The Case for the Integral Power Plant

Part I
by Sanford A Moss, PhD, LLD,

Consulting Engineer, Supercharger Engineering Div, General Electric Co

Pro, Middle, and Con opinions on this significant power plant question are offered in this timely two-part series. Included are the cogent views of —
With a terse consensus of industry leaders and service men providing his critical medium. the author augments his earlier proposals for integral and standardized aviation power plants.

Let us advance two related propositions: First, that aviation power plants, especially when they include turbosuperchargers, be planned as integral units, completely self-contained; and second, that for each general type of airplane assembly, all power plant mounts and all plane structure supports for power plant mounts be standardized only so far as connection to each other is concerned.

Then for each type and/or horsepower of airplane assembly, different power plants will be interchangeable on a given plane, or a given plane can interchangeably use different power plants. In accordance with the integral plan, an aviation power plant would be built to form the front section of a nacelle — designed, assembled, and tested as a unit by groups specializing on this job. These power-plant specialists would arrange the assembly of engines, turbosuperchargers, generators, propellers, and all accessories, to get a. certain overall performance.

Other groups of aerodynamic specialists would, in parallel, prepare the plane up to, and including, the plane structure support for the powerplant mount. They would provide the bosses terminating this plane structure support, to which the integral power plant mount afterward would be attached. A firewall might be a part of the powerplant section, with the various accessories bolted on both sides of it.

Standardized Power Plants

Integral power plants would readily lend themselves to a standardized arrangement, so that any plane of a given general type would take any integral power plant of a corresponding general type. One might even dare to hope for a British-American standard — so that an American integral power plant would fit a British plane, and vice versa. Of course, there would have to be standards for mount fastenings, weights, center of gravity, thrust, gasoline, electric and control connections, etc. (See Fig 1)

The propositions made herein were discussed briefly during a recent Detroit meeting of the Society of Automotive Engineers but with only two and a half columns of publication of plan and discussion 1. We now offer a full and improved presentation of the plans together with the pro and con views of a number of eminent engineers, their opinions being added to those of the author in order to give a complete survey.

The situation with respect to single-engine planes is presented by A Kartveli, chief engineer, Republic Aviation Corp:

"It is believed that integral power plants are feasible in the case of fairly simple installations, such as those involving unsupercharged or single-stage supercharged engines. It is also possible that an integral power plant could be designed, for two-stage or turbosupercharged engines, which would be satisfactory on large multi-engine airplanes. It is extremely doubtful, however, that an integral installation involving a large and complicated power plant could be made standard for all pursuit type airplanes without making serious sacrifices in the performance or other qualities of the airplanes."
Kartveli has written out in detail a number of difficulties with an integral power plant with such single-engine planes, and he concludes:
"Then there is the question of balance. The pilot should be located forward for good vision and the fuel must be near the CG. With all this weight located forward, balance can only be attained by moving the wing so far forward on the airplane that the principle wing structure passes through the power plant installation.

"If any serious attempt is made to develop the integral power plant idea, it is believed advisable to start with the simplest power plants. If these prove to be of sufficient advantage to merit wide acceptance, the study could be extended to the more complicated types."

It is to be borne in mind that Kartveli is considering single-engine planes. But it may be hoped that ways will be found to solve his problems.

The general propositions presented here have for some time found actual employment in England. A report about this was made by J Carlton Ward, Jr, president of the Fairchild Engine & Airplane Corp, who was a member of a recent commission to England. He wrote2:

"We saw air-cooled engines going into fighters and liquid-cooled engines into bombers. We saw airplanes that could take either liquid or air-cooled engines. In other words, we saw the 'power egg' at work. By 'power egg' I mean a power installation wherein the engine manufacturer's task is not complete until the power plant is so placed in the airplane that it can give a maximum thrust horsepower".

J E Ellor, an English engineer of Rolls-Royce, Ltd, Derby, England, and who now is representing Rolls-Royce with the Packard organization in Detroit, has had actual experience in England with the items here discussed. Writes Ellor:

"A number of years ago, engine builders realized the many [benefits] to be gained if the airplane designer could be supplied with a proved integral power plant. This entailed the promoting of an additional establishment, with a group of power plant experts, complete power plant ground testing equipment, and numerous airplanes, to obtain full scale flight data.

"The results have been most beneficial in that the airplane designer is furnished with complete data on power plant and its installation, which will furnish maximum thrust for minimum drag and weight with the knowledge that the reliability of the combination has been proved. The benefit of the work is shown by the fact that three well-known multi-engine machines in Britain have similar integral power plants developed up to the bulkhead by the engine builder; this is, of course, in conjunction with the airplane constructor.

"Prior to the commencement of the present war, the Society of British Aircraft Constructors formed a committee from representatives of engine builders, aircraft constructors, and propeller and aerodynamic experts to study the possibilities of the interchangeability of integral power plants with air-cooled radial types and inline liquid-cooled types.

"The result of the studies made were really very encouraging and showed that by grouping the various engines into power classes, interchangeability was not only possible but practical, with surprisingly little concessions on cross-section of the bulkhead size.

"This study was made with particular reference to nacelles mounted on wings. It is, of course, conceded that improved airplane design may warrant rearrangement of power plant units, particularly of single-engine and twin-engine combat types. However, there will always be the heavier multi-engine type of craft in which integral power plants can be used to great advantage, and Dr Moss' proposals are well worth careful consideration."

This endorsement by Mr Ellor is particularly pertinent. Fig 2 and Fig 3 show two such English integral power plants made by the Bristol and Rolls-Royce companies, respectively and in present use. Illustrations also have been published showing similar plans with German planes.

The plan has been talked about in a vague way in America under the name "package power plant", "unit power plant", and "power plant ahead of the firewall", as well as "integral power plant". The new names, "power egg" and "ready-to-fly power unit" are shown herewith. Henry Ford's organization also has exhibited an ingenious plan of this general kind (Fig 4).

It is understood that there are many plane designs in which it is not now feasible to execute the integral power plant plan. But if the plan is good, the time may come when this situation will change.

Lt Comdr Scrymgeour has very kindly written a discussion that he heads "Laying the Egg Plant". It reads:

"Let us assume, for the sake of argument, that the power plant egg is a good thing, Okay, who is going to design this egg, and for what plane?

"I see that we will have various types of eggs because we have various types of planes, each having different requirements. Well, then, will some central agency say: 'This type egg will be installed in all dive bombers, this one …, etc.? Will this agency be a governmental function or detailed from and by the industry?

"And suppose there are six or seven manufacturers of horizontal land-plane bombers who not only feel they can improve on the egg sent them but can also prove it. Do they still have to use the egg laid before them and thus allow the enemy this unnecessary advantage?

"Or is this egg to be constructed to each manufacturer's specifications? If so, then the ideal visualized by Dr Moss would be out of the picture. Dr Moss is quite specific in expecting a standardized arrangement so that any plane of a given general type would take any integral power plant of the corresponding specification. But he didn't mean each manufacturer's specification.

"It seems to me that this standardization thing is being gone about backwards. It must be admitted that it would be very nice for every pilot to know he could in an emergency land at any field and find replacement parts for damaged material. But wouldn't this be more easily accomplished if the planes themselves were standardized? For example, when the Army put out bids for a certain type bomber, three manufacturers bid on it. One later withdrew, leaving the other two to design, build, and test their versions of the Army's general specifications. Having done so, one was probably better than the other and should have been concentrated on, even though one company would be building a plane designed by another.

"The point is that the Army would be getting the better plane and more of them, and they would be identical. Now they have to be careful to have spare parts available at each field whether or not that type is stationed there. And why? Just to satisfy the ego of the manufacturer who produced the poorer plane.

"Now for the replacement feature: Here again there are two angles to be considered — military and commercial.

"As for the military, whether in the field or aboard ship it will be much more convenient for the operating personnel to handle comparatively small, light objects. Handling the whole egg would be impracticable, if not impossible, without especially heavy gear, and while this is available in a carrier or at a home field, it's a pretty good bet it won't be at an advanced base — just where it would be most needed. The same argument holds for convenience and storage, especially aboard ship.

"Very few items in the egg will need replacement or repair sufficiently urgently to warrant replacing the whole egg. If the trouble is due to hits from gunfire, either of large or small calibre, it is probable that more than the egg will need replacement. If any accessory needs replacement due to malfunctioning from other causes, it will probably be about as easy for the ground crew to replace the known miscreant as to change the whole setup, including all lines and wires.

"In the commercial field, the aviation world might offer a better nest for the power plant egg. I say 'might' advisedly, for the same arguments re: repair or replacement of parts when possible, rather than the whole egg, will hold even more tenaciously here because of one little item often forgotten when comparing military with commercial aviation — that is, manpower and the cost of maintaining same. In peacetime the armed forces not only can change at will the number of planes they operate, but they don't have to meet competitive schedules and they don't pay their men by the hour or have to show their shareholders a profit. Men work until their tasks are completed and they don't get anything extra in peace or war, much less time-and-a-half.

"All in all, then, many cases can be pictured where the power plant egg not only would be welcome but helpful. But in any case it would apply only to that model plane for which it was designed. The simplest answer to that is that no airplane manufacturer in the United States employs exactly the same power plant installation in any two of his own models, much less the same as that in the product of any competitor. In fact, many use different installations in the same model.

"In spite of the opinions of various fireside experts (Dr Moss obviously fails to fall in this category) this is not bullheadedness on the part of the manufacturers. They make what their customers want. If they don't, they go out of business. It is this very variety and competition between designers which is responsible for the extremely rapid advance in aircraft power plant installation design in the last few years. Competition is not only the life of trade — it is also the very essence of progress and improvement.

"In any case, my personal opinion is that Dr Moss' picture of interchangeability between plane models not only is not attainable but it is also undesirable if we expect or want improvements and progress, which we all most certainly do both in wartime and peace."

Thus, Comdr Schrymgeour concludes his side of the discussion, but it by no means eliminates an opposite point of view. Rather, it is to be borne in mind that the plan we are presenting in this two-part series (and as illustrated in Fig 1) will destroy no initiative but instead will lead to aviation power plants so specialized as to represent an united art. In this way, there will be accomplishment of all the progress hoped for both by Comdr Scrymgeour and by the author.

Advantages of Integral Power Plants

To American engineers and manufacturers, who have brought standardization to such a high pitch, the advantages of this integral power plant plan should seem obvious. No doubt the plan was originally started to permit rapid replacement of power plants or airplane structures damaged in the field during war. We in America have not been up against such problems very long, and so perhaps we have not caught up with the integral power plant scheme in spite of our boasted skill at mass production.

But ease of replacement is a major advantage both in war and peace. Rapidity of production so much needed in wartime now is being furthered by the manufacture of various components in parallel as independent groups which are later assembled to give a complete apparatus. The integral power plant helps this nicely.

The integral plan will enable improvements to be made with greater ease. A redesigned power plant section can be used with an existing plane design, or a redesigned plane with an existing power plant. And there surely will be redesigns.

Discussions of the Plans

After the brief presentation of these plans at the aforementioned SAE meeting, a little discussion was published. Since then a number of engineers have been kind enough to send the writer additional discussions. Here in Part I, four men have been quoted, and in our concluding Part II the views of various other men will be offered. Particularly it will be seen that these engineers have quite different ideas, both pro and con, all of which bear pertinently in our analysis.

We will open Part II with a consideration of turbosuperchargers in integral power plants. Then we will present our proposals of a definite plan for the integral plant system which it is hoped takes into account all of the pros and cons expressed by the industry and service men in our symposium.

1 SAE Journal, Feb 1943.
2 Aero Digest, Mar 1943.

The Case for the Integral Power Plant

Part II
by Sanford A Moss, PhD, LLD,

Consulting Engineer, Supercharger Engineering Div, General Electric Co.

Providing a critical medium through a terse consensus of industry leaders and service men. the author augments his earlier proposals for integral and standardized aviation power plants.

We Have Considered (Part I) our two related propositions of

  1. planning aviation power plants as integral self-contained units, and
  2. developing standardized mounts and plane strueture supports specifically for interconnection of the two.
Further, we have presented and discussed the views, concerning the integral plan, expressed by Messrs Kartveli, Ward, Ellor, and Comdr Scrymgeour.

We now will treat of turbosuperchargers in the integral power plant, following which we will quote the opinions of other men who have contributed discussions. And finally, following the subheading "Standardized Power Plant Plan" and again referring to our first Figure we will offer a definite plan which it is hoped takes into account the various pros and cons.

Turbosuperchargers in Integral Power Plants

The writer has been intimately associated with turbosupercharger development and hopes that the entire turbosupercharger addition to the airplane engine will become a part of the integral power plant. This would include the turbosupercharger itself, the flexible joint connecting it with the exhaust manifold, the ducts with ramming intake supplying cooling aid to turbosupercharger and air cooler, the supercharged air ducts from turbosupercharger to air cooler and air cooler to engine intake manifold, the air cooler, and the exhaust ducts. It is to be expected that this will be a marked improvement over many existing designs where the turbosupercharger parts are independent entities with lengthy duct connections.

Figs 5, 6, and 7 [not shown —JLM] show integral power plants with turbosuperchargers, designed and constructed in cooperation with the Army Air Forces, 1921 to 1924.

Later, when turbosuperchargers came to be applied to various sorts of existing airplanes, the integral power plant plan dropped into disuse, in spite of its advantages then and now. Fig 8 is a rough sketch of an integral power plant including a turbosupercharger, as it now might be laid out.

Robert Winslow, of the Continental Aviation & Engineering Corp, states:

"Putting the turbosupercharger so near the engine would have the effect of increasing the already too high exhaust gas temperatures, so this would require that exhaust coolers be used more often."

The author realizes that this has, in the past, been a consideration. However, the ability of the turbosupercharger to take high temperatures is improving, and perhaps the point that Winslow makes will become less of an item in the future.

Continuing now to the quite different ideas on the integral plant plan expressed by the various engineers pro and con — ideas all of which seem worthwhile to include — we will first consider the opinions of C A Stamm, engineer of the Chrysler Corp. Incidentally, the author hastens to say that he regrets that the space available does not permit inclusion of all of the discussions which were sent to him. Paragraphs given are quoted in full, and it is thought that they present the ideas of the various gentlemen.

Says Stamm:

"The adoption of integral power plants using either engine-driven or turbosuperchargers seems very desirable from the standpoint of airplane operators, airplane builders, and engine manufacturers. Service, maintenance, and overhaul should be simplified by having all units of the power plant located in one group, detachable from the airplane as a single unit. Design and construction should be simplified and expedited by centralization of these functions with the manufacturer of an integral power plant. Overall efficiency of the power plant should be increased because of optimum design of the component units and the connecting ducts.

"The adoption of an integral power plant unit to a large multi-engined airplane should present no difficulties, but the application to a single-engined airplane presents serious problems. These problems become even more severe when the trend in liquid-cooled engine installations is to move the radiator away from the engine to some point in the fuselage or wing in order to decrease the cooling power losses. This is contrary to the integral power plant idea."

Charles W. Morris, of the AiResearch Mfg Co:

"It was the writer's privilege to have been associated with Dr Moss during the past three years and to have reviewed this paper in the course of its preparation. This paper is its own testimonial to the continued mental agility of its author, and this subject is quite provocative of discussion — detailed discussion.

"The basic goal of Dr Moss' paper appears to be that complete power plant assemblies should be interchangeable between airplanes of different models and different manufacturers. In wartime, this is of tremendous importance. Whereas considerable debate will undoubtedly develop between the proponents of accessories which operate by electrical means or hydraulic means, it appears that engine mountings and basic engine connections might be standardized in some fashion. This would permit ready interchangeability for emergency operation of an airplane, if necessary. Such interchangeability would be the service engineer's dream; meanwhile, the present arrangement might be considered his nightmare.

"The present DC-3 type of airplane has Wright and Pratt & Whitney engine installations which are basically interchangeable. If this interchangeability could be extended to the other models of airplanes which are powered with these same models of engines, a marked improvement of service interchangeability might result.

"There is no question of the over-all desirability of such a manifold interchangeability, but there is a strong question as to its practicability. While I disagree with Dr Moss on some details of his proposed 'integral power plant,' his call for its reconsideration should produce some needed advancement in interchangeability. Some definite suggestions should and will be offered to the proper authorized standardizing group."

Kendall Perkins, of the McDonnell Aircraft Corp:

"The proposition advanced by Dr Moss, although frequently advanced, has never taken root in this country.

"First it should be remembered that in thinking of the national production problem there is not one engine to be considered, but many. There are perhaps two dozen engines of various power and type being built in this country after several years during which serious attempts have been made to eliminate unnecessary types. A few of these, such as the P & W R-1830 and the Wright R-1820, are interchangeable at least to the extent that one may be substituted for the other in a given airplane without major effect on performance. Even in such cases, however, it has not proved feasible to discontinue production of a recognized engine in the interest of standardization and there seems no hope of materially reducing this number.

"If we then accept the inevitable necessity for using a number of different engines of various power and type we can then say: 'Let us at least have a standardized integral unit to go with each engine model.' However, we are immediately faced with more variables. We find that one airplane can best perform its function when equipped with a turbosupercharger. Another does best with a two-speed gear-driven supercharger. The differences required in the power plant for these and other similar variables are, as it works out practically, enough to require a basically different arrangement in each case. While all the arrangements would not apply to all of the engines, it is quite possible that as many as 40 'standardized' combinations would eventually be needed.

"Reference was made to overlook no possible arrangement having its proponents, power plants may also soon be seen in the rear of the fuselage. Each position requires individual cowling and different ducting involving many basic variations in installation.

"Looking now at the other side of the coin. there is a great deal to be said for setting a limited objective along the path indicated by Dr Moss. It has been obvious to many within the industry that in time of war parallel work by a number of different manufacturers with the same or similar problems is wasteful. To a very limited extent this has been reduced by the interchange of information between manufacturers and to a somewhat greater extent by the migration of personnel. Much more could and should be done to prevent this wasted effort, particularly since personnel migration is being largely checked.

"There seems to be little doubt that in time of war such procedure could considerably accelerate the development of new aircraft and result in more and better airplanes. It is suggested that there is ample opportunity for carrying this a great deal further."

Louis E Barnes, of the Fisher Body Detroit Div, General Motors Corp:

"There are a great many of us who realize that we have for some time practiced in this country what might be reasonably called a quick-change of the engine itself, but aside from general discussion and experimental work on a small scale, nothing has actually been done in the matter of producing a quick-change of the power plant unit, even though we are, in the main, open-minded and production conscious.

"The most advantageous possibility it seems now, in considering the subject, is the interchangeability of power plant units of the same or similar design in one type of bomber or cargo plane. During war we like to maintain a bomber in flyable condition at all times. A badly damaged or inoperable power plant could be more quickly replaced than repaired in most instances, if the quick-change power plant unit were used. It no doubt would be far better to change a power plant quickly by this method than to attempt replacement or repair of a power plant part, Meanwhile holding up the whole airplane.

"The peacetime counterpart in maintaining flyable aircraft is obvious. We have, even now, several airplanes which are quite well adaptable to this type of power plant installation without appreciable change of anything except the attaching point; instead of concentrating on quick-change of the engine alone, it seems advisable to drop back a few more feet and take in, perhaps, the nacelle proper, which could possibly include all the immediate power plant accessories and others such as would comprise the entire engine oil and induction systems. This thing is not such a remote possibility. The necessity for it will bring about actual realization.

"The accomplishment to be gained as the result of determined study on this subject would indeed be of amazing value and quite an eye-opener. However, there is more than just power plant packaging lying beneath the surface of the subject; there is also, among other things, general standardization possibilities and service life computation of various parts.

"Time spent by a committee on this subject would surely be well worth while."

Col George C Crom, of the Army Air Forces Materiel Command, Wright Field:

"The idea of a unit power plant, integral and interchangeable, is a very logical one. It presupposes the layout of the engine and all its auxiliary apparatus by experts familiar with each part, with supervision by competent engineers such that each part has proper consideration for the operation of the other auxiliary plants. If the integral power plant were available at the present time, it would be of great benefit in the battles now being waged against our enemies.

"It seems essential in the development of the unit power plant that the aim be to incorporate all those devices that will increase the over-all efficiency of the power plant. The turbosupercharger, which largely utilizes waste power from the engine, definitely should be a part of the power plant.

"The proper utilization of the integral power plant can only be accomplished by unit type of control, which will allow the most efficient operation of the entire power plant when efficiency is desired, and also will allow the maximum power when maximum power is desired."

T P Hall, chief development engineer, Consolidated Vultee Aircraft Corp:

"For certain types of airplanes, built and employed in large numbers under wartime conditions, the adoption of integral power plants is desirable in the interest of production and maintenance alike. This is particularly true for large multi-engine airplanes with air-cooled engines.

"The problems pertaining to the creation of specifications and designs acceptable to all parties concerned could be handled through the Society of Automotive Engineers or the Aeronautical Chamber of Commerce of America.

"The integral power plant should include all the equipment needed for the propulsion of the airplane, fore and aft of the firewall. A certain flexibility of design with regard to the location of turbosuperchargers, intercoolers, and oil coolers will be necessary, in order to make a given integral power plant applicable to various installations with only minor changes in the arrangement of the ducts. Standard attachments should be provided for those accessories, which may vary with the type of aircraft. It will be necessary to overcome some unavoidable patent difficulties.

"An obvious advantage of the integral plant is its interchangeability in case of a major failure. It should be possible, however, to simplify assembly and maintenance work by well-planned designs since the entire power plant will be designed by a single engineering group for each integral type.

"It is expected that the integral power plants will be assembled by the aircraft manufacturers or their specialized subcontractors. This will be necessary to prevent dislocations of the present production setup and to avoid unnecessary shipping of parts and accessories back and forth across the continent.

"It is our opinion that the creation of integral power plants is a result of the present military necessity of obtaining a great number of standardized airplanes. We feel that the standardization of certain power plant installations should not be allowed to interfere with a continued progress in the design of new and unusual airplanes and power plants.

"A discussion of the possibilities of the integral power plant for commercial purposes appears to be premature at this time."

Engineering of Integral Plants

So far as can be told from current literature, the engine builders have taken the initiative with the integral power plant plan in both England and Germany. But an opposing idea suggested that the initiative for creating integral power plant design must remain with the plane builder along with the responsibility. But in any event, the integral power plant plan would best be executed by specialized groups devoting themselves exclusively to the design and manufacture of integral power plants. The designers and manufacturers who are producing modern airplanes have done a, wonderful job, but the complications are getting greater and greater. The integral power plant plan would advance the arrangement, which already exists to some extent, of specialization by independent experts, on design and manufacture for

  1. airplane design and construction;
  2. airplane engines;
  3. turbosuperchargers;
  4. propellers;
  5. generators, and other airplane accessories,
  6. assembly of (2), (3), (4) and (5) as the integral power plant.

    Such specialization already has come about in the design of steam power plants, and specialists design and erect an entire power plant, including boilers, engines, and all accessories. Exigencies of war now have introduced a similar plan so far as manufacture of only one aviation power plant is concerned, and all power plants for a certain type of plane now are being assembled and tested in a single factory and supplied to various other manufacturers among whom the production of the plane has been divided.

    Execution of the proposed plan may result in cutting a shoot from the parent aeronautical stem and starting to grow it as a separate integral power plant tree. As science and engineering have progressed in the past century or so, engineering groups often have been subdivided in this way. Once there were only military and civil engineers. Then as engineering complexity increased, there budded off from the parent stem of civil engineering shoots which have grown into mining engineers, mechanical engineers, electrical engineers and, recently, steam powerplant engineers. Engineering of water ships (we now have to say it this way) is divided between marine engineers and naval architects. The rapid increase of complexity of the airplane, since the Kitty Hawk model of 1903, would seem to demand similar specialization of the airplane and the power plant groups.

    Standardized Power Plant Plan

    A number of gentlemen have been kind enough to provide the written discussions which have been quoted, for which the author is greatly obliged. There seems to be no serious difficulty with the integral power plant plan, except possibly for single-engine planes. Difficulties that seem to be feared are mostly as regards standardization. A definite plan for this which would seem to meet most of the objections mentioned (see Fig 1) and the details, resulting from the discussions, are as follows:

    The integral power plant plan means that the structure which has been called the "engine mount" now becomes a "power plant mount" with four bosses, which carries the whole power plant. A part of the airplane is some sort of structure which supports four other mount bosses to which the power plant mount bosses are attached. This may be called the "plane support for power plant mount." This general plan of the two attached sets each of four bosses, is readily standardized, and it would seem easy to take the only remaining step.

    This is that center-distance and thickness of these mount bosses be standardized for each general type and/or horsepower of airplane assembly, on both the power plant mount and the plane support for power plant mount. the structure of the power plant, its mount, and of the airplane and its plane support for power plant mount, then can be as variable as different manufacturers want, so long as the center distances and thicknesses of both sets of bosses are standard for each type and/or horsepower.

    Perhaps there might be needed standards for distances of center of gravity from the section of the mount bosses, for various weights of power plant, in order to preserve a standard moment of the power-plant weight. Gasoline and electric and control connections also must be standardized.

    Presumably there would be a firewall at this section of the mount bosses, perhaps as part of the power plant section. But the outer diameter of the nacelle at this point need not be standardized; it could be different with every particular combination of power-plant section and airplane. Then there would be a standard maximum outer diameter of the firewall somewhat less than the smallest one of the diameters of the nacelles of the various combinations. There then could be a non-standard ring to extend the firewall to the nacelle diameter for each of the different combinations.

    There also could be non-standard designs of each cowl or outer skin, for each sort of power-plant section and each sort of airplane, extending to within a short distance on either side of a firewall at the mount bosses. There would then have to be a short cowl or skin section extending on either side of the firewall (different for each combination) in order to fair in with the non-standard skins of particular planes.

    Further discussion might disclose better details of the general plan than here proposed by the author, who is not an airplane designer. But it would seem that the proposed standardization merely concerns the minor item of the location of the mount bosses on power plant mount and plane support for power plant mount. There remains complete latitude for individual design of every essential part without any cramping of individual initiative of either plane builder or power plant designer.

    Various plans of the integral and standardized type here proposed have been talked about, but the present paper is written because the author thinks the matter needs pushing. The proposition of putting such plans into execution reminds the writer of a cartoon published some years ago: A number of executives were standing in a circle, and each one, when asked who should undertake responsibility in a certain matter, pointed to the next one in the circle and said, "It's up to him".

    One way to start might be the appointment of a committee of representatives, from the interested bodies, to study the situation. With existing experience here and abroad, a definite proposal might be agreed upon for standardization of the items here proposed or of similar ones. Let's start.

    This two-part article was originally published in the September and October, 1943, issues of Aviation magazine:
    Part I: September, vol 42, no 9, pp 150-151, 321, 323, 325-326.
    Part II: October, vol 42, no 10, pp 148-150, 276, 278-279, 281-282.
    The original article includes 6 photos and 2 diagrams, one repeated between parts.
    Photos are not credited. Diagrams are not credited, but seem to be from the author.