SAIB CE-16-09

FAA Aviation Safety

SPECIAL AIRWORTHINESS

INFORMATION BULLETIN SUBJ: AUTO FLIGHT - Autopilot SAIB: CE-16-09 Date: November 23, 2015 This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin advises you of an airworthiness concern, specifically that certain Honeywell/Bendix King autopilots (AP) can experience inadvertent disengagement without clear annunciation to the pilot and may also fail to engage with conflicting annunciation to the pilot. These failure conditions are the result of a resistor that can fail open in the autopilot computer.

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

This SAIB is the result of an open resistor (R259) found in the KCP 220 AP computer causing improper AP operation and annunciation to the pilot. Honeywell has determined that AP computers KC 190/191/192/193 will have the same failure effects as the KCP 220. These autopilot computers are associated with the KAP 100, KAP 150, KAP 150H, KFC 150, KFC, 275, and KFC 325 autopilot systems. The following describes the potential effects when the resistor (R259) in any of the respective AP computers fails open:

 If AP is not engaged with an opened resistor (R259)  No Effect  If resistor (R259) fails open while the AP is engaged  Pitch and Roll servos will disengage.

 AP Annunciator on the control panel will continue to illuminate and to indicate AP is engaged.

 If installed, AP Annunciator on the optional remote Annunciator Panel or EFIS EADI will continue to illuminate and to indicate AP is engaged.

 Aural Disengage Warnings will activate.

 If the pilot engages the AP with resistor (R259) already failed open  Pitch and roll servos will not engage.

 AP Annunciator on the control panel will continue to illuminate and to indicate AP is engaged.

 If installed, AP Annunciator on the optional remote Annunciator Panel or EFIS EADI will continue to illuminate and to indicate AP is engaged.

 Aural Disengage Warning will not activate.

 Flight Director commands will indicate a deviation if the aircraft drifts away from the selected mode targets (lateral and/or vertical).

 Effects of open resistor R259 can be felt by pilot during preflight test. Pilot (s) will not feel any friction or resistance on the Yoke/Control Wheel.

2 Honeywell revealed the excessive failure rate of the resistor (R259) manufactured by “OHMITE” prior to year 2000. The affected AP computers are listed below:

Model Part Number Serial Number KC 190 065-00055-0002 2076 and below KC 190 065-00055-0003 10412 and below KC 191 065-00054-0002 21594 and below KC 191 065-00054-0003 32189 and below KC 191 065-00054-0012 40028 and below KC 192 065-00042-0002 41566 and below KC 192 065-00042-0003 54321 and below KC 192 065-00042-0012 1021 and below KC 193 065-00144-0000 1177 and below KC 193 065-00144-0001 1177 and below KC 193 065-00144-0002 1177 and below KCP 220 065-00064-0000 2053 and below KCP 220 065-00064-0001 2053 and below KCP 220 065-00064-0005 2053 and below KCP 220 065-00064-0006 2053 and below KCP 220 065-00064-0007 2053 and below KCP 220 065-00064-0008 2053 and below KCP 220 065-00064-0009 2053 and below KCP 220 065-00064-0012 2053 and below KCP 220 065-00064-0015 2053 and below KCP 220 065-00064-0017 2053 and below KCP 220 065-00064-0020 2053 and below

Honeywell has issued alert service bulletins to inspect and modify the KC 190/191/192/193 and KCP 220 AP computer. These bulletins are identified as follows:

For KC 190/191/192: Honeywell Bendix King Service Bulletin KC 190/191/192-22-A0019

For KC 193: Honeywell Bendix King Service Bulletin KC 193-22-A0005

For KCP 220: Honeywell Bendix King Service Bulletin KCP 220-22-A0017

Recommendations

The FAA recommends that owners, operators, and maintenance personnel of the airplanes installed with the affected AP computer incorporate the appropriate Honeywell Bendix King Service Bulletin.

For Further Information Contact

Albert Ma, Aerospace Engineer, Wichita Aircraft Certification Office, 1801 Airport Rd., Wichita KS 67209; phone: (316) 946-4151; fax: (316) 946-4107; e-mail: albert.ma@faa.gov.

For Related Service Information Contact

Honeywell BendixKing; phone: 855-250-7027 (Toll Free U.S.A./Canada) or 505-903-6148 (International Direct). Website: www.BendixKing.com/support