With the advent of Giant Scale it seems there is considerable interest in providing fail safe measures in an effort to protect our sizable investments in time and money. There is a great psychological advantage in being able to fly your special creation with the assurance that the percentage of success is in your favor. An example of this is flying with a radio that has left us "down" and after getting it back from the factory we still are not certain that everything will be okay. The only thing that reestablishes our confidence in the system is more flights and most of us have a spare plane in which we install the "repaired" radio to help re-establish this confidence. The big question that persons are asking is, "How much repetition (redundancy) is necessary to establish a reasonable level of protection for my investment?"

Our first efforts in giant scale resulted in losing some planes due to happenings that we are unaccustomed to. Yes, giant scale is different and we had better do something about it if we want to spend less time and money on repairs. It didn't take long to learn the necessity of 4-40 rods and 1200 mah battery packs. It took a bit longer to arrive at a reasonable solution relative to the duplication of equipment.

We feel that our present position on redundancy has merit and you may want to consider some of the items and procedures that have proven of worth to us.

We are in no way saying that we have all the answers. Change is always present and we want to remain flexible enough to change when better ways and means are developed. Also, there are failures that do occur that no amount of redundancy can correct.

The first item that we recommend is a battery backer. The battery backer is an electronic device that will automatically switch from a discharged battery pack to a charged one. This does necessitate the purchase of a second flight battery and the backer. Battery backers are available from Ace R.C., Jomar Products, and R.A.M. Backers are good insurance and an excellent investment.

The second recommendation is the use of one servo on each aileron. We mount our servos out in the wing with relatively short 4-40 rods going directly to the aileron horns. Long, 24" to 30" aileron leads have been no problem with our Airtronic radios. The servo is accessible through an approximate 2 1/2" square 1/8" plywood "door" which is secured by 4 small flat head wood screws in basswood blocks. Heavy duty Rocket City ball links are used along with stainless steel machine screws and nuts. Rocket Cities new Nl-BRASS balls are excellent. Caltronics Labs has an excellent line of stainless steel hardware.

The third recommendation is the use of 2 servos for elevator control. We use one servo on each half of the elevator along with separate control rods to each elevator half. We have used 2 servos on a servo doubler system which is available from Bennett Specialities and C.B. Associates. While the doubler system is much superior to only 1 elevator servo, the final installation results is only 1 control rod going from the servo doubler (2 servos) to the elevator. We have used aluminum arrow shafts by B 8 B Specialities and heavy duty rods by Sullivan with good success. It should be pointed out that on the 2 servo, 2 rod system each elevator half works totally independent of the other half. The 2 servo arrangement uses a Y plug for electrical coupling.

The next recommendation is the use of coreless servos. A coreless servo will allow a "blow back" to neutral on an in flight servo failure. While it's possible to have a servo failure resulting in a full power, full deflection lock in, our experience has been that this is the exception rather than the rule.

Another recommendation is the use of servos with adequate torque. It is our belief that it is much better to have a bit of "overkill" on servos as opposed to lack of power. Presently we use 110 oz. inch heavy duty coreless Airtronic servos (94510) on elevators and 75 oz. in (94554) heavy duty, ball bearing coreless servos on each aileron and rudder. Any standard servo may be used on throttle. Yes, small servos will fly large models with properly balanced flying surfaces but we prefer the extra margin of safety that goes with more powerful servos.

While a bit off the subject of redundancy, another item that can save your plane is the selection of an engine. Don't be afraid to go with a little extra displacement. The additional power can get you out of tight spots and more often than not, the extra weight is an advantage in arriving at a properly balanced aircraft.

In analyzing our in flight failures over the past 8 years, most of them could have been prevented if we would have paid more attention to redundancy earlier. We wish all giant birds a long life. They deserve it.