Control Quadrant Upgrade

Posted on February 27, 2014

Control Quadrant Upgrade

Available for CIRRUS SR20, SR22

Tamarack Aerospace Group’s Control Quadrant Upgrade results in greater fuel efficiency with reduced engine wear by means of a propeller RPM control lever. The Prop control lever for CIRRUS SR20 and CIRRUS SR22 reduces noise significantly while providing a much more relaxing and enjoyable flight for both pilot and passengers.



Customer Feedback From the Forum:

“Although still expanding the envelope of experience with this upgrade, after roughly 20 hours and an inspection at Leading Edge I am confident this is the single most cost-effective modification made to my plane.  I am going slowly because of the adverse comments above, all of which so far appear unfounded.  Typically, on long cruises I am at 19,000′, MAP at 29.5 runnning between 15.5 and 16 gph at 2400 RPM, 80% power with no reduction in speed.  I do lose a couple knots reducing RPM to 2350.  I have no problem controlling temperatures which, across the board, remain well within normal for oil, CHT, EGT TIT.  If there are problems, they are not reflecting on the instrumentation.  The cabin is much quieter, but I can offer no db reduction measurements; however, if you would like to know how it will sound in your plane, take off your headset, reduce the RPM from 2700 to 2400 and listen.  Holding RPM constant, I am able to reduce FF to 15 gph without roughness and of course, power is reduced.  I believe the MT Propeller 4-blade is very efficient at these levels and further accounts for reduced vibration and noise levels.  The claimed fuel savings do not appear to be puffery.  At 1 gph and zero speed loss this mod will pay for itself in about 400 hours or less, and range is increased. If you don’t plan on that much flying, you will enjoy the enhanced control.  These guys deserve a round of applause.”

– Harvey Moore, SR22 G2 Owner on the COPA Forum


“We think the conversion is just perfect for us.  We only go as two and this allows us to literally carry anything we want.  Fortunately we’re healthy and active so this means golf clubs, mountain bikes, and enough shoes to hike, bike, golf, white water raft and yes even dress up (if needed).  I may even have a couple of rear seats for sale.  🙂   ”

– Don Belisle, Cirrus SR22 Owner & Pilot


Click here to find an Authorized TAG Dealer near you.


  • Simple non-structural installation
  • Traditional propeller RPM control, enabling “oversquare” operations as in other high performance aircraft (Columbia/Corvalis, Mooney, Piper, Cessna, Beech, etc.)
  • Reduced fuel consumption, 1+ gallon per hour in cruise and 5+ gallons per hour in a cruise-climb
  • Pays for itself in approximately 200 hours of operation
  • Dramatically reduced cabin noise and vibration
  • Airport/environmentally friendly noise abatement
  • Reduced engine wear and operational costs
  • Boost pump LED to remind pilots
  • Easy installation and easy return to OEM status
  • Compatible with the CIRRUS SR20 or SR22

Control Quadrant Upgrade – Flight Test Results (Rich of Peak) This “Butterfly Chart” compares the fuel flow and manifold air pressures (MAPs) at three different airspeeds. Red lines represent constant engine RPM, and blue lines represent constant indicated airspeed. In the example, at 2,300 RPM and 135 KIAS, the fuel flow is 13.2 gallons per hour (GPH) and MAP is 21 in. When indicated airspeed is held constant and RPM is decreased, the fuel flow also decreases in all three instances shown on this chart. The fuel flow at faster airspeeds drops more steeply, representing greater fuel savings.
Control Quadrant Upgrade Fuel Savings (Rich of Peak) – 135 KIAS Note the fuel savings when engine RPM is decreased from 2,500 RPM. When operating at lower RPM, significantly less fuel is consumed. At a constant 
135 KIAS, the fuel savings is about 7% when the engine RPM is reduced from 2,500 RPM to 2,250 RPM.
Control Quadrant Upgrade Efficiency (Lean of Peak) – 6,000 feet The aircraft’s performance at different RPMs compared to 2,500 RPM at 6,000 feet altitude and 50°F Lean of Peak is illustrated here. As the RPM is decreased, fuel efficiency is improved (% Fuel Savings and NM/gal) and the airspeed decreases slightly (% KTAS). For example: At 2,000 RPM, there is nearly a 20% increase in fuel savings, an 18% increase in fuel efficiency (nm/gal) with only a 10% decrease in true airspeed. Therefore, at 2,000 RPM, the aircraft is flying more slowly but more efficiently. Compare this to the SR22 Pilots Operating Handbook’s example of: ISA conditions, 6,000 feet pressure altitude, 2,500 RPM and MAP of 23.5 in, the fuel flow is 14.1 GPH at 59% power and an airspeed of 162 KTAS.

 ~ Limitations & Conditions ~

The installation should not be incorporated in any aircraft unless it is determined that the interrelationship between this installation and any previously approved configuration will not introduce any adverse effect upon the airworthiness of that aircraft. The approval of this modification applies to Cirrus Design SR20/22 airplane models delineated below.

  • This STC is applicable to the following serial blocks of the Cirrus Design Aircraft:
    • Cirrus SR20: Serial Numbers 1005 through 1885
    • Cirrus SR22 Serial Numbers 0002 and subsequent without Garmin Perspective Avionics installation
  • SR20 airplanes equipped with Hartzell BHC-J2YF-1BF/F7694 propeller assemblies must have a placard installed reading “Avoid operation between 1900 and 2200 RPM above 24” manifold pressure.