Airworthiness Directive · Amendment 39-18801 · Cabin systems
United Instruments, Inc. Series Altimeters
This AD applies to United Instruments, Inc. 5934 series altimeters that were manufactured between January 2015 and February 2016 and installed in airplanes and helicopters.
(1) The specific affected serial number altimeters can be found in United Instruments, Inc. Service Bulletin No. 13, dated March 25, 2016. Paragraph (j)(3) of this AD contains addresses for obtaining the service bulletin.
(2) Altimeters that have been corrected by United Instruments, Inc. following Service Bulletin No. 13, dated March 25, 2016, are not affected by this AD and no further action is necessary.
(3) Altimeters that have been corrected by United Instruments, Inc. can be identified by a yellow dot, approximately 1/4 inch (6 mm) in diameter, located approximately 1 inch (25 mm) to the left side of the nameplate. The corrected altimeters will also have a letter “M,” approximately 1/8 inch (3mm) high, metal stamped on the nameplate after the name “ALTIMETER.”
We are adopting a new airworthiness directive (AD) for certain United Instruments, Inc. 5934 series altimeters that were manufactured between January 2015 and February 2016 and installed in airplanes and helicopters. This AD was prompted by reports of certain altimeters displaying higher than actual altitude due to a slow diaphragm leak, which would affect the accuracy of the altimeters. This AD requires replacing the affected altimeters. We are issuing this AD to correct the unsafe condition on these products.
Within the next 12 months after April 7, 2017 (the effective date of this AD), replace any affected altimeter with a serviceable part following United Instruments, Inc. Service Bulletin No. 13, dated March 25, 2016.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Appliances and equipment
