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 dif fi 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 The chains had never been replaced by the operator since manufacture.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 speci fi 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 classi fi 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 Dif fi 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 modi fi 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 magni fi 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 speci fi 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 suf fi 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 1Issued: 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 26SB27001001Issued: June 6, 2013 Revised: April 8, 2014 26-27-001 R3 Page 8 of 8 

# SERVICE BULLETIN SA26 SERIES

FIGURE 2 CONTROL WHEEL ASSEMBLY 6M271001201 FWD 

# 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