# Aviat Service Bulletin 28: Revision A

- Rights: © Aviat. Filed by the FAA in regulations.gov docket FAA-2020-0715; AD 2020-16-06 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication.
- Document: [Aviat Service Bulletin 28](https://openairdocs.org/service-documents/aviat/sb-28.md)
- Title as filed: Service Bulletin No. 28 rev A Husky
- Pages: 4
- PDF: https://openairdocs.org/files/sha256/38/fd/38fddb8735d4fa9ed4c01b8a20cf6be012045920dcfe5d9e80c0aca51ee5b8ed
- Page: https://openairdocs.org/service-documents/aviat/sb-28/file/38fddb8735d4

## Text

Each page's text from the PDF; open the PDF at a page with #page=N.

### Page 1

SERVICE BULLETIN NO. 28                        Aviat Aircraft Inc.  
 
Husky Service Bulletin No. 28 
1
P.O. Box 1240 
Afton, WY 83110 USA 
Tel: 307-885-3151 
Fax: 307-885-9674 
E-mail: aviat@aviataircraft.com   
 
DATE: April 02, 2015 
 
SUBJECT: Stabilizer Support Tube Inspection and Repair  
 
REVISION: A  
 
HUSKY MODELS:     A-1, A-1A,  S/N 1468 & BELOW 
  A-1B,  S/N 2397 & BELOW 
  A-1B-WF,  S/N 0002 & BELOW   
   A-1B-NF,  S/N 0008 & BELOW 
   A-1C,  S/N 3198 & BELOW 
 
            Engineering Data is FAA Approved.  
_____________________________________________________________________ 
 
TABLE OF CONTENTS 
 
Description and Compliance…….....……………………………………………….…1 
Parts List…….....…………………………………………………………………....……...2 
Instructions……………...…………...….....……………...…………………….……….2-3 
Compliance Letter…...………….…………………………………………………………4 
 
 
DESCRIPTION 
 
The Rear  Stabilizer Support Tube , part number 30800-111  (All S/N’s), will be 
superseded by new part number 35001-112 in new production aircraft. The rear 
stabilizer support tube is located in factory master jigs, it is not suggested that the rear 
stabilizer support tube be replaced in the field due to alignment issues. This action is due 
to reported incidents of Stabilizer Support Tube failure.   
Refer to the Instructions section of this Service Bulletin for inspection and repair 
procedures for all previous Husky aircraft.  
 
COMPLIANCE 
 
 Before next flight and every 100 hours of flight t ime or during Annual Inspection 
thereafter, inspect rear stabilizer support tube p/n 30800-111 for damage.  Terminating 
action for this Service Bulletin will be the compliance repair and submission of Compliance 
Letter. 
     Please complete the Instruction  portion of this service bulletin; then complete 
the attached Compliance Letter , copy and send to addresses provided.

### Page 2

SERVICE BULLETIN NO. 28                        Aviat Aircraft Inc.  
 
Husky Service Bulletin No. 28 
2
 
 Field Repair PARTS LIST 
 
1.  Husky Repair Kit #SB-28 includes:  
                        (4 ea) Stabilizer mounting bolts, and self-locking nuts 
   (1 ea) Stabilizer Tube, Rear 
 
 
INSTRUCTIONS  
 
1.  Mandatory Inspection:   
a.  Begin by removing inspection access covers located above and below rear 
support tube.   
b.  Visually inspect entire circumference of support tube at weld joint between 
fuselage frame and fabric for corrosion or damage. 
c.  If damage is verified or suspected, proceed to Recommended Repair 
instructions.   
 
 
2.  Recommended Repair: 
a.  Mark and record adjustments of tail rigging and controls as necessary. 
b.  Loosen all attach bolts and remove elevators and stabilizers. 
c.  If you suspect damage to weld joints, perform a resonance test by tapping 
on support tube and listening for “dead” sounding resonance. 
d.  If mechanic is unable to effectively determine damage, it may be decided 
that fuselage fabric must be opened to enable access for a more thorough 
investigation or to perform a weld joint repair.  If damage is detected, 
proceed to (e).  If no damage is detected, proceed to (f/g). 
e.  Insert repair tube inside existing stabilizer support tube, align bolt holes, 
and weld both ends using AWS ER70S-2 welding rod in accordance with 
AC 43.13-1B, Chapter 5. 
f.  Make repairs to fuselage fabric as required.  For materials and process 
specification questions regarding fabrics, dopes, and paints, contact Aviat 
Aircraft Parts Department.  See contact information on page 1. 
g.  Reinstall stabilizers, elevators and controls.   
h.  It is recommended to replace all stabilizer mounting bolts & nuts.  Any 
questions on rigging, refer to Instructions for Continued Airworthiness Doc:  
Model A-1, A-1A; see 70192-002 section 1, 3.10, 
Model A-1B; see 70192-004 section 1, 3.10, 
Model A-1C; see 70192-006 section III, 5.2d. 
NOTE:  
• It is the responsibility of owner/operator to have FAA authorized 
repairmen perform this work.

### Page 3

SERVICE BULLETIN NO. 28                        Aviat Aircraft Inc.  
 
Husky Service Bulletin No. 28 
3
 
 
 
 
A A
      H U S K Y 
T A IL  S ID E  V IE W 
        N T S 
          
S T A B IL IZ E R   S U P P O R T   T U B E 
          R E P A IR   D E T A IL 
          SE C   A  - A 
E X IS T IN G 
F U S E L A G E  
F R A M E 
A L IG N   B O L T   H O L E S 
W IT H   E X IS T IN G   T U B E 
B O L T  H O L E S 
N E W   S U P P O R T 
T U B E   IN S E R T , 
P N : 30800-113 
IN S E R T   R E P A IR   T U B E 
A N D   W E L D   B O T H   E N D S 
F U S E L A G E   S K IN 
W E L D   JO IN T 
IN S P E C T IO N   P O IN T S , 
R E P A IR   W E L D   A S   R E Q 'D 
R E A R   S T A B IL IZ E R 
S U P P O R T   T U B E 
( 30800-111 ) 
1/16

### Page 4

SERVICE BULLETIN NO. 28                        Aviat Aircraft Inc.  
 
Husky Service Bulletin No. 28 
4
 
     SERVICE BULLETIN #28 COMPLIANCE LETTER 
 
This is to certify that I have complied with this Service Bulletin by completing Aviat  
Aircraft instructions for mandatory inspection and recommended service of the Stabilizer  
Support Tubes.   
 
Husky Model _______    Serial Number_________    Registration Number____________ 
      Date: __________________  Aircraft Hours: ___ _________ 
 
Authorized Mechanic ____________________________  Lic. No. _____________ 
Aircraft Owner: ________________________________________ 
Address: _______________________________________ 
              _______________________________________ 
Signed: _______________________________________ 
Send to: 
Aviat Aircraft Inc. Engineering Dept. 
P.O. Box 1240 
Afton, WY 83110 
Fax:  307-885-9674 
 
Send copy to: 
Federal Aviation Administration 
Denver Aircraft Certification Office 
Attn: Roger Caldwell 
26805 East 68 th  Avenue, Room 214 
Denver, CO 80249-6361 
Fax:  303-342-1088 
 
(Please attach comments on separate page)

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