Flight Controls-Aileron Control System

1

FAA Aviation Safety SPECIAL AIRWORTHINESS INFORMATION BULLETIN SUBJ: Flight Controls-Aileron Control System SAIB: NM-13-28 Date: April 12, 2013 This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin (SAIB) advises owners and operators of Hawker Beechcraft Corporation (Type Certificate Previously Held by Raytheon Aircraft Company) Model Hawker 4000 airplanes of an airworthiness concern regarding degradation of normal aileron control of the airplane due to disbonded or missing cable guards.

We have evaluated the risk associated with this specific aileron cable guide, and we have determined that the airworthiness concern is not considered an unsafe condition that would warrant airworthiness directive (AD) action under Title 14 of the Code of Federal Aviation Regulations (14 CFR) part 39.

Background

We received notification of field reports of disbonded or missing cable guards for the wing aileron cables. These guards are normally attached to the midboard and outboard spoiler actuator fittings. Two airplanes had higher-than-normal aileron forces during flight. The autopilot faulted off on one of these airplanes, followed by an amber “AP Roll Mistrim” CAS message, and a temporary restriction of aileron control. Reportedly, the pilot relaxed pressure on the ailerons and was able to operate them, although forces remained high. The flightcrew determined that operating the roll control disconnect mechanism to separate left and right aileron control was not necessary.

The cable guards are installed by adhesive bonding, which is disbonding, and the cause has not been determined. However, it has been determined that these cable guards are not necessary for proper functioning of the aileron control system and safe flight of the airplane. Removal of these cable guards will prevent the potential of loose or disbonded cable guards, which could result in degradation of aileron control.

Hawker Beechcraft Corporation issued Mandatory Service Bulletin SB 27-4116, dated December 2012, to provide operators with guidelines for removing the existing cable guards for the wing aileron cables.

Recommendations

The FAA recommends that all owners and operators of the subject airplanes incorporate the modifications outlined in Hawker Beechcraft Mandatory Service Bulletin SB 27-4116, dated December 2012.

We request that owners and operators report the date of removal of the cable guards, or if the cable guards were not removed, to Paul DeVore using the contact information below. Under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has approved the information collection contained in this SAIB, and assigned OMB Control Number 2120-0731.

2 For Further Information Contact

Paul DeVore, Sr. Aerospace Engineer, Mechanical Systems and Propulsion Branch, ACE-116W, FAA, Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, Wichita, Kansas, 67209; phone: (316) 946-4142; fax: (316) 946-4107; email: [email protected].

For Related Service Information Contact Hawker Beechcraft Corporation, B091–A04, 10511 E. Central Ave., Wichita, Kansas 67206; phone: (800) 429–5372 or (316) 676–3140; fax: (316) 676–8027; email: [email protected]; Internet: http://www.hawkerbeechcraft.com/customer_support/technical_and_field_support/.