86-05-02 UNITED INSTRUMENTS, INC.: Amendment 39-5317. Applies to altimeter Part Numbers 5934, 5934A, 5934M, 5934AM, 5934P, 5934PA, 5934PM, 5934PAM, 5934D, 5934PD, 5934AD, and 5934PAD with the following serial numbers:

	6C461 thru 6C999
	7C000 thru 7C999
	8C000 thru 8C999
	9C000 thru 9C999
	0D000 thru 0D999
	1D000 thru 1D999
	2D000 thru 2D869

NOTE 1: This AD is applicable to pressure sensitive altimeters that do not have encoding capabilities. The affected altimeters were manufactured after February 1, 1985.

Compliance: Required as indicated unless already accomplished.

To prevent possible erroneous altitude information from being displayed to the pilot, accomplish the following:

(a) For all altimeters that are installed in an aircraft, prior to further flight,

(1) Check each installed altimeter or check the aircraft's permanent maintenance record to determine if the altimeter falls within the Serial Number designations set forth in this AD. The owner/operator of the aircraft may make this check.

(2) If, as a result of this check, it is determined that the altimeter falls within these designations, check the altimeter by applying a slight outward pull on the adjustment knob while turning the knob and determine that the altitude indication pointers and the barometric pressure dial remain synchronized.

(3) The holder of a pilot certificate issued under Part 61 of the Federal Aviation Regulations (FAR) may conduct this check on any airplane owned or operated by him. The person accomplishing this must make the appropriate aircraft maintenance record entry as prescribed by FAR 91.173.

(4) If the altitude pointers do not move simultaneously with the barometric dial, prior to further flight remove the altimeter and return it to United Instruments, Inc., 3625 Comotara Avenue, Wichita, Kansas 67226, no later than July 1, 1986. Replacement altimeters must be serviceable units.

NOTE 2: It is recommended but not required by this AD, that the above check for synchronized movement be accomplished each time the altimeter barometric pressure dial is adjusted.

(b) Regardless of the results of the check specified in paragraph (a) of this AD, on or before July 1, 1986, for all affected altimeters installed in an aircraft, remove the altimeter and return it to United Instruments, Inc. at the above address. Replacement altimeters must be serviceable units.

(c) For all affected altimeters not installed in an aircraft, prior to further use but no later than July 1, 1986, return the altimeter to United Instruments, Inc., at the above address, for examination and modification as required.

(d) For each altimeter returned to United Instruments, Inc. per the instructions of paragraphs (a), (b) and (c) above, the examination and rework by United Instruments, Inc. will be identified by a yellow dot approximately 1/4 inch (6.4mm) diameter on the lower half of the rear case and the letter "M", approximately 1/8 inch (3.2mm) in height stamped on the data plate just before the word "altimeter". Units that have been reworked and so marked may be used as serviceable replacement parts.

(e) Aircraft may be flown in accordance with Federal Aviation Regulation (FAR) 21.197 to a location where this AD can be accomplished. Prior to dispatch, set the altimeter to field elevation and do not reset in flight.

(f) An equivalent method of compliance with this AD, if used, must be approved by the Manager, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209.

United Instruments Service Bulletin No. 2, dated February 24, 1986, pertains to the subject of this AD.

All persons affected by this directive may obtain copies of the documents referred to herein upon request to United Instruments, Inc., 3625 Comotara Avenue, Wichita, Kansas 67226, or FAA, Office of the Regional Counsel, Room 1558, 601 East 12th Street, Kansas City, Missouri 64106.

This amendment becomes effective on May 28, 1986, to all persons except those to whom it has already been made effective by priority letter AD from the FAA dated February 28, 1986, and is identified as AD 86­05­02.