Operation, Maintenance Manual, and Logbook for Propeller Systems HM-5V1-B1000-A, HM-6V1-A1000-A (2018)

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2. Troubleshooting

A. Surging

(1) Surging is characterized by a large increase/decrease in engine speed,

followed by a return to set speed after one or two occurrences.
(a) Check for trapped air in the propeller

Complete steps 1.A.(1) through 1.A.(6) under the Operational Tests

section in this chapter to release trapped air from the propeller.

(b) Check

the blades for excessive friction. If present:

Inspect the blade retention system.

Inspect the tachometer and drive.

(d) Check for sludge and dirt deposits.

Inspect and clean the propeller, beta valve, cylinder, and oil tubes.

(e) Check the connection from the beta valve to the actuator.

B. Pitch Change Sluggish

(1) Inspect the blade retention system for excessive friction.

(2) Check the oil pressure and flow (for low pressure).

(a) Inspect the oil supply and oil transfer openings.

(3) Inspect the beta tube passages for dirt deposits.

Pitch Lock Pin Installation

Figure 4-1

Pitch Lock

Bracket

Pitch Lock

Hole

Locking

Balls

103155

Pitch Lock Pin

Witness Hole

TI-300-002

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C. Loss of Thrust

(1) Inspect the hydraulic system for proper function.

WARNING: HOVERCRAFT OPERATION WITH THE 103155 PITCH LOCK

PINS INSTALLED WILL NOT PERMIT THRUST REVERSING

FUNCTION TO SLOW THE VEHICLE.

(a) If the hydraulic propeller pitch control system has failed, install the

103155 pitch lock pins to lock the propeller into a single pitch, permitting

a restricted mode of operation. Refer to Figure 4-1.
1

Shut down propeller thrust engines.

Remove any ice (or debris) in/over pitch lock holes.

CAUTION:

DO NOT DAMAGE THE LEADING OR TRAILING

EDGES OF THE BLADE WHEN DOING THE

FOLLOWING STEP.

Manually force the pitch of the propeller blades to a position where

the pitch lock bracket hole lines up with the hole in the blade ring.
a This

could require two crewmen to apply force to two separate

blades at the same time.

Push and hold the button on the 103155 pitch lock pin while putting

the pin into the pitch lock hole on the pitch lock bracket.
a

Push the 103155 pitch lock pin into the pitch lock hole until the

locking balls are lined up with the witness hole in the bracket,

then release the button on the pin.
(1) After releasing the button on the 103155 pitch lock pin,

move the pin until the locking balls "click" into the holes in

the pitch lock bracket.

CAUTION: DO NOT PUSH THE BUTTON ON THE 103155

PITCH LOCK PIN WHEN CHECKING THE PIN

INSTALLATION.

Pull the 103155 pitch lock pin to make sure it is locked into the

pitch lock bracket.
(1) If the 103155 pitch lock pin pulls out of the pitch lock

bracket, repeat 2.C.(1)(a)4 through 2.C.(1)(a)4 b.

Repeat steps 2.C.(1)(a)4 through 2.C.(1)(a)4 a(1) for

each blade.

Re-start the propeller thrust engines.

6 Operate

the Hovercraft propeller thrust engines within their limits of

RPM range.
a

Allow sufficient distance to slow and maneuver the Hovercraft.

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D. Vibration

WARNING: ABNORMAL VIBRATION CAN BE AN INDICATION OF A FAILING

PROPELLER BLADE OR BLADE RETENTION COMPONENT.

BLADE SEPARATION CAN RESULT IN A CATASTROPHIC

ACCIDENT.

CAUTION:

ANY VIBRATION THAT CAN BE DESCRIBED AS APPEARING

SUDDENLY, OR IS ACCOMPANIED BY UNEXPLAINED GREASE

LEAKAGE, SHOULD BE INVESTIGATED IMMEDIATELY BEFORE

FURTHER HOVERCRAFT OPERATION.

(1) Vibration problems due to propeller system imbalance are normally felt

throughout the RPM range, with the intensity of vibration increasing with RPM.

(2) Check:

(a) Control surfaces and exhaust system, etc. for excessive play, which may

be causing vibration unrelated to the propeller

(b) Uneven lubrication of the propeller

(d) Blade track (Refer to the Inspection and Check chapter of this manual for

procedure.)

(e) Static balance

(f) Airfoil profile identical between blades

Contact the Hartzell Propeller Inc. Product Support department for

additional inspection criteria.

(g)  Hub and blades for damage or cracking
(h)  Grease or oil leakage from a seemingly solid surface of the hub or blade
(i)  Blade delamination

NOTE: Dynamic balancing is recommended after installing or

performing maintenance on a propeller. While this is normally

an optional task, it may require the engine or Hovercraft

manufacturer to make certain the propeller/engine combination

is balanced properly before operation. Refer to the engine or

Hovercraft manuals, and the Maintenance Practices chapter of

this manual.

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E. Oil or Grease Leakage

(1) A new propeller may leak slightly during the first several hours of operation.

This leakage may be caused by the seating of seals and O-rings, and the

slinging of lubricants used during assembly. Such leakage should cease within

the first ten hours of operation.

CAUTION

GREASE LEAKAGE THAT CAN BE DESCRIBED AS EXCESSIVE

AND APPEARING SUDDENLY, ESPECIALLY WHEN

ACCOMPANIED BY VIBRATION, SHOULD BE INVESTIGATED

IMMEDIATELY BEFORE FURTHER OPERATION OF THE

HOVERCRAFT.

(2) Grease Leakage - 5 Blade Only - Probable Cause:

(a)  Improperly torqued or loose lubrication fitting
(b)  Defective lubrication fitting
(c)  Faulty seal at the blade socket between the blade and hub - Contact the

Hartzell Propeller Inc. Product Support department for replacement of the

seal.

(d) Cracked hub - A cracked hub is often indicated by grease emerging from a

seemingly solid surface, especially in the blade arm. Contact the Hartzell

Propeller Inc. Product Support department.

(3) Oil Leakage - Probable Cause

(a) Leaks between the hub halves - Faulty seal(s) - Contact the Hartzell

Propeller Inc. Product Support department for replacement of the seal.

(b) Leaks between the hub and engine - Faulty or missing seal between the

propeller hub and the engine flange.

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1. Pre-Operation Inspection

A. The following inspections should be performed on a daily basis before attempting to

operate the propeller.

WARNING:

ABNORMAL VIBRATION CAN BE AN INDICATION OF A FAILING

PROPELLER BLADE OR BLADE RETENTION COMPONENT. A

BLADE SEPARATION DURING PROPELLER OPERATION CAN

RESULT IN A CATASTROPHIC HOVERCRAFT ACCIDENT.

(1) Blades

(a) Visually inspect the entire blade and the erosion strip for nicks, gouges,

looseness of material, erosion, cracks, and debonds. Refer to the

Maintenance Practices chapter of this manual for composite blade

operable damage limits.
1

Defects or damage discovered during daily inspection must be

evaluated in accordance with allowables outlined in the Maintenance

Practices chapter of this manual to determine if repairs are required

before further operation.

(b) Blades should turn smoothly and freely, but should not have excessive

movement. If the blades do not turn freely, refer to the Testing and

Troubleshooting chapter of this manual for information.

limits, refer to the Loose Blades section of the Inspection Procedures

section of this chapter.

(2) Check for loose/missing hardware. Tighten or reinstall as necessary.
(3) Inspect for grease and oil leakage and determine the source.

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2. Required Periodic Inspections and Maintenance

A. Periodic Inspections

(1) Except for the blade and erosion shield coin-tap inspection in this section,

perform a detailed inspection at

100 hour intervals not be greater than

twelve (12) calendar months. Procedures involved in these inspections are

detailed below.

NOTE

: Inspection and maintenance specified by a Hovercraft manufacturer’s

maintenance program may not coincide with the inspection time

intervals specified. In this situation, the Hovercraft manufacturer’s

schedule may be applied with the exception that the calendar limit for

the inspection interval may be greater than twelve (12) months.

(a) Visually examine the blade and the erosion shield for nicks, gouges,

looseness of material, erosion, cracks, and debonds or bubbles in the

paint. Refer to the Composite Blade Repairs section in the Maintenance

Practices chapter of this manual for additional information.
1

A cracked blade must be referred to Hartzell Propeller Inc. Product

Support department. Do not attempt repair on a cracked blade.

(b) Visually examine the hub parts for cracks or wear. Refer to Grease and

Oil Leaks in the Inspection Procedures section of this chapter for the

procedure.
1

Contact the Hartzell Propeller Inc. Product Support department if a

cracked hub is found. Do not attempt repair on a cracked hub.

Inspection Procedures section of this chapter.

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B. Overhaul Periods

CAUTION 1: OVERHAUL PERIODS LISTED BELOW, ALTHOUGH CURRENT

AT THE TIME OF PUBLICATION, ARE FOR REFERENCE

PURPOSES ONLY. OVERHAUL PERIODS MAY BE INCREASED

OR DECREASED AS A RESULT OF EVALUATION.

CAUTION 2: REFER TO THE LATEST REVISION OF HARTZELL

PROPELLER INC. SERVICE LETTER HM-SL-001 FOR

THE MOST CURRENT INFORMATION.

(1) HM-5V1-B1000-A propellers must be overhauled at 2000 flight hours or

36 months, whichever occurs first.

(2) HM-6V1-A1000-A propellers must be overhauled at 1000 flight hours or

36 months whichever occurs first.

(3) Overhaul the propeller in accordance with Hartzell Propeller Inc. Hovercraft

Propeller Maintenance and Overhaul Manual 301.
(a) Contact the Hartzell Propeller Inc. Product Support Department for

recommended propeller repair stations.

3. Inspection Procedures

CAUTION:

INSTRUCTIONS AND PROCEDURES IN THIS CHAPTER MAY

INVOLVE PROPELLER CRITICAL PARTS. REFER TO THE

INTRODUCTION CHAPTER OF THIS MANUAL FOR INFORMATION

ABOUT PROPELLER CRITICAL PARTS. REFER TO THE

ILLUSTRATED PARTS LIST CHAPTER OF THE APPLICABLE

OVERHAUL MANUAL(S) FOR THE IDENTIFICATION OF SPECIFIC

PROPELLER CRITICAL PARTS.

The following inspections must be made on a regular basis, either before each

operation, during required periodic inspection, as described in this chapter, or if a

problem is noted. Possible corrections to problems discovered during inspections,

additional inspections, and limits are detailed in the following inspection procedures.
A. Blade Damage

(1) Refer to the Blade Maintenance section in the Maintenance Practices chapter

of this manual for information regarding blade damage.

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B. Grease or Oil Leakage

(1)

A new or newly overhauled propeller may leak slightly during the first several

hours of operation. This leakage may be caused by the seating of seals and

O-rings, and the slinging of lubricants used during assembly. Such leakage

should cease within the first ten hours of operation.

(a)

Leakage that persists beyond the first ten hours of operation on a new or

newly overhauled propeller, or that occurs on a propeller that has been in

service for some time, will require repair.
1

A determination should be made as to the source of the leak.

The only leakage that is field repairable is the removal and

replacement of the O-ring seal between the engine and propeller

flange.

Contact the Hartzell Propeller Inc. Product Support Department for

all other leakage repairs.

(2) An instance of abnormal grease or oil leakage should be inspected using the

procedure below:

CAUTION:

PERFORM A VISUAL INSPECTION WITHOUT CLEANING

THE PARTS. A TIGHT CRACK IS OFTEN EVIDENT DUE

TO TRACES OF GREASE LEAKING FROM THE CRACK.

CLEANING CAN REMOVE SUCH EVIDENCE AND MAKE A

CRACK VIRTUALLY IMPOSSIBLE TO SEE.

(a) Visually examine the hub for cracks.

A crack may be readily visible, or may be indicated by grease leaking

from a seemingly solid surface.

A crack may be indicated by red stain from the red-dyed oil on the

hub surface.

Extra attention should be given to the blade retention area of the hub.

(b) Visually examine the hub, blades, and blade retention areas to locate the

origin of leak.

part, such as an O-ring, gasket, or sealant, repairs can be accomplished

during scheduled maintenance, as long as operational safety is not

compromised.

(d) If a crack is suspected, additional inspections must be performed before

further operation. Contact the Hartzell Propeller Inc. Product Support

department if a crack is suspected.

(e) If cracks or failing components are found, these parts must be replaced

before further operation.

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C. Vibration

WARNING:

ABNORMAL VIBRATION CAN BE AN INDICATION OF A FAILING

PROPELLER BLADE OR BLADE RETENTION COMPONENT. A

BLADE SEPARATION DURING PROPELLER OPERATION CAN

RESULT IN A CATASTROPHIC HOVERCRAFT ACCIDENT.

(1) Instances of abnormal vibration should be investigated immediately.
(2) If the cause of the vibration is not readily apparent, the propeller may be

inspected following the procedure below:

NOTE

: It may sometimes be difficult to readily identify the cause of abnormal

vibration. Vibrations may originate in the engine, propeller, or

Hovercraft. Troubleshooting procedures typically begin with an

investigation of the engine. Components, such as engine mounts,

can also be the source of vibration. When investigating an abnormal

vibration, the possibility of a failing blade or blade retention

component should be considered as a potential source of the

problem.

(a) Troubleshoot and evaluate possible sources of vibration in accordance

with engine or Hovercraft manufacturer’s instructions.

(b) Check the blade play in accordance with section 3.D. of this chapter.
(c) Check to determine the possible cause of the vibration. If no cause is

found, then consider that the origin of the problem could be the propeller

and proceed with the remaining steps in this section.

(3) Visually examine the hub and blades for cracks. Pay particular attention to the

blade retention areas of the hub.

NOTE

: A crack may be readily visible or may be indicated by grease leaking

from a seemingly solid surface or red stain from the red-dyed oil on

the hub surface.

(4) If a crack is suspected, additional inspections must be performed before further

operation. Contact the Hartzell Propeller Inc. Product Support department for

additional inspection criteria. Such inspections typically include disassembly of

the propeller, followed by inspection of parts, using nondestructive methods in

accordance with published procedures.

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Blade Play

Figure 5-2

IN AND OUT PLAY

RADIAL PLAY

FORE AND AFT MOVEMENT

Checking Blade Track

Figure 5-1

BLADE END PLAY

TI-300-010

TI-300-006

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(5) Check the blades and compare blade-to-blade differences.

(a) Inspect the propeller blades for unusual looseness or movement. Refer to

Loose Blades in this chapter.

CAUTION

DO NOT USE BLADE PADDLES TO TURN BLADES.

(b) Manually (by hand) attempt to turn the blades. Do not use blade paddles.
(c) Visually check for damaged blades.

(6) If abnormal blade conditions or damage are found, contact the Hartzell

Propeller Inc. Product Support department for additional inspection criteria.

(7) If cracks or failing components are found, these parts must be replaced before

further operation.

D. Blade Track

(1) If a blade track problem is suspected, examine the blade track as follows.

(a) Refer to Figure 5-1. Place a fixed reference point beneath the propeller,

within 0.25 inch (6.4 mm) of the lowest point of the propeller arc.

NOTE

: This reference point may be a flat board with a sheet of paper

attached to it.

(b) Rotate the propeller by hand in the direction of normal rotation until a

blade points directly at the paper.

(c)  Mark the position of the blade tip in relation to the paper.
(d)  Repeat this procedure with the remaining blades.
(e)  Tracking tolerance is ± 0.125 inch (3.18 mm) or 0.25 inch (6.4 mm) total.

(2) Possible Correction

(a) Remove foreign matter from the propeller mounting flange.

Examine the engine and propeller flanges for damage.

Repair any damage to the engine or propeller flange. If necessary,

contact the Hartzell Propeller Inc. Product Support department.

(b) If no foreign matter is present, contact the Hartzell Propeller Inc. Product

Support department for additional inspection criteria.

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E. Loose Blades

(1) Refer to Figure 5-2. Limits for blade looseness are as follows.

End Play

See Note Below

Fore & Aft Movement

See Note Below

In & Out Play

None

Radial Play (pitch change) ± 0.5 degree (1 degree total)

measured

reference

station

NOTE

: Blades are intended to be tight in the propeller, however slight

movement is acceptable if the blade returns to its original position

when released. Blades with excessive movement, or that do not

return to their original position when released may indicate internal

wear or damage which should be referred to an appropriately certified

propeller repair station with the appropriate rating.

F. Preload Plate Set Screw

(1) Manually rotate the propeller and listen for possible noise caused by a broken

set screw that may be in the propeller hub.

(2) If there is noise indicating a loose part, remove the propeller and contact the

Hartzell Propeller Inc. Product Support department for additional inspection

criteria.

(3) If a broken set screw is found, the propeller must be inspected for damage that

may have been caused by the broken set screw.

(4) Report any such incidents to the Hartzell Propeller Inc. Product Support

department.

G. Corrosion

WARNING:

REWORK THAT INVOLVES COLD WORKING THE METAL,

RESULTING IN CONCEALMENT OF A DAMAGED AREA, IS NOT

PERMITTED.

(1) If heavy corrosion that results in severe pitting is found, contact the Hartzell

Propeller Inc. Product Support department.

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4. Special Inspections

A. Foreign Object Strike

(1) General

(a) A foreign object strike can include a broad spectrum of damage, from

a minor stone nick to severe ground impact damage. A conservative

approach in evaluating the damage is required because there may be

hidden damage that is not readily apparent during an on-wing, visual

inspection.

(b) A foreign object strike is defined as:

Any incident, whether or not the engine is operating, that requires

repair to the propeller other than minor dressing of the blades.

Any incident during engine operation in which the propeller impacts a

solid object that causes a drop in revolutions per minute (RPM) and

also requires structural repair of the propeller (incidents requiring only

paint touch-up are not included). This is not restricted to propeller

strikes against the ground.

A sudden RPM drop while impacting a yielding medium where

propeller blade damage is not normally incurred

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(2) Procedure

(a) In the event of a foreign object strike, an inspection is required before

further operation. If the inspection reveals one or more of the following

indications, the propeller must be removed from the Hovercraft. Contact

the Hartzell Propeller Inc. Product Support Department for additional

inspection criteria:
1

A loose blade in the hub

Any noticeable or

suspected

damage to the pitch change

mechanism

Any blade diameter reduction

A bent, cracked, or failed engine shaft

Vibration during operation that was not present before the event

(b) Perform a thorough visual and coin tap inspection of the exposed portion

of each blade, including the erosion strip (leading edge). Refer to the

Blade Maintenance section in the Maintenance Practices chapter of this

manual.

further operation. If the blade damage is beyond major repair limits, the

blade must either be returned to the Hartzell Propeller Inc. factory for

evaluation or removed from service.

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B. Overspeed

(1) An overspeed has occurred when the propeller RPM has exceeded the

maximum RPM.

(2) The duration of time at overspeed for a single event determines the corrective

action that must be taken to make sure no damage to the propeller has

occurred.

(3) The criteria for determining the required action after an overspeed are based on

many factors.
(a) The additional centrifugal forces that occur during overspeed are not the

only concern.

(b) Stresses at RPMs above the maximum rated for the frame/engine/

propeller combination.
1

When a propeller installed on an engine has an overspeed event,

refer to the Engine Overspeed Limits (Figure 5-3) to determine the

corrective action to be taken.

Make an entry in the propeller logbook to document the overspeed

event.

Duration of Overspeed in Seconds

Engine Overspeed Limits

Figure 5-3

PERCENT OVERSPEED

104%

105%

110%

102.5%

300

120%

100%

Requires Evaluation by a

Hartzell Propeller Inc. Approved

Propeller Repair Station

No Action Required

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C. Fire Damage or Heat Damage

WARNING 1: EXPOSING COMPOSITE BLADES TO HIGH TEMPERATURES

MAY LEAD TO FAILURE THAT MAY CAUSE PERSONAL

INJURY AND DEATH. COMPOSITE BLADES ARE SUBJECT TO

DELAMINATIONS DUE TO HIGH TEMPERATURES.

WARNING 2: HUBS ARE MANUFACTURED FROM HEAT TREATED FORGINGS

AND ARE SHOT PEENED. EXPOSURE TO HIGH TEMPERATURES

CAN DESTROY THE FATIGUE RESISTANCE BENEFITS

OBTAINED FROM THESE PROCESSES.

(1) On rare occasions a propeller may be exposed to fire or heat damage, such as

an engine or hangar fire. In the event of such an incident, contact the Hartzell

Propeller Inc. Product Support Department before further Hovercraft operation.

5. Packaging and Storage

CAUTION:

INSTRUCTIONS AND PROCEDURES IN THIS CHAPTER MAY

INVOLVE PROPELLER CRITICAL PARTS. REFER TO THE

INTRODUCTION CHAPTER OF THIS MANUAL FOR INFORMATION

ABOUT PROPELLER CRITICAL PARTS. REFER TO THE

ILLUSTRATED PARTS LIST CHAPTER OF THE APPLICABLE

OVERHAUL MANUAL(S) FOR THE IDENTIFICATION OF SPECIFIC

PROPELLER CRITICAL PARTS.

A. Overview

(1) When parts are shipped from the Hartzell Propeller Inc. factory, the "standard"

packaging or shipping container is not designed for use as a container for long

term storage.

(2) Hartzell Propeller Inc. can, at the customer’s request (and at an additional cost),

provide parts in "special" packaging.
(a) Such special packaging is suitable for a storage period of up to six months

assuming the following:
1

Use of the part at the first or second destination

Environmental exposure during shipping and transfers is minimal

Container is stored in warehouse conditions where environmental

elements are at a minimum, i.e., dry

(b) Hartzell Propeller Inc. will guarantee a part stored in original special

packaging for up to six months from the factory shipping date. Hartzell

Propeller Inc. is not responsible for a part stored using standard packaging

or for an item repackaged and stored.

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long term storage have undergone the following:
1

The propeller is wrapped in poly material that is impregnated with a

corrosion inhibitor.

A desiccant bag is enclosed inside the poly material with the propeller.

The poly material is then heat shrink sealed.

The propeller is then protected by foam and put in a plywood box.

(d) If the container is opened and the sealed poly material is opened, the poly

material and desiccant must be removed.
1

To put the propeller back into long term storage, refer to the

guidelines in section 5.B. of this chapter.

(e) If storage is expected to be longer than six months, visually inspect each

part for corrosion or other damage at six month intervals. Repackaging

may be required using the guidelines in section 5.B. of this chapter.

B. Guidelines

WARNING:

ADHESIVES AND SOLVENTS ARE FLAMMABLE AND TOXIC TO

THE SKIN, EYES, AND RESPIRATORY TRACT. SKIN AND EYE

PROTECTION ARE REQUIRED. AVOID PROLONGED CONTACT

AND BREATHING OF VAPORS. USE SOLVENT RESISTANT

GLOVES TO MINIMIZE SKIN CONTACT AND WEAR SAFETY

GLASSES FOR EYE PROTECTION. USE IN A WELL VENTILATED

AREA AWAY FROM SPARKS AND FLAME. READ AND OBSERVE

ALL WARNING LABELS.

(1) Refer to Table 3-2, Consumable Materials List.

(a)  Solvent CM23
(b)  Solvent CM109
(c)  Corrosion preventative CM108, or equivalent

(2) Packaging of Assembled Propellers

(a)  Using solvent CM23, clean all surfaces.
(b)  Permit the solvent CM23 to dry.
(c)  Protect parts that are not plated, anodized, or painted using corrosion

preventative CM108, or equivalent in conjunction with grease-proof

paper, MIL-B-121, Grade A, Type II.

(d) Wrap the entire propeller assembly in metal foil-backed paper,

MIL-B-131, Grade B.

(e) Put the propeller assembly, accompanied by a moisture retardant, in a

suitable storage container.

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(3) Packaging of Disassembled or Partially Disassembled Propellers

(a)  Using solvent CM23, thoroughly clean all surfaces.
(b)  Permit CM23 to dry.
(c)  Dip the blade butt in corrosion preventative CM108 or equivalent, and then

wrap in grease-proof paper, MIL-B-121, Grade A, Type II.
1

Put the grease-proof paper over the butt of the blade and up the

blade shank for approximately 6 inches (152 mm).

(d) Parts that are not plated, anodized, or painted must be protected using

corrosion preventative CM108 or equivalent, in conjunction with

grease-proof paper, MIL-B-121, Grade A, Type II.

(e) Wrap all the parts in metal foil backed paper, MIL-B-131, Grade B.
(f) Put all the parts accompanied by a moisture retardant in a suitable storage

container.

(4) Containers

(a) Make sure that the blades are held securely in their containers.

(5) Inspection

(a) Hartzell Propeller Inc. requires the stored parts to be inspected every six

months to make sure that corrosion is not developing.

(b) The moisture retardant must be replaced at the time of the inspection.

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6. Activating a Propeller Assembly After Long Term Storage

CAUTION:

INSTRUCTIONS AND PROCEDURES IN THIS CHAPTER MAY

INVOLVE PROPELLER CRITICAL PARTS. REFER TO THE

INTRODUCTION CHAPTER OF THIS MANUAL FOR INFORMATION

ABOUT PROPELLER CRITICAL PARTS. REFER TO THE

ILLUSTRATED PARTS LIST CHAPTER OF THE APPLICABLE

OVERHAUL MANUAL(S) FOR THE IDENTIFICATION OF SPECIFIC

PROPELLER CRITICAL PARTS.

A. General

(1) An operating hour/calendar limit between overhaul or MPI is 36 calendar

months. Contact the Hartzell Propeller Inc. Product Support Department

concerning propeller overhaul requirements.
(a) The start date for the operating hour/calendar limit is when the propeller is

first installed on an engine.

(2) These procedures apply to new propellers, propellers with zero hours since

overhaul, and propellers with time-in-service that have been in long-term storage.

(3) The start date for long-term storage begins at the date of manufacture, the

date of overhaul, or the date the propeller was removed from the Hovercraft,

whichever occurs last.

B. If storage period is less than two (2) years:

(1) Using a clean cloth soaked with solvent CM109, remove the corrosion preventative

CM108 or equivalent that may have been added at the time of storage.

(2) Make a general visual inspection of the condition of the parts. As necessary,

investigate and correct any questionable conditions.

(3) For a propeller with time-in-service, if the TBO calendar limit has been

exceeded for the stored propeller, the propeller must be overhauled before

further operation.
(a) New propellers or propellers with zero hours do not require overhaul.

(4) Check current Hartzell Propeller Inc. Hovercraft service documentation. There

may be documents issued since the date the propeller was put into storage that

require compliance.

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C. If storage is greater than two (2) years:

(1) T

he requirements in this section must be accomplished by an MCA certified or

a Hartzell Propeller Inc. approved (or foreign equivalent) propeller repair station

in accordance with the applicable Hartzell Propeller Inc. instruction or overhaul

manual.

(2) Comply with the requirements in section 2.B. and in addition:

(a) Inspect the propeller internally and externally for damage or corrosion.

Paint and plating need not be removed.

Total disassembly of the propeller (such as removing counterweights)

is not necessary unless corrosion or damage warrants.

(b)  Replace all seals and gaskets.
(c)  Replace parts as necessary.
(d)  Repaint and/or replate components as required.
(e)  After accomplishing required procedures, the propeller may be released

for the remaining TBO and calendar life.

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1. General

A. References used throughout this section for parts, consumable materials, and

tooling are defined in the Introduction chapter of this manual.

B. If a propeller assembly will not be immediately installed and must be stored for a

period of time, package and store the propeller in accordance with the procedure

specified in the Inspection and Check chapter of this manual.

C. Before placing a propeller into service after a lengthy storage, inspect the propeller

in accordance with the procedure specified in the Inspection and Check chapter of

this manual.

D. Safety using 0.025 inch (0.64 mm) or 0.032 inch (0.82 mm) safety wire, per

specifications MS-33540, unless otherwise specified.

E. Table 3-3, Torque Values, is a summary of torque values used during the installation

and maintenance of the Hovercraft propeller.

F. Table 3-1, Special Tools and Equipment, is a summary of special tools required for

the installation, removal, and maintenance of the Hovercraft propeller.

G. Table 3-2, Consumable Materials List, is a summary of consumable materials used

during the maintenance of the Hovercraft propeller.

Page 6-4

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2. Cleaning

CAUTION:

DO NOT USE PRESSURE WASHING EQUIPMENT TO CLEAN THE

PROPELLER. PRESSURE WASHING CAN FORCE WATER AND/OR

CLEANING SOLVENTS PAST SEALS, AND CAN LEAD TO INTERNAL

CORROSION OF PROPELLER COMPONENTS.

A. General Cleaning

CAUTION 1: WHEN CLEANING THE PROPELLER, DO NOT ALLOW SOAP

OR SOLVENT SOLUTIONS TO RUN OR SPLASH INTO THE HUB

AREA.

CAUTION 2: DO NOT CLEAN THE PROPELLER WITH CAUSTIC OR ACIDIC

SOAP SOLUTIONS. IRREPARABLE CORROSION OF PROPELLER

COMPONENTS MAY OCCUR.

(1) Wash the propeller with a noncorrosive soap solution.

CAUTION:

DO NOT USE ANY SOLVENT DURING CLEANING THAT COULD

SOFTEN OR DESTROY THE BOND BETWEEN CHEMICALLY

ATTACHED PARTS.

(2) To remove grease or oil from propeller surfaces, apply Stoddard Solvent or

equivalent to a clean cloth and wipe the part clean.

(3) Thoroughly rinse in water and allow the part to dry.

Page 6-5

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3. Lubrication

NOTE

: The 6 bladed propeller is oil-filled. This propeller model does not allow or

require lubrication.

A. Lubrication Intervals - 5 Blade Propeller Only

(1) The propeller must be lubricated at intervals not to exceed 400 hours or at 12

calendar months, whichever occurs first.
(a) If annual operation is significantly less than 400 hours, calendar lubrication

intervals should be reduced to six months.

(b) If the Hovercraft is operated or stored under adverse atmospheric

conditions, e.g., high humidity, salt air, calendar lubrication intervals should

be reduced to six months.

(2) Hartzell Propeller Inc. recommends that new or newly overhauled propellers be

lubricated after the first one or two hours of operation because centrifugal loads

will pack and redistribute grease, which may result in a propeller imbalance.

Redistribution of grease may also result in voids in the blade bearing area

where moisture can collect.
(a) Purchasers of a new Hovercraft should check the propeller logbook to

verify whether the propeller was lubricated by the manufacturer during

testing.

(b) If it was not lubricated, the propeller should be serviced at the earliest

convenience.

Lubrication Fitting - 5 Blade Propeller Only

Figure 6-1

Lubrication fitting

(cylinder side hub half)

Lubrication fitting

(engine side hub half)

APS6257A

Page 6-6

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B. Lubrication Procedure - 5 Blade Propeller Only

CAUTION:

FOLLOW LUBRICATION PROCEDURES CORRECTLY TO

MAINTAIN ACCURATE BALANCE OF THE PROPELLER

ASSEMBLY.

(1) Refer to Figure 6-1. Each blade socket has two (cylinder and engine) lubrication

fittings. Remove the lubrication fitting caps from both sides of the hub assembly.

(2) Remove the lubrication fittings from either the engine side or the cylinder side of

the hub assembly.

NOTE 1

: It is preferable to apply grease to the fitting located nearest the

leading edge. Lubricating at this location reduces the possibility of

grease bypassing the bearing area and entering the hub cavity.

(3) Use a piece of safety wire to loosen any blockage or hardened grease at the

threaded holes where the lubrication fitting was removed.

WARNING: WHEN MIXING AEROSHELL GREASES 5 AND 6, AEROSHELL

GREASE 5 MUST BE INDICATED ON THE LABEL (HARTZELL

PROPELLER INC. P/N A-3594) AND THE HOVERCRAFT MUST BE

PLACARDED TO INDICATE THAT OPERATION IS PROHIBITED IF

THE OUTSIDE AIR TEMPERATURE IS LESS THAN -40°F (-40°C).

CAUTION:

USE HARTZELL PROPELLER INC. APPROVED GREASE ONLY.

EXCEPT IN THE CASE OF AEROSHELL GREASES 5 AND 6, DO

NOT MIX DIFFERENT SPECIFICATIONS AND/OR BRANDS OF

GREASE.

(4) Aeroshell greases 5 and 6 both have a mineral oil base and have the same

thickening agent; therefore, mixing of these two greases is acceptable in

Hartzell Propeller Inc. propellers.

(5) A label (Hartzell Propeller Inc. P/N A-3494) is normally applied to the propeller

to indicate the type of grease previously used (Figure 6-2).
(a) This grease type should be used during re-lubrication unless the propeller

has been disassembled and the old grease removed.

(b) Purging of old grease through lubrication fittings is only about 30 percent

effective.

disassembled in accordance with the applicable overhaul manual.

Page 6-7

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CAUTION 1: OVER LUBRICATING AN ALUMINUM HUB PROPELLER MAY

CAUSE THE GREASE TO ENTER THE HUB CAVITY, LEADING TO

EXCESSIVE VIBRATION AND/OR SLUGGISH OPERATION. THE

PROPELLER MUST THEN BE DISASSEMBLED TO REMOVE THIS

GREASE.

CAUTION 2: IF A PNEUMATIC GREASE GUN IS USED, EXTRA CARE MUST BE

TAKEN TO AVOID EXCESSIVE PRESSURE BUILDUP.

CAUTION 3: GREASE MUST BE APPLIED TO ALL BLADES OF A PROPELLER

ASSEMBLY AT THE TIME OF LUBRICATION.

(6) Pump 1 fl. oz. (30 ml) grease into the fitting located nearest the leading edge

of the blade, or until grease emerges from the hole where the lubrication fitting

was removed - whichever occurs first.

NOTE

: 1 fl. oz. (30 ml) is approximately 6 pumps with a hand-operated

grease gun.

(7) Reinstall the lubrication fittings.
(8) Torque the lubrication fittings in accordance with Table 3-1 in the Installation

and Removal chapter of this manual.

(a) Make sure the ball of each lubrication fitting is properly seated.

(9) Install a lubrication fitting cap on each lubrication fitting.

Lubrication Label - 5 Blade Propeller Only

Figure 6-2

A-3594

Page 6-8

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C. Approved Lubricants - 5 Blade Propeller Only

(1) The following lubricants are approved for use in Hartzell Propeller Inc.

propellers:
Aeroshell 6 - Recommended "all purpose" grease. Used in most new

production propellers since 1989. Higher leakage/oil separation

than Aeroshell 5 at higher temperatures (approximately 100°F

[38°C]).

Aeroshell 5 - Good high temperature qualities, very little oil separation or

leakage. Cannot be used in temperatures colder than -40°F

(-40°C). Hovercraft serviced with this grease must be placarded

to indicate that operation is prohibited if the outside air

temperature is less than -40°F (-40°C).

Aeroshell 7 - Good low temperature grease, but high leakage/oil separation

at higher temperatures. This grease has been associated

with sporadic problems involving seal swelling.

Aeroshell 22 - Qualities similar to Aeroshell 7.
Royco 22CF - Not widely used. Qualities similar to Aeroshell 22.

Page 6-9

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4. Blade Maintenance

A. Component Life and Service

(1) Composite Blade Life

(a) Blade life is expressed, and must be tracked in the Propeller Logbook as

the following periods indicate:
1

Time Since New (TSN)

Time Between Overhauls (TBO)

Hours of Service Since Overhaul (TSO, or Time Since Overhaul).

(b) Both TSN and TSO references are necessary in defining the life of the

component. Some parts are "life limited" which means that they must be

replaced after a specified amount of use (TSN). TBO is usually stated

as an allowable time that may accumulate prior to the performance of a

function, i.e., overhaul or replacement.

returned to zero hours. TSN can never be returned to zero.

NOTE: Repair without overhaul does not affect TBO or TSO.

(2) Overhaul or Major Periodic Inspection (MPI)

(a) Overhaul, or MPI, is the periodic disassembly, inspection, repair, refinish,

and reassembly of the composite blade assembly.

NOTE: The term “overhaul” is used throughout the text of this manual.

(b) At such specified periods, the blade assemblies are completely

disassembled and inspected for cracks, wear, corrosion, and other

unusual or abnormal conditions. As specified, some blades are refinished,

and other blades are replaced. The blades can then be reassembled and

balanced.

chapter of this manual for information about overhaul periods.

Operation, Maintenance Manual, and Logbook for Propeller Systems HM-5V1-B1000-A, HM-6V1-A1000-A (2018) - page 3