Transcript ICING
DOES STRUCTURAL ICE CONCERN YOU? IT SHOULD! SAFETY THROUGH PROFESSIONALISM WE WILL DISCUSS NASTY STATISTICS The Reg’s applicable to ICG Recognizing hazardous conditions Avoiding hazardous conditions Escaping without losing control References for more details SAFETY THROUGH PROFESSIONALISM NASTY Facts about ICING Accidents 11% of weather accidents involve ICING 57% of ICING accidents involved SINGLE ENGINE FIXED GEAR AIRCRAFT 49% of Pilots involved had >1000 PIC 25% of Pilots had >100 <500 PIC SAFETY THROUGH PROFESSIONALISM MORE NASTY Facts… 53% of icing accidents occurred in MOUNTAINOUS AREAS 14% occurred near large bodies of WATER 57% of Pilots received WX Briefings and ICING CONDITIONS were indicated 49% OF ICING ACCIDENTS resulted in FATALITIES SAFETY THROUGH PROFESSIONALISM AT HIGHEST RISKEXPERIENCED PILOTS Who received WX BRIEFINGS Flying SINGLE ENGINE FIXED GEAR AIRCRAFT Near MOUNTAINS or LARGE BODIES of WATER SAFETY THROUGH PROFESSIONALISM REGULATION MISCONCEPTIONS FAR 91- DOES NOT SPECIFICALLY ADDRESS ICING for small aircraft 91.517 is in Subpart F and applies only to large and turbojet powered aircraft BEWARE- NTSB Case law SAFETY THROUGH PROFESSIONALISM WHAT IS “KNOWN” ICE? NTSB Case Law DEFINITION: Icing conditions are considered to exist if these conditions are forecast or reported. SAFETY THROUGH PROFESSIONALISM “KNOWN” ICE FORECASTS AIRMET ZULU FOR ICE – AIRMET ICE...MA CT RI NY PA NJ WV MD DE DC VA AND CSTL WTRS FROM ALB TO 140ENE ACK TO 200SE ACK TO SBY TO 50WSW BKW TO HNN TO AIR TO ERI TO ALB OCNL MOD RIME/MXD ICGICIP BTN 100 AND FL210. CONDS ENDG 19-21Z N OF AIR TO CYN TO 160ESE ACK LN. CONDS CONTG BYD 21Z THRU 03Z ELSW. – FRZLVL...020-050 NRN HLF ME. 060-100 RMNDR N OF 40W ROD-EWC-CYN-160ESE ACK LN. 100-130 S OF 40W ROD-EWC-CYN-160ESE ACK LN. SAFETY THROUGH PROFESSIONALISM “KNOWN” ICE REPORTS PIREPS– AUW UA /OV 22 NE AUW /TM 2028 /FL 070 /TP C208 /SK BL /TA -2C /IC LGT CLR /RM B/L LVN – UA /OV FGT/TM 1917/FLUNKN/TP B737/TA 01 @ 100/M07 @ 180/IC LGT RIME 100-180/RM DURGC SAFETY THROUGH PROFESSIONALISM REGULATION MISCONCEPTIONS COMBINE “KNOWN ICE” WITH: 91.9 Manuals, placards, and markings – Placards or POH/AFM MAY state “Flight in known ice is prohibited” 91.13 Careless & Reckless Operation – MAY apply if you get into icing trouble in an unequipped airplane SAFETY THROUGH PROFESSIONALISM REGULATION MISCONCEPTIONS Parts 121 AND 135 DO address icing extensively – EXCELLENT GUIDANCE BUT “OPTIONAL” FOR G.A. OPERATION SAFETY THROUGH PROFESSIONALISM REMEMBER Aviate, Navigate, Communicate, Litigate ATC wants you on the ground safe Chance of paperwork or FAA Sanction is remote SAFETY THROUGH PROFESSIONALISM STILL... SOME PILOTS will CONTINUE to attempt to fly unprotected aircraft IFR when icing is forecast SOME PILOTS (IFR & VFR) will continue to have inadvertent icing encounters SOME PILOTS will DIE in icing SAFETY THROUGH PROFESSIONALISM WE WILL EXPLOREENVIRONMENTAL FACTORS PROMOTING ICE STRUCTURAL ICING CHARACTERISTICS ESCAPE AND AVOIDANCE TECHNIQUES HANDLING ICING EMERGENCIES SAFETY THROUGH PROFESSIONALISM ENVIRONMENTAL WEATHER DROPLET SIZE COLLECTION EFFICIENCY SAFETY THROUGH PROFESSIONALISM WEATHER BASICS ICE REQUIRES: – VISIBLE MOISTURE – TEMPERATURES BELOW FREEZING VISIBLE MOISTURE CAN BE: – CLOUDS OR – PRECIPITATION SAFETY THROUGH PROFESSIONALISM WEATHER BASICS WARMER AIR holds more moisture than COLDER AIR AIR is cooled by UPLIFTING (ADIABATIC COOLING) UPLIFTING CAN BE LOCALIZED OR WIDESPREAD SAFETY THROUGH PROFESSIONALISM WEATHER BASICS LIQUID WATER CAN EXIST AT TEMPERATURES BELOW FREEZING (SUPER-COOLING) +2 TO –15 dg C = HIGH PROBABILITY OF ICING CLOUDS COLDER THAN –15 dg C ARE FREEZING (Cloud Glaciation) SAFETY THROUGH PROFESSIONALISM DROPLETS GROW WITH: INCREASED LIQUID WATER CONTENT (LWC) FURTHER COOLING (CONDENSATION) MORE TIME TO COALESCE ATMOSPHERIC MOVEMENT TO PROMOTE COALESCENCE SAFETY THROUGH PROFESSIONALISM ICING TYPES Smallest to Largest Droplets: RIME ICE (Small Droplets) “SNAP” CLEAR ICE (Larger droplets) “SPLAT” SAFETY THROUGH PROFESSIONALISM TYPES OF ICE SAFETY THROUGH PROFESSIONALISM ICING TYPES Smallest to Largest Droplets: MIXED ICE (Rime/Clear/Rime/Clear) SLD ICE (Supercooled Large Droplets range from just smaller than mist to FREEZING DRIZZLE / RAIN) FREEZING PRECIPITATION SAFETY THROUGH PROFESSIONALISM RISK INCREASES WITH DROPLET SIZE LARGER DROPLETS IN: – – – – – SMALLER DROPLETS IN: CLOUD TOPS OLD CLOUDS BUMPY AIR “WARM” (-5 TO +2 C) CUMULUS (LIFTING) – – – – – CLOUD BASES YOUNG CLOUDS SMOOTH AIR “COLD” (<10 C) STRATUS (FLAT) SAFETY THROUGH PROFESSIONALISM WHERE WILL WE FIND MORE SEVERE ICING? – – – – – TOWERING Cu (above freezing level) THUNDERSTORMS JUST BELOW INVERSIONS** LAKE EFFECT CUMULUS STRONG OROGRAPHIC UPLIFTING SAFETY THROUGH PROFESSIONALISM WHERE ARE THE WORST ICING CONDITIONS? FREEZING DRIZZLE AND RAIN – ASSOCIATED WITH WARM / OCCLUDED FRONTS – PRECIP FALLS AS LIQUID THROUGH WARMER AIR INTO FREEZING AIR BELOW INVERSION SAFETY THROUGH PROFESSIONALISM SAFETY THROUGH PROFESSIONALISM SAFETY THROUGH PROFESSIONALISM SLD PROBABILITY SAFETY THROUGH PROFESSIONALISM COLLECTION EFFICIENCY SMALLER RADIUS FEATURES GATHER ICE FASTER – – – – – – – – Sharp vs. rounded leading edges Ice itself Horizontal / Vertical Stabilizers Tips vs. roots Struts Propeller blades Antennas OAT Probes and Windshield Wipers SAFETY THROUGH PROFESSIONALISM PROPELLER BLADE ICE SHARP LEADING EDGE- MORE ICE SAFETY THROUGH PROFESSIONALISM WING VS. TAIL, ROOT VS. TIP, CESSNA VS. MOONEY SAFETY THROUGH PROFESSIONALISM RECOGNIZING POTENTIAL ICING CONDITIONS ACTUAL ICING AREAS TYPICALLY LOCALIZED – ALTITUDE +/- 3000 FEET – WIDTH VARIABLE, OFTEN LESS THAN 50 MILES – Synoptic Weather (moisture & lifting) – Surface features (lakes & mountains) SAFETY THROUGH PROFESSIONALISM WEATHER BRIEFING: – – – – – – Advisories (Airmet And Sigmet Warnings) SYNOPSIS and AREA FORECASTS SURFACE and 500 MB CHARTS Winds and Temperatures Aloft Pilot Reports A.D.D.S. Neural Network Icing Forecasts SAFETY THROUGH PROFESSIONALISM SAFETY THROUGH PROFESSIONALISM PRE-FLIGHT PLANNING ROUTE & ALTITUDE VS: – – – – – – Weather Briefing Terrain Obstruction Clearance LARGE Bodies of “Warm” Water Suitable Alternates Payload And Fuel Vs. Performance SAFETY THROUGH PROFESSIONALISM PRE-FLIGHT PLANNING DEVELOP ESCAPE ROUTES SELECT ALTERNATE AIRPORTS – Approaches – Runway lengths – Surrounding Terrain RESOLVE FUEL QUANDARY – More is required when running high power – Less is desired to keep weight down SAFETY THROUGH PROFESSIONALISM ENROUTE VIGILANCE Watch & listen for: – – – – – – Temperature Changes Cloud Heights And Characteristics Surface Weather Changes Center Weather Advisories New Pilot Reports STRANGE NEW NOISES, HUMS, MOANS, ETC. SAFETY THROUGH PROFESSIONALISM CHARACTERIZING ICING ACCUMULATION TRACE– Barely forming, not hazardous LIGHT ICING– Less than 1 inch accumulation per hour – Ice protection systems keep up easily – Unprotected aircraft can escape but must do so within 20 – 30 minutes SAFETY THROUGH PROFESSIONALISM SAFETY THROUGH PROFESSIONALISM CHARACTERIZING ICING ACCUMULATION MODERATE ICING- 1 – 3 inches per hour, – NEED ice protection systems – DANGEROUS for unprotected aircraft SAFETY THROUGH PROFESSIONALISM SAFETY THROUGH PROFESSIONALISM CHARACTERIZING ICING ACCUMULATION SEVERE ICING– rapid buildup, – more than 3 inches per hour, (CAN EXCEED 24 INCHES PER HOUR) – ice protection systems cannot keep up, – ice forming on unprotected areas causing significant drag, – Runback causes feathers and ridges spoil lift SAFETY THROUGH PROFESSIONALISM SAFETY THROUGH PROFESSIONALISM SAFETY THROUGH PROFESSIONALISM SAFETY THROUGH PROFESSIONALISM SAFETY THROUGH PROFESSIONALISM EFFECT OF ICING ON PERFORMANCE ICE MODIFIES AERODYNAMICS – INCREASES PARASITE DRAG – SERIOUSLY MODIFIES AIRFOIL – LEADS TO: • HIGHER ANGLES OF ATTACK • INCREASED STALL SPEED • AWKWARD CONTROL CHARACTERISTICS SAFETY THROUGH PROFESSIONALISM EFFECT OF ICING ON PERFORMANCE ICE ACCUMULATION RESULTS IN– – – – REDUCED CLIMB PERFORMANCE POTENTIAL ALTITUDE LOSS REDUCED STALL MARGINS SERIOUS CHANGES IN PITCH AND ROLL RESPONSE SAFETY THROUGH PROFESSIONALISM PILOT RESPONSE TO ONSET OF ICING INCREASE POWER• USES MORE FUEL AND COULD EFFECT PITCH CONTROL MAINTAIN HIGHER SPEED & LOW ANGLE OF ATTACK- • AVOID INCREASING COLLECTION AREA • AVOID SLOW AIRSPEED STEEP ANGLE CLIMBS • AVOID APPROACHING HIGHER STALL SPEED DESCEND IF NEEDED TO AVOID UPSET SAFETY THROUGH PROFESSIONALISM RESPONSE TO CONTINUED ICING ESCAPE! FOLLOW PRE-PLANNED EXIT STRATEGY – CHANGE COURSE OR ALTITUDE – CLIMB IMMEDIATELY IF POWER MARGIN ALLOWS – DO 180 IF NEEDED – TURN AWAY FROM ICE PRODUCING CLOUD STRUCTURES – DESCEND TO ABOVE FREEZING ABOVE MEA/MOCA – DESCEND IF NEEDED TO MAINTAIN CONTROL SAFETY THROUGH PROFESSIONALISM STILL ACCUMULATING? LAND BEFORE LOSS OF CONTROL OR UNCOMMANDED DESCENT! DO NOT DEPEND UPON ICE PROTECTION SYSTEMS INDEFINITELY! ESCAPE! SAFETY THROUGH PROFESSIONALISM NASA VIDEO Discusses effect of ice on aircraft performance and control Discusses appropriate pilot response to loss of control SAFETY THROUGH PROFESSIONALISM WING DIRECTION OF FLIGHT TAIL DIRECTION OF FLIGHT SAFETY THROUGH PROFESSIONALISM FLOW SEPARATION SAFETY THROUGH PROFESSIONALISM ROLL UPSET Collection efficiency- wingtip leading edge Occurs more when slow and clean Separation Bubble forms Bubble moves aft and reduces ailerons effectiveness SAFETY THROUGH PROFESSIONALISM ROLL UPSET CHARACTERIZED BY: – Uncommanded roll, aileron “snatch”, neutral/reversed roll pressure RELIEVE BY: – Increasing airspeed – Reducing angle of attack – Deploying flaps SAFETY THROUGH PROFESSIONALISM TAILPLANE STALL / PITCH UPSET Collection efficiency- horizontal tail Occurs more when flaps are extended Separation Bubble moves aft and effects elevators SAFETY THROUGH PROFESSIONALISM TAILPLANE STALL / PITCH UPSET CHARACTERIZED BY: – Lightened pitch control, elevator pulsing, porpoising, difficulty trimming, sudden and severe nose down elevator snatch COUNTER-INTUITIVE RELIEVE BY: – PULLING back on yoke – Retracting flaps – Consider Reducing power and airspeed SAFETY THROUGH PROFESSIONALISM PITCH AND ROLL UPSETS Ice Accumulation reduces controllable speed range Auto-pilot masks onset of control issues Tail plane stall on short final may be unrecoverable SAFETY THROUGH PROFESSIONALISM REVIEW AVOID ICING CONDITIONS KNOW ESCAPE ROUTES UNDERSTAND CHARACTERISTICS OF DANGEROUS ICING CONDITIONS AVOID USING FLAPS WHEN ICED KNOW UPSET RECOVERY TECHNIQUES SAFETY THROUGH PROFESSIONALISM NASA GLENN HANDOUTS CD ROM: INTER-ACTIVE TRAINING FOR G.A. PILOTS DVD: – – – – ICING FOR REGIONAL AND CORP PILOTS ICING FOR GENERAL AVIATION PILOTS SUPERCOOLED LARGE DROPLET ICING TAILPLANE ICING SAFETY THROUGH PROFESSIONALISM