Ice Protection Presentation_draft

ANTI-ICE/DE-ICEKING AIR C90 SERIES

FOCUS

• This module improves our ability to manage risks associate with icing conditions by:– Understanding where they exist– Being confident in system operation– Ensuring equipment is functional and

effective

LINE-UP

• Accidents• Preflight Preparation• System Components– Thermal–Mechanical– Chemical

• System Operation• Operational Checks

ACCIDENT REVIEW• Air Florida Flight 90– Where: Washington, D.C.– When: January 13th, 1982– What:

• Aircraft was unable to maintain positive rate of climb

• Struck the 14th street bridge• 78 fatalities/9 injuries

– Why:• Pilots failed to activate engine anti-ice systems that

resulted in sensors becoming obstructed with ice resulting in erroneous engine thrust indications.

ACCIDENT REVIEW

• American Eagle Flight 4184– Where: Roselawn, IN– When: October 31st, 1994– What:

• Pilots lost aircraft control• Aircraft impacted ground at such vertical velocity that

wreckage and remains were unidentifiable• 68 fatalities

– Why:• Aircraft encountered freezing rain while holding to enter

Chicago airspace• De-ice systems were unable to protect critical surfaces

from freezing rain and super cooled liquid drops (SLDs)

ACCIDENT REVIEW

• Colgan Air Flight 3407–Where: Buffalo, NY–When: February 12th, 2009–What:• Aircraft stalled while on final approach• 50 fatalities/4 injuries

–Why:• Crew executed improper technique for

recovery from a stalled condition

ACCIDENT REVIEW

• Air France Flight 447– Where: Atlantic Ocean– When: June 1st, 2009– What:

• Aircraft entered a stall at high altitude• Remained stalled for 3 minutes, reaching a rate of 10,912

feet per minute towards the ocean• 228 fatalities

– Why:• Flight crew received abnormal airspeed information from

pitot tubes obstructed with ice• Stall induced by flight crew

FAA INTERPRETATION

• What is “known icing”?– The pilot knows or reasonably should

know about weather reports in which icing conditions are reported or forecast.

**Consider this when operating with icing equipment MEL’d!**

PREFLIGHT PLANNING

• FIKI, yes….but– No aircraft is certified for severe icing– Equipment should be used to fly THRU

icing conditions – not remain in them

PREFLIGHT PLANNING

• Two common structures:– Icing associated with vertical

developmentOr – Icing associated with widespread cloud

layer

PREFLIGHT PLANNING

• AIRMETs– Forecasts are for MOD icing conditions– Freezing levels (can be used with cloud

base/top)

PREFLIGHT PLANNING

• CIP/FIP Charts– www.aviationweather.gov– Great SUPPLEMENT to AIRMET

PREFLIGHT PLANNING

• PIREPs– Remember…• Absence of reports does not indicate an

absence of icing conditions• Consider aircraft type, time, etc.

SYSTEM COMPONENTSAnti-Ice/De-ice

PROTECTED SURFACES

• Thermal– Pitot (2)– Stall Vane (1)– Fuel Vents (2)– Propellers– Engine Inlet Lip–Windshield– Oil-Fuel Heat Exchanger

PROTECTED SURFACES

• Mechanical–Wings– Horizontal Stabilizer– Vertical Stabilizer– Engine

PROTECTED SURFACES

• Chemical– Prist

SYSTEMS CONTROLLED FROM FLIGHT DECK

• L/R Pitot Heat• Stall Warning Heat• L/R Fuel Vent Heat• L/R Windshield Heat• Propeller De-Ice• Surface De-Ice• L/R Engine Anti-Ice

PITOT HEAT

• L/R PITOT HEAT Switch(s) are located on the Captain’s right-hand sub-panel (ICE PROTECTION group)

• Normally ON inflight• Two position switch:– ON– OFF

• Left pitot heat switch is battery powered in the event of a dual gen failure

STALL WARNING VANE HEAT

• STALL WARN Switch – located on Captain’s right-hand sub-panel (ICE PROTECTION group)

• Normally ON inflight• Two position switch:– ON– OFF

• Sheds automatically with dual gen failure

FUEL VENT HEAT

• L/R FUEL VENT Switch(s) – located on the Captain’s right-hand sub-panel (ICE PROTECTION group)

• Normally ON inflight• Two position switch:– ON– OFF

• Sheds automatically with dual gen failure

WINDSHIELD HEAT

• L/R WSHLD ANTI-ICE Switch(s) – located on Captain’s right-hand sub-panel (ICE PROTECTION group)

• Recommended NORM inflight• Mild vision distortion (more

pronounced at night)• Sheds automatically with dual gen

failure

WINDSHIELD HEAT

• Three position switch:– NORM– HI– OFF

WINDSHIELD HEAT

• NORM/HI Modes– Selecting either mode provides electrical

power to the heat elements laminated w/in the windshield

– Power cycles automatically to help maintain a pre-set temperature

WINDSHIELD HEAT

• Surface size is the only thing that changes between NORM and HI modes– NORM• Entire windscreen is heated• Recommended for use during normal

operations– Increases windscreen strength– Prevents fogging during descent– Reduces risk of cracking if turned on after a cold

soak at cruise altitudes

WINDSHIELD HEAT

• Surface size is the only thing that changes between NORM and HI modes– HI• Outer 2/3 of each windscreen is heated

– Smaller surface = greater WATTs per square inch

• Think…– NORM = normal WATTs– HI = high WATTs

WINDSHIELD HEAT

• Issues associated with…– Heat module failure• Results in complete loss of heat

– Element failure• Elements may glow at night• Failed areas may ice over while operating in

icing conditions

WINDSHIELD HEAT

• Issues associated with…–Windshield Shatter

**INSERT CAUTION FROM POH PG. 4-15**

PROP HEAT

• PROP HEAT Switch – located on the Captain’s right-hand sub-panel (ICE PROTECTION group)

• ON while operating in icing conditions

• Two position switch:– ON– OFF

PROP HEAT

• ON– Propeller de-ice module cycles power

between #1 and #2 engines–When switched ON…• #1 receives power for 90 secondsThen…• #2 receives power for 90 seconds

PROP HEAT

INSERT ELECTRICAL SCHEMATIC FOR PROP HEAT

PROP HEAT

• Proper operation is verified on the PROP AMPS gauge– Located on the overhead panel–Within green band = good• Any drop outside of the green band, down to

zero, indicates one or more propeller blade heating pads are not receiving electrical power

PROP HEAT

• If PROP AMPS drop below green band…– CHECKLIST?– Turn OFF, exit icing conditions– Cycle propeller RPM• Blade flex with RPM change will crack and

shed ice

PROP HEAT

• Limitations– Do not operate propeller heat

w/propellers static– Avoid rotating the propeller in opposite

direction of normal rotation• Use propeller “bras” when leaving aircraft

on ramp in windy conditions

PNEUMATIC BOOTS

• SURFACE DE-ICE Switch – located on the Captain’s right-hand sub-panel (ICE PROTECTION group)

• Activate once ½ inch of ice has formed on leading edge of any surface

• 3 position switch:– SINGLE– OFF– MANUAL

PNEUMATIC BOOTS

• SINGLE Mode– Switch is spring loaded to OFF position–When selected it activates a SINGLE

boot cycle:• Wings – 6 secondsThen…• “Tail” – 4 seconds

PNEUMATIC BOOTS

• MANUAL Mode– Spring loaded to OFF position–When selected it activates ALL booted

surfaces while the switch is held in the MANUAL position

PNEUMATIC BOOTS

• Boot Operation– Engine bleed air is regulated and used

to inflate/deflate the de-ice boots– DEFLATE• PRESSURE air (regulated bleed air) is routed

through an ejector pump which creates a vacuum to hold the boots against the airframe

PNEUMATIC BOOTS

• INFLATE– A valve re-routes PRESSURE air to

INFLATE the de-ice boots

PNEUMATIC BOOTS

• Pneumatic/Suction Pressure Gauges– Located on the Co-pilot’s right-hand sub-

panel– Allows the pilot to ensure proper

pressure is maintained during INFLATE/DEFLATE modes of operation• Cycle (from DEFLATE-to-INFLATE) is

indicated by a “flick” of each needle

PNEUMATIC BOOTS

• Limitations– Do NOT use when OAT is -40°C and

colder• De-ice boots are made of layered rubber –

this becomes fragile at cold temperatures

– One of the only aircraft approved/required to allow ice build-up prior to boot activation• Ensures proper separation of ice

– Residual Ice

PNEUMATIC BOOTS

• Routine MX– Keep boots clean – this improves

effectiveness of the boots• BF Goodrich ICEX II

ENGINE ANTI-ICE

• L/R ENGINE ANTI-ICE Switch(s) – located on the Captain’s left-hand sub-panel– Grouped with L/R ACTUATOR Switch(s)

• Recommend ON during ground operations– Prevents ingestion of FOD– Reduces engine performance

• ON when operating in icing conditions– OAT less than 5°C and visible moisture

ENGINE ANTI-ICE

• Actuator(s)– One electric motor which contains two

separate electrical elements/coils– One motor (each side) moves two

panels (vanes) inside the engine air intake duct

ENGINE ANTI-ICE

• OFF-to-ON– FWD panel extends, forcing airflow to

make a 90° turn– AFT panel retracts, opening an exhaust

duct which allows dense objects (ice/water) to exhaust overboard due to it’s inertia

ENGINE ANTI-ICE

• OFF-to-ON– Pilot will notice a slight drop in TQ and a

slight rise in ITT• Less air (into engine) = less power = less TQ• Less air (into engine) = less cooling = higher

ITT

ENGINE ANTI-ICE

• ON-to-OFF– FWD panel retracts, allowing airflow to

make a shallow turn into the engine– AFT panel extends, closing exhaust duct

and forcing all of the airflow into the engine

ENGINE ANTI-ICE

• ON-to-OFF– Pilot will notice a rise in TQ, approx. 100-

200 LBS-TQ, and decrease in ITT• More air = more power = more TQ• More air = more cooling = lower ITT

ENGINE ANTI-ICE

• Annunciators– L/R ENG ANTI-ICE (green)

• Indicates ice vanes have reached the ON position– Monitored by proximity switch(s)

– L/R ENG ICE FAIL (amber)• Immediate illumination

– Indicates loss of electrical power to actuator(s)

• Delayed illumination– Indicates vanes failed to reach proper position – failed

actuator(s)**HOW CAN ENGINE INSTRUMENTS HELP WITH THIS PROBLEM?**

ENGINE INLET LIP HEAT

• Exhaust air is routed through the leading edge of the engine air intake lip

• No pilot action• Issues associated with…– Broken duct or fitting• Soot found in unusual location on engine

nacelle (i.e. FWD of exhaust stacks)

OIL-TO-FUEL HEAT EXCHANGER

• Manifold allows engine oil to warm fuel– Fuel cools engine oil!

• POH chart illustrates ambient temperature and engine oil temperature when PRIST is required

PRIST

• Prevents water suspended in fuel from freezing

• Recommend use at ALL times

SYSTEM OPERATION

• Monitor Atmospheric Conditions– “Approaching icing conditions…”

• What goes ON?– Check “HOT 5”– ENGINE ANTI-ICE– PROP HEAT

• Verify proper operation• Avoidance strategy

– Accumulation of ice WILL decrease performance– Operation of ENGINE ANTI-ICE will decrease

performance– Residual ice may require ground de-icing

SYSTEM OPERATION

• Monitor Atmospheric Conditions– “IN icing conditions…”• What goes ON?

– Monitor ice build-up, activate SURFACE DE-ICE when appropriate

– Indications of proper operation– Exit strategy

» Avoid continuous operation in icing conditions• Lateral deviations• Vertical deviations

PREFLIGHT CHECKS

• When are preflight checks required?– Every flight:• “HOT 5”

– “When required”:• ENGINE ANTI-ICE• WNDSHLD ANTI-ICE• PROP DE-ICE• SURFACE DE-ICE

PREFLIGHT CHECKS

• Every Flight– “HOT 5”• Check during preflight inspection

– FUEL VENT (1)– STALL VANE (1)– PITOT HEAT (2)

» Grab “elbow” to prevent injury– FUEL VENT (1)

INDUSTRY DISCUSSION

MODULE REVIEW