Lowering ailerons to gain cruise speed

[olypenflyr]

Two of my friends with 1960-70 vintage C-172s have dropped their ailerons about 1/4 to 3/8” relative to the flaps and have seen a significant increase in cruise airspeed. Has this been done on 170s with positive results?

[counsellj]

I would think, raising them would help more than lowering them .

[GAHorn]

Lowering them increases induced drag and results in slightly reducing stall speed... it does not increase cruise speed... but it may change the AOA and relative wind during cruise which may result in changing CAS/Instrument error and erroneously show an increase in IAS.

[ghostflyer]

The only way to ensure your aircraft is performing to its best is have all the flight controls rigged exactly as Mr Cessna requested . Every 100hrly that comes through our shop the controls are always checked and the high percentage that are incorrectly rigged is mind blowing. Also check your cable tensions also . They do stretch over time . Another point is check your rod end bearings . If the are worn and allow movement , a small flutter of the control surface can happen. The skin condition of your flight controls also has a big part to play on drag. Hangar rash and repairs not done correctly does have a big impact . While I am preaching , my aircraft Lh aileron has repairs to the hangar rash and looks like a dog has chewed it but the aircraft flies hands off and I do not want to up set the status quo.

[olypenflyr]

Thanks for the info. My rigging looks great and it flies nicely hands off. Was repainted and everything rerigged and inspected about 4 years ago. I’m going to leave things as is. Sometimes these things sound great but in reality don’t gain anything.