TKS – A Clear Solution to Icing, Part 5

This is the fifth installment of a seven-part series “TKS – A Clear Solution to Icing,” by Jeffrey Brewer, CEO/Founder of Connecting Aviators.

It makes sense that an aircraft builder based in Minnesota wouldn’t just slip up on the idea of ice protection. For decades, Cirrus airplanes have flown with an ever-evolving clear solution for ice.

Known Ice Protection FIKI, Cirrus SR22 G3-G6 (2009 & later)

By 2009, Cirrus and CAV Ice Protection had designed a system to meet certification requirements for Flight Into Known Icing. The FIKI system has upgraded components, redundancy and new features. 

The titanium panels can thoroughly and evenly coat all critical flight surfaces and flow more fluid. Cirrus added mini titanium panel “horns” to the elevator mass balance to reduce the risk of ice bridging. And the vertical stabilizer front edge was given a fluid panel. Ice accretion can change a plane’s angle of attack, so a heated stall vane and angle of attack sensor were added to the leading wing edge and a high-heat-capacity pitot tube. Dual OATs were added on the G6.

At night, split-prism LED lights illuminate both wings and horizontal stabilizer surfaces. And the onboard EVS infrared-plus-visible spectrum sensor camera can help pilots see and avoid clouds after sunset.

The FIKI system has capacity to carry more fluid. Each wing has a 4-gallon fluid reservoir for a total capacity of 8.0 gallons. Pumps automatically cycle between each tank to keep levels roughly even and reduce pilot workload. Three pumps provide fail-safe redundancy.

As with the basic TKS ice protection, a slinger ring protects the prop blades. Some fluid slung from the prop will flow onto the fuselage and windshield, but the FIKI system includes a windshield spray nozzle to help safeguard pilot forward visibility. The windshield pump can also be used to prime the system if air gets trapped in the lines from running the tanks dry.

The pilot can select between three pump rates: normal, high and maximum. In normal mode, full tanks allow an operating time up to 150 minutes. In high mode, operating time is up to 75 minutes. With repeated maximum mode usage, expect an operating time of less than 37 minutes.The FIKI system provides full operating envelop protection. Maximum anti-ice performance is available with airspeeds between 95 KIAS (best climb angle) and 177 KIAS at any altitude, but not to exceed 204 KTAS. When the TKS system is turned on, Cirrus Perspective by Garmin monitors the airspeed. If the airspeed drops too low or exceeds upper limits, the CAS will notify the pilot.

Pilot critical decision-making is supported with real-time info from Cirrus Perspective by Garmin, including 1) Amount of TKS fluid in each tank, 2) Nautical range remaining for flow rate selected, 3) Available anti-icing time for each flow rate (normal, high or maximum), 4) Alerts to inadequate system pressure or malfunctions, and 5) Icing forecasts and freezing areas with SiriusXM datalink weather.

The FIKI system added about 61 pounds of weight without TKS fluid, or 23 pounds more than the basic ice protection. The additional weight depends on how much fluid you’re carrying. Two full reservoirs add 73 pounds for a total system weight of 134 pounds (73 + 61 = 134 lbs). TKS weighs 9.125 pounds per gallon. 

In 2009, the plane’s empty weight decreased by using a new Hartzell propeller with a lighter hub as standard equipment. The forward weight reduction allowed for the removal of a tail ballast. This design change offset the incremental weight of the known ice protection system without fluid. In 2013, Cirrus innovated again with another re-engineered wing and numerous changes that certified the Generation Five SR22 for an extra 200-pound increase in useful load.

Cirrus SR22 FIKI TKS Rudder Leading Edge, by wikiWings.Wordpress.com
Cirrus SR22 FIKI TKS Rudder Leading Edge, by wikiWings.Wordpress.com
Cirrus SR22 FIKI TKS Elevator Leading Edge, by wikiWings.Wordpress.com
Cirrus SR22 FIKI TKS Elevator Leading Edge, by wikiWings.Wordpress.com
Cirrus SR22 FIKI Monitor Display
Cirrus SR22 FIKI Monitor Display, photo by wikiWings

© Copyright 2014 – 2023, Jeffrey S. Brewer, all rights reserved

TKS – A Clear Solution to Icing, Part 4

This is the fourth installment of a seven-part series “TKS – A Clear Solution to Icing,” by Jeffrey Brewer, CEO/Founder of Connecting Aviators.

It makes sense that an aircraft builder based in Minnesota wouldn’t just slip up on the idea of ice protection. For decades, Cirrus airplanes have flown with an ever-evolving clear solution for ice.

Basic TKS Ice Protection, Cirrus SR22 G3 (models mfg. 2007-2009)

In 2007, Cirrus introduced the Generation Three SR22, which sported a re-engineered wing with improved ice protection. This subsequent version was, likewise, a safety feature for escape from inadvertent icing.

The G3 system has a main pump, priming pump, fluid reservoir, titanium panels on the wing leading edges and elevator, a prop hub slinger ring and fluid level monitoring. The vertical stabilizer does not have ice protection and the elevator mass balance leading edge lacks fluid coverage. Pilots should understand the associated risk for ice bridging.

The redesigned wing moved the cabin fresh air inlet from the left-wing root into a NACA scoop on the right side of the cowling. And the original stall warning arrangement was redesigned. These changes allowed the TKS panels to begin near the wing root and extend to the outer wing edge. You’ll notice the G3 wing is longer with smaller wing tip caps than its G2 brethren. But both planes have the same tip-to-tip wing measurements (see photo).

The G3 wing design also allowed the fluid reservoir and filler port cap to be relocated from the fuselage into the left wing (see photo). The new filler port position eases the refill process, allows a visual to the fluid level and helps avoid spills. Reservoir capacity increased to 3.5 gallons.

The G3 includes a primer pump. If you run the tank dry, turn the TKS system on and off two or three times in 10-12 second cycles and the main pump will be primed with fluid after a TKS refill.  Then follow the POH and perform a ground check. 

Two pump rates can be selected: normal and maximum. In normal mode, operating time is up to 80 minutes. In max mode, expect the operating time to be less than 40 minutes.

Early G3 planes with Avidyne Entegra avionics don’t track TKS fluid levels. In 2008, Cirrus Perspective by Garmin was released, which included a TKS tank float monitor to display fluid level on the MFD, but the design doesn’t stop there. A Crew Alert System (CAS) provides visual and audible alerts.

The latest generation CAS monitors more than 15 possible anti-icing system alerts.  For example, Advisory Anti-Ice System off and fluid quantity is between 0.5 – 1.0 gallon. Caution Anti-Ice System on and fluid quantity is between 0.5 – 1.0 gallon. Warning Anti-Ice System on and fluid quantity is less than 0.5 gallon. Caution Anti-Ice Pressure. Warning Flap Ice.

Cirrus SR22-G3 TKS wing root and TKS wing filler cap, photo by wikiWings
Cirrus SR22-G3 TKS panel begins at wing root. TKS filler cap shown for 3.5 gallon wing tank, photo by wikiWings
Cirrus SR22-G3 TKS wing leading edge to tip, photo by wikiWings
Cirrus SR22-G3 TKS panel goes to wing tip edge, photo by wikiWings

© Copyright 2014 – 2023, Jeffrey S. Brewer, all rights reserved

TKS – A Clear Solution to Icing, Part 3

This is the third installment of a seven-part series “TKS – A Clear Solution to Icing,” by Jeffrey Brewer, CEO/Founder of Connecting Aviators.

It makes sense that an aircraft builder based in Minnesota wouldn’t just slip up on the idea of ice protection. For decades, Cirrus airplanes have flown with an ever-evolving clear solution for ice.

Basic TKS Ice ProtectionCirrus SR22 G1, G2 (models mfg. 2002-2006)

In 2002, Cirrus released its first ice protection option. It was a non-certified system designated as the “basic TKS ice protection package.” The new safety feature was intended to assist pilots in escaping inadvertent icing.

The system included a single pump, small TKS reservoir, titanium panels on the wings and elevator, and a slinger ring on the propeller hub. Fluid is pumped from a 2.9-gallon reservoir located in the fuselage. Two pump rates can be selected: normal and maximum. In normal mode, operating time may be up to 60 minutes, but expect less than 30 minutes in max mode. 

The titanium panels do not extend across the entire wing. The wing root and outer wing lack TKS coverage. Also, the vertical stabilizer and elevator mass balance leading edge do not have ice protection. The G1 and G2 versions can be identified by spotting the filler port located in front of the baggage compartment door beneath the passenger window and by observing the leading-edge flight surfaces that lack protection. (see photos 1 and 2).

Caution: The G1 and G2 systems don’t have TKS fluid level monitoring or low pump pressure or low fluid level alerts. It’s important to note there’s no primer pump. Air could be in the lines if the system was run dry which may prevent fluid delivery after refilling the reservoir. If the system was run dry, you’ll need to sump TKS under the wing until air is removed from the lines. To ensure the system is safely primed follow the Pilot Operating Handbook (POH) procedures on the ground before flight.

Cirrus SR22-G2 TKS wing Root, photo by wikiWings
Cirrus SR22-G2 TKS inner wing root, no TKS protection, photo by wikiWings
Cirrus SR22-G2 TKS wing leading edge to tip, photo by wikiWings
Cirrus SR22-G2 TKS outer wing leading edge to tip, no TKS protection, photo by wikiWings
Cirrus SR22-G2 TKS side de-icing fluid filler port, photo by wikiWings
Cirrus SR22-G2 TKS side de-icing fluid filler port, left side of luggage door, photo by wikiWings

© Copyright 2014 – 2023, Jeffrey S. Brewer, all rights reserved

TKS – A Clear Solution to Icing, Part 2

This is the second installment of a seven-part series “TKS – A Clear Solution to Icing,” by Jeffrey Brewer, CEO/Founder of Connecting Aviators.

It makes sense that an aircraft builder based in Minnesota wouldn’t just slip up on the idea of ice protection. For decades, Cirrus airplanes have flown with an ever-evolving clear solution for ice.

The TKS solution centers on weeping titanium panels added to the leading-edge flight surfaces. The panels are laser perforated with 800 tiny holes per square inch. A porous membrane behind the panels assists with even fluid distribution. On the propeller hub, a slinger ring with a port on each blade releases ethylene glycol fluid that flows over the propeller then back onto the fuselage and windshield.

In 2002, inadvertent ice protection was introduced on the first-generation Cirrus SR22. The same design continued forward on Generation Two planes. But by 2007, the Generation Three SR22 sported a re-engineered wing and was released with noteworthy TKS enhancements.

For those unfamiliar with Cirrus planes, the initial G1, G2 and G3 TKS systems are not certified for flight into forecasted or known ice. It’s an inadvertent “no hazard” system for normal operations only.  No certified determination has been made for its capability to prevent or remove ice accumulation.

In 2009, Cirrus and CAV Ice Protection announced a FIKI-certified system that has additional features and upgraded components over the previous inadvertent ice protection option. The FIKI system was a clean-sheet redesign that increased fluid availability, flow rates, distribution and equipment reliability.

Jerry Jordan, CAV Ice Protection VP of Design Engineering said, “The Cirrus Flight Test group performed 33 natural ice flight tests with the FIKI system. Of those, 30 provided extensive encounters in icing conditions, which produced some great real-world data on the system’s operation.”  Cirrus states, its “Known Ice Protection is an actual FAA re-certification of the SR22 plane to permit pilots to legally fly into known icing conditions.”

Both FIKI and inadvertent anti-icing systems use an ethylene glycol-based liquid, called TKS, that shifts the freezing temperature of water to minus 76° F (-60° C). When supercooled water in the cloud mixes with TKS, the freezing point is depressed below ambient temperature and allows the combined mixture to flow off the aircraft without freezing.

© Copyright 2014 – 2023, Jeffrey S. Brewer, all rights reserved