Transcript Helicopter Performance, Limitations, and Load Calculations

S-271 Helicopter Crewmember
UNIT 5
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-1
S-271 Helicopter Crewmember
1. Describe general aspects of helicopter
design, flight controls, and terminology.
2. Define “in-ground-effect” and “out-ofground-effect” as they relate to helicopter
performance.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-2
S-271 Helicopter Crewmember
3. Describe air density altitude and the effects
on helicopter performance.
4. Describe the process for completing a load
calculation form.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-3
S-271 Helicopter Crewmember
Basic Helicopter Design Rotor Systems
Single-Rotor Helicopter - The most common design
uses a single main rotor which imparts lift and thrust,
and a smaller tail rotor, which compensates for torque
induced by the powered turning of the main rotor.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-4
S-271 Helicopter Crewmember
Basic Helicopter Design Rotor Systems
Dual-Rotor Helicopter – Some helicopters have dual
main rotors, mounted in tandem or side-by-side.
Torque compensation is achieved by turning the rotors
in opposite directions.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-5
S-271 Helicopter Crewmember
Basic Helicopter Design
Helicopter Controls
There are four controls that are used in conjunction
with each other when flying a helicopter.
- Collective pitch control
- Throttle control
- Anti-torque
- Cyclic control
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-6
S-271 Helicopter Crewmember
Basic Helicopter Design
Helicopter Controls
Collective Control
This changes the angle of the pitch (of angle of attack)
of each main rotor blade simultaneously. The
collective is controlled by the left hand.
As the pitch of the blades is increased, lift is created
causing the helicopter to rise from the ground, hover
or climb, as long as sufficient power is available.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-7
S-271 Helicopter Crewmember
Basic Helicopter Design
Helicopter Controls
Throttle Control
On the turbine-powered helicopters, this
power coordination is accomplished
automatically through the fuel control and
governor systems of the turbine engine.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-8
S-271 Helicopter Crewmember
Basic Helicopter Design
Helicopter Controls
Anti-Torque Control
Two anti-torque pedals are provided to
counteract the torque effect of the
main rotor. This is done by increasing
or decreasing the thrust of the tail rotor.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-9
S-271 Helicopter Crewmember
Basic Helicopter Design
Helicopter Controls
Anti-Torque Control
The anti-torque pedals accomplish this
by changing the pitch (angle of attack)
or the tail rotor blades.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-10
S-271 Helicopter Crewmember
Basic Helicopter Design
Helicopter Controls
Anti-Torque Control
Heading and directional control in
hover and at low air speeds as forward
air speed increases, the tail rotor
becomes less necessary (slip streaming
effect).
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-11
S-271 Helicopter Crewmember
Basic Helicopter Design
Helicopter Controls
Cyclic Control
The “cyclic” is controlled by the pilot’s right hand.
Aircraft moves in the direction that pressure is applied
to the cyclic.
If the pilot moves the cyclic forward, the lift in the
rear half of the rotor disk is increased, and the aircraft
moves forward.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-12
S-271 Helicopter Crewmember
Basic Helicopter Design
Landing Gear
Skids – Skids are the most common type of landing
gear used in light and medium-class helicopters.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-13
S-271 Helicopter Crewmember
Basic Helicopter Design
Landing Gear
Wheels – Wheels are primarily used on medium and
heavy helicopters.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-14
S-271 Helicopter Crewmember
Basic Helicopter Design
Landing Gear
Floats – Floats can be used on land as well as water.
There are two types; fixed or inflated. “Pop Outs” are
inflated only as needed.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-15
S-271 Helicopter Crewmember
Helicopter Loading
Center of Gravity Effects
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-16
S-271 Helicopter Crewmember
Helicopter Loading
Center of Gravity Effects
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-17
S-271 Helicopter Crewmember
Helicopter Loading
Floor Loading
Careful attention must be given to small,
heavy parcels loaded into helicopters to
determine that the maximum poundsper-square-inch limitations are not
exceeded.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-18
S-271 Helicopter Crewmember
Being familiar with terms commonly used
in helicopter flight characteristics is
important to persons involved with
helicopter use.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-19
S-271 Helicopter Crewmember
Ground Effect
A condition of improved rotor system
performance encountered when the
helicopter is hovering near the ground.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-20
S-271 Helicopter Crewmember
Hover-In-Ground-Effect (HIGE) occurs when
helicopter is hovering approximately less
than one-half the rotor diameter distance
from the ground.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-21
S-271 Helicopter Crewmember
HIGE the airflow is interrupted by the
ground under the helicopter; this reduces
downward velocity of the air and produces
an outward airflow pattern.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-22
S-271 Helicopter Crewmember
Hover-Out-Of-Ground-Effect (HOGE)
occurs when the helicopter exceeds
about one-half of the rotor diameter
distance from the ground, and the
cushion of air disintegrates.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-23
S-271 Helicopter Crewmember
HOGE no cushion of air and maximum
performance of helicopter is required.
Payload may have to be reduced.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-24
S-271 Helicopter Crewmember
Ground Effect – Hover-Out-Of-GroundEffect (HOGE)
It is important to understand the
capabilities and limitations presented by
ground effect when choosing a landing
site
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-25
S-271 Helicopter Crewmember
Ground Effect – Translational Lift
Translational lift occurs when the
helicopter approaches 15 to 18 MPH
indicated airspeed and when hovering
with a 15 MPH steady headwind.
Can be felt as an aircraft transitions from
a hover to forward flight.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-26
S-271 Helicopter Crewmember
Autorotation
Autorotation is a non-powered flight
condition in which the rotor system
maintains flight RPM by reversed airflow.
It provides the pilot a means of safely
landing the helicopter after an engine
failure or other mechanical emergency.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-27
S-271 Helicopter Crewmember
Autorotation
Helicopters have a freewheeling unit in
the transmission which automatically
disengages the engine from the rotor
system in the event of failure. This allows
the main rotor to rotate freely.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-28
S-271 Helicopter Crewmember
Autorotation
When the helicopter is powered by the
engine, airflow is downward through the
rotors. During an autorotation airflow is
upward, “wind milling” the rotor blades
as the helicopter descends.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-29
S-271 Helicopter Crewmember
Height Velocity
Diagram
In flight manuals for
each helicopter types
is a chart which
provides necessary
information to
complete a safe
autorotation.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-30
S-271 Helicopter Crewmember
Maximum Performance
Takeoff
Occurs when the
helicopter HOGE before
or after translational lift.
The helicopter is totally
power dependent and
the margin for safety is
significantly reduced.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-31
S-271 Helicopter Crewmember
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-32
S-271 Helicopter Crewmember
Maximum Performance Takeoff
When possible, avoid confined areas, or
large obstructions that require the pilot to
use maximum power for extended
periods.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-33
S-271 Helicopter Crewmember
Density Altitude
Density altitude refers to a theoretical air
density which exists under standard
conditions of a given altitude.
By definition, density altitude is pressure
altitude corrected for temperature and
humidity.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-34
S-271 Helicopter Crewmember
Density Altitude
Can have a profound effect on aircraft
performance. Air, like other gases and
liquids, is fluid. It flows and changes
shape under pressure. Air is said to be
“thin” at higher elevations.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-35
S-271 Helicopter Crewmember
Density Altitude
There are more air molecules per cubic
foot at sea level feet than at 8,500 feet.
As density altitude
increases, air thins
out and aircraft
performance
decreases.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-36
S-271 Helicopter Crewmember
Density Altitude
There are three factors that affect density
altitude in varying degrees; atmospheric
pressure, temperature, and to some
degree, humidity.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-37
S-271 Helicopter Crewmember
Density Altitude Chart
Exercise - Density Altitude Chart
Density altitude affects helicopter
performance.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-38
S-271 Helicopter Crewmember
8400 ft.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
8400 ft.
Slide 5-39
S-271 Helicopter Crewmember
Density Altitude Effects Performance
High elevation, high temperature, and high
moisture content all contribute to high density
altitude conditions and lessen performance.
Performance is reduced because the thinner air
at high density altitudes reduces blade
efficiency.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-40
S-271 Helicopter Crewmember
At sea level the cool, dense air provides
optimum helicopter performance.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-41
S-271 Helicopter Crewmember
But at higher altitude, or hotter conditions,
the air is less dense and performance is
significantly reduced.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-42
S-271 Helicopter Crewmember
Load Calculation Form
One of the most important documents
you will need to become familiar with is
the Load Calculation Form.
For a helicopter to fly safely it is critical
that you obtain an allowable payload
from the Load Calculation form.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-43
S-271 Helicopter Crewmember
• The AMD-67 and FS-5700-17 load calculation
is required for all helicopter flights conducted
on interagency fires and project work.
• Any 5 degree C change in outside air
temperature or any 1,000 pressure altitude
feet change, a new load calculation will need
to be completed to ensure safe operations.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-44
S-271 Helicopter Crewmember
Many accidents have happened that
involved aircraft that were operating in
conditions that were too high or too hot
for the weight of the aircraft.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-45
S-271 Helicopter Crewmember
INTERAGENCY
HELICOPTER LOAD CALCULATION
Electronic Version (12/03)
MODEL
Bell 407
N#
123WH
PILOT(S)
Bo Duke
DATE
MISSION
Initial Attack
TIME
1 DEPARTURE
Helibase
PA
4000
OAT
25
2 DESTINATION
Helispot
PA
6000
OAT
20
2911
3 HELICOPTER EQUIPPED WEIGHT
206
4 FLIGHT CREW WEIGHT
5 FUEL WEIGHT
50
gals X
7
350
lbs/gal
3467
6 OPERATING WEIGHT (3 + 4 + 5)
Non-Jettisonable
HIGE
7a PERFORMANCE REFERENCE
(List chart/supplement from Flight Manual)
7b COMPUTED GROSS WEIGHT
(From Flight Manual Performance Section)
8 WEIGHT REDUCTION
(Required for all Non-Jettisonable loads)
9 ADJUSTED WEIGHT
(7b minus 8)
10 GROSS WEIGHT LIMITATION
(From Flight Manual Limitations Section)
11 SELECTED WEIGHT
(Lowest of 9 or 10)
12 OPERATING WEIGHT
(From Line 6)
13 ALLOWABLE PAYLOAD
(11 minus 12)
HOGE
Jettisonable
HOGE- J
FMS 3 4-2 FMS 3 4-4 FMS 3 4-4
5000
5000
5075
155
155
0
4845
4845
5075
5000
5000
5500
4845
4845
5075
3467
3467
3467
1378
1378
1608
14 PASSENGERS/CARGO
15 ACTUAL PAYLOAD
(Total of all weights listed in Item 14)
Line 15 must not exceed Line 13 for the intended mission (HIGE, HOGE or HOGE-J)
Unit 5
0
PILOT SIGNATURE
HazMat Onboard
MANAGER SIGNATURE
Yes
Helicopter Performance, Limitations, and Load Calculations
No
Slide 5-46
S-271 Helicopter Crewmember
INTERAGENCY
HELICOPTER LOAD CALCULATION
Electronic Version (12/03)
MODEL
Bell 407
N#
123WH
PILOT(S)
Bo Duke
DATE
MISSION
Initial Attack
TIME
1 DEPARTURE
Helibase
PA
4000
OAT
25
2 DESTINATION
Helispot
PA
6000
OAT
20
2911
3 HELICOPTER EQUIPPED WEIGHT
206
4 FLIGHT CREW WEIGHT
5 FUEL WEIGHT
50
gals X
7
350
lbs/gal
3467
6 OPERATING WEIGHT (3 + 4 + 5)
Non-Jettisonable
HIGE
7a PERFORMANCE REFERENCE
(List chart/supplement from Flight Manual)
7b COMPUTED GROSS WEIGHT
(From Flight Manual Performance Section)
8 WEIGHT REDUCTION
(Required for all Non-Jettisonable loads)
9 ADJUSTED WEIGHT
(7b minus 8)
10 GROSS WEIGHT LIMITATION
(From Flight Manual Limitations Section)
11 SELECTED WEIGHT
(Lowest of 9 or 10)
12 OPERATING WEIGHT
(From Line 6)
13 ALLOWABLE PAYLOAD
(11 minus 12)
HOGE
Jettisonable
HOGE- J
FMS 3 4-2 FMS 3 4-4 FMS 3 4-4
5000
5000
155
155
5075
0
4845
4845
5075
5000
5000
5500
4845
4845
5075
3467
3467
3467
1378
1378
1608
•
•
•
•
•
•
Aircraft model
N Number
Mission
Date/Time
Departure
Destination
14 PASSENGERS/CARGO
15 ACTUAL PAYLOAD
(Total of all weights listed in Item 14)
Line 15 must not exceed Line 13 for the intended mission (HIGE, HOGE or HOGE-J)
Unit 5
0
PILOT SIGNATURE
HazMat Onboard
MANAGER SIGNATURE
Yes
No
Helicopter Performance, Limitations, and Load Calculations
Slide 5-47
S-271 Helicopter Crewmember
INTERAGENCY
HELICOPTER LOAD CALCULATION
Electronic Version (12/03)
MODEL
Bell 407
N#
123WH
PILOT(S)
Bo Duke
DATE
MISSION
Initial Attack
TIME
1 DEPARTURE
Helibase
PA
4000
OAT
25
2 DESTINATION
Helispot
PA
6000
OAT
20
2911
3 HELICOPTER EQUIPPED WEIGHT
206
4 FLIGHT CREW WEIGHT
5 FUEL WEIGHT
50
gals X
7
350
lbs/gal
3467
6 OPERATING WEIGHT (3 + 4 + 5)
Non-Jettisonable
HIGE
7a PERFORMANCE REFERENCE
(List chart/supplement from Flight Manual)
7b COMPUTED GROSS WEIGHT
(From Flight Manual Performance Section)
8 WEIGHT REDUCTION
(Required for all Non-Jettisonable loads)
9 ADJUSTED WEIGHT
(7b minus 8)
10 GROSS WEIGHT LIMITATION
(From Flight Manual Limitations Section)
11 SELECTED WEIGHT
(Lowest of 9 or 10)
12 OPERATING WEIGHT
(From Line 6)
13 ALLOWABLE PAYLOAD
(11 minus 12)
HOGE
Jettisonable
HOGE- J
FMS 3 4-2 FMS 3 4-4 FMS 3 4-4
5000
5000
155
155
5075
0
4845
4845
5075
5000
5000
5500
4845
4845
5075
3467
3467
3467
1378
1378
1608
• Helicopter equipped
weight +
• Flight crew weight +
• Fuel weight =
• Operating weight
14 PASSENGERS/CARGO
15 ACTUAL PAYLOAD
(Total of all weights listed in Item 14)
Line 15 must not exceed Line 13 for the intended mission (HIGE, HOGE or HOGE-J)
Unit 5
0
PILOT SIGNATURE
HazMat Onboard
MANAGER SIGNATURE
Yes
No
Helicopter Performance, Limitations, and Load Calculations
Slide 5-48
S-271 Helicopter Crewmember
INTERAGENCY
HELICOPTER LOAD CALCULATION
Electronic Version (12/03)
MODEL
Bell 407
N#
123WH
PILOT(S)
Bo Duke
DATE
MISSION
Initial Attack
TIME
1 DEPARTURE
Helibase
PA
4000
OAT
25
2 DESTINATION
Helispot
PA
6000
OAT
20
2911
3 HELICOPTER EQUIPPED WEIGHT
206
4 FLIGHT CREW WEIGHT
5 FUEL WEIGHT
50
gals X
7
350
lbs/gal
3467
6 OPERATING WEIGHT (3 + 4 + 5)
Non-Jettisonable
HIGE
7a PERFORMANCE REFERENCE
(List chart/supplement from Flight Manual)
7b COMPUTED GROSS WEIGHT
(From Flight Manual Performance Section)
8 WEIGHT REDUCTION
(Required for all Non-Jettisonable loads)
9 ADJUSTED WEIGHT
(7b minus 8)
10 GROSS WEIGHT LIMITATION
(From Flight Manual Limitations Section)
11 SELECTED WEIGHT
(Lowest of 9 or 10)
12 OPERATING WEIGHT
(From Line 6)
13 ALLOWABLE PAYLOAD
(11 minus 12)
HOGE
Jettisonable
HOGE- J
FMS 3 4-2 FMS 3 4-4 FMS 3 4-4
5000
5000
155
155
5075
0
4845
4845
5075
5000
5000
5500
4845
4845
5075
3467
3467
3467
1378
1378
1608
14 PASSENGERS/CARGO
15 ACTUAL PAYLOAD
(Total of all weights listed in Item 14)
Line 15 must not exceed Line 13 for the intended mission (HIGE, HOGE or HOGE-J)
Unit 5
0
PILOT SIGNATURE
HazMat Onboard
MANAGER SIGNATURE
Yes
•
•
•
•
•
•
•
•
Performance reference
Computed gross weight
Weight reduction
Adjusted weight
Gross weight limitation
Selected weight
Operating weight
Allowable payload
No
Helicopter Performance, Limitations, and Load Calculations
Slide 5-49
S-271 Helicopter Crewmember
INTERAGENCY
HELICOPTER LOAD CALCULATION
Electronic Version (12/03)
MODEL
Bell 407
N#
123WH
PILOT(S)
Bo Duke
DATE
MISSION
Initial Attack
TIME
1 DEPARTURE
Helibase
PA
4000
OAT
25
2 DESTINATION
Helispot
PA
6000
OAT
20
2911
3 HELICOPTER EQUIPPED WEIGHT
206
4 FLIGHT CREW WEIGHT
5 FUEL WEIGHT
50
gals X
7
350
lbs/gal
3467
6 OPERATING WEIGHT (3 + 4 + 5)
Non-Jettisonable
HIGE
7a PERFORMANCE REFERENCE
(List chart/supplement from Flight Manual)
7b COMPUTED GROSS WEIGHT
(From Flight Manual Performance Section)
8 WEIGHT REDUCTION
(Required for all Non-Jettisonable loads)
9 ADJUSTED WEIGHT
(7b minus 8)
10 GROSS WEIGHT LIMITATION
(From Flight Manual Limitations Section)
11 SELECTED WEIGHT
(Lowest of 9 or 10)
12 OPERATING WEIGHT
(From Line 6)
13 ALLOWABLE PAYLOAD
(11 minus 12)
HOGE
Jettisonable
HOGE- J
FMS 3 4-2 FMS 3 4-4 FMS 3 4-4
5000
5000
155
155
5075
0
4845
4845
5075
5000
5000
5500
4845
4845
5075
3467
3467
3467
1378
1378
1608
•
•
•
•
•
Passengers and cargo
Actual payload
Pilot signature
Manager signature
HazMat
14 PASSENGERS/CARGO
15 ACTUAL PAYLOAD
(Total of all weights listed in Item 14)
Line 15 must not exceed Line 13 for the intended mission (HIGE, HOGE or HOGE-J)
Unit 5
0
PILOT SIGNATURE
HazMat Onboard
MANAGER SIGNATURE
Yes
No
Helicopter Performance, Limitations, and Load Calculations
Slide 5-50
S-271 Helicopter Crewmember
1. Describe general aspects of helicopter
design, flight controls, and terminology.
2. Define “in-ground-effect” and “out-ofground-effect” as they relate to helicopter
performance.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-51
S-271 Helicopter Crewmember
3. Describe air density altitude and the effects
on helicopter performance.
4. Describe the process for completing a load
calculation form.
Unit 5
Helicopter Performance, Limitations, and Load Calculations
Slide 5-52