(See Page 1263, Whole No. 234)
Lieutenant R. G. Pennoyer, U. S. Navy.—Commander Jackson has given the service an excellent idea of the "Employment and Tactics of Aircraft in Naval Warfare," and in view of the fact that his article is one of the first and most exhaustive ever written on this subject for the benefit of the Naval Service, it is of particular interest and value.
The author has been careful to state in his footnote that since the author is not an aviator, many of the statements in this article regarding conditions in the air have been taken from the expert opinions of aviators. Undoubtedly these advisers have been heavier than air pilots, and from the standpoint of the heavier than air pilot there is very little in this article to criticize.
On the other hand these advisers have had very little if any experience with lighter than air craft, particularly rigid airships, and in consequence the author has made a very bad case for this type of aircraft.
In paragraph 15 he states, "The largest dirigibles must above all have endurance and ability to keep the air under adverse conditions of weather. Their speed and climbing power are moderate." To state that the speed of this type of craft is moderate is quite true if one compares their speed with that of a fighting plane; on the other hand they have a full speed over twice as great as the speed of our fastest destroyers, a cruising speed of two and one-half times the cruising speed of a destroyer, and a full speed of about eighty-five per cent of that of a large scout seaplane. Furthermore, the statement that their climbing power is moderate is entirely inaccurate. Experiments to determine the rate of climb of rigid airships, made by the German Navy during the late war, gave in one instance a climb of 3,250 feet per minute, and all craft of this type are capable of climbing 20,000 feet in ten minutes without difficulty. I am safe in declaring that no airplane in our navy or in any other navy is capable of such a rate of climb. The ability of an airplane to climb falls off rapidly with increase in altitude, whereas altitude makes no difference in the climbing of a rigid airship.
In paragraph 16 Commander Jackson makes the following statement, "Dirigibles can operate only from the shore, and therefore cannot be counted on for reliable use with the fleet. This was demonstrated at the Battle of Jutland, by the failure of the German Zeppelins, in spite of the proximity to their bases at which the action took place." The first day of this battle was undoubtedly a failure on the part of the Zeppelins, brought about by the adverse weather conditions (fog) existing at the time, and although four Zeppelins were out they were not of much assistance. Eleven Zeppelins did, however, go out on the second day and assist the High Sea Fleet in regaining its base without loss. Since the Battle of Jutland the British have perfected the mooring mast which makes the rigid airship independent of all except the worst possible weather, which in this respect certainly places the rigid airship on a par with any other type of aircraft.
In this connection the mooring mast experiments carried out with an obsolete underpowered type of airship, H.M.A.R.-33, at the British Airship Base, Pulham, England, will probably be of interest:
Number of days at the mast, 111
Number of flights from the mast, 50
Number of night landings at mast, 4
Hours flying, 171 hours 9 minutes
Maximum wind on leaving mast, 40 mph
Maximum wind on landing at mast, 26 mph
Maximum wind experienced while moored, 55 mph
Maximum wind experienced during flight, 50 mph
Heavy rain, hail, snow and thunder storms were experienced with the ship riding readily at the mast.
In addition to the above, work like changing engines, removing and replacing gas bags, and repairs to outer cover were carried on. Naturally operations like refueling, gassing, etc., were also carried on at the mast. As a result of these experiments the Navy Department has erected a larger and more efficient type of mooring mast at the Naval Air Station, Lakehurst, N.J. With such masts erected at all Fleet Bases, rigid airships can certainly be depended upon for "reliable use with the fleet." The next step which naturally suggests itself is the erection of a similar mast on a special aircraft carrier. It is suggested that an obsolete battleship could be taken for this purpose, and the foremast readily converted into a mooring mast, and thus a mobile base for rigid airships obtained. Mooring masts for rigid airships are a fact, and are outside of the experimental state. The application of mooring masts to surface ships, is a suggestion which the writer believes is entirely sound and practical.
As a matter of fact rigid airships can be towed by ships much more readily than can kite balloons, and in good weather gassed and fueled as kite balloons are today. During the war a German rigid, the L-23, actually landed on the water alongside of a merchant ship and put a prize crew on board, after which the ship was successfully navigated into a German port.
Paragraph 41 states, "Seaplanes are in existence with a radius of 1,200 miles." If the author means by radius the total distance the seaplane can fly before refueling he is quite correct, but on the other hand the total distance this type can perform scout duty is only one half of this distance, or 600 miles. This distance would be increased a bit if the seaplane were scouting ahead of an aircraft carrier or tender, by the distance covered by the tender, possibly 250 miles additional. On the other hand rigid airships are in existence with a scouting radius of over 3,500 miles, capable of flying a total distance of over 7,000 miles without refueling, and this at a speed of over 50 miles an hour. The L-72 for instance, now in the possession of the French, was designed for the express purpose of bombing New York. It is readily seen the tremendous areas aircraft of this type are able to cover in a short time. The author further states that dirigibles cannot be employed in the face of effective aerial opposition. No more can these comparatively slow moving scouting seaplanes. They are no more of a match for fighting type of aircraft than is the rigid airship. The latter can depend upon its climbing ability to keep away from pursuit planes, and can also carry a fighting plane for defensive purposes. On the other hand the only defense a scouting seaplane has against pursuit planes is to land on the sea, such that the fighting plane will not be able to dive downward on the seaplane delivering machine-gun fire directly at the sea plane, but must be content with rapid maneuvering and fire at the sea plane while stationary on the water. It is easy to see the great disadvantage at which the sea plane is placed. Commander Jackson has stated that due to the comparatively low speed of the scouting plane it would not be able to escape when discovered by enemy fighting planes out of supporting distance of its own fighting planes. In this respect the rigid airship is quite superior since it can depend upon its superior climbing ability to escape.
On the other hand it is not expected that effective aerial opposition will be met with, except by chance, until in the vicinity of the enemy surface forces. It is true that a rigid airship is not as easy to conceal as an airplane, but certainly it should be able to see as quickly as she is seen, and then depend upon her superior climbing ability to escape, and her powerful long range radio equipment to get information to the Commander-in-Chief. The position of the enemy forces thus obtained will be much more accurate than where obtained from scouting planes. Commander Jackson is quite correct when he states, "Astronomical observations are difficult to take and untrustworthy due to the inaccuracy of estimating the height of eye, and the discomfort and exposure of the observer," provided that he is speaking only of heavier-than-air craft and small dirigibles. The navigation of rigid airships presents problems not greatly in excess of those found on a destroyer or submarine. The navigator works in a closed comfortable cabin, and by the use of accurate bubble or pendulum sextants (now on the market), he can make observations any time day or night and not have to depend upon a horizon or height of eye, with an average error of about ten miles, and at the worst certainly not more than twenty miles in error.
Again in paragraph 62 the author states, "The difficulty of maintaining large rigid dirigibles with the fleet far from their shore bases would practically preclude them from this duty," (protective scouting). I have already stated the means by which these craft may be maintained with the fleet, that is, by mooring masts at all fleet bases, by a mooring mast installed on a surface ship, or simply by towing from a surface ship as a kite balloon is towed. The difficulties are no greater, if as great, as the present difficulty of maintaining kite balloons with the fleet.
The author has stated that, "In any case it cannot be seen that dirigibles possess any greater advantages over surface craft for protective scouting except speed and greater radius of vision due to their higher altitude." After all is said and done are not these the two most important considerations? Then again he states that, "against aeroplanes they would be helpless." I admit that in case the rigid dirigible remained stationary and permitted the enemy aeroplanes to come up and shoot at her, it would very probably prove disastrous for the airship. On the other hand the safety of the airship depends upon its climbing ability. The pursuit planes at present in use in our navy have a maximum rate of climb of 15,000 feet in twenty-four minutes and a ceiling of 20,000 feet; against this a rigid airship can climb 15,000 feet in seven minutes and has a ceiling of 25,000 feet. The answer is quite obvious.
The purpose of this discussion has not been to detract from the aeroplane, for Commander Jackson has very ably presented its case, but on the other hand I have attempted to show the value of the rigid airship.