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ENSTROM TH-28 Series Maintenance Manual Supplement

Supplement 2 emergency pop out floats
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ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL
SUPPLEMENT 2
EMERGENCY POP OUT FLOATS
The Airworthiness Limitations Section is FAA approved and specifies
inspections and other maintenance required under 14 CFR §§ 43.16 and
91.403 of the Federal Aviation Regulations unless an alternative program
has been FAA approved.
Copyright 2001, 2016 by
The Enstrom Helicopter Corporation
nd
2209 22
Street
Menominee, Michigan 49858-3515
Telephone: 906-863-1200
Fax: 906-863-6821
UNCONTROLLED COPY WHEN DOWNLOADED OR PRINTED
Rev. 3
i
Mar 21/16
Visit www.enstromhelicopter.com for instructions to order an original manual and to register for email notification of updates.

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  • Page 1 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 EMERGENCY POP OUT FLOATS The Airworthiness Limitations Section is FAA approved and specifies inspections and other maintenance required under 14 CFR §§ 43.16 and 91.403 of the Federal Aviation Regulations unless an alternative program has been FAA approved.
  • Page 2 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 INTENTIONALLY LEFT BLANK UNCONTROLLED COPY WHEN DOWNLOADED OR PRINTED Rev. 3 Mar 21/16 Visit www.enstromhelicopter.com for instructions to order an original manual and to register for email notification of updates.

  • Page 3: Recommended Change Report

    This maintenance manual is prepared and distributed by The Enstrom Helicopter Corporation and is intended for use by personnel responsible for maintaining Enstrom TH-28, 480, and 480B helicopters. This manual is periodically revised. If, in the opinion of the user, any information has been omitted or requires clarification, please direct your comments to Enstrom via this form (duplicate) or other similar form.
  • Page 4 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 INTENTIONALLY LEFT BLANK UNCONTROLLED COPY WHEN DOWNLOADED OR PRINTED Rev. 3 Mar 21/16 Visit www.enstromhelicopter.com for instructions to order an original manual and to register for email notification of updates.

  • Page 5: Record Of Revisions

    ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 RECORD OF REVISIONS ISSUE DATE REV NO. ISSUE DATE DATE INSERTED DATE INSERTED Mar 21/16 UNCONTROLLED COPY WHEN DOWNLOADED OR PRINTED Rev. 3 Mar 21/16 Visit www.enstromhelicopter.com for instructions to order an original manual and to register for email notification of updates.
  • Page 6 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 INTENTIONALLY LEFT BLANK UNCONTROLLED COPY WHEN DOWNLOADED OR PRINTED Rev. 3 Mar 21/16 Visit www.enstromhelicopter.com for instructions to order an original manual and to register for email notification of updates.

  • Page 7: Table Of Contents

    ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 TABLE OF CONTENTS Paragraph Description Page Cover Page ..................i Recommended Change Report ............iii Record of Revisions ................v Table of Contents ................vii Effective Page List ................ix Section 1 Introduction 1-1.

  • Page 8: Table Of Contents

    ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 TABLE OF CONTENTS Paragraph Description Page 5-4. Repair ..................5-1 5-5. Valve Removal/Replacement ............. 5-2 5-6. Cover Replacement ..............5-3 5-7. Installation................... 5-5 5-8. Packing ..................5-5 5-9. Reservoir Cylinder ................5-6 5-10.
  • Page 9 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 EFFECTIVE PAGE LIST Page Date Page Date Mar 21/16 Mar 21/16 Mar 21/16 Mar 21/16 Mar 21/16 Mar 21/16 Mar 21/16 viii Mar 21/16 Mar 21/16 Mar 21/16 Mar 21/16 Mar 21/16 Mar 21/16...
  • Page 10 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 INTENTIONALLY LEFT BLANK UNCONTROLLED COPY WHEN DOWNLOADED OR PRINTED Rev. 3 Mar 21/16 Visit www.enstromhelicopter.com for instructions to order an original manual and to register for email notification of updates.

  • Page 11: Introduction

    Bulletin is superseded by the maintenance manual. Enstrom distributes maintenance manual reissues and revisions in hardcopy form via mail to owners and operators who are registered with Enstrom. Notice of recently released Service Information Letters and Service Directive Bulletins is provided via a postcard mailing.

  • Page 12: Application Of Warnings, Cautions, And Notes

    ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 1-3. Application of Warnings, Cautions, and Notes A. Throughout this supplement, it is necessary to highlight or emphasize important points to avoid injury to personnel, damage to equipment, or unnecessary confusion while performing maintenance procedures. The terms “WARNING”, “CAUTION”, and “NOTE” are used to draw attention to instructions or information deserving special consideration.

  • Page 13: General Information

    (over pressurization), servicing the cylinder, and deploying the pop out floats. D. Enstrom 480 model aircraft equipped with the Increased Rotor Speed Kit, P/N 4230002, have additional fuel cell support structure and additional support struts installed in the pylon.

  • Page 14: Equipment And Consumables

    ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 Total Ship Weight is approximately 106 lbs/48.2 kg for Enstrom 480 model aircraft equipped with the Increased Rotor RPM Kit, P/N 4230002. 2-2. Equipment and Consumables A. The following listed equipment is required for maintaining and servicing the pop out floats: Table 2-2.

  • Page 15: Vendor Manuals

    Apical Industries, Inc. Maintenance/IPC manual and the installation/float repack manuals listed below. Apical Industries Emergency Helicopter Float Assemblies Enstrom Helicopter TH-28/480, TM480-1, Latest Revision. 480/TH28 Installation and Packing Instructions, II 480-100, Latest Revision.
  • Page 16 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 INTENTIONALLY LEFT BLANK UNCONTROLLED COPY WHEN DOWNLOADED OR PRINTED Rev. 3 Mar 21/16 Visit www.enstromhelicopter.com for instructions to order an original manual and to register for email notification of updates.

  • Page 17: Airworthiness Limitations

    ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 SECTION 3 AIRWORTHINESS LIMITATIONS 3-1. Airworthiness Limitations A. The Airworthiness Limitations section is FAA approved and specifies maintenance required under 14 CFR §§ 43.16 and 91.403 unless an alternative program has been FAA approved.
  • Page 18 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 INTENTIONALLY LEFT BLANK UNCONTROLLED COPY WHEN DOWNLOADED OR PRINTED Rev. 3 Mar 21/16 Visit www.enstromhelicopter.com for instructions to order an original manual and to register for email notification of updates.
  • Page 19 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 SECTION 4 SERVICING AND PERIODIC INSPECTIONS 4-1. Servicing 4-2. Reservoir Cylinder WARNING Ensure that the diffuser cap, P/N 20322, is installed on the outlet port and the pull cable detent with warning tag, P/N's...
  • Page 20 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 NOTE: Serviceable pressure range is ± 50 psig (345 kPA) for corresponding ambient temperature. Figure 4-1. Reservoir Cylinder Charge UNCONTROLLED COPY WHEN DOWNLOADED OR PRINTED Rev. 3 Mar 21/16 Visit www.enstromhelicopter.com for instructions to order an original manual and to register for email notification of updates.

  • Page 21: General Maintenance

    ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 4-3. General Maintenance 4-4. Testing NOTE Following the repair/overhaul of float assemblies, perform a float pressure test before returning the equipment to service. The relief valve and topping-off valve tests may be performed in conjunction...

  • Page 22: Topping-Off Valve Leakage Test

    ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 CAUTION Cap and plug all open lines and fittings to prevent contamination of the system. A. Disconnect the hose(s) for the float(s) at the fitting located at the landing gear leg if not already accomplished.

  • Page 23: Pressure Relief Valve Test

    ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 NOTE This test may be performed as a part of the float pressure test while the floats are inflated to 1.5 psig/10.3 kPa after the activation test. A. Apply leak solution (detergent soap and water) with a soft bristle brush at the mounting patch on the float.

  • Page 24: Troubleshooting

    ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 4-11. Troubleshooting TROUBLE PROBABLE CAUSE REMEDY Float will not maintain operating Hole in fabric Patch hole pressure Tear in fabric Patch tear Leaking PRV Check valve and base threads Check valve and base threads...

  • Page 25: Periodic Inspection Checklist

    2. Inspect for correct pressure in reservoir cylinder (Refer to Figure 4-1). _______ 3. Inspect the pylon support struts for security of installation, damage, and proper torque (Refer to paragraph 5-27). (Only Enstrom 480 model aircraft equipped with Increased Rotor RPM Kit, P/N 4230002) _______ 4.

  • Page 26: Recommended Overhaul Cycles

    ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 4-14. Recommended Overhaul Cycles A. The following components of the pop out float system have a recommended overhaul cycle. COMPONENT PART NUMBER OVERHAUL CYCLE Valve Assembly 20306-2 3 years to coincide with hydrotesting of...

  • Page 27: Float Assembly

    ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 SECTION 5 SYSTEM MAINTENANCE NOTE Disassembly of components as described in this section is subjective and when routine periodic inspections are due. The decision to disassemble detail assemblies should be based on the presence of leaks, visible damage, or functional discrepancies discovered during testing procedures.
  • Page 28 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 seam, valve installation reinforcement, or other structural attachment. Repair patches may not overlap. Repair of the attachment girt is not authorized. 1. Using a clean cloth, dry the surface to which the patch is to be applied.
  • Page 29 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 1. Using the valve wrench, P/N B-51025, remove the valve by turning counter- clockwise. Check the threads on the valve and in the flanged fitting for damage. Replace the valve if the threads are damaged. Replace the float assembly if the threads in the flange are damaged.
  • Page 30 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 Figure 5-1. Float Cover Installation UNCONTROLLED COPY WHEN DOWNLOADED OR PRINTED Rev. 3 Mar 21/16 Visit www.enstromhelicopter.com for instructions to order an original manual and to register for email notification of updates.
  • Page 31 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 5-7. Installation – Float Assembly A. Install the chamber interconnect hose if it was removed from the float assembly. Torque the fittings to 215-245 in-lb/24.4-27.8 Nm. B. Install the supply hose if it was removed from the float assembly. Torque the fitting to 460-510 in-lb/52.3-58.0 Nm.
  • Page 32 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 J. Tuck in the loose ends of the lacing cord. Close out the side hook and pile fasteners along the length of the cover and close the end flaps with the hook and pile fasteners.
  • Page 33 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 C. Hydrotest reservoir cylinder every 3 years. D. Service reservoir cylinder with correct pressure charge. E. Overhaul reservoir valve assembly after activation or 3 years. 5-13. Valve Overhaul – Reservoir Cylinder WARNING Ensure the reservoir cylinder has been discharged before performing any maintenance on the reservoir cylinder valve.
  • Page 34 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 H. Install new o-rings (15,17) on the fusible plug adapter (16) and the fusible plug (18). Install the adapter and torque to 30 ft-lb/40.9 Nm. Install the fusible plug and torque to 25 ft- lb/34.1 Nm.
  • Page 35 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 Valve Body O-Ring O-Ring Fusible Plug O-Ring O-Ring Safety Disk Gauge Safety Disk Retainer O-Ring O-Ring Outlet Fitting Puncture Disk Pull Cable Ball Puncture Disk Retainer Pull Cable Piston Fill Fitting Piston O-Ring...
  • Page 36 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 5-15. Activation Cable 5-16. Removal – Activation Cable WARNING Install the pull cable detent with warning tag, P/N's 306D and 306T, in the pull cable housing before performing any maintenance on the activation cable.
  • Page 37 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 E. Ensure the activation cable handle is fully seated and the guard is installed over the handle. WARNING Ensure the pull cable detent with warning tag, P/N's 306D and 306T, is installed in the pull cable housing.
  • Page 38 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 5-20. Hoses, Lines, and Fittings 5-21. Removal – Hoses, Lines, and Fittings WARNING Install the pull cable detent with warning tag, P/N's 306D and 306T, in the pull cable housing before performing any maintenance on hoses, lines, and fittings for the pop out float system if the reservoir cylinder is installed.
  • Page 39 D. Remove the pull cable detent after the system is returned to service. 5-25. Pylon Support Struts Refer to Figure 5-4 NOTE The pylon support struts are only installed in Enstrom 480 model aircraft equipped with the Increased Rotor Speed Kit, P/N 4230002. These struts may be either removed or remain installed when the float assemblies are not installed on the aircraft.
  • Page 40 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 2. Alternating from side to side on the aircraft, evenly lengthen the strut assemblies (increase the torque load) in 100 in-lb/11.4 Nm increments until a 500 in-lb/56.8 Nm torque load is applied. 3. Tighten the jam nuts on the rod end fittings and slippage mark.
  • Page 41 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 Figure 5-4. Pylon Support Strut Installation UNCONTROLLED COPY WHEN DOWNLOADED OR PRINTED Rev. 3 5-15 Mar 21/16 Visit www.enstromhelicopter.com for instructions to order an original manual and to register for email notification of updates.
  • Page 42 ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 2 INTENTIONALLY LEFT BLANK UNCONTROLLED COPY WHEN DOWNLOADED OR PRINTED Rev. 3 5-16 Mar 21/16 Visit www.enstromhelicopter.com for instructions to order an original manual and to register for email notification of updates.

This manual is also suitable for:

Th-480 seriesTh-480/b

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