6/15/22, 12:55 PM
BHT - Technical Publications
WEIGHING
Weight and balance
(DMC-505-A-08-30-00-00A-169A-A, Issue 002 - 2017/04/28, ECCN EAR99)
1.
General
The weighing gives the data and procedure to weigh the helicopter.
2.
Preparation
NOTE
Empty Configuration includes basic helicopter plus the weight of installed kits, special equipment, fixed
ballast, transmission, gearbox, engine oil, hydraulic fluid, and unusable fuel.
Record the weighed configuration. Ensure helicopter configuration is as near to the documented Empty Weight
configuration as possible. An example of a completed weighing checklist is provided in Table 1.
1.
2.
Complete the weighing checklist.
Remove unwanted dirt, grease, and moisture from the helicopter.
3.
4.
Remove all the items that are not part of the Empty Weight configuration.
Install all the missing items necessary for the Empty Weight configuration at their appropriate
locations.
5.
Make sure that the baggage compartment is empty.
6.
7.
-
Make sure that the following fluid levels are correct (full):
Engine oil (DMC-505-A-12-10-05-00A-369A-A)
Transmission oil (DMC-505-A-12-10-03-00A-369A-A)
-
Tail rotor gearbox oil (DMC-505-A-12-10-04-00A-369A-A)
Hydraulic fluid (DMC-505-A-12-10-02-00A-369A-A)
Drain the fuel system (DMC-505-A-12-10-01-00A-221A-A).
3.
Procedure
Support equipment
Nomenclature
Identification no.
Quantity
Remarks
Electronic loadcell
Commercial
3
Range:
Electronic platform scale
Commercial
(alternate)
Mechanical scale (alternate) Commercial
3
0 to 4000 pounds (0 to 1814 kg)
Precision:
0.1% of applied load
3
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NOTE
Do not weigh the helicopter outside or in an open building. The wind, flapping rotors, and body sway can seriously
affect the accuracy of the scale readings.
1.
Put the helicopter on a hard and level surface, inside a closed hangar (DMC-505-A-10-00-00-00A-00SA-A).
2.
Install the weighing devices as follows:
NOTE
Follow the scale manufacturer’s instructions for the warm-up procedure.
NOTE
Make sure that you do not allow the cables that connect the scales to the control unit to cross each other and
-
that you do not allow any weight on the cables.
When using electronic loadcells, install them on the jacks used to lift the helicopter. Make sure that the
-
When using electronic platform scales, put each scale in position below the jacking point and align the center
-
of the scale with the jack fitting.
When using mechanical scales, put each scale in position below the jacking point and align the center of the
loadcells and their adapters are tightened to the pads of the jacks.
scale with the jack fitting.
3.
Adjust each scale to read zero with no-load.
DO NOT LET PERSONNEL IN OR ON THE HELICOPTER WHILE IT IS LIFTED. THE HELICOPTER CAN BE
UNSTABLE. INJURY TO PERSONNEL AND DAMAGE TO THE HELICOPTER CAN OCCUR IF YOU DO NOT
OBEY.
Lift the helicopter and adjust the jacks to make it level longitudinally and laterally. Refer to DMC-505-A-08-20-
4.
00-00A-169A-A for the leveling procedure.
5.
Make sure that there is no side loads applied to the jacks, scales, or loadcells.
6.
Refer to the scale manufacturer’s instructions to find the weight shown.
7.
8.
Record the scale readings for each scale.
Lower the helicopter (DMC-505-A-07-10-00-00A-912A-A). Do not remove the jacking/weighing equipment.
9.
Make sure that there is no contact between the helicopter and the jacking/weighing equipment.
10.
-
Tare Weight - The weight of chocks, blocks, stands, etc.. that are used during weighing. Scale reading includes
this weight.
Record the tare weight for each scale.
Mechanical scales: The weight of chocks, blocks, stands, etc. that are used during weighing. This weight is
included in the scale readings.
Electronic scales: Consult the scale manufacturer’s data.
NOTE
11.
-
Calculate and record the net weight for each scale as follows:
Net Weight = Scale Reading - Tare Weight
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12.
Add the three net weights that you calculated to get the as-weighed weight of the helicopter. Record the
13.
value.
After the first weighing, move the three scales, or loadcells, one jack point position clockwise and go to step 3.
to do a second weighing to make sure the scale readings are accurate.
14.
Make sure that the results of the two consecutive weighings meet the following conditions. Refer to Table 2
for an example:
-
The difference between the first and the second as-weighed weight must be less than 10 pounds (4.5 kg).
-
The difference between the calculated differences of the forward and aft net weights of the first and second
weighings must be less than 5 pounds (2.3 kg).
15.
Apply corrective actions, as necessary, when the conditions at step 14. are not met and do the weighing
procedure again until you get acceptable results.
16.
17.
Lower the helicopter (DMC-505-A-07-10-00-00A-912A-A).
Remove the jacks and the weighing devices.
Table 1. Weighing checklist (example)
Helicopter serial number: XXXXX
Weighing kit name:
_
Date weighed: XX-XX-XXXX
XXX
Calibration expiry date:
_
_
XX-XX-XXXX
_
Table 1. Weighing checklist (example)
Item
Description
Yes
Basic aircraft configuration
Fuel
No
Item
Description
Yes No
Ballast
Empty (cell drained)
X
Nose
Undrainable in system
X
Tailboom
0 pounds (___ kg) @
FS ___ (___ mm)
0 pounds (___ kg) @
FS ___ (___ mm)
Oil
Engine full
X
Transmission full
X
Optional kits
Engine and transmission X
Dual controls
X
Carpet
X
Rotor brake
X
topped-up post ground
run
Hydraulic fluid
Battery fitted
Fire extinguisher
Interior installed
Headset(s)
First aid kit
Finish paint
Baggage
compartment
Ground handling
wheels
Helicopter level
Cowlings, doors,
and panels
Tail rotor gearbox full
X
Full
X
Quantity installed: 2 _
Empty
X
X
X
X
X
X
X
Removed
X
Forward and aft / Lateral X
Closed/installed
X
Table 1. Weighing checklist (example)
Parts Added:
Parts Omitted:
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Table 1. Weighing checklist (example)
Notes:
Table 2. As-weighed weighing results (example)
Date weighed: __________________________
Serial number: _________________________
Weighing kit: ___________________________
Calibration expiry: ______________________
First weighing result
Table 2. As-weighed weighing results (example)
Scale location (scale letter) Scale reading
Lb
Kg
Tare weight
Lb
Kg
Net weight
Lb
Kg
Forward Left (A)
364.0
165.1
6.0
2.7
358.0
162.4
Forward Right (B)
Aft (C)
As-weighed weight
356.0
1544.5
2264.5
161.5
700.6
1027.2
0.0
4.5
10.5
0.0
2.0
4.8
356.0
1540.0
2254.0
161.5
698.5
1022.4
Table 2. As-weighed weighing results (example)
Second weighing result
Scale location (scale letter) Scale reading
Tare weight
Net weight
Lb
Kg
Lb
Kg
Lb
Kg
Forward Left (D)
Forward Right (E)
361.0
359.0
163.7
162.8
6.0
0.0
2.7
0.0
355.0
359.0
161.0
162.8
Aft (F)
As-weighed weight
1543.5
2263.5
700.1
1026.7
4.5
10.5
2.0
4.8
1539.0
2253.0
698.1
1022.0
Table 2. As-weighed weighing results (example)
Confirmation of weighing results
Scale location (scale letter)
Net weights lb (kg)
Scale location (scale letter)
Net weights lb (kg)
Forward Left (A)
Forward Right (B)
Aft (C)
358.0 (162.4)
356.0 (161.5)
1540.0 (698.5)
Forward Left (D)
Forward Right (E)
Aft (F)
355.0 (161.0)
359.0 (162.8)
1539.0 (698.1)
Total first net weight (G)
2254.0 (1022.4)
Total second net weight (H)
2253.0 (1022.0)
Table 2. As-weighed weighing results (example)
Total as-weighed weight difference (G-H) (must be < 10 pounds (4.5 kg)) = 1 pounds ( 0.4 kg).
Forward versus aft weight difference (A+B-C-D-E+F) (must be < 5 pounds (2.3 kg)) = -1 pounds ( -0.3 kg).
NOTE
If total helicopter as-weighed weight difference is less than 10 pounds (4.5 kg), and forward versus aft net weight
difference is less than 5 pounds (2.3 kg), the weighing results are acceptable.
End of data module
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