service Bulletin VN 411B-21, dated November 1996. 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 AlliedSignal, Inc., 23500 W. 105th Street, Olathe, Kansas 66051-1950. Copies may be inspected at the FAA, Central Region, Office of the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW, suite 700, Washington, DC. (f) This amendment becomes effective on July 23, 1999. ## Rule preamble ### Supplementary information Events Leading to the Issuance of This AD A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to certain AlliedSignal Inc. VN 411B very high frequency (VHF) navigation receivers installed in aircraft was published in the Federal Register as a supplement notice of proposed rulemaking (NPRM) on December 22, 1998 (63 FR 70698). The supplemental NPRM proposed to require replacing any VHF navigation receiver that does not have Modification 21 incorporated with one where an AlliedSignal Bendix/King-owned service center has incorporated Modification 21. Accomplishment of the proposed action as specified in the supplemental NPRM would be in accordance with AlliedSignal Bendix/King Service Bulletin VN 411B-21, dated November 1996. The NPRM was the result of a report of navigation receiver interference during landing operations. Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposed rule or the FAA's determination of the cost to the public. The FAA's Determination After careful review of all available information related to the subject presented above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed except for minor editorial corrections. The FAA has determined that these minor corrections will not change the meaning of the AD and will not add any additional burden upon the public than was already proposed. Cost Impact The FAA estimates that 19 VHF navigation receivers in the U.S. registry will be affected by this AD, that it will take approximately 2 workhours per receiver to accomplish this action, and that the average labor rate is approximately $60 an hour. The manufacturer is not charging the owner/operator for exchanging the navigation receiver unit and is offering 2 workhours of labor warranty credit to accomplish this action. Based on these figures, this AD imposes no cost impact on U.S. operators. The FAA has no way of determining if any of the affected airplanes have navigation receivers with Modification 21 incorporated. Compliance Time of This AD The condition specified by this AD is not caused by actual hours time-in-service (TIS) of the aircraft where the affected VHF navigation receivers are installed. The need for replacing the VHF navigation receiver with one that incorporates hardware modifications has no correlation to the number of times the equipment is utilized or the age of the equipment. For this reason, the compliance time of this AD is presented in calendar time instead of hours TIS. Regulatory Impact The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore,in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A copy of the final evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption "ADDRESSES". List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. Adoption of the Amendment Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: PART 39 - AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. 39.13 [Amended] 2. Section 39.13 is amended by adding a new airworthiness directive (AD) to read as follows: ## Affected data sheets (3) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A-817](https://openairdocs.org/tcds/A-817): Fokker Services B.V.; names 1 of 8 models: F27 Mark 050 - [TCDS A10CE](https://openairdocs.org/tcds/A10CE): Learjet Inc.; names 1 of 29 models: 31A - [TCDS A27NM](https://openairdocs.org/tcds/A27NM): BAE Systems (Operations) Limited; names 1 of 1 models: ATP ## 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: 104 (104 by airframe model, 0 by engine model) - Makers: Learjet 104 Models with the most aircraft: - [Learjet 31A](https://openairdocs.org/model/learjet-31a): 104 aircraft (airframe model) All 1 models: https://openairdocs.org/ad/99-12-06/models.md Every aircraft: https://openairdocs.org/ad/99-12-06/aircraft.md ## Related documents - [Proposed rule 95-CE-91-AD](https://openairdocs.org/proposed/95-CE-91-AD): Notice of proposed rulemaking (NPRM), published Jun 11, 1996 - [Proposed rule 95-CE-91-AD](https://openairdocs.org/proposed/95-CE-91-AD): Supplemental notice of proposed rulemaking (NPRM); Reopening of the comment period, published Dec 22, 1998 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.