Remote SensingRemote Sensingofof

Inflight Icing ConditionsInflight Icing Conditions

Dr. Charles C. RyersonDr. Charles C. Ryerson

Cold Regions Research and Engineering LaboratoryCold Regions Research and Engineering LaboratoryEngineering Research and Development Center Engineering Research and Development Center

U.S. Army Corps of EngineersU.S. Army Corps of Engineers

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• Inform of emerging capability for remote detection and dissemination of tactical inflight structural icing information

• Seek proponency for more rapid development and fielding

PurposePurpose

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• Inflight Icing Problems

• Technological Solutions

• Development Program

• Conclusions

• Content applicable to all five

User Forum presentation areas

OutlineOutline

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• Icing forecasts (strategic) can unnecessarily restrict and cancel flights (tactical)

• Low, slow aircraft <20,000', laminar flow air- foils, & rotorcraft have most icing problems

• Control anomalies• Tail plane stalls

• Simulated Kosovo winter warfight for DARPA: • ~ 58% flights affected• ~ 24% flights canceled

• Hunter UAV only flown April-October in Kosovo due to icing - Inside the Army - 21 Feb 2000

ProblemsProblems

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Inflight Icing AccidentsInflight Icing Accidents

RQ-1 Predator accident report released

Released: 23 Dec 1999 ------------------------------------------------

----------LANGLEY AIR FORCE BASE, Va. (AFPN) -- Officials investigating the April 18 crash of an RQ-1 Predator unmanned aerial vehicle near Tuzla Air Base, Bosnia, have determined the accident resulted from a combination of mechanical and human factors.

The Predator, which belonged to the 11th Reconnaissance Squadron at Nellis Air Force Base, Nev., was returning from a reconnaissance mission over Kosovo in support of Operation Allied Force. It was destroyed upon impact.

According to the accident investigation board report, the Predator experienced a fuel problem during its descent into Tuzla. Upon entering instrument meteorological conditions and experiencing aircraft icing, the Predator lost engine power.

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• Remotely sense icing conditionsRemotely sense icing conditions ahead of aircraftahead of aircraft

• Disseminate icing information for Disseminate icing information for use as a tactical decision aid touse as a tactical decision aid to improve safetyimprove safety

• Allow aircraft to avoid and exitAllow aircraft to avoid and exit

• Ground-based and airborne systems Ground-based and airborne systems

Technological SolutionsTechnological Solutions

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Ground-Based SensingGround-Based Sensing

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Airborne SensingAirborne Sensing

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Multi-Band RadarMulti-Band Radar

Drizzle detectionwith polarization

X Ka

W

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Multi-Band RadiometerMulti-Band Radiometer

22 and 60 GHz

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• Differential brightness temperatures at 37 and 89 GHz

2 degrees

2 degrees

Cloud

Flight Level TemperatureDrizzle

Cool Brightness from cloud, upper atmosphere

Polarized Radiance ifDrizzle present

Cold Brightness from Space, Upper Atmosphere

Hot Brightness from surface, lower atmosphere

Warm Brightness from cloud, lower atmosphere

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m/k

m

Airborne Microwave RadiometerAirborne Microwave Radiometer

• Polarization to detect ice vs liquid water• Neural network retrievals• Emphasize quiet frequencies

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• Partners: DoD, NASA, FAA, NOAA, NCAR, industry, universities, MSC coordination

• Programs:• NASA: 5-yr ground-based plan, 10-yr airborne plan,

FY01 ground-based radiometer evaluation• FAA/NCAR: 7-yr plan, FAA Inflight Aircraft Icing

Plan, ground-based radar build• CRREL: coordinate with NASA/FAA, DoD

emphasis, Concept Evaluation Program

• Approach: Operational, Meteorological, Technological

Development ProgramDevelopment Program

ALLIANCE ICING RESEARCH STUDY

“Worst Weather in the World”6288’

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Documented ProgressDocumented Progress

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ConclusionsConclusions

• Prototypes: Ground - next few yrs Airborne - 2-5 yrs depending upon funding

• Technical Issues: cost, size, power, weight, range, resolution, accuracy, temperature,down-select of best technologies

• Operational issues: Cockpit Integration (AWIN), weather system infrastructure, hazard characterization

• Possible DARPA program: icing, thunderstorms,turbulence, visibility, wires

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cryerson@crrel.usace.army.milcryerson@crrel.usace.army.milhttp://www.crrel.usace.army.milhttp://www.crrel.usace.army.milhttp://icebox.grc.nasa.govhttp://www.faa.gov/aua/awrhttp://www.faa.gov/aua/awr