TacAero, the CubCrafters authorized flight training organization, which also conducts advanced flight training for U.S. Government and Military organizations, is currently performing product development for a classified military program. As part of that program, TacAero recently evaluated several of the leading suspension systems for CC-11/CCX airframes. Because this subject matter interests the broader cub-flying community, TacAero was kind enough to allow CalCubs to share its report, which follows:*

December 12TH, 2017

Strut Suspension Test for Carbon Cub FX-3 TacCub call sign “Black Bird”


Struts Tested:
1. Stock Bungees
2. Alpha Omega Suspension System – AOSS
3. TK 1
4. ACME AERO – Black OPS Gen 3

Test Purpose(s):
· To test, assess and identify a leading/superior shock option for specific TacAero customers.
No controlled studies comparing these strut options head to head were known or available for study.

Test Parameters:
· Test all 4 struts correctly installed and calibrated (per the rigging instructions associated with each strut) on the Carbon Cub FX-3 with 3+3 gear and 29” Bush Wheels / Scott 3200 Tail Wheel (N844FC).
· Test all 4 strut options at full gross weight (2000lb) & at ¼ tank fuel load, no other weight added other than the pilot (200lbs) and 20lbs weight in far aft position of storage compartment.
· All Landings will be controlled to the briefed landing area (rough, gopher hole infested, 1’-1.5’ dirt berm/lips, gravel, dirt and grass).
· 8 landings per strut set up. 2x per.
o 4-5’ full stall drop landing
o Cross Control 3-point landing to recovery
o One wheel landing / Drop
o Fast landing with brake control / response
· Go Pro attached to undercarriage for video data and comparison.
· Full Debrief after each tested strut.

Environmental: 12/02/17 - OAT 33deg F, Wind 080-070 / 4-5 knots / Ceilings 3000
12/07/17 - OAT 30deg F, Wind 080-070 / 4-5 knots / Ceilings 4500
12/11/17 - OAT 28deg F, Wind 080-070 / calm / Ceilings 4000
Pilots:
· Mike Sasser
· Jeremy Young

Test Days:
· December 02, 07, 11, 2017


TESTS

Stock Struts / Bungees

1. 4-5’ full stall drop landing
a. This test was modified for unsafe / unnecessary risk to aircraft. 2-3’ drops were performed instead of 4-5’.
i. Bungees performed as expected. Significant bounce and “springiness” experienced.
2. Cross Control 3-point landing to recovery
a. Results as expected / directional control standard with effort/skill. Significant wing dip and “hopping’ of the gear.
3. One wheel landing / Drop
a. Significant shudder, with associated anticipated bounce.
4. Fast landing with brake control / response
a. Sluggish response, shudder in the gear, expected response and outcome.

Notes- Stock struts offered a base line. Pros and Cons of this suspension are well known.



Alpha Omega Suspension System – AOSS

1. 4-5’ full stall drop landing
a. 1’-1.5’ consistent bounce at light weight configuration.
b. Loud “POP” with 1’ bounce at gross – unexpected.
2. Cross Control 3-point landing to recovery
a. Results as expected / directional control standard with effort/skill. Struts performed well.
3. One wheel landing / Drop
a. Springy feel on one gear. Gear slide on transition felt when contact was made by opposing gear.
4. Fast landing with brake control / response
a. Sinking feel when brakes are applied. Sluggish, dipping response when performing the wheel landing and applying brakes.

Notes- AOSS are a nice strut that performs well with a skilled pilot. Superior to the stock bungees.


TK 1

1. 4-5’ full stall drop landing
a. No bounce. Hard to tell when the gear actually touched the ground. Impressive absorption.
b. Great drop recovery at both light and gross weight configurations.
2. Cross Control 3-point landing to recovery
a. Very poor results. Aircraft wants to dart when one side compresses more than the other especially at gross configuration.
3. One wheel landing / Drop
a. “Squishy” feel on one gear. Darting tendency compounds significantly. Difficult to maintain control. Hard to tell when contact was made with the ground.
4. Fast landing with brake control / response
a. Sinking feel when brakes are applied. Sluggish, dipping response when performing the wheel landing and applying brakes. Almost identical feel to the AOSS.

Notes- TK 1 Struts look beefy and rugged. These shocks performed well with high drops and rolling over obstacles, bumps etc. These struts require an advanced pilot to maneuver and utilize in all the conditions tested.

ACME AERO – Black Ops Gen3 (heavy spring configuration)

1. 4-5’ full stall drop landing
a. No bounce. Hard to tell when the gear actually touched the ground. Extremely Impressive absorption.
b. In light weight configuration the gear is a little springy, but not as bad as the above tested struts.
c. Great drop recovery at both light and gross weight configurations. Uncanny, as the drop feels like a smooth, controlled, three-point touchdown.
2. Cross Control 3-point landing to recovery
a. Excellent feel and control. Gear is responsive with excellent feel and control.
3. One wheel landing / Drop
a. Solid, positive control. We are curious to test this gear in high crosswind conditions.
4. Fast landing with brake control / response
a. Positive response, gear reacts well with braking.
b. Absorbs bumps and uneven terrain without transferring energy to the cockpit.

Notes- The Gen3 struts performed far above expectation. From the online research TacAero did prior to this test, we thought the AOSS or TK 1 struts would be the best performers. The only struts from this test we did not purchase prior were the Gen3.
Hands down, the Gen3 was the highest scoring throughout this test. We have left the Gen3 Black Ops ACME AERO struts on N844FC. We are certain these are the struts our customer will need and live up to their name. We are anxious to do further testing with this set up and really put these struts through the fire as we continue to demonstrate to performance and capabilities of the FX-3.

*CubCrafters has scheduled the Acme "Black Ops" Gen3 suspension for a full landing gear analysis, including testing for fuselage structural loading and compatibility by the CubCrafters EPD test labs. CalCubs is not aware of any other suspension system that has undergone such analysis.