8/3/2019 30_Hansen 110607 MACC Briefing
1/25
Hovercraft Wing-In-Ground (WIG)Platform Research
Eric Hansen15 June 2011
DISTRIBUTION STATEMENT A: Approved for Public Release; distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
2/25
26/24/2011 DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
Getting Popular Knowledge Behind Us:
Wing in Ground (WIG) craft compress air against the surface of the
earth effectively increasing efficiency (L/D)
The Soviets in the 50s built numerous flying ships (Caspian Sea
Monster) which had questionable utility and the technology never wentanywhere
Despite numerous initiatives, WIGs have never found sufficientutility and value to be successful and prolific
Activity in commercial (Europe / Asia primarily) development havebeen ongoing for transport, military and hobby applications.
The Advantages of Cost Efficiency for marine transport remaincontroversial
8/3/2019 30_Hansen 110607 MACC Briefing
3/25
36/24/2011
A Quick History
Wing in Ground (WIG) craft compress air against thesurface of the earth effectively increasing efficiency (L/D)
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
4/25
46/24/2011
Iranian Bavar-2
Iranian Sacred Defense celebrations, Sept 2010 Operational Squadron of Ground Effect Vehicles (GEV)
Domestically Built 1 & 2 Seat; Oceangoing; 130 km/hr (est.)
Reverse Delta wings / Large Tail; Lippisch design (similar to X-114)
Machine Guns, Surveillance Equipment, Radar Evading (claimed)
Patrol, Recon. & Harass; Work with Zulfikar fast patrol boats armed with Iranian Nasr-1medium range anti-ship missiles / swarm
[Mehr News Agency]
[Mehr News Agency]
[Photo: Fars news agency, by Vahid reza Alaei.]
[Mehr News Agency]
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
5/25
56/24/2011
Classifications
Type A: No Out of Ground Effect Capability
Type C: Full Flight Capability (Aircraft)
International Civil Aviation Organization (ICAO) and IMO agreed
Type A and B WIGs will come under the jurisdiction of theIMO. Type C WIGs however will be classified as aircraft and
will come under the jurisdiction of the ICAO.
Type B: Flight Capability up to 150 meters; ~ 500 feet
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
6/25
66/24/2011
Two Types of WIG Design Approaches
Span Dominated Ground effect (SDGE)
Aspect Ratio (wingspan to chord) is increased Improved Lift / Drag Ratio (more efficient)
Chord Dominated Ground Effect (CDGE) Air is captured (Ram Effect) Lift is increased
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
7/2576/24/2011
Considerations
ADVANTAGESLife Cycle & Operating costs / logistics same as Boats
Operational (flight) training ~ 20hrs; Similar to boats
Low Infrastructure and Basing Requirements
Low Operator physical stress; higher comfort level
High Fuel Efficiency
LIMITATIONSCurrently impacted by weather conditions
Operations in High Sea States not mature
Take-off and Landing
Variable L/D due to large waves
Current designs are not highly maneuverable in flight
Transport profile closer to aircraft than boats
[Ref. 1]
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
8/2586/24/2011
What Small Wing in Ground CraftARE good for:
Certain Aircraft CONOPS (low altitude)
Low operational costHigh Speed Range
40 knts to +200 knts Rapid ingress and egress capability
Pursuit & Intercept of conventional craft
Operations in shallow, hazardous Waterways(logs, mines, obstacles, etc.)
Less vulnerable to torpedoes and mines
Signature Advantages Nap of the earth flight; reduced radar detection range
Stealth shape possible (fly by wire)
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
9/2596/24/2011
Wing in Ground Craft are NOT Good For
Current Boat CONOPS and Mission Scenarios
Carrying comparable weight in current CONOPS;troops, armor, etc.
However, WIGs can be designed to carry weight athigh efficiencies / speed; high transport factors at
different CONOPs
Close in maneuvering at speed Tight turns in flying mode
Operations in High Sea States (currently) Suitable flight within ground effect in high sea states Takeoff and landing in high Sea States
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
10/25106/24/2011
Interdiction of Fast Boats
All Go-Fast Boats operate in the same speed regimes
Aircraft are required to intercept in reasonable time
Rapid response in a harbor or coastal area to a need
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
11/25116/24/2011
Rapid Response over Wide Areas
Multi-mission WIG pursuit variants
would not replace Navy Helicopters or fastconventional craft. It would complement andfree them for more demanding missions.
Lower cost to operate than a helicopterand faster than any water born craft, WIGscan traverse uncertain, shallow water,minefields, low land terrains, and can bevery stealthy.
Multiple units could be staged at any small
base (like other boat craft) which couldprovide the rapid response and interceptionsimilar to aircraft over wide areas at anaffordable cost.
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
12/25
126/24/2011
Existing Navy Prototype History
Acquired by NSWCDD in CY06 for SLY FOX.
Transferred to NSWCCD in CY07 from NSWCDD
Restored to safe operational condition and modified forexperimentation as a Navy test asset
Unmanned / Manned applications
Surrogate Enemy, JFCOM Empire ChallengeMay / June 2011
(UH owned sister craft was used; Navy craft mods not completed in time)
Universal Hovercraft developed the first flying hovercraft.
The prototype first took flight in 1996 near Cordova,Illinois on the Mississippi River.
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
13/25
136/24/2011
Modified Universal HovercraftModel UH-19XRW
Hovercraft mode:Speed: 75+ mph
Cruise: 50 mphPayload: 1,000 lbsPassengers: 2 Cabin: 7 x 4
Endurance: 3.5 hoursLength: 19.5 feet Width: 7.5 feetEngine: 2.0 L Chevy EcotecSupercharged
Hoverwing modeSpeed: 70 mphCruise: 55 mph in flightPayload: 600 to 1,000 lbs in flight
Passengers: 2Endurance: 2.5 hoursLength: 24.5 feetWing Span: 22 feetCruise altitude: 3 to 4 feetMaximum altitude: 15 to 20 feet
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
14/25
146/24/2011
Research Capabilities Supported
Utility for Force Protection and Patrol
Capability vs. Cost based on hard data.
High Sea State operations
Launch and Landing (elevated flight deck)
Nap of the Earth Flight technology
Signatures
Bogie (surrogate enemy) Unmanned Applications
Payload experiments[Ref. 2]
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
15/25
156/24/2011
Take Off and Landing Variants
HydroskiHigh Hydrodynamic Lift
Poor L/D for Take OffGood for Landing
HydrofoilsHigh Hydrodynamic LiftGood L/D for Take OffLow heave
X114-H Accident
PAR (Power-Augmented-Ram)High Thrust to Lift
High Take-Off Weight/PowerLow Efficiency
HovercraftLow Thrust to LiftLow Hydro & Hump DragHigh Heave / Bad in Sea State
Taxi over flat land & obstacles
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
16/25
166/24/2011
Nap of the Sea Flight
Average h/c 50% (.5) for IMO Ruling
19XRW cruises at 3-4 ft; SS3-4 Larger chord will be required for higher
Sea State operations as class B
Stability and Control Issues:Non linear dependence of aerodynamic
characteristics with height
Stable in height
Unstable in pitch Long period (phugoid) oscillations Currently manageable by design andmodern control technologies
Stable in YawZoom Turns; Flying higher and banking
Flat turns; requires vertical foils
[Ref. 2]
[WMO]
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
17/25
176/24/2011
Pitch Stability and Solutions
Problem:The lift vector of a wing is located far aft at very
small ground clearances and moves foreword whenclimbing out of ground effect.
Large Tail: (Ekranoplan)Increased pitch control authorityHigher Drag, Most popular solution
Tandem Bi-Wing DesignLimited stability rangeIncapable of OGELow Seaworthiness
S shape Airfoil SectionReduced CP movement , Not as Efficient
Reverse Delta Wing (Lippisch)
Low CP movement and high L/D
Canard DesignTake Off Advantage (feeds air to main wing)Very efficient, Long pitch moment armIdeal for Fly by Wire; promising, however, unstudied
[Ref. 1]
[Typical]
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
18/25
186/24/2011
Angle of Attack effect on PC and Height
Large Change in Pressure
Coefficient with small changes inaltitude between h/c 0.08 and 0.3.
Lift varies with Close WaveCrossings leads to vibrational
heave
Precise control surface motionrequired to stay in .5 h/c averagefor class B
Implies Higher Speeds at LowAngles of Attack in Sea State
[Ref. 2]
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
19/25
196/24/2011
Consideration of Low Flight over Waves
Flight Dynamic Frequency with Aspect: Wave Speed + Flight Speed (into Sea) Wave Speed Flight Speed (with Sea)
Intelligent Control System to manage
SS3 Waves: 3.5 to 5 ft 2.5 - 7.5 sec periods
Wave length ~ 46 65 ftSS4 Waves: 6 to 7.5 ft
2.5 - 9.5 sec periods Wave length ~ 72 92 ft
SS5 Waves: 8 to 12 ft
3 12 sec periods Wave length ~ 105 to 158 ft
h = 1.54 (Hs)/2 + 0.1 x chord
USSR operational experience Safe Operating Height:
(Hs = the average of the 1/3 highest wave)
Hoverwing UH-19XRWPredicted Estimation: Efficient / Safe SS3 Operational SS4
[Ref. 3]
[Ref. 1]
[See References for larger Table]
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
F t D i C t l T h l i
8/3/2019 30_Hansen 110607 MACC Briefing
20/25
206/24/2011
Fast Dynamic Control TechnologiesFor High Sea State Prolonged Flight
Elevator / Canard deflection (pitch varies)
Trailing-Edge Flap dynamic deflection
Dynamic Spoilers
Dynamic Venting (air valves in wing)
Wave Sensing K band Radar / LIDAR Ongoing current research
Wave Prediction Technology Ongoing current research MIT & ONR
Height Sensing Phase Radio Altimeter (RA)
Fly By Wire(Computer controlled flight)
Take Off and Landing in a Sea StateRemains an Engineering Challenge!
Acceleration in Waves
Velodyne LIDAR
ICX K-Band Radar
X-Band Radar
[Typical]
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
21/25
216/24/2011
Unmanned WIG Cooperative AutonomousSWARM Missions
Current Maritime Cooperative Autonomy is Maturing
Obstacle Avoidance & COLREGs development
Advanced Perception, Multi-sensor Fusion Radar, Stereo EO & IR, LIDAR, Acoustic
4 USV cooperative; TW11 July HVA protection
UxS CFT Oct Experiment; 4 USV Non Lethal Weapons
Secure Network (certified net to JEC3)Adjustable Autonomy: Human In, On, and Out of the
loop.
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
USV Non Lethal Weapons Layered Defense
8/3/2019 30_Hansen 110607 MACC Briefing
22/25
226/24/2011
USV Non-Lethal Weapons Layered DefenseManned Unmanned Integration
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
23/25
236/24/2011
10 Conclusions & Closing Thoughts
2) Small WIGS promise affordable wide area rapid access & control Protected Waters near term / Open Ocean far term
1) Small WIGS should not be applied to current boat CONOPs
5) Large WIGS for efficient material transport remain controversial
4) Class B status allows aircraft performance at small boat costs
7) High Sea States point to larger chords and higher speeds
6) High Sea State operations feasible, but TO & LD is a challenge
8) Hovercraft capability is a very good solution to TO & LD
drag reduction and has overland benefits
3) No special basing or logistics are required and flying is easy
9) Intelligent lethal SWARMs of stealthy expendable WIGs fit intothe DoD vision of integrated robotic warfare
10) A Next Generation combat craft..
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
24/25
246/24/2011
References / Notes
References:
[1] Halloran, M. and OMeara, S. Wing in Ground Effect Craft Review DSTO-GD-0201, DSTOAeronautical and Maritime Research Laboratory (1999).
[2] Christopher Gamble, Joel Martin, Matthew Eggert, Michael Trott; U.S. Air Force Academy, RobertButler, Steven Morris, Jean Slane; Engineering Systems Inc., Billy Crisler, Possum Works. (2008)Analysis of a Wing and Hoverwing in Ground Effect, U.S. Air Force Academy, Air Force Research
Laboratory, CO
[3] Pierson, W. J.; Moscowitz, L. (1964), "A proposed spectral form for fully developed wind seasbased on the similarity theory of S A Kitaigorodskii", Journal of Geophysical Research 69 (24): 51815190
[4] Morris, S., Butler, R., and Slane, J. Characterization of a Hovercraft (HC)/Hoverwing (HW). Aero471 Aeronautics Laboratory Spring 2007 Research Project List.
Notes:
1) Typical For illustration purposes only
2) Unreferenced pictures and illustrations from multiple sources in the public domain
DISTRIBUTION STATEMENT A: Approved for Public Release;
distribution is unlimited
8/3/2019 30_Hansen 110607 MACC Briefing
25/25
256/24/2011
References / Sea Spectrum
[Ref. 3]
DISTRIBUTION STATEMENT A: Approved for Public Release;