Abstract- Consideration is given to the effects of the contributions of
Dr. Edsel Murphy to the discipline of Model Aeronautics and
Modeling in general. His law is stated in both general and
Special form. Examples are presented to corroborate the
Authors thesis that the law is universally applicable.


Ever since the first scientific experiment and attempts at flight, man have been plagued by the unceasing antagonism of Nature. Only his patience, adaptability and forbearance have permitted the experimenter to learn a few minor facts about the operation of the universe.

Over the years a series of laws have evolved. The laws actually represent a distillation of experience of thousands of experimenters, but they were never recorded for the study and edification of the younger members of our hobby because they had no derivation – no proof. They are true because they have always been true. Look into your own experience and see if this is not so.

It has long been my consideration that the contributions of Murphy, specifically his general and special laws delineating the behavior of inanimate objects, have not been fully appreciated. It is deemed that this, in large part, due to the inherent simplicity of the law itself.

It is my intent to show that the law of Edsel Murphy has produced numerous corollaries. It is hoped that by noting these examples, the reader may obtain a greater appreciation of Murphy, his law, and its ramification in modeling and all of the science’s.

As is well known to those versed in the state-of-the-art, Murphy’s Law states that “If anything can go wrong, it will.” Or, to state it in more exact mathematical form :
1 + 1 à 2

Where “ à “ is the mathematical symbol for “hardly ever”.
Some authorities have held that Murphy’s Law was first expounded when he stated that “If anything can go wrong, it will.”

In fact, the Law first came to him in all it’s simplicity when his bride-to-be informed him of the impending birth of an heir to the family fortune….

This man who developed one of the most profound concepts of the twentieth century is practically unknown to most. He is a victim of his own law. Destined for a secure place in the Hall of Fame, something went wrong !!!

His real contribution lay not merely in the discovery of the Law but more in it’s universality and it’s impact. The law itself, though inherently simple, has formed a foundation on which all future generations will build. He was also the first man to discover the magnetic attraction between balsa wood and trees, to this day a very little know fact.

To show the all-pervasive nature of Murphy’s work, I offer a small sample of the application of the Law of Murphy as it relates to Modeling and Science.

I GENERAL

I.1 Submission of a design to a model airplane kit manufacturer will be preceded by one week by a similar application make by another living across the country from you.

I.2 All warranty and guarantee clauses become void upon payment of the invoice.

I.3 The necessity of making a major design change increases as the fabrication of your new project approaches completion.

I.4 Firmness of delivery dates is inversely proportional to the urgency of your needs.

I.5 An important instruction manual or operating manual will have been discarded by you or your wife (or ?) upon receipt of your C.O.D. order.

I.6 Dimensions will always be expressed in the least usable terms. Velocity, for example, will be expressed in furlongs per fortnight.

I.7 Original drawings of your new design will be mangled by the copy machine.

I.8 The new house pet cannot distinguish between contest balsa wood and the litter box.

II MATHMATICS

II.1 In any given miscalculation, the fault will never be placed if more than one person is involved.

II.2 Any error that can creep in, will. It will be in the direction that will most weaken the air frame structure.

II.3 All constants are variables.

II.4 In any given computation, the figure that is most obviously correct will be the source of the error.

II.5 A decimal will always be misplaced.

III DESIGN AND CONSTRUCTION

III.1 Any wire cut to length will be too short.

III.2 A dropped tool will land where it can do the most damage. (Also known as the law of selective gravitation).

III.3 All servos will rotate in the wrong direction.

III.4 The probability of a dimension being omitted from a plan or drawing is directly proportional to it’s importance.

III.5 Interchangeable parts won’t.

III.6 Construction parts that must not and cannot be assembled improperly will be.

III.7 A failure will not appear until your model has passed all preflight checks.

III.8 If an obviously defective component is replaced in a transmitter or receiver with an intermittent fault, the fault will reappear only after the system is returned to service.

——————————————————————————————

Dr. Edsel Murphy also was the first person to provide safety standards which, prior to his time, were not understood or practiced. In fact it is possible, through his efforts, he may have been a direct influence on the development of the Academy of Model Aeronautics Safety Code. I do not know for sure. I do know his safety standards are applicable today and are included for your benefit.

SAFETY COMMANDMENTS
(provided by Dr. Edsel Murphy)

1. Beware of the lightening that lurked in an uncharged condenser lest it cause thee to bounce upon thy buttocks in a most embarrassing manner.

2. Cause thou not, the tangle of electric cords that supplieth large quantities of juice under thy work bench to short, that thy days be long in the earthly vale of tears.

3. Tarry thou not amongst these fools that engage in leaning over or standing in line with rotating propellers for they are not long for this world and are surely nonbelievers.

4. Work thou not with energized batteries and metal fuel containers for if thou doest so, thy friends will surely be buying beers for thy widow and consoling her in ways not generally acceptable to thee.

5. Trifle thee not with mixtures of epoxies, solvents and substances unknown to thee, lest thou commence to glow in the dark like a lightening bug, and thy wife be frustrated and have no further use for thee except for thy wages.

Collected and Presented by: Rich Horvath AMA #823

The day of the maiden flight. The airplane performed very well and looked like a real P-51 Mustang in the air. Several passes proved the trim was near perfect and the modifications made to the control surfaces worked as well. With the flaps extended and gear down the approach and landing were flawless. The next two flights I had concerns with the engine acting as if it was set too lean. What I determined to be the cause was actually overheating of the engine. I took the plane home and removed the nose cowling and cut a much larger opening toward the rear on the underside of the plane so as to let out more of the hot air inside of the cowl during flight.

My first “ARF” was a model “Edge 540t” from Aeromodels. This was my first ARF and I have been extremely pleased both with it’s construction as well as it’s flying characteristics. We all know the excitement of the “First Flight” of a new model aircraft. That is the way I felt when I fired up the engine for the first flight. I taxied around for a minute to get the feel of the plane, and that was all I intended to do………..but it handled so well on the ground that I elected to fly it. That first flight was great to say the least. I had set the plane up with both “high and low rates” on the control surface’s…… When taking off it required just a small amount of right rudder and we were off. It flew “right off the board” as they say, requiring about 1 or 2 clicks of up elevator for hands off level flight. I put the plane through rolls, inverted flight, Cuban eights and several other maneuvers before setting up for a landing. On reduced throttle the aircraft remained very stable and landed like a dream with no concerns. Someone asked me if that was the very first flight as they did not believe it was.
Aeromodels have several ARF models in the 60 to 90 size and I would recommend, if you are looking for a great flying, easy building ARF look them up and try one of their ARF’s. I do not believe you will be dissatisfied with it and they fly extremely well.

The difference between these two ARF’s. The Aeromodels ARF was the most easy aircraft that I have worked with. Everything fit perfectly and the model balanced right off the building board without adding any ballast weights. The World Models ARF Mustang 60.….the best thing I can say is, If you are not familiar with building model kits or building from scratch, I would not recommend this ARF. It required much modification to achieve the specifications on the instruction sheet. Further, there was not a great deal of instructions included so without building experience I believe someone would have some concerns assembling this air craft.
This is my opinion and not that of the Lorain County R/C club or any affiliate.

Rich Horvath