FAA 

Aviation Safety

EMERGENCY 

AIRWORTHINESS DIRECTIVE

www.faa.gov/aircraft/safety/alerts/ 

DATE: December 23, 2011 

AD #: 2011-27-51 

Emergency airworthiness directive (AD) 2011-27-51 is sent to owners and operators of Hawker 

Beechcraft Corporation Models 1900, 1900C, and 1900D airplanes. 

Background 

 This emergency AD was prompted by the following reported problems of the elevator bobweight (stabilizer weight) traveling past its stop bolt, which allowed the attaching linkage to move 

over-center, reducing nose down elevator control. 

 In one instance, a Model 1900C airplane experienced jammed elevators on take-off after a 

loud bang was heard in the cockpit shortly after rotation. The flight crew noticed that they were 

unable to move the control column to a nose down position. Elevator movement was only available 

between neutral to full deflection nose up. The airplane pitch was controlled with the elevator trim 

and the airplane returned to base, landing safely. Upon inspection, mechanics noticed that the bobweight interconnect link, part number (p/n) 101-524112-1, was upside down and trailing FORWARD 

from the control column weld assembly instead of trailing AFT as it should. With the link travel 

over-center, the geometry of the bob-weight was completely changed relative to its stop. This 

condition made the bob-weight hit its stop mid-travel, where it should actually have positive 

clearance from its stop at the full nose down position. The elevator could now only move between 

nose full up and neutral. 

 In another instance, on a Model 1900D airplane, during the takeoff roll the elevator controls 

felt heavy and appeared to be jammed/sticking, requiring more force than usual to rotate. The crew 

then aborted the takeoff run. Subsequent investigation revealed that the elevator bob-weight attaching 

link assembly traveled over-center, thus preventing full nose down elevator control authority. 

The Model 1900 airplanes have the same type design and thus are subject to this unsafe 

condition. 

This condition, if not corrected, could result in reduced nose down elevator control and loss of 

airplane control. 

Relevant Service Information 

We reviewed Hawker Beechcraft Corporation Safety Communiqué #321, dated December 

2011. The service information provides information to assist in doing the actions of this AD. 

FAA’s Determination 

We are issuing this AD because we evaluated all the relevant information and determined the 

unsafe condition described previously is likely to exist or develop in other products of the same type 

design. 

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AD Requirements 

This AD requires inspecting the elevator bob-weight and attaching linkage for correct 

installation and for damage or deformation to the weight and/or weight bracket with corrective action 

as necessary. 

Interim Action 

 We consider this AD interim action to address the immediate unsafe condition affecting these 

airplanes. We may take further AD action at a later date. 

Authority for this Rulemaking 

Title 49 of the United States Code specifies the FAA’s authority to issue rules on aviation 

safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, 

Aviation Programs, describes in more detail the scope of the Agency’s authority. 

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, 

Subpart III, Section 44701, “General requirements.” Under that section, Congress charges the FAA 

with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, 

methods, and procedures the Administrator finds necessary for safety in air commerce. This 

regulation is within the scope of that authority because it addresses an unsafe condition that is likely 

to exist or develop on products identified in this rulemaking action. 

Presentation of the Actual AD 

We are issuing this AD under 49 U.S.C. Section 44701 according to the authority delegated to 

me by the Administrator. 

2011-27-51 Hawker Beechcraft Corporation: Directorate Identifier 2011-CE-044-AD. 

(a) Effective Date 

This Emergency AD is effective upon receipt. 

(b) Affected ADs 

None. 

(c) Applicability 

 This AD applies to the following Hawker Beechcraft Corporation airplanes, certificated in 

any category: 

Models Serial Numbers 

(1) 1900 UA-3 

(2) 1900C UB-1 through UB-74 and UC-1 through UC-174 

(3) 1900C (Military) UD-1 through UD-6 

(4) 1900D UE-1 through UE-439 

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 (d) Subject 

Joint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 

27, Flight Controls. 

(e) Unsafe Condition 

This AD was prompted by reports of the elevator bob-weight (stabilizer weight) traveling past 

its stop bolt, which allowed the attaching linkage to move over-center. We are issuing this AD to 

detect and correct conditions that could result in reduced nose down elevator control and loss of 

control of the airplane. 

(f) Compliance 

Comply with this AD within the compliance times specified, unless already done. 

(g) Inspections 

Within the next 10 hours time-in-service after receipt of this emergency AD, inspect the 

elevator bob-weight installation for the following conditions. Use Hawker Beechcraft Corporation 

Safety Communiqué #321, dated December 2011. 

 NOTE: The term “nose down” corresponds to the airplane nose down, down elevator, and 

control column forward position as used in this AD and Hawker Beechcraft Corporation Safety 

Communiqué # 321, dated December 2011. 

 

 (1) The correct positioning of the elevator control column link assembly, (part number (P/N)

101-524112-1 (1900/1900C) or P/N 101-524112-5 (1900D)). With the elevator control column in the 

full nose down position (control column forward), the link must form an angle between the link 

attachment point at the control column and the bell crank pivot point as shown in the Hawker 

Beechcraft Corporation Safety Communiqué photo labeled “Correct Link Orientation.” The link 

should be trailing AFT from the control column assembly. 

 

 (2) The clearance of the bob-weight stop bolt. With the elevator control column in the full 

nose down position (control column forward), the stabilizer weight stop bolt must have positive 

clearance with the face of the stabilizer weight. 

 (3) The condition of the bob-weight and alignment with the stop bolt. Inspect for evidence of 

scraping along either side of the weight by the stop bolt. With side pressure applied by hand to the 

stabilizer weight, no part of the stop bolt should protrude beyond the face of the stabilizer weight on 

either edge. 

 (4) The condition of the bob-weight support bracket. Inspect for evidence of damage or 

deformation by contact with the weight assembly. 

(h) Corrective Actions 

 If any discrepancies are found in the inspections required in paragraph (g) of this AD, before 

further flight, do the following: 

(1) Contact Hawker Beechcraft Corporation Technical Support by telephone at (800) 429-

5372 or (316) 676-3140 to obtain FAA-approved repair or replacement instructions. 

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 (2) Incorporate the repair or replacement specified in the FAA-approved instructions. 

(i) Alternative Methods of Compliance (AMOCs) 

(1) The Manager, Wichita Aircraft Certification Office (ACO), FAA, has the authority to 

approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In 

accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight 

Standards District Office, as appropriate. If sending information directly to the manager of the ACO, 

send it to the attention of the person identified in the Related Information section of this AD. 

(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking 

a principal inspector, the manager of the local flight standards district office/certificate holding 

district office. 

(j) Related Information 

(1) For further information about this AD, contact one of the following: 

(i) Paul DeVore, Aerospace Engineer, Wichita ACO, FAA, 1801 Airport Road, Room 100, 

Wichita, Kansas 67209; telephone: (316) 946-4142; fax: (316) 946-4107; email: 

paul.devore@faa.gov; or 

(ii) Don Ristow, Aerospace Engineer, Wichita ACO, FAA, 1801 Airport Road, Room 100, 

Wichita, Kansas 67209; telephone: (316) 946-4120; fax: (316) 946-4107; email: 

donald.ristow@faa.gov. 

(2) For copies of the service information referenced in this AD, contact Hawker Beechcraft 

Corporation at P.O. Box 85, Wichita, Kansas 67201-0085; telephone: (800) 429-5372 or (316) 

676-3140; Internet: http://pubs.hawkerbeechcraft.com. 

 (3) You may review copies of the referenced service information at the FAA, Small Airplane 

Directorate, 901 Locust, Kansas City, Missouri 64106. For information on the availability of this 

material at the FAA, call (816) 329-4148. 

Issued in Kansas City, Missouri, on December 23, 2011. 

John Colomy, 

Acting Manager, Small Airplane Directorate, 

Aircraft Certification Service.