VOL. 3, NO. 4, OCTOBER - DECEMBER 1976 Second Printing Aug ust 1982

A SERVICE PUBL•CATIOt>I OF LOCKHEfO ·GEOn Gr ... \ COMPANY. A DIVISION O F LOCKHEED t\IACAAFT CORPORATION

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Hercules Gets New APU

A SERVICE PUBLICATION OFLOCKHEED-GEORGIA COMPANYA DIVISION OFLOCKHEED AIRCRAFT CORPORATION

EditorJay V. Roy

Associate EditorsDon H. HungateJames A. Loftin

Art Direction & ProductionAnne G. Anderson

Hercules Gets New APU

Cover: The Hercules “FrontOffice ” emphasizes spaciousness,comfortable seating and convenientgrouping of instruments and con-trols.

Published by Lockheed-Georgia Company, a Division ofLockheed Aircraft Corporation. Information contained inthis issue is considered by Lockheed-Georgia Company tobe accurate and authoritative; it should not be assumed,however, that this material has received approval from anygovernmental agency or military service unless it isspecifically noted. This publication is for planning andinformation purposes only, and it is not to be construedas authority for making changes on aircraft or equipment,or as superseding any established operational ormaintenance procedures or policies. The following marksare registered and owned by Lockheed AircraftCorporation: “ “, “Lockheed”, “HercuIes”, and“JetStar”. Written permission must be obtained fromLockheed-Georgia Company before republishing anymaterial in this periodical. Address all communications toEditor, Service News, Department 64-22, Zone 278,Lockheed-Georgia Company, Marietta, Georgia 30063.Copyright 1976 Lockheed Aircraft Corporation.

Vol. 3, No. 4, October - December 1976

CONTENTS

3 Herky’s New APU

11 Torq-Set * Screws and Tools

StarTips

11 Starter Servicing

15 Safety Wire for HerculesMLG Torque Tube Yoke Assembly

DIRECTOR

MANAGER

FIELD SERVICE & INVENTORY MGMT

T.J. CLELAND

D.L. BRAUND

A.H. McCRUM

CUSTOMER TRAINING A.R.LOVE

JETSTAR SUPPORT H.L. BURNETTE

SPARES STORES & SHIPPING J.K. PIERCE

MANAGER M.M. HODNETT

SUPPLY PROCUREMENT R.C. WEIHE

SUPPLY SYSTEMS & INVENTORY CONTROL C.K. ALLEN

SUPPLY SALES & CONTRACTS H.T. NISSLEY, JR.

SUPPLY TECHNICAL SUPPORT J.L. THURMOND

Herky'sNew

APUThe Hercules has proven to be a very versatile airplane. Aprime reason for this versatility is its capability to operateinto remote, unimproved areas without the need forground support equipment. Much of this capability is dueto an on-board GTC (Gas Turbine Compressor) which pro-vides high pressure bleed air for pneumatic system pre-flight checks and engine starting. The former GTC has

Figure 1

served well for many years, but in our continuing effortsto improve the Hercules, the GTC is being replaced by amore reliable APU (Auxiliary Power Unit) which is identi-fied on C-130H aircraft as GTCP85-180L. and on theL-100 series aircraft as GTCP85-185L. AiResearch, thesame manufacturer that provided the GTC for previousHercules, also supplies the new APU.

The former GTC system provides bleed air to power anATM (Air Turbine Motor) which in turn, drives an ACgenerator. The new APU has a 40 KVA, AC generatordriven directly from the shaft of the gas turbine com-pressor. The 40 KVA generator is interchangeable withthe engine driven generators of the Hercules. The func-tions of the new APU are essentially the same as theearlier AiResearch Model GTC 1 with some newadvantages. The new APU engine produces approximately20% more bleed air at a higher pressure which gives betterstarting of aircraft engines at high temperatures and alti-tudes. Also, the MTUR (Mean Time to UnscheduledReplacement) of system components is greatly increased.

3

VIEW L O O K I N GF O R W A R D / I N B O A R D

Figure 2

1. BLEED AIR OUTLET 8. R E L A Y S

2. ENGINE EXHAUST 9. IGNITION UNIT

3. OUTPUT DRIVE PAD 10. COMBUSTOR

4. HOUR METER 11. TURBINE EXHAUST FLANGE

5. STARTER 12. 0 I L COOLER EXHAUST DUCT

6. UNIT CONTROL ELECTRICAL 13. OIL COOLER

CONNECTION 14. TACW GENERATOR

7. COMPRESSOR AIR INLET DUCT 15. GENERATOR COOLING AIR WITH SCREEN 16. COOLlNG FAN AIR INLET

A U X I L I A R Y P O W E R U N I T C O M P O N E N T LOCATIONS

Although there are many similarities between the former and stopping the APU; and the otherGTC system and the new APU, there are also some im- to open or close the bleed air valve.

to energize circuits

portant differences. Let’s take a brief look at the majorcomponents and operation of this new APU. (ReferenceFigure 2.)

Electrical loads on the generator are controlled from theoverhead electrical control panel, which includes a manualcontrol switch for the APU generator.

APU Control Panel

4The APU control panel is located in the flight stationoverhead control panel. (Reference Figure 3 .) Tacho-meter and temperature gages have been added for moni-toring the speed and temperature of the APU. Althoughengine operation is automatic, you can decrease the loador turn off the APU if the instruments indicate a problemthat could cause permanent damage.

Three indicator lights are located on the APU controlpanel. They are:

DOOR OPEN - When illuminated, this light indicates aresponse to the start circuit, and that the air intakedoor is at least partially open.

START - Illuminates after door opens and the auto-matic start is initiated - Extinguishes when speedexceeds 35% RPM.Two toggle switches are located on the APU control

panel : one to energize the circuits for starting, running,

Figure 3APU CONTROL PANEL ON THE OVERHEAD ANTI - IC ING

CONTROL PANEL

ON SPEED - Illuminates when the APU is operatingabove 95% RPM - Indicates that the APU is ready forservice to the pneumatic and electrical systems.

Airflow Through the APU Centrifugal Speed Switch

The air supply for the APU enters an opening just abovethe unit in the forward left wheel well fairing. A singledoor, hinged at the back edge, opens automatically to oneof two positions when the APU control switch is turnedto START. On the ground the door opens to 35’; inflight it stops at 15’ to prevent scooping in too much airfrom the slipstream, thereby causing a flameout. A screenover the opening prevents entry of objects over 0.250” insize.

The centrifugal speed switch is mounted on the left sideof the accessory housing, and contains mechanicallydriven flyweights which operate three microswitches atapproximately 35%, 95% and 110% of the APU rotorspeed. Also, air pressure taken from the APU compressoris introduced into the flyweight cavity to actuate the110% switch for normal shutdown of the APU. The func-tion of the centrifugal speed switch is to control thesequence of operation of the electrical control systemcomponents. (See Figure 4.)

The compressor is a two-stage centrifugal type. The firststage has two opposing inlets for two similar impellerspositioned back-to-back.The second stage is a singleimpeller handling less volume at higher pressure. The twostages operate efficiently through a wide range of shaftand bleed air loads.

Fuel System

Fuel for the APU is gravity fed from the aircraft’s No. 2fuel tank. A motor-operated shutoff valve in the No.2drybay prevents a standing pressure of fuel to the APUwhen not needed, and shuts off fuel in an emergency. If

COMPRESSOR AIR

FROM OVERSPEED

TEST SOLENOID VALVE

SWITCH

ACTUATING

LEVER

OIL

S E A L

INPUT

FLYWEIGHT

SUPPORT

ELECTRICAL

C O N N E C T O R

CENTRIFUGAL SPEED SWITCH SCHEMATICFigure 4

The second-stage discharge air is directed into the turbineplenum. Here some of the air is bled off through thebleed air duct located on the turbine plenum to provideair for the Hercules pneumatic systems. The combinationbleed air shutoff and load control valve is located in thisduct.

circuits in the APU controls are deenergized, the fuel valvecloses and the APU shuts down.

Fuel Control

Operation of the fuel system is fully automatic. The fuelcontrol unit, with input from the pneumatic thermostat,protects the turbine from overtemperature during startingand during on-speed operation without a bleed load.Under bleed load operation, the pneumatic thermostatoperation is automatically shifted to the bleed air shutoffand load control valve.

A relatively large diameter exhaust pipe leads forward inthe APU compartment, and then turns 180’ up and aft toexit about seven feet above ground level. Near this exit asection of the pipe is enlarged to form a ring shaped open-ing for jet pump action which aids in ventilating and cool-ing the APU compartment.

During on-speed operation of the APU, the fuel flow isvaried so that the power developed by the turbine equals

load requirements as determined by an on-speed gover- shuts off fuel to the nozzle atomizer in the combustor.nor. (Reference Figure 5.) During APU starting, the valve opens at approximately

10% APU RPM, and is energized by the oil pressure se-

All of the fuel pump output passes through a high pres- quencing switch.

sure fuel filter. The filter element and O-ring seals should If the APU loses oil pressure or if the APU overspeeds, thebe replaced at intervals prescribed in your maintenance valve circuit will be deenergized, closing the valve.manual as there is no bypass. Therefore if the filtershould become clogged, it would restrict flow and could Bleed Air Shutoff and Load Control Valveresult in abnormal APU operation.

This double name for the APU bleed air valve is derived

Fuel Shutoff Valve from its versatility: (1) When the bleed air valve switch isin the CLOSE position or the API-J RPM is below 95%, the

The solenoid-operated fuel shutoff valve is located at the valve remains closed to prevent bleeding air from the com-fuel control unit outlet. When the valve is deenergized, it pressor during starting, warmup, and before shutdown.

(2) When the switch is in the OPEN position, the valveopens and modulates in response to exhaust gas temper-atures (EGT) acting as a bleed load control valve. (SeeFigure 6.)

Pneumatic Thermostat

The pneumatic thermostat is mounted in the exhaust pipeflange and projects into the flow of the exhaust gases tomonitor the EGT.

Air Pressure Regulator

The air pressure regulator controls air pressure supplied tothe actuator of the bleed air shutoff and load controlvalve. This enables the valve to control loading of theAPU engine relatively independent of the effect of am-bient conditions on the compressor.

Lubrication System

The APU lubricating system is a positive-pressure, dry-sump-type system; and it provides lubrication of the APUmain bearings and accessory drive gears. The total volumeof the supply tank is 5.28 quarts, allowing for four quartsof oil (MIL-L-23699 or MILL7808) plus expansionspace. The oil tank is mounted in the lower aft end of theAPU compartment.

The oil pump assembly is mounted on the lower left sideof the accessory drive housing. System pressure is limitedby a pressure regulating valve which bypasses a portion ofthe pump output. The pressure regulating valve is set tomaintain an operating pressure of 90 PSI+-10 with theAPU on speed (100% RPM).

Figure 6 PNEUMATIC LOAD CONTROL SYSTEM

CENTRIFUGAL

SWITCH

PNEUMATIC THERMOSTAT

( EX C E S S TEMP O P E N S)

EXHAUST GASES

BLEED AIR VALVE - -SWITCH L EXHAUST PIPE

F L A N G E

ENERGIZED

THERMOSTAT COMPRESSOR

SELECTOR DISCHARGE AIR

SOLENOID VALVE

ON SPEED

R E L A Y A C C E L E R A T I O N

VEN

ENERGIZED SOLENOID

SOLENOID\ 1 I

SWITCHER

V A L V E

LIMITER VALVE

ELECTRICAL

C O N N E C T O R

METERING VALVE

A C T U A T O R

D I A P H R A G M

CONNECTION TO

COMPRESSOR

D I S C H A R G E

D I A P H R A G M

BLEED DUCT

EXHAUST VALVE

O I L C O O L E R0 I L PRESSURE

SEQUENCING S W I T C H

( SL E E V E)

B E A R I N G

L O W O I L P R E S S U R E

S W I T C H

(DOOR C O N T R O L )

HIGH

P R E S S U R E

F I L T E R

F I L T E R

B Y P A S S

VALVE

R E G U L A T I N G

VALVE

O I L P U M P

A S S Y

COO LI NG

F A N -

3

t

Figure 7 OIL VENT

LUBRICATING OI L SYSTEM

NG

SUREUREOIL

8

A micronic paper, oil filter element is located downstreamof the pressure pump. A filter bypass valve allows ade-quate flow in case the filter element becomes clogged tothe point of restricting oil flow; and is set to open atapproximately 55 PSI differential pressure. (ReferenceFigure 7.)

Oil Pressure Switches

Two oil pressure switches are utilized in the operation andcontrol of the APU: the oil-pressure sequencing switchand door-control oil-pressure switch.

The oil-pressure sequencing switch completes circuits tothe fuel solenoid shutoff valve, and to the ignition exciterwhen the lubricating oil pressure reaches 2.5 to 3.5 PSIG.This sequence prevents starting the engine without lubri-cation; it also ensures motoring speed to produce ade-quate airflow for combustion before fuel is introducedand ignition is initiated. The oil-pressure sequencingswitch will automatically shut down the APU if loss oflubrication oil pressure occurs.

The air-intake-door actuator circuit includes the door con-trol oil pressure switch. This switch completes the circuitto automatically close the door when the oil pressuredecreases to approximately 20 PSI during APU shutdown.

Starting and Running the APU

Before starting the APU and during its run, make sure afire guard is at hand, and that all equipment and personnelare clear of the area around the APU. Especially avoid theexhaust outlet and the planes of rotation of the turbineand compressor blades.Ensure that foreign objects willnot enter the air intake.

Head the airplane into the wind if there is a likelihoodthat exhaust gas will be blown into the air intake. The useof ground support, external DC power, is preferable to abattery start if the equipment is available. Set electricalcontrols accordingly. Ensure that the lubricating oil levelis to the full mark; that there is a minimum of 2000pounds of fuel in the No. 2 main tank; and drain the fuelstrainer sump.

Circuit breakers to be closed are: APU Control, APUStart, Door Warning, and Touchdown Relay. The APUBLEED AIR VALVE switch should be in the CLOSEposition and the APU generator switch turned off.

On the preflight inspection, the air intake opening shouldbe inspected for foreign material with the door open.This can be accomplished by placing the APU controlswitch in the RUN position which allows the door to open

fully without initiating an engine start. The DOOR OPENlight illuminates. After completion of the inspection,return the switch to the STOP position; the door closesand the DOOR OPEN light extinguishes.

For routine APU starts, move the APU control switch tothe START position. The inlet door opens and the openlight illuminates. When the door reaches the 15’ position,power is supplied to the starter. At 10% RPM, fuel flowand ignition are initiated by the oil pressure switch. Thefuel ignites and the APU accelerates. The START lightilluminates while the starter is running; it should extin-guish in less than 35 seconds, or when the APU reaches35% RPM. The centrifugal speed switch controls thissequence.

Do not exceed the starter duty cycle of one minute onand four minutes off, and do not reengage the starterwhile the turbine is rotating.

The ON SPEED light comes on at 95% RPM and stays on.The APU is self sustaining at this point, and the tacho-meter will indicate 100% RPM +/- 2%.

When 100% RPM is reached, the on-speed governor con-trols and limits turbine speed. If the governor fails, allow-ing an overspeed to 110% the third centrifugal controlswitch opens the circuit to the fuel solenoid shut-offvalve, shutting off the fuel.

Allow at least one minute running time after the ONSPEED light illuminates before loading the APU.

Stopping the APU

Position the bleed air valve switch to CLOSE and the APUgenerator switch to OFF. After allowing the EGT tostabilize at approximately 320°C, position the APU con-trol switch to STOP. The APU stops before the intakedoor closes to prevent negative pressure buildup whichcould collapse the intake ducts. The intake door starts toclose after oil pressure decreases to approximately 20 PSI,which occurs at about 18% RPM. Lights on the APUcontrol panel extinguish after the door is closed.

One functional difference exists between a normal shut-down of the APU and an actual overspeed shutdown. Ifan actual overspeed shutdown occurs, the APU air inletdoor remains open until the APU control switch is posi-tioned to STOP. Normally, the door starts to close at18% RPM during deceleration.

Normal Shutdown for the APU

Normal shutdown is accomplished through the samesequence of events as provided for in the automatic shut-down in case of overspeed (more than 110% RPM).Therefore, the same circuits are utilized when the APUcontrol switch is placed in the STOP position.

Before placing the APU switch in the STOP position,remove the pneumatic and electrical loads from the APUand allow the engine to run free for two to three minutes.This will allow normal heat dissipation and a return to acooler operating temperature.

Place the APU switch in the STOP position. The over-speed test solenoid is energized and this introduces com-pressor discharge air pressure into the centrifugal switchassembly which actuates the 110% RPM switch to themore than 110% RPM position. This action checks theoverspeed switch operation at each shut-down.

When in the STOP position, a switch is closed in serieswith the low oil pressure (20 PSIG) switch which, in turn,completes the circuit to close the APU air inlet door. Thedoor starts to close when oil pressure drops below 20PSIG (approximately 18% RPM).

9

Fire Emergency Handle

A fire warning detector is located in the APU compart-ment along with the emergency fire extinguishing system.When the APU fire emergency handle is pulled, all DCpower is removed from the APU control circuit. At thesame time, a circuit is established to close the APU inletdoor the same way as during normal shutdown. The fuelshutoff valve closes, immediately shutting off the fuelsupply to the APU.

APU Overspeed ProtectionAPU Start in Flight

Should some abnormal conditions cause the APU to over-speed 110% RPM, the APU is automatically shut down.When the centrifugal switch moves to the more than 110%RPM position, the following relays are deenergized:

Fuel Holding Relay (fuel is shut off)

On-speed relay (DC power removed from control cir-cuit)

Door control relay (latch type: open - door closes)

APU fuel valve relay (fuel supply is shut off)

The APU is started in flight only in an emergency; such as,all the main engine-driven generators dropping off theline.

While the Hercules is in flight, the touchdown switchcircuit prevents the flow of current from the battery tothe essential bus. However, battery current is supplied tothe APU starter motor from the isolated bus when theAPU control switch is positioned to START. The APUcontrols, starter motor, and door actuator are powered

from the isolated DC bus. The APU air intake doorwarning light is powered by the main DC bus.

NOTE: Since this APU has not been demonstrated inflight to the FAA or certified for in-flight operation, thecommercial flight manual restricts U.S. licensed commer-cial operators to only ground operation of the APU.

actuator connector, the APU can be safely operated. Ifthe door fails in the closed position on the ground, it can(in an emergency) be opened by removing the actuatoraccess panel; relocating the actuator to the emergencylocation; and connecting the actuator dummy electricalplug to allow APU starting.

APU AC Generator

Boor Operation

When the APU control switch is placed to RUN orSTART, power is supplied to open the APU inlet door.The door opens approximately 35’ on the ground and15’ in flight. An oil pressure switch is used to auto-matically close the door; when the oil pressure decreasesto approximately 20 PSI, an electrical circuit is completedwhich energizes the actuator to close the door.

If the door fails open in either the flight (15’) or ground(35’) position, and there is electrical continuity at the

The APU driven AC generator supplies 115/200 VAC, 400Hz, 3-phase power to the aircraft essential AC bus. (Re-ference Figure 8.) This capability provides for operationof all electrical systems requiring DC power, and of thoseAC systems that receive power from the essential AC bus.

The APU requires a source of 24 VDC for starting. Rou-tinely, external power is used when available; but whenthe Hercules operates independent of ground supportequipment, starting must depend on the aircraft battery.The battery in turn is recharged by the APU or aircraftgenerator.

10

NOTE: It is very important that the battery be wellcharged at all times and that battery condition be closelymonitored prior to and during aircraft operation at loca-tions where ground support equipment may not be avail-able.

Auxiliary Hydraulic S ys tern

Electric output from the APU can power the auxiliaryhydraulic system when other sources are not available.The auxiliary hydraulic system operates from a 115/200VAC, 400 Hz motorpump on the ground or in flight. Theauxiliary pump can power the utility system for groundtesting of components through a ground test interconnectvalve provided for this purpose On the ground theauxiliary hydraulic system electric motorpump output canbe switched into the utility hydraulic system by manuallypositioning the ground test interconnect valve handle tothe ground test position.

Specifications

Operation, inspection and maintenance instructions areavailable in the various technical manuals for commercialand military operators. These manuals should be referredto for complete specifications and instructions.

STARTER SERVICING

by J. H. Hunt, Service Representative

For servicing starters on the Hercules, a usefultool can be quickly assembled from a Spectrom-

rocedure (SOAP) sample tuben ordinary Plews-type oil can.

tubing is installed on the oiler spouty operating the oiler, the starter is easily

serviced without spilling a drop,

11

A recent request from the field brought to our attentionthat in many cases there is very little information availableon Torq-Set* screws and their installation/removal tools.As these fasteners are used in the JetStar, Galaxy, and - toa limited extent - in the Hercules, we are providing thefollowing information. We hope it proves helpful.

Why Torq-Set*?

The distinctive cross recess of the Torq-Set* fastener wasdeveloped for screws requiring very high installationtorque. The Torq-Set* recess is designed so that eachdriving wall is on a radius of the screw. The fact that theremoval wall is not on a radius is compensated for to somedegree by its substantially increased area. These twofactors permit the use of a thicker screwdriver bit withoutan increase in the overall size of the recess. The walls ofthe recess are not tapered. Thus, the driver remains seated

in the screw head during application of high torque sincethere is no camming surface tending to force the bit outof the recess.

The basic design for Torq-Set* screws is given inMS33781, Military Design Standard; “Recess-Torq-Set*,Dimensions of Recess, Gage and Driver for”. Thisdocument is for standardizing basic dimensions and doesnot identify individual screws by part numbers. NationalAerospace Standard (NAS) drawings give complete detailson individual screws and assign part numbers.

A Word of Caution

Through observation if not experience mechanics in theaerospace industry have discovered how difficult removinga machine screw can be if someone has used the wrongscrewdriver in the screw head.

*Torq-Set is a registered trade mark of Phil l ips international Co.,

Division of Phillips Screw Co.

Torq-Set* screws look deceivingly enough like other crossrecess types that someone not familiar with them mightbe tempted to use just any cross-point screwdriver -Don’t! In addition to using the correct type driver, do notunderestimate the importance of using the correct sizeTorq-Set* bit for the size of Torq-Set* screw in use.

PHILLIPS REED AND PRINCE TORQ-SET*

Screws designed for high installation torque values willalmost certainly be damaged by a tool that doesn’t fit.Think about the experience of drilling out a screw and thesubsequent problems if you are tempted to make do withthe wrong tool.

Here Are the Tools

Reports from some areas say that part numbers for thedesired tools are not readily available. The tables providedhere include part numbers for Torq-Set* tools necessaryfor the most commonly used screw sizes.

NOTE :ALL DlMENSlONSGIVEN IN INCHES. SCREW

SIZE

NO. 2NO. 3NO. 4NO. 5NO. 6NO. aNO. aNO. 10No. 10l/41/41/45/1 65/1 65/1 63/83/83/87/161/29/1 65/8

NO. 2NO. 3NO. 4NO. 5NO. 6NO. 8NO. 101/4NO. 8NO. 101/45/1 63/8

PART NUMBERS FOR

HEXSIZE

1/4

1/45/1 61/45/1 67/l 65/1 61/47/165/1 61/47/1 65/1 61/47/1 65/85/85/8

1/4A

1/45/1 6

5/1 6

LOCKHEEDSTANDARD TOOL

291 B-400DASH NO.

-001 A-002A-003A-004A-005A-006A

-007A

-008A

-O09A

--010A-

-011A-012A-013A-014A

-105A-110A-115A-120A-125A-130A-135A-140A-145A-150A-155A-160A-165A

In Figure 1, the numbers in the first column are thestandard screw sizes most commonly found in aircraft.The second column tells you the hex size of the bit andthe size that the hex socket must be to accommodate thebit.

The next four columns are driver bit part numbers. Thefirst of these are the dash numbers to the LockheedStandard Tool Series Number 291B-400. Next are listedpart numbers for three other suppliers. The U.S. FederalStock Numbers are in the last column.

NOTE: There are, no doubt, other suppliers. Data forthe ones we list happened to be readily available to us.

The first four digits in a Federal Stock Number (FSN) arethe classification number and,in most cases, this number isthe same for items that will fall into a specificclassification. Most of the Torq-Set* tools listed have thenumber 5120 as the first (classification) number in theFSN. However, a few of the bits have the number 5130.The numbers following identify the sizes, not by apredetermined pattern, but by arbitrary assignment.

TORQ-SET* SCREW BITS . .

VENDOR PART NUMBERSFEDERAL

APEX

170-2-3-4-5-6-a%A-10-1 OA-1/4-1/4A-1 /4B-5/1 6-5/1 6A-5/1 68-3/8-3/8A-3/8 8-7/1 6-1/2-9/1 6-5/8

FOR BITS

AMERICANSCREW CO.

EX1 70-2-3-4-6-6-a

AIR INDUSTRIESSTOCK NUMBERS

FOR BITS CORP.

A 1 Cl 70-2-34-5

-6-8-

-10-

-1/4-

-5/1 6-

-3/8-

-7/1 6-1/2-9/1 6-5/8

Al C212-2A l C212-3

-4-5-6-8-10

A1C212A-8-10-1/4-5/1 6

5130-798-0825-0826 -0828 -0829

5130-805-3793-726-7873 -226-5604 -774-7130 -226-6605 -6728671 -226-5607

5120-226-6606 5130-672-8679

-226-56095120-226-5608

-511-0210 5130-226-561 1 5120-226-5610

-511-0212 -511-0208 -51 I-0207 -624-7973

5120-082-8529 -226-6562 -888-5829 -7 56-2209-888-5827

-5826 -5831 -5830

5120-888-5828

-515-2814

-10

-1/4

-5/1 6

-3/8

-7/1 6-1/2-9/16-5/B

212-2 EX-212-2-3 -3-4 -4-5 -5-6 -6-8 -a-10 -10-1/4 -1/4-8A %A-10A -10A-1/4A -1/4A-5/l 6A -5/16A-3/8A -3/8A

Combination hand drivers with hex sockets to accom-modate interchangeable bits are listed in Figure 2. Torq-

standard adapters available separately. If you have been

Set* hand drivers are listed in Figure 3. Adapters forusing other standard bits, you may already have suitableadapters.

standard square drive service tools and power tools areshown in Figure 4.

A tool kit for Torq-Set* screws is available under oneApex part number (TS-Kl) or one Federal Stock Number(5180-602-9550) if you wish to avoid ordering the toolsseparately. The kit includes hand screw drivers andcombinations. The bits included in the kit can be usedwith square drive service or power equipment using

Complete packaged tool kit including all hand drivers, combination

hand drivers and bits, as specif ied under Federal Stock No. 5180-

6 0 2 . 9 6 6 0

Order by Apex Part Number . . . . TS-Kl

hand drivers for screw sizes 2, 4,6, 8, 10, 1/4

1 combination hand driver and two 5/16” hex shank bits for

screw sizes 5/1 6, 3/8

1 comb ina t ion hand d r i ve r and f i ve 1/4” hex shank bits for

screw sizes 4. 6, 8. 10,1/4

Figure 3

APEX HAND DRIVERS FOR TORQ-SET” SCREWS

SUPERLOID H A N D L EScrew Blade

W O O D H A N D L E

Size Pro jec t ion Overa l l Federa l Par t Overa l l Federa l Par t

Leng th S tock No . N u m b e r Leng th S tock No . N u m b e r

01 1-1/4 3

2 6 8 P - o

-1

2 5 1 2 0 - 0 3 3 - 9 0 3 5 268P-2 268W-23 3-l /8 6-1/4 - 3 - 34 5 1 2 0 - 7 1 4 - 7 4 0 0

- 48-1/4

- 45 5 1 2 0 - 0 3 4 - 3 0 6 6 -5 - 5

6 48 7-1/2 5120-675-0867 -65 1 2 0 - 6 7 4 - 9 2 1 6 9-1/8 268W-6

-8 - 8

1 0 4 7-1 /2 5 1 2 0 - 6 7 4 - 9 2 1 5 268P-10 5 1 2 0 - 8 2 9 - 6 7 2 4 268W-10 O R D .

1/4 6 10-1/8 5120-7 1 Z-0400268P-1/4

12-1/85 1 2 0 - 0 6 6 - 4 2 5 7 268W-1/4

5/163/8 8 1 2-5/8

5120-033-9033 268P-5/16 14-3/8 5 1 2 0 - 8 2 9 - 6 7 2 3 268W-5/16

-3/8 -3/8

13

N O T E : A L L D I M E N S I O N S G I V E N I N I N C H E S .

6

Kit consists of:

Figure 4 SERVICE DRIVE BIT HOLDERSFOR POWER EQUIPMENT

NOTE. ALL DIMENSIONS GIVEN

IN INCHES.

STOCK NO.

5120-528-2891

5120-528-2892

5120-331-5502

ADAPTERSI

I l-l /4 5120-735-4805 SC-l 08l/4l/43/83/8l/2l/2

l/47/l 6l/47/l 67/l 65/8

1 -203-9618 -114l-l /2 -062-3372 -308l-l /4 -203-9619 -314l-3/8 -565-9751 -514l-l / 2 -203-9620 HE-3320

14

Caution should be exercised in the use of powerscrewdrivers. The time saved by these tools can be morethan offset by the damage they can do if one gets out ofcontrol. Electric power tools are doubly hazardousbecause of the possibility of sparks and shocks. Airpowered tools are safer but require experience andcaution to avoid damage to the screw recess.

The following partial listing gives the NAS numbers forthe most commonly used Torq-Set* screws:

NATIONAL AEROSPACE STANDARD (NAS) NUMBERS

NATIONAL

A E R O S P A C E TORQ-SET MACHINE SCREW

STANDARD

NUMBERSTYPE HEAD REMARKS

NAS1lOl FLAT FILLISTER FULL THREAD

NASl102 FLAT 100� FULL THREAD

NASl121 FLAT FILLISTER SHORT THREAD,

through CLOSE TOLERANCE

NASI 128

NAS1151

through

NAS1158

FLAT 100' SHORT THREAD,

CLOSE TOLERANCE

NAS 1620

through

NASl628

F LAT 1OO' SHORT THREAD

NASl630

through

NAS1634

FAN SHORT THREAD

N A S P A R T N U M B E R S A R E F R O M N A T I O N A L A E R O S P A C E S T A N D A R D

DRAWINGS

A more detailed description of these may be obtainedfrom :

National Standards Association, Inc.132 1 Fourteenth Street, N. W.Washington, D. C. 200053

TORQ-SET” SCREWS USED ON THE HERCULES

,INSTALLATlON

TORQ-SET

SCREW

NAS 1101

NAS 1102

AIR CONDITIONING FLIGHT DECK

SCOOP, AIR CONDITIONING FLIGHT DECK

TRANSDUCER ELEVATOR, HORIZONTALSTABILIZER MOD

TRANSDUCER

TRANSDUCER

FAIRING

ANTENNA, TACAN

DUCT

RUDDER, EMPENNAGE MOO

AILERON, OUTER WING MOD

LH MLG WHEEL WELL

CENTER FUSELAGE KIT

APU BLEED AIRSUPPLY KIT

NAS 1621

TAIL CONE

RING SEGMENT

CHINE ANGLE

TAIL CONE MOD

FS245 UPPER FORWARD

60 INCH FORWARDFUSELAGE EXTENSION

CHINE ANGLE 100 INCH FORWARDFUSELAGE EXTENSION

NAS1622

NAS1631

NAS 1632

ANTENNA &SUPPORT

SURGE BOX

SUPPORT

HF ANTENNA, FS798, EC-130G

EXTERNAL FUEL TANK

CONVERTER, LIQUID

O X Y G E N

RETAINER CO2 BOTTLE, LIFE RAFTCOMPARTMENT LINER

NAS 1633 TUBE & VALVE Al R TURBINE MOTOR

HEATING KIT

This list gives you an idea of where you will findTorq-Set* screws on your Hercules, depending on itsconfiguration, and the modifications of the componentslisted. The original Hercules design did not includeTorq-Set * screws.

We have tried to provide sufficient data to make your jobeasier. We hope we have succeeded.

service

SAFETY WIRE FOR HERCULES MLGTORQUE TUBE YOKE ASSEMBLY

Cotter pins and castellated nuts normally go together toprovide fasteners with a positive measure of safety. Insome approved locations, however, safety wire can be justas effective as cotter pins and may even function betterunder certain circumstances. Four locations in theHercules main landing gear (MLG) fit into this category.

The use of safety wire at these locations on the Herculeshas been approved by Lockheed engineers. The com-ponent drawing now shows the safety wire in place of thecotter pins. Hercules in production at this time have thischange incorporated. Operators in the field can make thechange at any convenient time. Only the flange assem-blies at these specific locations (Illustrated in Figure 1) areinvolved in this change.

Companion flanges join each MLG vertical torque-tubeyoke assembly to the splined socket that fits over the endof the ball screw, one location for each MLG strut. Theflanges are held together by four bolts. A continuouslength of 0.041 (inches diameter) safety wire passesthrough each nut and bolt in a circle around the flangeyoke (See Figure 1). The ends are twisted and bent backagainst the yoke.

All Hercules airplanes have removable inspection plates inthe wheel well wall that allow access to each of theseassemblies in flight if it becomes necessary to lower thegear with the MLG emergency extension wrench. (Emer-gency extension of the landing gear is covered in yourHercules Flight Manual.)

In each of these flange assemblies the one piece of safetywire, used to safety the four nuts, eliminates the previousrequirement for four cotter pins and thereby, the extrawork involved in their installation - and in their removal

Figure I

when necessary. Time saved in removing the safety wireinstead of pins during a stuck landing gear emergency canbe very significant. One or two cuts in the wire allows thelengths to be easily removed from the bolts.

Incidentally, the position of the bolts is head down afterinstallation on the airplane. This unusual position is forconveniency in removal when necessary for inflightemergencies.

Follow the instructions in your Hercules MaintenanceManual for installing and torqueing these nuts and for thesafety requirements on all other landing gear assemblies.

CUSTOME R SERVICE OIVISION LOCKHEED-GEORGIA COMPANY A OIVIStQf'( 0 1' LOCKMEEO 4 t RCRAl' 'T COAPOR.ATION

The new JetStar II issho\vn taking o ff fo r its first fl ight on August 18 , 1976. which \Vas the sraft o f a co1tlp rehensive fl ight test p l'o9r<1n1. Altho ugh the JetStar 11 retains t hose system and design features pro ven through timo and service .. it also incorpo ra tes nC\v technological advances to 1>rovide a quiel.er, r11ore econon1ic.al and efficient airplane.