Specifications
LENGTH: 75"
WING SPAN: 68"
WING AREA: 875 sq. in.
WEIGHT: "T" Version - 16.5-18 lbs. • "VF" Version - 15-16 lbs.

balsa Bandit
Airframe Directive (A.D.)
And other helpful notes

Aileron servo mount braces

(4) Laser cut 1/16” ply parts per servo mount are now used to strengthen the aileron servo mounting. Add these 1/16” ply parts to both ribs that border the 1/8” ply servo mount. If you already have the 1/8” ply mount installed it may be necessary to bevel the top edge of the ply to clear the glue fillet. Apply Slow ZAP to each part and insert them as shown.

The Rudder

As we mentioned September 21, 2000, there have been two in-the-field problems with the rudders coming off in flight.

Though no models were lost, we caution users to hold down the speed until the below listed fixes can be implemented and flight-tested.

The Aerodynamic Fix

Add the 1/8" plastic angle stock to both sides of the trailing edge of the rudder. Use C.A. glue to adhere.

This is an aerodynamic fix commonly used on full size aircraft control surfaces. It is also being employed on giant scale aerobatic models (as flown in the T.O.C.) to solve some control surface buzzing. It may be all that is required to prevent a problem from occurring but we want to be certain by adding the mechanical changes.

Mechanical Fixes

• Use a metal gear servo such as the Airtronics 94141
• Be certain that the hinges are scuffed with #80 grit sandpaper and then glued in securely.
• Use a 4-40 clevis system with 3/32" control rod.
• Use a ball clevis system to connect to the rudder.
• Use a heavy duty servo arm.
• All balsa Bandit owners will be shipped necessary parts (except servo and arm) as soon as possible but before 1 November 2000. Please notify BVM if you do not receive your "balsa Bandit rudder update kit".

	A patch panel of .010" poly ply will reinforce the slot in the bottom of the fin. The new JRPA 215 heavy duty servo arms fit well onto the Airtronics 94141 metal gear servo (available in reverse type with JR compatible plug). Use a Sullivan 4-40 threaded clevis with keeper, drill with 3/32 bit and solder on to the 3/32" wire pushrod. A 3/8" x 5/8" long dowel is embedded into the balsa block at front of fin to allow a 4-40 x 1" bolt to further secure the fin to the fuse.
	Solder a 4-40 threaded coupler onto the 3/32" push rod and apply the 4-40 Dubro swivel type rod end. The brass stand-off (custom made by BVM) accepts a 6-32 x 3/4" bolt through the dowel in the rudder. Outboard end accepts the 4-40 screw through the clevis ball. Apply Loctite to all threaded connections (except plastic). Note: Finished models have a 6-32 bolt for rudder horn, you can cut the bolt off to accept the brass stand-off or heat it with a soldering iron and back it out if it was glued in place.
	Servo shown installed, tighten mounting screws very securely. Access to front hold down bolt is through leading edge.

Wing Sheeting Notes

Balsa is a product of nature and therefore it naturally varies in grain type and hardness. The wing, stab and fin skins are pre-joined and laser cut to fit the structures after a selection process is performed at the BVM factory. The skins are of good quality but of course, cannot be perfectly uniform (natures way), so here are some tips to help you best apply the skins.
Choose 2 wing & stab skins that are the hardest (heaviest) of the 4 provided. Designate them to be used on the top of the surface. This will provide the sub surface for the best finish after the resin, cloth, and paint are applied. The tougher skins on the top will also provide the maximum resistance to positive "G" loads when the top skins are in compression.
Check both sides of the skins for any unsanded saw marks. If any are visible, designate this side to face inward to the structure. If the skins are a bit too hard to conform to the curvature of the wing toward the L.E. the old technique of applying a 50/50 mix of ammonia and water to the outside surface really facilitates the bending process. Apply with a fine spray or wipe on with a dampened sponge.
We check the skins for a continuous glue joint but you may check them as well. If a void exists between the 3" or 4" panels, apply thin CA to a razorblade and then to the skin joint. Block sand this area on a smooth surface with #320 paper.

Rudder linkage
	The 1/32" pull-pull wires are sleeved with 1/16" brass tubes (1/2" long), then soldered into a Sullivan 2-56 threaded coupler. This can be attached to the servo arm with a safety clip (Sullivan). This idea and photo from David Ribbe is the best linkage for this critical control system if you plan to go really fast.

RUDDER
A Bandit with a standard fin experienced a severe rudder flutter as a result of servo gear failure and the unfortunate result was a crashed model. This is the first time that this has occurred in 4 years and thousands of Bandit flights that we are aware of. Since the standard fin has a larger rudder than the swept fin it would follow that it would be more prone to a flutter problem. Flutter can occur if there is any spring in the control system. This dictates that the servo be very tightly screwed to the mounting rails and that the mounting rails be very securely glued to the internal fin structure.

By switching to a metal gear servo, we also can remove a possible weak link in the system. Worn nylon gears can also be a spring source. We have been using JR 3321 servos for the rudder but these servos do not feature metal gears and currently there are no plans to change it.

We just received a sample 94141 servo from Airtronics that comes with a JR compatible plug. This is a high torque precision unit with a metal gear train and a uniquely variable mounting system. It looks like a great candidate for operating some control surfaces (like the Bandit rudder) on jets. See your Airtronics dealer.

Another consideration: If a control surface gets a hard rap from accidental handling as can happen in transport or just sitting in the pit area, nylon gear trains could be damaged. If undetected, this damage could show up in flight. If there is some concern in this area it is worth the time to change the servo before flight and have it checked out later.