Remote Sensing of Inflight Icing Conditions Dr. Charles C. Ryerson

1. Remote Sensing of Inflight Icing Conditions Dr. Charles C. Ryerson Cold Regions Research and Engineering Laboratory Engineering Research and Development Center U.S. Army Corps of Engineers

2. Purpose • Inform of emerging capability for remote • detection and dissemination of tactical • inflight structural icing information • Seek proponency for more rapid • development and fielding

3. Outline • Inflight Icing Problems • Technological Solutions • Development Program • Conclusions • Content applicable to all five • User Forum presentation areas

4. Problems • 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

5. Inflight 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.

6. Technological Solutions • Remotely sense icing conditions • ahead of aircraft • Disseminate icing information for • use as a tactical decision aid to • improve safety • Allow aircraft to avoid and exit • Ground-based and airborne systems

7. Ground-Based Sensing

8. Airborne Sensing

9. Multi-Band Radar Drizzle detection with polarization X Ka W

10. Multi-Band Radiometer 22 and 60 GHz

11. Airborne Microwave Radiometer • Differential brightness • temperatures at • 37 and 89 GHz Cold Brightness from Space, Upper Atmosphere Cloud Cool Brightness from cloud, upper atmosphere Flight Level Temperature 2 degrees Drizzle Polarized Radiance if 2 degrees Drizzle present 35 m/km Warm Brightness from cloud, lower atmosphere • Polarization to detect • ice vs liquid water • Neural network retrievals • Emphasize quiet frequencies Hot Brightness from surface, lower atmosphere

12. Development Program • 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

13. ALLIANCE ICING RESEARCH STUDY “Worst Weather in the World” 6288’

14. Documented Progress

15. Conclusions • 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

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