chapter 8 — weight and balance · bht-412-mm-2 8-00-00 eccn ear99 1 may 2012 rev. 15 page 3...

BHT-412-MM-2

8-00-001 MAY 2012 Rev. 15 ECCN EAR99

TABLE OF CONTENTS

Paragraph Chapter/Section Page Number Title Number Number

CHAPTER 8 — WEIGHT AND BALANCE

WEIGHT AND BALANCE

8-1 Weight and Balance ......................................................... 8-00-00 38-2 Leveling Helicopter ........................................................... 8-00-00 38-3 Weighing .................................................................... 8-00-00 38-4 Determining Center of Gravity Location ..................... 8-00-00 58-5 Determining Amount of Ballast Required ................... 8-00-00 58-6 Weight Empty Center of Gravity Charts — Kits ................ 8-00-00 78-7 Weight and Balance Sample Problem

(S/N 33001 - 33107) ......................................................... 8-00-00 108-8 Weight and Balance Sample Problem

(S/N 33108 and Sub.and S/N 36001 and Sub.) ............... 8-00-00 108-9 Ballast ............................................................................... 8-00-00 198-10 Nose and Cabin Ballast (Weight) ............................... 8-00-00 198-11 Nose and Cabine Ballast (Weight) — Removal... 8-00-00 198-12 Nose and Cabine Ballast (Weight) —

Installation............................................................ 8-00-00 198-13 Nose and Cabin Ballast (Weight) Alternate

Location (S/N 33001 – 33107) ................................... 8-00-00 208-14 Nose and Cabin Ballast (Weight) Alternate

Location (S/N 33001 – 33107) — Removal ......... 8-00-00 208-15 Nose and Cabin Ballast (Weight) Alternate

Location (S/N 33001 – 33107) — Installation ...... 8-00-00 238-16 Tail Ballast (Weight) ................................................... 8-00-00 238-17 Removal............................................................... 8-00-00 238-18 Installation............................................................ 8-00-00 238-19 Tail Ballast (Lead Shot) Alternate Method ................. 8-00-00 268-20 Tail Ballast (Lead Shot) Alternate Method —

Removal............................................................... 8-00-00 268-21 Tail Ballast (Lead Shot) Alternate Method —

Installation............................................................ 8-00-00 26

FIGURES

Figure Page Number Title Number

8-1 Tool Application — Helicopter Leveling Plumb Bob ................................... 48-2 Weight and Balance ................................................................................... 68-3 Weight Empty Center of Gravity (S/N 33001 thru 33107)........................... 88-4 Weight Empty Center of Gravity (S/N 33108 and Sub. and

S/N 36001 and Sub.) .................................................................................. 9

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FIGURES (CONT)

Figure Page Number Title Number

8-5 Weight Empty Center of Gravity with 412-706-007-109 or -110 Auxiliary Fuel Kit (one only) Installed (S/N 33001 thru 33107)................... 11

8-6 Weight Empty Center of Gravity with 412-706-007-109 and -110 Auxiliary Fuel Kits Installed (S/N 33001 thru 33107) .................................. 12

8-7 Weight Empty Center of Gravity with 412-706-007-113, -114, -119, and -120 Auxiliary Fuel Kit (one only) Installed (S/N 33108 and Sub. and S/N 36001 and Sub.)................................................................... 13

8-8 Weight Empty Center of Gravity with 412-706-007-113, -114, -119, and -120 Auxiliary Fuel Kits Installed (S/N 33108 and Sub. and S/N 36001 and Sub.) ........................................................................... 14

8-8A Weight Empty Center of Gravity for Internal Hoist Operations ................... 14A8-9 Actual Weight Record — Sample (S/N 33001 through 33107 Not

Modified by BHT-412-SI-66)....................................................................... 168-9A Actual Weight Record — Sample (S/N 33001 through 33107 Modified

by BHT-412-SI-66) ..................................................................................... 16A8-10 Actual Weight Record — Sample (S/N 33108 through 33213 and

S/N 36001 through 36233 Not Modified by BHT-412-SI-66) ...................... 16B8-10A Actual Weight Record — Sample (S/N 33108 through 33213 and

S/N 36001 through 36233 Modified by BHT-412-SI-66 and 36234 andSubsequent) ............................................................................................... 17

8-11 Nose and Cabin Ballast (Weight) Installation ............................................ 218-12 Nose and Cabin Ballast Alternate Location Installation ............................. 248-13 Tail Ballast (Weight) Installation ................................................................. 27

TABLES

Table Page Number Title Number

8-1 Weight and Balance Sample Problem (S/N 33001 - 33107) ...................... 188-2 Weight and Balance Sample Problem (S/N 33108 and Subsequent and

S/N 36001 and Subsequent) ...................................................................... 19

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8-00-001 MAY 2012 Rev. 15 ECCN EAR99

WEIGHT AND BALANCE

8-1. WEIGHT AND BALANCE

The Center of Gravity (CG) is considered to be thebalancing point of a body of weight for balancepurposes. The helicopter can be compared to apendulum; the point of suspension being where themain rotor hub intersects the mast, the pendulumweight being the helicopter. If the pendulum weight isallowed to stop, it will come to rest directly below thesuspension point. For example: If the CG of ahelicopter is aft of the hub-mast intersection, thehelicopter will be tail-low in flight. The pilot can correctthis condition by moving the cyclic control stickforward. If required movement of the stick is greatenough, the pilot will use all available control, thuslimiting maneuverability and forward speed. Sincesuch loss of maneuverability is unsafe, it is imperativehelicopter CG remains within operational limits.Moving the CG is accomplished by adding andremoving ballast.

NOTE

For additional weight and balanceinformation, operators in territorial UnitedStates should refer to FAR 29. Operatorsoutside territorial United States should referto information issued by the licensingauthority.

8-2. LEVELING HELICOPTER

NOTE

Leveling plate (2, Figure 8-1) is marked inincrements of 1/4°. The leveling plate islocated on cabin floor just inside leftpassenger cargo door. A slotted hole islocated in upper door frame above levelingplate to support plumb bob (1).

1. Support helicopter as desired (Chapter 7).

2. Hang plumb bob (1) in slotted opening in doorframe with point of plumb bob just above levelingplate (2).

3. Adjust height of jacks to bring plumb bob exactlyover the point where two lines intersect at 0° onleveling plate (2). The helicopter will then be leveledlongitudinally and laterally.

4. After requirement to level helicopter is complete,remove plumb bob.

5. Remove jacks (Chapter 7).

8-3. WEIGHING

The helicopter should be weighed in a configuration asnear Weight Empty as possible. Weight emptycondition for helicopters S/N 33001 through 33107 isdifferent from that for S/N 33108 and subsequent andS/N 36001 and subsequent. Refer to paragraph 8-7and paragraph 8-8 for expanded definition of conditionfor both effectivities. Also, refer to FAR 29.

1. All kits, transmission oil and hydraulic fluid canremain aboard.

2. Make sure baggage compartment is empty.

3. Scale accuracy shall be within ±1%.

4. Position scales in an approximately level area,and check for proper adjustment to zero position.

CAUTION

WEIGHING SHOULD NOT BEATTEMPTED OUTDOORS OR IN ANOPEN BUILDING BECAUSE OF THEADVERSE EFFECT OF WIND, FLAPPINGROTORS AND BODY SWAY.

BHT-412-MM-2

8-00-00 Rev. 15 1 MAY 2012 ECCN EAR99

Figure 8-1. Tool Application — Helicopter Leveling Plumb Bob

BHT-412-MM-2

8-00-00Rev. 5

5. Position a scale and jack assembly under eachjack pad or under each forward jack pad and one aftjack pad and raise helicopter clear of floor.

6. Level helicopter (paragraph 8-2).

7. Balance each scale and record its reading.

8. Lower helicopter to surface. Weigh jacks, blocks,and any other equipment used between scales andhelicopter. Deduct this weight (tare) from actual (first)scale readings to obtain net scale weights.

9. Total ‘As Weighed’ weight is the sum of theindividual net scale weights.

8-4. DETERMINING CENTER OF GRAVITYLOCATION

1. The distance from F.S. 0.0 to a line throughcenters of forward jack pads is called the forward arm,and the distance from F.S. 0.0 to a line through centerof aft jack pads is called the aft arm. The forward armis 61.69 in. (1.57 m). The aft arm is 211.58 in. (5.37 m)(figure 8-2).

2. Multiply total net weight on forward scales byforward arm. The product is called the forwardmoment and is expressed in in.-lbs.

3. Multiply total net weight on aft scales by aft arm.This is the aft moment in in.-lbs.

NOTE

The procedure in the following step 4. maybe stated in equation form as follows:

4. Add forward and aft moments and divide by total‘As Weighed’ weight. The quotient is the helicopter ‘AsWeighed CG’ in inches aft of F.S. 0.0.

8-5. DETERMINING AMOUNT OF BALLASTREQUIRED

NOTE

In steps 1. and 2. below refer to paragraph8-6 for center-of-gravity charts that areapplicable when listed kits are installed.

THE WEIGHT EM PTY CENTER O FGRAVITY CHARTS ARE PRESENTED ASA GUIDE TO PROPERLY BALLAST THEHELICOPTER. IF HELICOPTER CANNOTBE BALAN CED WIT HIN T HESERESTRICTIONS, DO NOT EXCEEDGR OSS WEIG HT VS . CEN TER OFGRAVITY LIMITS PRESENTED IN THEAPPROPRIATE BHT-412-FM.

1. Weight Empty Center of Gravity chart, figure 8-3,is to be used for S/N 33001 to 33107 except when thefollowing kits are installed:

a. 412-706-007-109 Auxiliary Fuel

b. 412-706-007-110 Auxiliary Fuel

c. 412-706-007-109 and -110 Auxiliary Fuel

2. Weight Empty Center of Gravity chart, figure 8-4,is to be used for S/N 33108 and sub. and S/N 36001and sub. except when the following kits are installed:

a. 412-706-007-113 Auxiliary Fuel

b. 412-706-007-114 Auxiliary Fuel

c. 412-706-007-113, -114, -119, and -120Auxiliary Fuel

As Weighed CG =

(Net Wt. Fwd Scales) (61.69) +(Net Wt. Aft Scales) (211.58) =

Total Net (As Weighed) Weight

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Figure 8-2. Weight and Balance

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3. Figures 8-3 and 8-4 have a forward CG limit andan aft CG limit.

4. Actual Weight Empty CG can be anywherebetween aft and forward CG limits and be acceptable.However, if ‘Derived CG’ is aft of ‘Required CG’ and noaft ballast is installed, add forward ballast as required.If ‘Derived CG’ is aft of ‘Required CG’ and aft ballast isinstalled, reduce aft ballast as required. When all aftballast is removed, add forward ballast if necessary. If‘Derived CG’ is forward of ‘Required CG’ and forwardballast is installed, reduce forward ballast as required.When all forward ballast is removed, add aft ballast ifnecessary. If ‘Derived CG’ is forward of ‘Required CG’and no forward ballast is installed, add aft ballast asrequired.

DO NOT EXCEED BALLAST LIMITSSHOWN. IF HELICOPTER CANNOT BEBALANCED WITHIN THIS RESTRICTION,CONTACT LOCAL BELL HELICOPTERCUSTO M ER SUPPO RTREPRESENTATIVE FOR ASSISTANCE.

NOTE

‘Derived Weight’ and CG are ‘As Weighed’values plus those Weight Empty itemswhich may have been omitted and minusthose items which are not part of ‘WeightEmpty’.

NOTE

‘Required CG’ is approximately byintersection of ‘Derived Weight’ and nearestCG limit line on figures 8-3 and 8-4.

5. When ‘Weight Empty CG’ is not within acceptablerange shown in figures 8-3 and 8-4, use the followingformula to determine approximate amount of ballastrequired.

6. Weight and Balance Sample Problem - S/N33108 and sub. and S/N 36001 and Sub.

NOTE

Refer to paragraph 8-7 for weight andbalance sample problem for S/N 33001 thru33107. Refer to paragraph 8-8 for weightand balance sample problem for S/N 33108and sub.

7. Check ‘Derived Weight’ plus ballast and resultantCG on figures 8-3 and 8-4. Add or remove ballast asnecessary to arrive at desired CG.

8-6. WEIGHT EMPTY CENTER OF GRAVITYCHARTS — KITS

1. When any of the following kits are installed inhelicopter S/N 33001 to 33107, the applicablereferenced center-of-gravity chart shall be used.

a. 412-706-007-109 (figure 8-5)

b. 412-706-007-110 (figure 8-5)

c. 412-706-007-109 and -110 (figure 8-6)

2. When any of the following kits are installed inhelicopter S/N 33108 and sub. and S/N 36001 andsub., the applicable referenced center-of-gravity chartshall be used.

a. 412-706-007-113 (figure 8-7)

b. 412-706-007-114 (figure 8-7)

c. 412-706-007-113, -114, -119, and -120 (figure8-8)

3. When either internal hoist kit (412-899-223 or214-706-003) is installed in any model 412 helicopter,refer to weight empty center of gravity for internal hoistoperations chart, figure 8-8A.

Required Ballast =

Derived Weight (Required CG – Derived CG)

Ballast Arm – Required CG

BHT-412-MM-2

8-00-00

Figure 8-3. Weight Empty Center of Gravity (S/N 33001 thru 33107)

8-00-0013 AUG 2004 Rev. 9

Figure 8-4. Weight Empty Center of Gravity (S/N 33108 and Sub. and S/N 36001 and Sub.)

8-00-00 Rev. 9 13 AUG 2004

8-7. WEIGHT AND BALANCE SAMPLEPROBLEM (S/N 33001 - 33107)

NOTE

Use two forward jack pads/load cells andthe one left jack pad/load cell whenweighing helicopter.

The Actual Weight Record-Sample, figure 8-9 or 8-9A,can be used as a guide to follow a helicopter fromweighing to weight and balance check withintermediate steps to change weight emptyconfiguration.

The ‘As Weighed’ condition (paragraph 8-3) is shownin the block at top of Actual Weight Record. The ‘NetWeight’ is ‘Scale Weight’ less tare.

Center-of-gravity determination (paragraph 8-4) isshown directly below the ‘As Weighed’ block.

This helicopter is assumed to be dry so all ‘WeightEmpty Fluids’ must be added in determining ‘DerivedWeight’. These fluids include hydraulic fluid and alltransmission and gearbox oils together with unusablefuel and undrainable engine oil. This helicopter wasweighed without passenger seats, so they, also, areadded. These items added to ‘As Weighed’ weightcomprise the ‘Derived Weight’ and CG to be used indetermining ballast required. The ‘Derived Weight’ is6246.3 lbs., and the CG is F.S. 146.32. Using theformula in paragraph 8-5, step 4, we find:

The required CG is located by using figure 8-9.Assume approximately 100 lbs. of ballast and use aCG within desired CG range for new weight (6246 +100). Ballast Arm is –4.3.

NOTE

Alternate location for helicopters notequipped with float bottles is Ballast Arm+5.2.

Thus,

Figure 8-6 presents ballast weight and locations. Theballast selected should be placed as symmetrically aspossible. The amount used shall not be less than theamount necessary to ensure satisfactory CG location.

In figure 8-9 or 8-9A, the ‘Derived Weight and Moment’plus ‘Ballast Weight and Moment’ is ‘Weight EmptyWeight and Moment’. The ‘Weight Empty Moment’divided by ‘Weight Empty’ is ‘Weight Empty CG’. Thisaddition indicates, as shown, the helicopter weighs6322.3 lbs. with a 144.51 in. CG. A recheck of figure8-3 indicates a satisfactory operating condition.

Further calculations on the Actual Weight Record willconfirm operation is within flight limits for most forwardand most aft conditions.

Sample flight calculations demonstrating fuel burn, off-loading passengers, etc., are presented in flightmanual. Different Weight Empty and CG were used,but the principles are the same.

The configuration of the helicopter will probablychange several times due to addition of kits, enginechange, etc. These changes shall be documented,and a current ‘Weight Empty’ and CG shall beavailable at all times.

8-8. WEIGHT AND BALANCE SAMPLEPROBLEM (S/N 33108 AND SUB. AND S/N36001 AND SUB.)

NOTE

Use two forward jack pads/load cells andthe one left jack pad/load cell whenweighing helicopter.

The actual Weight Record-Sample (figure 8-10 or8-10A) can be used as a guide to follow a helicopterfrom weighing to weight and balance check withintermediate steps to change ‘Weight Empty’configuration.

The ‘As Weighed’ condition described in paragraph8-3 is shown in the block at top of Actual WeightRecord. The ‘Net Weight’ is ‘Scale Weight’ less tare.

Center-of-gravity determination (paragraph 8-4)is shown directly below the ‘As Weighed’ block.The helicopter, as weighed, contains hydraulicfluid, transmission oil, and gearbox oil.Unusable fuel, undrainable oil, and

6246.3 (Required CG – 146.32)Ballast Arm – Required CG

------------------------------------------------------------------------------------ Ballast=

6246 (144.50 – 146.32)–4.3 – 144.50

-------------------------------------------------------------- Ballast=

6246 (–1.82)–148.8

---------------------------------- 76 pounds=

BHT-412-MM-2

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Figure 8-5. Weight Empty Center of Gravity with 412-706-007-109 or -110 Auxiliary Fuel Kit (one only) Installed (S/N 33001 thru 33107)

BHT-412-MM-2

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Figure 8-6. Weight Empty Center of Gravity with 412-706-007-109 and -110 Auxiliary Fuel Kits Installed (S/N 33001 thru 33107)

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Figure 8-7. Weight Empty Center of Gravity with 412-706-007-113, -114, -119, and -120 Auxiliary Fuel Kit (one only) Installed (S/N 33108 and Sub. and S/N 36001 and Sub.)

85

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

140.0 140.5 145.0144.5144.0143.5143.0142.5142.0141.5141.0

CENTER OF GRAVITYFUSELAGE STATION - INCHES

WE

IGH

T E

MP

TY

- P

OU

ND

S X

100

FORWARDLIMIT

AFTLIMIT

412-M-8-7

MODEL 412WEIGHT EMPTY CG CHART

FOR USE WHEN 412-706-007-113, -114, -119, AND -120 (ONE ONLY) INSTALLED

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Figure 8-8. Weight Empty Center of Gravity with 412-706-007-113, -114, -119, and -120 Auxiliary Fuel Kits Installed (S/N 33108 and Sub. and S/N 36001 and Sub.)

BHT-412-MM-2

Figure 8-8A. Weight Empty Center of Gravity for Internal Hoist Operations

8-00-00Rev. 2 Page 14A/14B

BHT-412-MM-2

8-00-0013 AUG 2004 Rev. 9 Page 15

passenger seats are added to ‘As Weighed’ condition. Added to the ‘As Weighed’ weight, these items comprise ‘Derived Weight’ and CG to be used in determining ballast required. The ‘Derived Weight’ is 7311.2 lbs., and the CG is F.S. 144.42, a check of figure 8-4 shows this condition to be aft of aft CG limit. Using formula in paragraph 8-5, step 4, we find:

The required CG is located by using figure 8-10. Assume approximately 90 lbs. ballast and use a CG within ‘Desired CG Range’ for the new weight (7311 + 90). Ballast is –4.3.

Thus,

Figure 8-4 presents ballast weight and locations. The ballast selected should be placed as symmetrically as

possible. The amount used shall not be less than the amount necessary to ensure satisfactory CG location.

In figure 8-10 or 8-10A the ‘Derived Weight and Moment’ plus ‘Ballast Weight and Moment’ is ‘Weight Empty Weight and Moment’. The ‘Weight Empty Moment’ divided by ‘Weight Empty’ is ‘Weight Empty CG’. This addition indicates, as shown, helicopter weighs 7399.2 lbs. with a 142.65 in. CG. A recheck of figure 8-4 indicates a satisfactory operating condition.

Further calculations on the Actual Weight Record confirms operation is within flight limits for most forward and most aft conditions.

Sample flight calculations demonstrating fuel burn, off-loading passengers, etc., are presented in BHT-412-MD Manufacturer’s Data Manual. Different weight empty and CG were used, however the principles are the same.

The configuration of the helicopter will probably change several times due to addition of kits, etc. These changes must be documented, and a current Weight Empty and CG must be available at all times. Table 8-1 demonstrates steps necessary when changes are made.

7311.2 (Required CG – 144.42)Ballast Arm – Required CG

------------------------------------------------------------------------------------ Ballast=

7311 (142.6 – 144.42)–4.3 – 142.6

----------------------------------------------------------- Ballast=

7311 (–1.82)–146.9

---------------------------------- 86 pounds=

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Figure 8-9. Actual Weight Record — Sample (S/N 33001 through 33107 Not Modified by BHT-412-SI-66)

412_MM_08_0009

1 Refer to applicable fuel loading tables (BHT-412-MD-1, Section 1).

NOTE

1

1

BHT-412-MM-2

ECCN EAR99

Figure 8-9A. Actual Weight Record — Sample (S/N 33001 through 33107 Modified by BHT-412-SI-66)412_MM_08_0010

1 Refer to applicable fuel loading tables (BHT-412-MD-1, Section 1).

NOTE

1

1

8-00-0029 OCT 2009 Rev. 13 Page 16A

BHT-412-MM-2BHT-412-MM-2

ECCN EAR99

Figure 8-10. Actual Weight Record — Sample (S/N 33108 through 33213 and S/N 36001 through 36233 Not Modified by BHT-412-SI-66)

412_MM_08_0011

1 Refer to applicable fuel loading tables (BHT-412-MD-2, Section 1 or BHT-412-FM-3/-4, Section 5).

NOTE

1

1

8-00-00Page 16B Rev. 13 29 OCT 2009

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Figure 8-10A. Actual Weight Record — Sample (S/N 33108 through 33213 and S/N 36001 through 36233 Modified by BHT-412-SI-66 and 36234 and Subsequent)

412_MM_08_0012

1 Refer to applicable fuel loading tables (BHT-412-MD-2, Section 1 or BHT-412-FM-3/-4, Section 5).

NOTE

1

1

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Tables 8-1 and 8-2 do not cover Lateral CG. The method of calculating Lateral CG is shown on the Actual Weight Record. Maximum asymmetric limits are shown in BHT-412-FM-1 and will not be approached unless extreme lateral payload position is encountered.

If it is necessary to load in this manner, a lateral check should be made.

Table 8-1. Weight and Balance Sample Problem (S/N 33001 - 33107)

Add dual controls, copilot instrument, and emergency flotation.

Weight Longitudinal Lateral

Previous Weight Empty 6322.3 144.51 913612 +0.1 +677Add: Dual Controls +23.5 35.2 +827 –22.5 –529 Copilot Instruments +30.8 22.7 +699 –11.8 –363 Emergency Flotation +380.0 86.4 +32870 –1.5 –570

——— ——— —————— ——— ———Derived Weight 6756.6 140.31 948008 –0.1 –785

A check of figure 8-3 shows the CG to be too far forward, indicating a need for removal of nose ballast. The ballast computation formula may be used, but trial and error is acceptable. In this case, the removal of the previously added 76 lbs. is acceptable.

–76.0 +327 0——— ——— —————— ——— ———

Weight Empty 6680.6 141.95 948335 –0.1 +785

A recheck on figure 8-3 verifies this CG at the indicated weight to be acceptable.

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8-9. BALLAST

8-10. NOSE AND CABIN BALLAST (WEIGHT)

8-11. Nose and Cabine Ballast (Weight) —Removal

1. Remove ballast (12, Figure 8-11) as follows:

a. Remove battery (Chapter 96).

b. Remove nuts (11 and 14), washers (10 and13), and eyebolts (3 and 6).

c. Remove bolts (1 and 7), washers (2 and 8),and brackets (5 and 9).

d. Remove pan (4) and ballast (12).

NOTE

Remove ballast in equal amounts from bothsides of nose shelf.

2. Remove ballast (21, 33, 34, 35, and 36) asfollows:

a. Remove nuts (22), washers (23), bolts (25),and washers (24).

b. Remove nuts (17), washers (18), bolts (30),and washers (29). Remove ballast (21).

c. Remove nuts (15), washers (16), bolts (32),and washers (31). Remove ballast (36).

d. Remove nuts (19), washers (20), blocks (26),washers (27), and bolts (28). Remove ballast (33, 34,and 35).

8-12. Nose and Cabin Ballast (Weight) —Installation

1. Refer to paragraph 2 for procedure to determineamount of ballast and location where ballast isinstalled. If ballast is installed or removed from tailskid, refer to Chapter 32. To install or remove ballast innose compartment, perform the following steps:

2. Install ballast (12, Figure 8-11) as follows:

Table 8-2. Weight and Balance Sample Problem(S/N 33108 and Subsequent and S/N 36001 and Subsequent)

Add customizing

Weight Longitudinal Lateral

Previous Weight Empty 7399.2 142.65 1055513 +0.3 +2294Add: Customizing 64.5 160.0 10320 –1.7 –110

——— ——— —————— ——— ———Derived Weight 7463.7 142.80 1065833 –0.3 –2184

A check of Figure 8-4 shows the CG to be too far aft,indicating a need for addition of nose ballast. Theballast computation formula may be used. In this case,an additional 10 pounds. of ballast is required.

+10.0 –4.3 –43 0 0——— ——— —————— ——— ———

Weight Empty 7473.7 142.61 10657090 +0.3 +2184

A recheck on Figure 8-4 verifies this CG at theindicated weight to be acceptable.

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a. Remove battery (Chapter 96).

b. Remove nuts (11 and 14), washers (10 and13), and eyebolts (3 and 6).

c. Remove bolts (1 and 7), washers (2 and 8),and brackets (5 and 9).

d. Remove pan (4).

e. Position ballast (12) on shelf.

f. Position pan (4) on ballast (12).

g. Position brackets (5 and 9) on pan (4).

h. Install eyebolts (3 and 6), washers (10 and13), and nuts (11 and 14).

i. Install bolts (1 and 7) with washers (2 and 8).

j. Install battery (Chapter 96).

NOTE

Add ballast in equal amounts to both sidesof nose shelf.

3. Install ballast (21, 33, 34, 35 and 36) as follows:

a. Remove nuts (22), washers (23), bolts (25),and washers (24).

b. Remove nuts (17), washers (18), bolts (30),and washers (29).

c. Remove nuts (15), washers (16), bolts (32),and washers (31).

d. Remove nuts (19), steel washers (20), blocks(26), washers (27), and bolts (28).

e. Position required ballast on shelf.

NOTE

For ballast installations using less than themaximum configuration, some installationhardware may not be required.

f. Install bolts (25), washers (24 and 23), andnuts (22).

g. Install bolts (30), washers (29 and 18), andnuts (17).

h. Install bolts (32), washers (31 and 16), andnuts (15).

i. Install bolts (28) washers (27), blocks (26),washers (20), and nuts (19).

8-13. NOSE AND CABIN BALLAST (WEIGHT)ALTERNATE LOCATION (S/N 33001 - 33107)

8-14. Removal

NOTE

Remove ballast in equal amounts from bothsides of nose compartment.

1. Remove ballast (21 through 25, figure 8-12) fromleft side of nose compartment as follows:

a. Remove bolt (9) and washer (10).

b. Remove nut (18), washer (17), bolt (13), andwasher (14).

c. Remove bolt (15) and washer (16).

d. Remove nut (20), washer (19), bolt (11), andwasher (12).

e. Remove ballast.

2. Remove ballast (32 through 36) from right side ofnose compartment as follows:

a. Remove nut (31), washer (30), bolt (3), andwasher (4).

b. Remove nut (27), washer (26), bolt (7), andwasher (8).

c. Remove bolt (1) and washer (2).

d. Remove nut (29), washer (28), bolt (5), andwasher (6).

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Figure 8-11. Nose and Cabin Ballast (Weight) Installation (Sheet 1 of 2)

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Figure 8-11. Nose and Cabin Ballast (Weight) Installation (Sheet 2)

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e. Remove ballast.

8-15. Nose and Cabin Ballast (Weight) AlternateLocation (S/N 33001 – 33107) — Installation

NOTE

The following installation instructionspertain to a maximum ballast configuration.Some listed hardware may not be requiredfor partial ballast configurations.

1. Install ballast (21 through 25, Figure 8-12) asfollows:

a. Position ballast on lower shelf of nose area forinstallation.

b. Install bolt (9) with washer (10).

c. Install bolt (13), washers (14 and 17), and nut(18).

d. Install bolt (15) with washer (16).

e. Install bolt (11), washers (12 and 19), and nut(20).

2. Install ballast (32 through 36) as follows:

a. Position ballast on lower shelf of nose area forinstallation.

b. Install bolt (7), washer (8 and 26), and nut(27).

c. Install bolt (3), washers (4 and 30), and nut(31).

d. Install bolt (1) with washer (2).

e. Install bolt (5), washers (6 and 28), and nut(29).

8-16. TAIL BALLAST (WEIGHT)

8-17. Tail Ballast (Weight) — Removal

NOTE

If tail skid removal is required, refer toChapter 32.

1. Determine amount of ballast to be removed(paragraph 8-5).

2. Remove both light fairings (1, Figure 8-13) (ifrequired) by removing screws (2) and disconnectingelectrical connectors.

NOTE

Washer halves (7 and 11) are used only onend of ballast stack as a filler for clamphalves (5 and 10).

3. Remove tail skid ballast.

a. Remove nuts (9) and bolt (4) from each end ofballast (weight) halves (6 and 12).

b. Remove clamp halves (5 and 10) andwashers halves (7 and 11). Remove ballast halves.

c. Install washer halves (7 and 11) and clamphalves (5 and 10) with bolts (4) and nuts (9) on end ofremaining ballast stack. Tighten securely.

4. Connect electrical connectors and install lightfairings (1) with screws (2) (if removed).

8-18. Tail Ballast (Weight) — Installation

NOTE

If tail skid removal is required, refer toChapter 32.

1. Determine amount of ballast required (paragraph8-5).

2. Remove both light fairings (1, Figure 8-13) byremoving screws (2) and disconnecting electricalconnectors.

NOTE

Washer halves (7 and 11) are used only onend of ballast stack as a filler for clamphalves (5 and 10).

3. Install tail skid ballast.

BHT-412-MM-2

8-00-00Page 24 Rev. 18 30 JUN 2013 Export Classification C, ECCN EAR99

Figure 8-12. Nose and Cabin Ballast Alternate Location Installation (Sheet 1 of 2)

BHT-412-MM-2

8-00-00Page 25

Figure 8-12. Nose and Cabin Ballast Alternate Location Installation (Sheet 2)

BHT-412-MM-2

8-00-00Page 26 Rev. 15 1 MAY 2012 ECCN EAR99

a. Position ballast (weight) halves (6 and 12),washer halves (7 and 11), and clamp halves (5 and 10)on tail skid (8).

b. Install bolts (4) and and nuts (9).

c. Torque nuts (9) 30 to 35 inch-pounds (3.4 to4.0 Nm).

d. Gently tap clamp halves (5 and 10) with a softmallet and check the torque. Repeat until torquestabilizes.

e. Install additional ballast as required in thesame manner.

f. Inspect roll pin (3) for secure installation.

4. Connect electrical connectors and install lightfairings (1) with screws (2).

8-19. TAIL BALLAST (LEAD SHOT) ALTERNATEMETHOD

8-20. Tail Ballast (Lead Shot) Alternate Method— Removal

1. Remove tail skid (Chapter 32).

2. Determine amount of ballast to be removed(paragraph 2).

3. Use a heat gun to remove adhesive from aroundthe plug (13, Figure 8-13) in end of tail skid (8).

4. Remove plug (13).

5. Remove required lead shot or equivalent ballastfrom inside tail skid (8).

6. Remove decal (14) when alternate ballast is to bereplaced by primary method ballast weights (6and 12).

8-21. Tail Ballast (Lead Shot) Alternate Method— Installation

1. Determine amount of ballast to be removed(paragraph 2).

NOTE

Do not pack lead shot into tail skid.

2. Add required No. 8 lead shot, or equivalentballast, inside tail skid (8, Figure 8-13).

3. Install plug (13) into end of tail skid (8) with zincchromate primer (C-201).

4. Make sure that fastener hole in plug (13) alignswith hole in tail skid (8).

5. Install tail skid (8) (Chapter 32).

6. Apply decal (14) to skid tube (8) (Chapter 11).

MATERIALS REQUIRED

Refer to BHT-ALL-SPM for specification and source.

NUMBER NOMENCLATURE

C-201 Zinc Chromate Primer

BHT-412-MM-2

8-00-0030 MAR 2007 Rev. 11 Page 27

Figure 8-13. Tail Ballast (Weight) Installation (Sheet 1 of 2)

SEE DETAIL B

DETAIL B

SKID TUBE

FASTENER

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

Light fairing

Screw

Roll pin

Bolt

Clamp half

Ballast (weight) half

Washer half

Tail skid

Nut

Clamp half

Washer half

Ballast (weight) half

Plug

Decal

Maximum allowable number of ballast

(weights) are illustrated. Determine

number of weights required from text.

Center of ballast location STA 441.0.

TAIL SKID

13

14

5

7

8

1

3

4

2

1 2 1.0 IN.

(2.54 cm)

6

412_MM_08_0001

BHT-412-MM-2

8-00-00Page 28 Rev. 11 30 MAR 2007

Figure 8-13. Tail Ballast (Weight) Installation (Sheet 2 of 2)

1

2

3

4

5

6

7

8

Two ballast (weight) halves make a set.

Nominal weight of each ballast (weight) half is 6.3 pounds (2.86 kg). Actual

weight is stamped on each ballast (weight) half.

Alternate ballast, No. 8 lead shot or equivalent installed inside tail skid.

“BALLAST INSIDE” decal installed when alternate ballast installed.

Install plug with primer C-201.

204-071-566-1 ballast installation typical three places.

204-071-566-3 ballast.

204-071-566-5 ballast.

412_MM_08_0002

NOTES

chapter 8 — weight and balance · bht-412-mm-2 8-00-00 eccn ear99 1 may 2012 rev. 15 page 3...

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