CH-53K
Heavy Lift Helicopter
A Survivability Focused Design
Kathy Russell
Martin Krammer
Richard Gardner
Nicholas Gerstner
kathy.russell@navy.mil martin.krammer@navy.mil richard.gardner@navy.mil nick.gerstner@survice.com
Vulnerability Analyst Vulnerability Test Engineer
Survivability Lead
Survivability Analyst
NAVAIR
NAVAIR
NAVAIR
SURVICE Engineering
China Lake, California
China Lake, California
Patuxent River, Maryland
Dayton, Ohio
Presented at the American Helicopter Society 67th Annual Forum
Virginia Beach, VA
May 3-5, 2011
This is a work of the U.S. Government and is not subject to copyright protection in the U.S.
Introduction
Next Generation
Heavy Lift Helicopter for the US Marine Corps
• Operational
Requirements
• Survivability
Key Performance
Parameters
• Air Vehicle
Specification
More Survivable Design
CH-53E
CH-53K
Background
Balanced Survivability Approach
• Susceptibility - the inability of an aircraft to avoid being hit
 Susceptibility Reduction - missile warning and missile jamming or
decoying further enhance the survivability capabilities of the
platform
• Vulnerability - the inability of an aircraft to sustain damage
once hit
 Vulnerability Reduction – threat tolerant design
Susceptibility and Vulnerability Reduction Verification
• Analysis • Flight Test • Live Fire Test
Susceptibility
Reduction
Threat Avoidance
Susceptibility reduction for the CH-53K consists of an
integrated Aircraft Survivability Equipment (ASE) suite
Radar Warning Receiver
AN/APR-39B(V)2 (RWR)/Electronic
Warfare Management System
Missile Warning System (MWS)
*update – Laser Detection incorporated with
MWS
Directional Infrared Countermeasures
System (DIRCM) AN/AAQ-24(V)
Countermeasure Dispenser System (CMDS)
AN/ALE-47
Susceptibility
Verification
Susceptibility Analysis
• Incorporates threat systems
• Aircraft performance data
• Various models and simulations
– Moderate Transmittance (MODTRAN)
– Modeling System for Advanced Investigation of
Countermeasures (MOSAIC)
– Future Operational Combat Unified Simulation
(FOCUS)
– Multi-Service Electro-Optics Signature
(MuSES)
Analysis and Flight Test will assess the ASE system
effectiveness against AVS threats
Survivability
Requirements
CH-53K Key Performance Parameters
Two of the seven system KPP’s are Survivability Requirements
• Fly Away Capability – Ballistic Tolerant Design
• Force Protection – Cockpit and Cabin Armor
Meeting the KPP requirements
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•
•
•
Challenging yet achievable Air Vehicle Specification (AVS)
Continuous Survivability Analyses
Early Ballistic Tests
Early involvement and a coordinated survivability team
Vulnerability
Reduction
Vulnerability
Verification
Analysis and Test
MODEL
TEST
Vulnerability
Verification
Vulnerability Analysis – Critical Data Sets
Geometry Conversion Techniques
• SAC CATIA to BRL-CAD format
• Streamlines the modeling effort
• Ensures precise and accurate
component representation
Traditional Data Sets
• DMEA
• Pd/h and Pk/d
• FALT
Vulnerability
Verification
Vulnerability Analysis – Critical Data Sets
Traditional Flight Regimes
Discrete Mission Points
• Define specific flight conditions
• Correlate to susceptibility analyses
Mission Points
Vulnerability
Verification
Design Impact
Initial Assessment – Not compliant
Assessment Updates
•
•
Updated preliminary designs
Integrated CH-53E JLF results
Design Enhancements
•
•
•
•
MGB redundant lube system
Supplemental fuel feed system
Main rotor actuator redesign
Tail rotor drive shaft growth
Risk Reduction Testing
•
•
•
Identified components for testing to refine design and analysis
Tail rotor drive shaft and Flexbeam successfully tested
Additional items identified for testing
Vulnerability
Verification
Assessment Progression
Milestone Assessments – Compliant
4.5
Initial assessment
4.0
Status
Spec
Normalized Value (1=Spec)
3.5
3.0
2.5
2.0
Risks From CDR
Design Challenges
1.5
RR testing
PDR
1.0
CDR
0.5
0.0
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Analysis Update Reference No.
Force Protection
Verification
Design Impact
Initial and Milestone Assessments – Compliant
Assessment Progression
•
•
•
KPP requirements addressed cockpit and cabin occupant protection
Weight optimization studies conducted to minimize
ineffective armor and maximize protection
Design changes assessed for impact on
protection levels
CDR Cabin Armor
Current CDR Design
CDR
Cockpit Armor
CH-53K Survivability
• Risk Reduction Tests
─ Tail Rotor Flex Beam
─ Tail Rotor Drive Shaft
─ Sponson Material - Fuel Cell Interaction
─ Fuel Line Leak Containment
• Live Fire Tests
Risk Reduction Test
Tail Rotor Flex Beam Test
Ballistic Impact
Test Conclusion
Test articles were able to maintain
the loads after damage
Test Damage
Risk Reduction Test
Tail Rotor Drive Shaft Test
Ballistic Impact
Test Conclusion
Tail Rotor Drive Shaft
is tolerant to the AVS
ballistic threat
Test Damage
Test Set-up
Risk Reduction Test
Sponson Material –
Fuel Cell Interaction
Fuel Line Leak Containment
Demonstrates structural capability
to respond to hydrodynamic ram
• Sponson composite wall
construction
• Self sealing performance of
candidate fuel bladder
Proposed solutions tested for leak
mitigation / fire suppression initiated
by ballistic impacts on fuel feed lines
LFT&E
• CH-53K is designated as a covered LFT&E system
– U.S. Code Title 10, Section 2366 (10USC2366)
•
Alternative LFT&E (ALFT&E) strategy uses analysis to aid in
identification of critical components and viable test shots
•
Key Focus Areas
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–
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Collateral and cascading effects
Assess potential crew and passenger casualty
Assess CH-53K Battle Damage Assessment and Repair procedures
Provide survivability comparison of CH-53K with legacy CH-53E
What modifications can be made to reduce the vulnerability of the CH-53K?
Component Level
Ballistic Tests
Stationary and Rotating
Scissors
TR Pitch Beam
Pitch Control Link
Main and Tail Rotor Servos
•
•
•
•
•
MRGB
IGB & TGB
TR Drive Shaft
TR Flex Couplings
TR Disconnect
Couplings
• TR Hangar Bearings &
Mounts
• Stationary Scissors
• Swash Plate
• MR & TR Servos
• Sponson structure & cell
•
•
•
•
•
•
•
TR Blade, Flex Beam
TR Pitch Link
TR Pitch Change Shaft
TR Shaft
TR Pitch Beam
Armor – Crew, Cabin
Propulsion – GE 38
GTV System Level Tests
• Drive System Tests
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MRGB Rear Module
TR Gearbox
Intermediate Gearbox
TR Drive Shaft
TR Flex Coupling
TR Disconnect Coupling
TR Hanger Bearing and
Bracket
– NGB-MRGB Shaft, Coupling
Hanger Bearing
– Rotor Brake
– NGB & Mounts
• Fire Tests
– Engine Nacelle
• Fire detection / ext. system
– Fuel System
•
•
•
•
Sponson / SEFS
Feed (Engine)
Dump & Refuel
Fuel line Sleeves
– Hydraulic System
• Flight Control Tests
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Control boxes & wiring
MR Servo Actuator
TR Servo Actuator
TR Blade
TR Hub
TR Pitch Beam
TR Control Link
TR Pitch Change Shaft
Swashplate
• Armor Tests
– Cabin floor / wall
– Cockpit seat & wing
• Structure Tests
– Transition and Tail
CH-53E
(mounted on a hover stand at WSL during JLF Tests)
Model - Test - Model
Trade Studies
MODEL
TEST
ENSURES SURVIVABLE DESIGN
Questions ?