MICRO ConOpsMICRO ConOpsModel of Icing Conditions for Real-time OperationsModel of Icing Conditions for Real-time Operations

An integrated diagnosis and forecast system for in-flight and ground icing conditionsAn integrated diagnosis and forecast system for in-flight and ground icing conditions

Chronology and Major IssuesChronology and Major IssuesIcing Weather Tools Workshop (Boulder, CO) Icing Weather Tools Workshop (Boulder, CO)

15 November 201315 November 2013

AgendaAgenda

Executive SummaryExecutive Summary Chronology of ConOps DevelopmentChronology of ConOps Development Proposed Critical Icing IssuesProposed Critical Icing Issues

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Executive SummaryExecutive Summary

MICRO: Improved Flight Safety ToolMICRO: Improved Flight Safety Tool─ Engineering (ensemble of model input)Engineering (ensemble of model input)─ Scientific (Hi-res inputs) Scientific (Hi-res inputs)

ISC address critical issues to improve ISC address critical issues to improve end user outputs for decision-making end user outputs for decision-making

ISC decisions will improve the approach ISC decisions will improve the approach of flight planning against icing hazardsof flight planning against icing hazards

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Chronology of ConOps DevelopmentChronology of ConOps Development March 2013March 2013

– Initial strawman coordinated internally w/NCARInitial strawman coordinated internally w/NCAR– Comments Resolution Matrix (CRM) developed Comments Resolution Matrix (CRM) developed

April 2013April 2013– Subsequent versions/meetings + presentation for ISC Subsequent versions/meetings + presentation for ISC

conference on 30conference on 30thth w/latest ConOps draft w/latest ConOps draft May-August 2013May-August 2013

– Comments compiled from FAA ISC membersComments compiled from FAA ISC members– Subsequent ConOps version updatesSubsequent ConOps version updates

September 2013September 2013– Adjudication Meeting with ISC members that commented onAdjudication Meeting with ISC members that commented on documentdocument– Subsequent ISC comments and update v0.17 ConOps versionSubsequent ISC comments and update v0.17 ConOps version– Expanded icing community audience for review/commentExpanded icing community audience for review/comment

October 2013October 2013– Shutdown delay ConOps feedback into NovemberShutdown delay ConOps feedback into November– Deliverable 13.4.1 v0.18 made to ANG-C61 (formatted draft)Deliverable 13.4.1 v0.18 made to ANG-C61 (formatted draft)

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Executive Summary of MICRO IssuesExecutive Summary of MICRO Issues

Shaping future MICRO Products and ServicesShaping future MICRO Products and Services1.1. Should only Appendix C and O conditions be depicted? Exceedance Should only Appendix C and O conditions be depicted? Exceedance

and no icing conditions as well? and no icing conditions as well?

2.2. Should severity (specific) or “standard” accretion rate be included Should severity (specific) or “standard” accretion rate be included for pilot avoidance?for pilot avoidance?

3.3. Terminology to define or describe icing conditionsTerminology to define or describe icing conditions

a)a) Define severity as light, moderate, heavy or Appendix C, O, Define severity as light, moderate, heavy or Appendix C, O, exceedanceexceedance

b)b) Language if maintaining mixed-icing conditions that includes Language if maintaining mixed-icing conditions that includes super-cooled liquid water and ice crystals super-cooled liquid water and ice crystals

4.4. How should icing products be displayed or available in gridded How should icing products be displayed or available in gridded formats?formats?

5.5. When is work expected to commence on Decision Support Tools When is work expected to commence on Decision Support Tools (DSTs) to estimate aircraft-specific severity using MICRO-produced (DSTs) to estimate aircraft-specific severity using MICRO-produced weather parameters?weather parameters?

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Proposed Critical ISC Issues (1)Proposed Critical ISC Issues (1) Use Severity or Ice Accretion Rates for conditionsUse Severity or Ice Accretion Rates for conditions

ProblemProblem: No consensus among ISC, AFS or Certification: No consensus among ISC, AFS or Certification ProblemProblem: What’s the point of this if using Appendix C & O: What’s the point of this if using Appendix C & O

A rate-based icing indexA rate-based icing index ProblemProblem: If indices are recognized as useful in preparation of final : If indices are recognized as useful in preparation of final

product then does this obviate the need for DSTs?product then does this obviate the need for DSTs?

TerminologyTerminology

ProblemProblem: language for type of icing condition varies … needed to : language for type of icing condition varies … needed to improve NAS efficiency and safetyimprove NAS efficiency and safety

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Proposed Critical ISC Issues (2)Proposed Critical ISC Issues (2)

Standard Accretion Rate on Standard airfoilStandard Accretion Rate on Standard airfoil ProblemProblem: The reliability computing accretion rates even : The reliability computing accretion rates even

with just instituting the Standard Accretion Rate, to then with just instituting the Standard Accretion Rate, to then properly validate it and then there's the regulatory issues properly validate it and then there's the regulatory issues and impacts.and impacts.

Aircraft-specific severity estimates for IcingAircraft-specific severity estimates for Icing ProblemProblem: the ice accreted in Appendix O conditions : the ice accreted in Appendix O conditions

(previously referred to as “SLD” conditions) has effects on (previously referred to as “SLD” conditions) has effects on drag and performance that are not well-characterized by drag and performance that are not well-characterized by rate of accretion and this must be accommodated in the rate of accretion and this must be accommodated in the MICRO outputMICRO output

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Proposed Critical ISC Issues (3)Proposed Critical ISC Issues (3)

Mixed-Phase Icing (classify as Appendix D) Mixed-Phase Icing (classify as Appendix D) - - developing developing an aircraft-specific accretion product referring to rime, glaze, and mixedan aircraft-specific accretion product referring to rime, glaze, and mixed

ProblemProblem: ISC on record as not supporting this and data : ISC on record as not supporting this and data will be there to support ice accretion but not what specific will be there to support ice accretion but not what specific icing is actually present.icing is actually present.

Mix-Icing needed in addition to Appendix C and OMix-Icing needed in addition to Appendix C and O ProblemProblem: Identification of ice crystal or mixed phase : Identification of ice crystal or mixed phase

conditions is not believed to be an important issue as far conditions is not believed to be an important issue as far as structural icing is concerned.  It is important for engines as structural icing is concerned.  It is important for engines and air data probes when the total water content is high. and air data probes when the total water content is high.

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Proposed Critical ISC Issues (4)Proposed Critical ISC Issues (4) Scale of Probabilities (i.e.; Appendix C)Scale of Probabilities (i.e.; Appendix C)

ProblemProblem: What is scientifically can be accomplished on : What is scientifically can be accomplished on continuous scale and within 10% accuracy. Is that kind of continuous scale and within 10% accuracy. Is that kind of accuracy possible? accuracy possible?

Probabilistic curve forecast approach Probabilistic curve forecast approach (forecast and expand (forecast and expand gridded forecast to include a probability curve for each accumulation gridded forecast to include a probability curve for each accumulation category – e.g., subjective icing intensity terms, ice accretion rates category – e.g., subjective icing intensity terms, ice accretion rates aircraft performance)aircraft performance)

ProblemProblem: Is within 10% accuracy good enough? If so, : Is within 10% accuracy good enough? If so, need to ensure forecast approach aligned to earlier need to ensure forecast approach aligned to earlier probabilistic study is correct segwayprobabilistic study is correct segway

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Proposed Critical ISC Issues (5)Proposed Critical ISC Issues (5) Defining Appendix ThresholdsDefining Appendix Thresholds

ProblemProblem: How to manage droplet threshold is still : How to manage droplet threshold is still uncertain given the current equipage measuring capability uncertain given the current equipage measuring capability limitations to distinguish between <or> than 40 for FZDZ. limitations to distinguish between <or> than 40 for FZDZ. From IPHWG was certifying to one of the distributions From IPHWG was certifying to one of the distributions envisioned as an option? Only small percentage of new envisioned as an option? Only small percentage of new aircraft certified for MVD >40 and partial Appendix O.aircraft certified for MVD >40 and partial Appendix O.

Loophole Scenario of MVD >50 but Dmax <100Loophole Scenario of MVD >50 but Dmax <100 ProblemProblem: Does fall into either Appendix C or O categories: Does fall into either Appendix C or O categories ProblemProblem: Complex model outputs to determine what falls : Complex model outputs to determine what falls

out of Appendix C or O. Maybe winter stratus conditions. out of Appendix C or O. Maybe winter stratus conditions. NWS has no icing criteria for CBs because of convective NWS has no icing criteria for CBs because of convective SIGMETS – do they need one? SIGMETS – do they need one?

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Proposed Critical ISC Issues (6)Proposed Critical ISC Issues (6) DST converting atmospheric conditionsDST converting atmospheric conditions

ProblemProblem: Converting conditions into ice accretion rate : Converting conditions into ice accretion rate based on airframe type and airspeed using intensity vice based on airframe type and airspeed using intensity vice severity icing conditions for determining both icing severity icing conditions for determining both icing conditions intensity and aircraft performanceconditions intensity and aircraft performance

ProblemProblem: Whether to use severity/accretion forecast : Whether to use severity/accretion forecast (DST) vice Appendices C & O(DST) vice Appendices C & O

Upgrade all ASOS stations (similar to EPI) to detect Upgrade all ASOS stations (similar to EPI) to detect

FZDZ/FZRA when snow reported (mix-precip)FZDZ/FZRA when snow reported (mix-precip) ProblemProblem: GA and partial Appendix O certified aircraft : GA and partial Appendix O certified aircraft

(business Lear Jets) most seriously effected by these mix-(business Lear Jets) most seriously effected by these mix-precipitation scenariosprecipitation scenarios

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SummarySummary

ISC decisions down-the-road will lay out ISC decisions down-the-road will lay out the direction of ConOps language and the direction of ConOps language and aviation operational approachaviation operational approach─Need to start addressing issues now to Need to start addressing issues now to

establish scientific and engineering positions establish scientific and engineering positions for approval or rejection at the Annual ISC for approval or rejection at the Annual ISC Conference in the spring 2014 Conference in the spring 2014

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