### April 3, 1998 DATE ISSUED January 10, 2012 Revision 3 

### REVO,Inc. SERVICE BULLETIN B-78 R3 TECHNICAL ASPECTS OF THIS SERVICE BULLETIN ARE FAA APPROVED
(Corrections to Rigging TablePg4) 

### SUBJECT: EFFECTIVITY: COMPLIANCE:

Description: Horizontal TailAttachmentFittings All Colonial C-1, C-2 andLakeLA-4, LA4A, LA4P, LA-4-200 Models In-Situ Inspection: Within 10 hrs, then every 50 hours thereafter. Replacement of(1)-2200-14 and 2-2200-21 Fittings: Every 850 hours. NOTE: Rev R2 and R3 ofthis Service Bulletin affects**2200~14** or**1~2200-14** fittings installed on C-1 aircraft. 2-2200-21 Fittings are FAA approved replacements for these fittings. 

### A recent incidentinvolving failure ofthe attachment fitting ofthe lefthand horizontal stabilizerto the vertical fin has shown that a cause for initiation ofa crackin the fitting can exist. The area in question is shown below.

---- -'li· 

# i- 

# + 

# + ···--t-1 I;**---.L---=-t~·** ":j·_·-t
. 

# ·-t--1 li t t {1)-2200-14 

### or2-2200-21 

### FITTING

## 2;,------~~:t 

# ,,, 

# ------· /_t-:j II 

# -----;-+-- __



# -_-:+-f/'I**·~-f..** 

## .**~** 

## \ I 

# 'I f I 

### I

- G7AB'tt..tZC:K..:. Se:A/111 /)00t?t..e'R fltv'oLt5'**..;rAilt4'c~R. .8'~N1**  eHtfAf,./et_

Page 1 of4

### REVO,Inc. SERVICE BULLETINB-78 R3 IN-SITUINSPECTIONPROCEDURE: The fitting in the area ofits attachmentto the horizontal stabilizer rear beam may be initially inspected byraising the elevator and determiningthe distance between the fitting and the flanges ofthe beam doubler angles, and any contact ofthe fitting with the skin. (See below). Both left and right stabilizer halves, top and bottom, must be checked for adequate clearance and any evidence ofcracking where the inboard stabilizer beam channel and the stabilizer fitting meet.

1. Measure the clearance between the horizontal stabilizer skin and the fitting. Ifthere is less than 1/16" clearance, trim the edge ofthe skin to provide at least 1/16" clearance. 2. Measure the gap between the horizontal stabilizer rear beam doubler angle and the fitting. The shank ofa 5/32" drill bitmaybe used to checkthe gap. 3. Ifthe gap is at least 5/32": a) Clean the top and bottom ofthe fitting and visually inspect the top and bottom ofthe fittings using a magnifying glass orhoroscope. Pay extra attention to the front edge ofthe fitting in the area noted onthe Figure on page 1 ofthis bulletin. Repeat this inspection every 50 hours until 850 hours oftime is reached on the fitting. b) Ifcracks, fretting or corrosion is evident or suspected in this area, the fitting must be removed from the airplane (follow the removal instmctions found in the APPENDIX of this bulletin) and inspected in accordance with the "DETAILED INSPECTION and REPLACEMENT" section of this bulletin. Ifcracks, fretting or corrosion are present, the fitting mustbe replaced with a new fitting (follow the replacement instructions in the "DETAILED INSPECTION and REPLACEMENT" section ofthis bulletin). 4. Ifthe gap is less than 5/32", it will be necessary to remove the fitting in orderto properly inspect it. Remove the fitting by following the removal instructions found in the APPENDIX ofthis bulletin and Inspect, and replace ifnecessary, iu accordance with the "DETAILED INSPECTION and REPLACEMENT" section ofthis bulletin. Atthe next 50 hour inspection the inspections in Item 3 above may be followed. 5. Whenthe partreaches 850 hours time in service the part must be removed from the airplane and replaced with a new fitting (follow the removal and replacement instmctions in the APPENDIX and the DETAILED INSPECTION and REPLACEMENT sections). Page 2 of4

### REVO,Inc. SERVICE BULLETIN B-78 R3 DETAILEDINSPECTION and REPLACEMENT 1. 2200-14, 1-2200-14 and 2-2200-21 fittings have a life limit of850 hours T.I.S. 

### Ifa fitting has over 850 hrs TIS, ortotal time cannot be determined, itmust bereplaced; proceed to step 3. 2. With the fitting removed, inspect its forward face and edge for evidence ofactual contact with the stabilizerbeam or any adjacent structure. Ifcontact has been present, the fitting 

### will show signs offretting orpossibly the start ofa crack. Removal ofpaint (by light sanding) will be necessary for this inspection. Inspectthe area with a magnifying glass. Dye checking, per MIL-I-6866B or equivalent, is also recommended. Ifcracks, fretting orcorrosion are present, the fitting must be replaced with a new 2-2200-21 fitting. 3. New fittings may come with or without the (20) 0.191" rivet holes. This is to allow the holes to be drilled in the field for improved alignment and fit 4. Before drilling these (20) rivet holes in the field, centerthe new fitting midway between the upper and lower beam and doubler flanges, with the centerline ofthe 3/8" bolt holes 15/16" ( ± 1/16") inboard ofthe beam end. Checkto assure that the fitting location meets the inspection requirements ofitems #1 and #2 ofthe "IN-SITU INSPECTION PROCEEDURE" above. 5. Locate the rivet holes onthe fitting by marking the forward face ofthe fitting through several ofthe rivet holes in the stabilizer beam. Remove the fitting from the beam and mark the remaining rivet holes using the old fitting as a template. Checkholes for minimum edge distance of5116". 6. Drill the (20) rivet holes with a #11 drill bit, using the old fitting as a drill template. 7. Before installing any fitting, trim the inboard edge ofthe stabilizer skin 

### ifnecessary to keep at least 1116" clearance between the skin and the fitting. Trimmed edges should be filed smooth with no sharp edges. 8. Prior to reassembly, use brush Alodine and primer on all bare metal exposed during the inspection and repairprocesses. 9. Install the new 2-2200-21 fitting using AN470AD6 rivets.

Page3 of4

### REVO,Inc. SERVICE BULLETINB-78 R3
APPENDIX
REMOVAL and REINSTALLATION ofHORIZONTAL TAIL HALVES:

1. Disconnect the pushrod from the elevator horn inside the vertical tail. Allow the pushrod to lower out ofthe way. 2. Disconnect the trim surface torque tubes near the inboard end ofthe horizontal tail. 3. Unboltthe elevator from the elevator hom welded assembly. 4. Remove the elevator from the stabilizer by pulling the hinge pin. 5. With the horizontal tail supported, remove the AN4 bolt from the forward beam attach point, and remove the two AN6 bolts from the rear beam attach fitting. 6. Remove the fitting from the stabilizer by carefully drilling out the AN470AD6 rivets. 7. Repeatthe procedures 2 through 6 for the other stabilizer halfifnecessary. 8. After installing a new or corrected fitting onto the stabilizer rear beam, reverse the above procedure for reinstallation ofthe horizontal tail. (Existing bolts and hinges in good condition may be reused.) 9. Install all seals and access covers. (Existing parts may be re-used.) 10. Checktravels and operation ofelevator, 

### trim surfaces, and rudder. MODELS> Colonial Colonial C-2 and SURFACE C-1 Lake LA4, LA4A, LA4P, LA4-200 ElevatorUP 20.5° 26°±1..
.. 0 ElevatorDOWN 20°
... 23° ±1°
.... Trim Tab UP 

# -- 36°+2°/-1° Trim Tab DOWN 

# -- 240 +20/-10 Rudder Left & Right 25° ±1° 25o ±l.
... o
---End---

Page 4of4