greetings from limoges. i hear claims and read online that there is up to 5knts to be gained from a properly rigged cessna. has anyone found that to be the truth and if so do you know a decent engineer who can do it for me?
There is a very knowledgeable guy based at Chambery called Jacques Raissiguer. He is both a ferry pilot and a licensed engineer and knows about Cessnas. His e mail address is: [email protected] Give him a try.
I have a Peterson converted Cessna 182, converted into a King Katmai by Todd Peterson in Kansas. Todd says two identical 182's can vary as much as 8 knots in speed, it's just how they come out of the factory so you need to decide if spending the money is worth it, particularly if your aircraft currently flys well.
Finally, may I wish this forum well and I look forward to some really good information.
you can easily determine whether your Cessna needs rigging: if you can trim it to fly straight and level with hands off and it makes book speed while doing so, then there is nothing to be gained.
The cams in the rear spar attachment allow the angle of incidence of the wings to be independently adjusted. While that adjustment is being made, there can be an unintended outcome: While moving the trailing edge either up or down at the up and down extremes of the travel, in the intermediate positions, the cam is also positioning the wing tip more forward or more aft.
You get to pick more forward or more aft depending upon which way you turn the cams. The worst selection is one forward one aft, as the collective "wing" is no longer pointed that same direction as the fuselage. The angles are very small, But effect is there.
A Cessna Tech Rep told me a long time ago to sweep the wings back for faster cruise speed, and sweep them forward for a slightly slower stall speed. My buddy and I experimented with our two otherwise identical C 150s (144 serial numbers apart from each other). The effect seemed to be only 1 or 2 MPH difference between the planes - which we determined by flying fast and slow in formation.
That said, I have seem more improvement in cruise speed from a wash, and a good coat of wax! But every little bit helps!