| AD Number | 89-20-06 | Status | Active |
| Effective Date | October 10, 1989 | Issue Date | Not specified |
| Docket Number | 89-NM-97-AD | Amendment | 39-6335 |
| Product Type | ["Appliance"] | Product Subtype | Not specified |
| CFR Part | --- - Part 39 | CFR Section | N/A |
| Citation | This information is not available. | ||
| Manufacturer(s) | Honeywell, Inc. |
| Model(s) | Flight Management System |
89-20-06 HONEYWELL, INC.: Amendment 39-6335. (Docket No. 89-NM-97-AD)
Applicability: Sperry FMZ-800 Flight Management Systems (FMS), Model NZ-600, NZ-800, and NZ-900 series Navigation Computers, part numbers 7004402-653, -654, -801, -803, -804, -805, -806, -811, -812, -813, -823, -824, -832, -833, -834, -843, -844, -845, -901, -902, -903, -904, -905, and -906, if installed with two or more inertial reference systems and one or more omega/VLF sensors. These FMS navigation computers are known to be or have been installed in, but not limited to, Avions Marcel Dassault Model Mystere-Falcon 900, British Aerospace Model BAe 125-800A, Canadair Model CL-601-3A, and Gulfstream Model G-IV series airplanes.
Compliance: Required as indicated, unless previously accomplished.
To prevent FMS navigation errors caused by an erroneous omega/VLF sensor, accomplish the following:
A. Within 15 days after the effective date of this AD, add the following to the Limitations Section of the FAA-approved Airplane Flight Manual (AFM) or FAA-approved Airplane Flight Manual Supplement (AFMS). This may be accomplished by inserting a copy of this AD in the AFM or AFMS.
ON ALL FLIGHT EXTENDING OFFSHORE ONE HOUR OR MORE BEYOND VOR/DME RANGE:
(1) WHEN NAVIGATING WITH TWO FLIGHT MANAGEMENT SYSTEMS (FMS), AND WITH ONE OR MORE OPERATIONAL INERTIAL REFERENCE SENSORS AND WITH A SINGLE OPERATIONAL OMEGA/VLF SENSOR, THE OMEGA/VLF SENSOR MUST BE DESELECTED FROM ONE OF THE FMS NAVIGATION COMPUTERS.
(2) IF NAVIGATING WITH ONLY ONE FMS NAVIGATION COMPUTER, (BECAUSE OF AN IN-FLIGHT FMS FAILURE), AND WITH TWO OR MORE INERTIAL REFERENCE SENSORS AND WITH A SINGLE OPERATIONAL OMEGA/VLF SENSOR, THE OMEGA/VLF SENSOR MUST BE DESELECTED FROM THE OPERATING FMS NAVIGATION COMPUTER.
B. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region.
NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who may add any comments and then send it to the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region.
C. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.
This amendment (39-6335, AD 89-20-06) becomes effective on October 10, 1989.