Due to having done some modifications such as adding the modified “Bender baffle” and moving the voltage regulator onto the baffle … plus, installing interior baggage carpet and padded side panels to the interior I know the weight and balance has changed since the time the first W&B measurements were made.
Because the plan is to do some flight testing with the airplane loaded close
to gross weight, felt it prudent to make new weight and balance measurements
before blindly trying to test fly the RV-12 near the forward and aft CG (center
of gravity) limits. As such, all the fuel was drained from the fuel tank and
the airplane was leveled on the scales so new weight measurements could be
obtained. For those interested, the procedure for determining weight &
balance was covered in the August 10, 2016 post found at the following link.
Performing weight & balance measurements on the RV-12
After taking the new weight measurements, the weight and balance sheets were
updated to reflect the changes and per FAA regulations, an updated copy is kept
inside the aircraft. Also updated the aircraft maintenance log books as well.
My CG did move forward some as I expected it would from the
modifications. As it sits, the DOG aviation RV-12 will hit the forward CG limit
when there is only one gallon of fuel left in the tank when I fly solo … and
with a 230 pound passenger, the forward CG limit will be hit with 3 gallons of
fuel left. So I feel I’m in the sweet spot because I know when the RV-12 gets
painted, the CG will move aft … so hitting the forward CG limit after painting
should not be an issue when giving rides to most people who are capable of
comfortably fitting into the RV-12 cockpit.
Chad (an A&P mechanic that works on lots of airplanes on the field)
was nice enough to loan me 230 pounds of sand bags for the test flight …. Thanks
Chad! I borrowed one 50 pound of play
sand and three 60 pound bags of tube sand. The plan was to get close to gross
weight but not over while keeping near the center of the RV-12’s CG range which
is 80.49 inches to 85.39 inches. With myself, 230 pounds of sand, 19 gallons of
fuel and no baggage, the takeoff CG was 82.66 inches. Although not perfectly in
the center of the CG range 82.66 inches is close enough. In this configuration,
the CG will slowly move forward as fuel is burned and at approximately the 3
gallon point the forward CG limit will be met. As such, I plan to fly down to about
5 gallons so as to get close to the forward CG limit and check out the handling.
Because the RV-12 is a proven design, I don’t expect any control issues or
After removing the passenger’s seatback and seat bottom cushion the 50
pound bag of play sand was placed on the passenger seat floor. Because the sand
bags have been used quite a bit, some were showings signs of wear … so as an
insurance policy, the decision was made to place all the sand bags into trash
bags just in case there was an unwanted rupture.
First 50 pound bag of play sand placed into a trash bag and placed on
the passenger seat floor.
The next three 60 pound bags of sand are of the tube variety and those
were placed upright on the 50 pound bag of sand. This arrangement actually
worked out quite well in that the sand bags did not interfere with the flap
handle or the ELT mounted on the far right … and more importantly did not interfere
with control stick movement. Cargo straps were placed around the bottom of the
tube sand bags and fed through the handle for spar pin as an anchoring point to
prevent the sand bags from sliding to the left towards the flap handle. A
second cargo strap was placed higher up and secured to the fuselage cross brace.
Mr. Sandy Ballast bravely volunteered to become the first passenger to
receive a flight in the DOG Aviation RV-12. With the three bags of tube sand positioned two aft and one centered forward there was plenty of clearance between the stick and Mr. Sandy Ballast.
The test flight occurred during a beautiful hot morning. The air was
perfectly smooth throughout the flight and even though Mr Sandy Ballast was
very quiet during the entire test flight, I think he had a great time as the
airplane made tight turns, stalls, and some touch-and-go landings.
There were no surprises during the test flight … the extra weight and
warm temperatures (high 80’s) make for a little longer ground roll than when
solo. Climb-out was good just not as sporty compared to being solo. Landings
were uneventful, but I did notice more brake was required to slow down and the
stopping distance was longer than when flying solo. All the things one would expect
with a heavy passenger.
The RV-12 is simply a nice flying Light Sport aircraft.