Issued: June 6, 2013

Revised: April 8, 2014

26-27-001 R3

Page 1 of 8

SERVICE BULLETIN

SA26 SERIES

Flight Controls

Inspection and Lubrication of the Aileron Control Cable Chain in the Pilot's and 

Copilot's Control Columns

1. PLANNING INFORMATION

A. Effectivity:

All SA26-T, S/N T26-2 thru T26-99

All SA26-AT, S/N AT26-100 thru AT26-180E

B. Reason:

An operator has reported an incident where the ailerons became jammed in fl ight 

due to the aileron control cable chain climbing back on itself and jamming within the 

control column housing. There was no report of stiffness or diffi culty in the controls 

by the pilot prior to this incident. The chains had never been replaced by the operator 

since manufacture.

Revision 3 corrects the part number of the chain in Steps 1.D.(1)(a)NOTE, 1.D.(4), 

2.A.(2), and Table 1. It also states that this part number chain must be used with new 

sprocket per Kit 26K71004-001. All changes are denoted by revision bars in the left 

margin.

C. Description:

Inspect the pilot's and copilot's aileron control cable chains in the control columns for 

defective condition or wear. Replace the bearings and chain sprocket inside each control 

column. Ensure the instructions for chain/sprocket lubrication during replacement is 

performed to prevent jamming. Lubricate chain and sprocket upon replacement.

D. Compliance:

Mandatory

Comply with this service bulletin within the compliance times specifi ed unless already 

done.

(1) For aircraft that have records showing replacement of the control column chains 

and lubrication (using the correct lubricant per Table 1) at installation, perform 

the following:

(a) Replace and lubricate the chain, sprocket, and bearings by 10,000 hours 

or 13 years, from the date of the last chain replacement, or within the next 

24 months from the date of this service bulletin, whichever occurs later.
Issued: June 6, 2013

Revised: April 8, 2014

26-27-001 R3

Page 2 of 8

SERVICE BULLETIN

SA26 SERIES

NOTE: The 27-71026-003 aileron control chain is usually sold as part of the aileron 

control cable assembly. Replacement of this control cable assembly (including 

the chain) complies with the chain replacement requirement of this service 

bulletin.

(b) Check aileron control cable tension at the same time as step 1.D. (1)(a).

(2) For aircraft that have records showing the chains were replaced within the last 10,000 

hours, but does NOT indicate if they were lubricated, perform the following:

(a) Comply with step 1.D.(3)(a), (b), and (c) by 10,000 hours aircraft time since last 

chain replacement or within the next 1,000 hours, whichever occurs later, but 

not to exceed 24 calendar months from the date of this bulletin.

(3) For aircraft that have no records showing replacement of the control column chains 

within the last 10,000 hours, perform the following:

(a) Replace and lubricate the control chain during installation in each control column. 

This can be coordinated with aileron control cable replacement if desired.

(b) Replace the sprocket and two bearings (see Table 1) in each control column.

(c) Check aileron control cable tension.

(d) Comply with (a) (b), and (c) within the following schedule:

1) For aircraft with less than 10,000 hours Total Aircraft Time (TAT), perform 

by 10,000 hours or within the next 1,000 hours, whichever occurs later, 

not to exceed 24 calendar months from the date of this bulletin.

2) For aircraft with 10,000 - 20,000 hours TAT, perform within the next 1,000 

hours or 12 calendar months, whichever occurs fi rst, from the date of this 

service bulletin.

3) For aircraft with 20,001 - 30,000 hours TAT, perform within the next 750 

hours or 6 calendar months, whichever occurs fi rst, from the date of this 

service bulletin.

4) For aircraft with 30,001 hours TAT or more, perform within the next 400 

hours or 3 calendar months, whichever occurs fi rst, from the date of this 

service bulletin.

(4) Repetitive Replacement

On a repetitive basis, perform replacement per step 1.D.(4)(a). Ensure chain is 

lubricated during installation. The 27-71026-003 aileron control chain is usually 

sold as part of the aileron control cable assembly. Replacement of this control cable 

assembly (including the chain) complies with the chain replacement requirement of 

this service bulletin. See step 2.

(a) Replace and lubricate the chain, sprocket, and bearings by 10,000 hours or 

13 years from the date of the last chain replacement, whichever occurs fi rst. 

Check aileron control cable tension.

(5) See step 2 for accomplishment instructions.
Issued: June 6, 2013

Revised: April 8, 2014

26-27-001 R3

Page 3 of 8

SERVICE BULLETIN

SA26 SERIES

NOTE: 

1. It is permissible to perform the repeat replacement prior to the 10,000 hours (13 

calendar years) to align the repeat action with other maintenance schedules of 

the operators.

2. Aircraft that have already complied with this bulletin at an earlier revision do not 

have to repeat the initial action outlined in steps 1.D.(1) thru 1.D.(3). They may 

proceed with repeat replacement per step 1.D.(4). If during compliance with an 

earlier revision of this bulletin, chain P/N 27-71026-001 was installed, it needs to 

be removed and replaced with chain P/N 27-71026-003 if using the sprocket from 

Kit 26K71004-001. This replacement must be accomplished before next fl ight. If 

chain P/N 26-71026-001 and sprocket P/N 26-71010-001 were installed during 

this prior replacement, this is satisfactory. See Note 1 on page 5.

E. Approval:

FAA Approved for Engineering Design.

F. Manpower:

M7 Aerospace estimates 20 manhours to perform the actions of this service bulletin. 

This estimate includes time to gain access, perform the inspection, replacement and 

lubrication, and re-assembly of both control columns. This estimate is for direct labor 

only accomplished by an experienced crew. Adjust the estimate with operator task hour 

data if necessary.

G. Material - Cost and Availability

 Contact M7 Aerospace Spares/Sales Department for Cost and Availability. See 

 Table 1.

H. Tooling-Price and Availability:

No special tooling is required.

I. Weight and Balance:

None

NOTE: It is recommended the aircraft operating weight be re-established after 

incorporating 20 service bulletins classifi ed as having negligible impact on 

aircraft weight and balance. This recommendation is derived from data provided 

in FAA Advisory Circular 120-27.

J. Reference:

SA26 Maintenance Manual. 

M-5585 - M7 Aerospace Memorandum Aileron Control Chain Service Diffi culty Report 

(SDR).
Issued: June 6, 2013

Revised: April 8, 2014

26-27-001 R3

Page 4 of 8

SERVICE BULLETIN

SA26 SERIES

NOTE: References are for manufacturers’ use only.

K. Other Publications Affected:

SA26 Maintenance Manual.

SA26 Illustrated Parts Catalog

2. ACCOMPLISHMENT INSTRUCTIONS

A. For replacement of any or all chains, sprocket, and bearings in control columns, 

perform the following and comply with Note 1 on page 5.

Gain access to pilot's and copilot's control columns in the cockpit by removing any fl oor 

panels, kick panels, and control column boots as required. Refer to SA26 Maintenance 

Manual, Section 2 for fl oorboard details. Retain all hardware for reinstallation of same.

(1) Remove the lower access panel on the pilot's side control column only (which 

gives access to the cable turnbuckle). Refer to SA26 Illustrated Parts Catalog 

(IPC), Section VII, Figure 45 for details. Retain all hardware.

(2) Follow the guidelines per SA26 Maintenance Manual, Supplement B to Section 

3, for control wheel disassembly (ref Supplement B to Section 3, Figure 201 for 

details of control wheel). This gives access to the chain (27-71026-003), sprocket, 

and bearings on the control wheel.

(a) The February 1987 FACTS article contained some helpful advice for removal 

of the control wheel assembly which is reprinted here.

 The process of removing the control wheel assembly is complicated because 

removal is hampered by interference of electrical wiring. A modifi ed tool for 

breaking loose the control wheel nut is made by making a cutout on a special 

1-1/4 inch socket as shown in Figure 1 below. This tool will clear all wiring 

at the control wheel nut and save precious time while, at the same time, 

protecting the wiring from damage.

(3) Replace the sprocket and bearings with those contained in Kit 26K71004-001 per 

Table 1. The bearings are located in the front and rear supports (26-71009-001) 

in the control wheel assembly. Visually inspect the removed sprocket and existing 

chain with 10X magnifi cation and good light for chips, gouges, damaged rollers, 

missing teeth, peeling metal, and signs of abnormal wear.

(4) Replace the chain.

(5) Lubricate control wheel chain with Table 1 lubricant (by hand) per SA26 Maintenance 

Manual, Section 2.

(a) The instructions for lubrication shall follow this bulletin and NOT apply the 

Corrosion Preventative (CP) to the chain. 

 NOTE: The CP IS applicable to the cable.
Issued: June 6, 2013

Revised: April 8, 2014

26-27-001 R3

Page 5 of 8

SERVICE BULLETIN

SA26 SERIES

(b) When the aircraft was delivered from the factory, or new chains are supplied 

from the factory, the CP was/is installed. The chain must be cleaned to 

remove the CP prior to the application of the lubricant. Clean the chain with 

a degreasing solvent per MIL-PRF-680 or equivalent. 

 CAUTION: SEVERAL OF THE TYPE OF SOLVENTS PER THIS 

SPECIFICATION ARE FLAMMABLE (E.G. MINERAL SPIRITS) AND 

CAUTIONS SHALL BE TAKEN AS APPLICABLE.

(c) Once the chain has been cleaned and dried, the lubricant can be added. 

Ensure the lubricant is added adequately to cover the length of the chain. 

Work the lubricant into the chain by exercising the chain by hand.

(6) Ensure all other parts of the control wheel assembly are fi t for service. (See Figure 

2 for parts)

(7) Restore the control wheel assembly to operating condition per SA26 Supplement 

B to Section 3.

(8) Reinstall all access panel on the control column removed in step 2.A.(1).

(9) Perform aileron control cable tension and rigging checks per SA26 Maintenance 

Manual, Section 3, Page 3-12.

(10) Reinstall all components, structure, and hardware per applicable sections of the 

SA26 Maintenance Manual.

(11) Complete aircraft records in accordance with 14 CFR 43.9.

(12) Complete and return service bulletin Compliance Form to M7 Aerospace Technical 

Publications Department at MetroTech@M7Aerospace.com.

NOTE 1 FOR ACCOMPLISHMENT INSTRUCTIONS

The SA26 aircraft were supplied with Chain P/N 26-71026-001 and Sprocket P/N 26-71010-

001 from the factory. This chain and sprocket are a matched set. The new replacement 

Chain P/N 27-71026-003 and Sprocket included in Kit P/N 27K71004-001 are also a 

matched set. Do not cross mix and match these chains and sprockets as the sprockets 

have different teeth pitch to mate with their respective chain. Only install either the Chain 

P/N 27-71026-003 with Sprocket Kit P/N 27K71004-001 as a matched set or alternatively 

the Chain P/N 26-71026-001 with Sprocket P/N 26-71010-001 as a matched set.
Issued: June 6, 2013

Revised: April 8, 2014

26-27-001 R3

Page 6 of 8

SERVICE BULLETIN

SA26 SERIES

3. MATERIAL LISTING

Notes:

* Chain is usually sold as part of the aileron control cable assembly. However, this bulletin 

requests this specifi c chain be replaced.

** The bearing contained in the kit is the replacement for KP16B bearing. KP16B bearing 

still valid to use as replacement.

*** MIL-PRF-81322 supercedes MIL-G-81322 however, MIL-G-81322 is still a valid grease 

to use in this application.

**** A degreasing solvent meeting the requirements of MIL-PRF-680 is suggested to be 

used to remove the Corrosion Preventative compound from the chain. Equivalent 

alternatives are permitted to remove this compound. Follow the solvents MSDS sheet 

for usage.

‡ Spacer, P/N 26-71004-025 ia a 0.090 inch thick spacer installed in earlier control column 

assemblies. This spacer was replaced by a 0.016 inch thick spacer, P/N 26-71004-095. 

This change was incorporated to provide improved adjustment of the control wheel 

assembly. The 26-71004-095 is sold in quantities of ten to ensure suffi cient quantities 

are available at reassembly of the control wheel assembly. Each control wheel assembly 

(left hand or right hand) may require up to ten P/N 26-71004-095 spacers. Refer to step 

2.A.(7) for instructions.

Description Part Number Quantity

Chain * 27-71026-003 1

Sprocket and Bearing Kit ** 26K71004-001 1

Lubricant MIL-PRF-81322 *** A/R

Degreasing Solvent MIL-PRF-680 **** A/R

The following part is optional:

Support, Front and Rear 26-71009-003 2

Small Spacer ‡ 26-71004-095 A/R

TABLE 1
Issued: June 6, 2013

Revised: April 8, 2014

26-27-001 R3

Page 7 of 8

SERVICE BULLETIN

SA26 SERIES

FIGURE 1

REMOVE

MATERIAL 1.10

1.00

MODIFIED

1 1/4” 12-POINT SOCKET 26SB27001001
Issued: June 6, 2013

Revised: April 8, 2014

26-27-001 R3

Page 8 of 8

SERVICE BULLETIN

SA26 SERIES

FIGURE 2

CONTROL WHEEL ASSEMBLY

FWD

6M271001201

A

A

BEARING

REAR SUPPORT

SPACER

SHAFT

WOODRUFF

KEY

RETAINING

NUT

CONTROL WHEEL

BEARING

FRONT

SUPPORT

SPACER

CHAIN AND

SPROCKET

WOODRUFF

KEY SLOT

CONTROL COLUMN

KEEPER

CABLE

MASTER

LINK

SPACER (OPTIONAL)

MAY BE SPLIT FOR

INSTALLATION

COVER

PLATE