The court having thoroughly inquired into all the facts and circumstances connected with the loss of the U.S.S. Shenandoah, and having considered the evidence adduced, finds as follows:
I. Matters entirely antecedent to the inception of last trip of Shenandoah but having a material bearing on this inquiry.
Facts
1. The design of the Shenandoah was begun under the cognizance of the Bureau of Construction and Repair in 1919. When the Bureau of Aeronautics was created and organized in 1921 all matters connected with the design and construction of the airship were transferred to that bureau.
2. At the request of the Bureau of Aeronautics, the National Advisory Committee on Aeronautics appointed a technical committee of five, composed of scientists and engineers of national reputation, to examine the design, methods, and assumptions used, as well as the actual design of the Shenandoah. This committee, after prolonged study, completely approved the design of the airship as prepared.
3. The airship was built at the United States Naval Air Station, Lakehurst, New Jersey, was completed in 1923, made its first flight on September 4, 1923, and was commissioned as the U.S.S. Shenandoah in October of the same year.
4. In the design of the Shenandoah approximately 4 per cent more of the total lift was assigned to the hull structure and fittings than in the design of certain foreign rigid airships for which comparative figures were available. As finally completed, the weight of the ship exceeded the designed weight by approximately 1 per cent.
5. The only major casualty suffered by the Shenandoah prior to the start of the Midwest flight occurred in January, 1924, when it was torn from the mooring mast at Lakehurst by stress of weather. The ship was thoroughly inspected and repaired after this accident.
6. Prior to the Midwest flight, the Shenandoah had cruised a total of approximately 740 hours in the air, covering approximately 25,835 statute ground miles, of which 605 1/2 hours and 20,761 miles, including a transcontinental flight, was made subsequent to January 16, 1924.
7. A majority of the officers and crew had served in the Shenandoah continuously from the time of commissioning up to and including the Midwest flight of September 2, 1925. Many of these had received previous training on rigid airships abroad.
8. In accordance with the provisions of the National Defense Act of 1920, and upon recommendation of the Joint Army and Navy Board, approved by the Secretaries of War and Navy, the Navy was charged with the sole responsibility for the procurement and development of rigid airships for use over both land and water.
9. The U.S.S. Los Angeles was obtained through an international agreement that it should be used for commercial purposes only and was assigned to the Navy for operation. The Navy is charged with the development of rigid airships for commercial as well as for military purposes.
Opinions
1. The Shenandoah represented the best practices in design and construction at the period of its building.
2. The proportionately greater weight for structure and fittings of the Shenandoah resulted in increased strength.
3. The damage to the Shenandoah due to breaking away from the Lakehurst mooring mast was fully repaired and no loss of strength ensued as a result thereof.
4. The officers and crew of the Shenandoah were skilled and competent operators of rigid airships.
5. The operation of rigid airships over land, as well as over the sea, is a proper and powerful function of the Navy.
II. Matters leading up to the flight of the Shenandoah beginning September 2, 1925.
Facts
10. The Navy Department had received 248 requests from public officers, public and semi-public bodies, and individuals for a flight of a rigid airship over the Middle West.
11. On June 7, 1925, in obedience to orders from the Navy Department, the Los Angeles started a flight to Minneapolis, but due to engine trouble returned to Lakehurst in accordance with the decision of the commanding officer after completing only the first part of the flight.
12. On June 9 the Chief of Naval Operations informed the commanding officer of the United States Naval Air Station, Lakehurst, and the commanding officer of the Shenandoah that that airship, which was then deflated, would be ordered to make the trip previously scheduled for the Los Angeles as soon as the former could be made ready, helium transferred, and the airship placed in active service.
13. In letter, dated June 15, the commanding officer of the Shenandoah recommended that such a flight be postponed until September on account of the probability of unfavorable weather Conditions in the Midwest during July and August. Prior to the receipt of this letter the Chief of Naval Operations had issued orders, dated June 19, for a flight over the Midwest by the Shenandoah as soon as ready.
14. Upon its receipt the letter to the commanding officer of the Shenandoah of June 15 was considered by both the Chief of Naval Operations and the Chief of the Bureau of Aeronautics. As a result the commanding officer of the Shenandoah was ordered to Washington for consultation. On June 30 the consultation was held, at which the Chief of Naval Operations, the Chief of the Bureau of Aeronautics, the commanding officer of the Shenandoah, and the head of the Ships’ Movement Division of Operations were present.
15. As a result of this conference, the orders of June 19 were revoked.
16. A mooring mast for rigid airships had been erected at Detroit, Michigan, by Henry Ford, and was completed about July 9. The Navy Department had been requested to send a rigid airship to Detroit to test this mast, the first to be erected in this country by private enterprise.
17. In letter dated July 20, the Chief of Naval Operations directed the commanding officer of the Shenandoah to submit an itinerary for a Midwest flight to pass over as many of certain specified cities as practicable on dates in the early part of September, when state and county fairs were scheduled to be held, and to test the mooring mast at Detroit.
18. In reply, dated August 4, the commanding officer of the Shenandoah recommended two separate flights, the first during the last week in August to Detroit to test the new mooring mast and the second beginning September 7 over the entire route covering the specified cities.
19. The Chief of Naval Operations after consultation with the Chief of the Bureau of Aeronautics, directed one flight only in lieu of two, this flight to begin September 2. The orders dated August 12 directed this flight.
Opinions
6. The commanding officer of the Shenandoah was fully consulted and given every opportunity to state his views in regard to the Midwest flight.
7. The commanding officer of the Shenandoah did not at any time express opposition to or any reluctance in undertaking the flight beginning September 2 on the ground of possible adverse weather conditions.
8. The object of the Midwest flight was threefold, viz.: to test the mooring mast at Detroit, to continue training of personnel, and to comply with many requests received from citizens of that section of the country that such a flight be made.
9. While recognizing the propriety and necessity of the legally constituted authorities in the naval service being the sole judges of the sufficiency of the reasons actuating all orders to naval craft, and further recognizing that the practice of ordering movements of naval vessels for the purpose of complying with public requests is in accord with long-established custom, it is considered that such movements should be limited to essentially naval and military operations insofar as possible especially in the case of new and experimental types.
III. The condition of ship and crew at time of flight.
Facts
20. The ship was fully manned and equipped and in material readiness for flight.
21. Frequent and careful inspection of the entire structure of the ship had been made throughout its life. In addition, material similar to that in the structure of the ship had been kept under observation and been subjected to tests under instructions of the Chief of the Bureau of Aeronautics.
22. Extensive tests of material selected from widely separated parts of the structure after the wreck were made by the Bureau of Standards.
23. Both sets of tests have shown a limited deterioration of the material in the form of inter-crystalline corrosion, which deterioration to the extent found does not affect in any substantial degree the ultimate tensile or compressive strength or the modulus of elasticity of the material but does largely reduce its ductility.
24. The design of the structure of the Shenandoah was based on ultimate failure of individual girders in compression. The design of these individual girders was such that under compression they would fail through flexure by instability. This failure would occur before the stress in the separate members of the girder had reached the elastic limit of the material and was, therefore, dependent upon the modulus of elasticity only, and not upon the ultimate strength of the material.
25. In letter, dated September 16, 1924, the commanding officer of the Shenandoah first proposed certain changes in the system of gas valves of that ship and subsequently renewed his recommendations in letters dated December 15, 1924, January 9, and May 12, 1925, and in telephone conversation of May 28, 1925. The commanding officer of the Naval Air Station, Lakehurst, concurred in this recommendation. Although the Bureau of Aeronautics at first questioned the advisability of this change, it finally approved it in letter of May 28, as an experimental installation, and in letter of June 13 transmitted to the commanding officer of the Shenandoah a design memorandum showing the effect of this change in reduction of the maximum safe rate of rise above pressure height of an airship, so equipped. This change, involving a reduction in number of automatic valves, was made in the latter part of May and early part of June. As a result, the Shenandoah was equipped with automatic valves in gas cells Nos. 4, 5, 8, 9, 12, 13, 16, and 17 and with maneuvering valves in gas cells Nos. 4, 6, 7, 10, 11, 14, 15, and 18. Subsequent to this change and prior to the Midwest flight, the Shenandoah had cruised about 186 hours, covering about 6,750 statute ground miles, not including Midwest flight.
26. Certain other changes, not contemplated in the original design, including removal of No. 6 engine, installation of water recovery apparatus, removal of manometers, due to the fact that no entirely satisfactory type has yet been developed, and other minor alterations, were made subsequent to the completion of the Shenandoah.
27. The Shenandoah was equipped with only two parachutes, which were carried for the purpose of landing personnel in order to make ground preparations in case it became necessary on any flight to make an emergency landing at a point where preparations had not previously been made.
28. The manual of the Bureau of Aeronautics required: “Parachutes— (a) Parachutes will be worn by all personnel in all types of aircraft when available. Specific exemptions may be made by commanding officers when their use increases the hazards of the personnel.” The established practice at the Naval Air Station, Lakehurst, on both the Shenandoah and the Los Angeles was to carry only two parachutes.
29. The officers and crew of the Shenandoah were well organized, well trained, and highly skilled in performance of their duties.
Opinions
10. Deterioration of structural material was not a direct or indirect cause of the loss of the ship.
11. The deterioration shown to exist was not due to local causes but was generally distributed throughout the structure. It was not due to any lack of care or inspection in its manufacture and fabrication nor to neglect of proper measures for care and preservation in the ship after completion.
12. The court concurs in the opinions of expert witnesses that the rate of deterioration would not affect the safety of the structure of an airship for a much longer period than that covered by the life of the Shenandoah.
13. Material of this character will, until more thoroughly known and understood, require careful handling and observation during fabrication and while in service, but no evidence adduced before this court indicates that its use in the structure of rigid airships is unsafe or inadvisable.
14. The court concurs in the opinions of all qualified experts in the operation of rigid airships, who appeared before it, that the wearing of the present types of parachutes would add to the general risks and hazards of handling such ships due to their interference, especially in emergencies, with the quick and efficient performance of duty by the personnel. The court is, therefore, of the opinion that the judgment of the commanding officer in regard to carrying parachutes was sound. The present practice is adequately covered by the paragraph in the Manual of the Bureau of Aeronautics quoted in F-28.
15. None of the changes referred to in F-26 were contributory to the loss of the ship. The successful development of a thoroughly dependable type of manometer or gas pressure gauge giving accurate readings in the control car for each gas cell would be a contribution to safe operation of rigid airships.
16. Every effort should be made to develop and perfect such type of parachute as could be worn in an emergency without undue handicap in the performance of duty.
IV. The flight from start to about 5:22 a.m. (Eastern Standard Time), September 3, 1925.
Facts
30. The flight was made in obedience to lawful orders, issued by competent authority, and containing a prudential clause as follows: “Should the dictates of safety and the weather conditions existing make it advisable, the commanding officer of the Shenandoah is authorized to make such modifications in the above itinerary as he deems necessary, remembering, however, that this route will be published in the press and that many will be disappointed should the Shenandoah fail to follow the approved schedule.”
31. Before leaving the Naval Air Station, Lakehurst, the commanding officer of the Shenandoah obtained and considered in consultation with the aerological officer of the ship the latest weather maps and reports.
32. The Shenandoah left the mooring mast at the Naval Air Station, Lakehurst, at 2:52 p.m., September 2, and proceeded on the Midwest flight.
33. The 8:00 p.m. weather reports were received, mapped, and studied by the aerological officer about 11:30 p.m., September 2. The scheduled weather report from Lakehurst for the region being traversed was received about midnight. These reports were discussed by the aerological officer with the executive officer who was on duty in the control car.
34. Between 3:00 and 3:30 a.m., the commanding officer, executive officer, and aerological officer, all of whom were in the control car, observed and discussed the first apparently unfavorable weather conditions. For the next two hours the weather conditions were under constant observation and discussion by the commanding officer and the aerological officer, who were in complete agreement in their conclusions except at one point when the aerological officer advised a change of course to the south. The commanding officer, after consideration and discussion, which developed that the aerological officer based his opinion not on any close or immediate danger but on the unusual movements of storm areas twenty-five to fifty miles to the northward, decided to adhere to the course of 260 degrees true.
Opinions
17. The commanding officer was entirely justified in starting the flight at the time chosen, as the weather maps and reports indicated nothing which would have rendered it unsafe or unadvisable.
18. The weather reports which were received and mapped between 11:00 p.m. and midnight, September 2, indicated nothing which rendered it unsafe or inadvisable to proceed.
19. A more extensive meteorological service, which would require more weather stations and more frequent broadcasting of reports, probably would greatly have contributed to the safe navigation of the Shenandoah on this trip.
20. Although subsequent events showed that a change of course to south when suggested by the aerological officer would have been advisable, the commanding officer’s decision to maintain his course was a matter for his decision only, was made on his best judgment after discussion and consideration, and was based on the facts and conditions as then known or observed. Any error of judgment involved in this decision was entirely without negligence or blame.
V. The flight from 5:22 a.m. to 5:47 a.m. (Eastern Standard Time).
Facts
35. During this period, constant watch was kept on aerological conditions by the commanding officer and the aerological officer, but none of the usual cloud formations indicating abnormal air currents in the immediate vicinity of the ship were observed.
36. Prior to arrival at pressure height, all valve covers had been removed.
37. At the beginning of this period the Shenandoah was proceeding on a course 300 degrees true at a height of 1,800 feet, but was making little or no ground speed due to strong adverse winds. The airship at this time had a pressure height of 3,800 feet. At 5:22 a.m. the airship began to rise under the influence of vertical air currents; rose to a height of 3,150 feet in eight minutes; was brought under control and steadied at that level for six minutes; then rose again and more rapidly to 6,100 feet in ten minutes; dropped rapidly to 3,000 feet in three minutes, and finally rose again, sharply up by the nose, to probably 3,700 feet, at which point the ship broke. This last rise was accompanied by a movement of rotation of the whole ship in a horizontal plane and by violent rolling and pitching. During all these movements the ship was out of control. All the above figures are approximate only.
38. The average rate of rise during the first part was 170 feet per minute; during the second part 300 feet per minute, with a probable maximum of 700 feet in the last forty-two seconds. The average rate of fall was 1,000 feet per minute. The rate of the final rise is not ascertainable, but is immaterial, as the ship broke before reaching pressure height.
39. The existence of high velocity vertical air currents without accompanying cloud formations or other visible indications is unusual, but is a phenomenon known to meteorologists.
40. During this period of uncontrolled movements various recognized methods for bringing the ship under control, such as opening the maneuvering valves for five minutes, nosing down by means of controls, speeding up engines and letting go ballast, were utilized, but without result so far as obtaining full control of the movements of the ship was concerned.
41. The following sequence of events in the final destruction of the ship is indicated by the evidence. At or about the time the ship was at its highest altitude, unusual sounds within the body of the ship were heard. These sounds are variously described by different witnesses, but seem clearly to indicate the existence at that time of unusual stresses in some part or parts of the structure. The sharp rise by the nose, the rotation in horizontal plane, and the rolling and pitching of the ship during the final uncontrolled rise indicate the existence of large unbalanced external aerodynamic forces acting on the ship at that time. The next abnormal event was a cracking of the struts of the control car. The first break in the main structure of the ship occurred between frames 120 and 130, resulting in separating the ship into two parts, the control car remaining attached to the forward section. In something less than a minute thereafter the control car broke loose from the forward section and dropped to the earth. About the same time a second break occurred in the aftersection of the ship between frames 100 and no. The mid-ship action thus broken off, with power cars Nos. 4 and 5 attached thereto, dropped almost directly. The aftersection dropped more slowly and was carried by the wind a distance of about one third of a mile before reaching the earth. The forward section was operated as a free balloon by the personnel left therein and was landed safely about twelve miles from the scene of the disaster.
Opinions
21. During this period the measures taken by the commanding officer to bring the Shenandoah under control were in accordance with the best- established practice.
22. During this period of extreme danger the conduct of all officers and men was deserving of the highest praise. The commanding officer showed skill, courage, and fine qualities of leadership. All other officers and men showed an intimate knowledge of their duties, fine discipline and morale, and great courage. The handling of the forward section of the ship as a free balloon by Lieutenant Commander Rosendahl and Lieutenant Mayer was particularly deserving of commendation.
23. Although testimony of both operating and scientific experts is to the effect that, subject to certain qualifications, gas pressures sufficient to produce permanent strains or actual damage in the structure probably did not exist at the highest point of rise of the ship, the facts (a) that sounds of a nature indicating unusual stresses in the structure were heard at this time, (b) that the calculations on which expert testimony is based are arrived at through assumptions which are of necessity open to error, and (c) that some of these assumptions for their validity depend upon precision in the action of personnel and material, all taken together justify the opinion that gas pressure due to altitude and rate of rise may well have reached values sufficiently high to produce some damage to structure.
24. The exact nature or extent of this damage is not ascertainable, but was probably not sufficient to have endangered the ship under normal operating conditions.
25. Valve covers having been removed prior to arrival at pressure height, they could not have had any influence on the loss of the ship. Nevertheless, the practice of leaving any valve covers in place at any time after an airship takes the air is considered unsafe and inadvisable.
26. The final destruction of the ship was due primarily to large, unbalanced, external, aerodynamic forces arising from high velocity air currents. Whether the ship, if entirely intact and undamaged, would have broken under the forces existing, or whether prior minor damage due to gas pressure was a determining factor in the final break-up, are matters which this court is unable definitely to determine.
27. The change resulting in a reduction of the number of gas valves was inadvisable. The initiation and urging of this change by the commanding officer of the Shenandoah, the recommendation for its approval by the commanding officer of the Naval Air Station, Lakehurst, and its final approval as an experimental installation by direction of the Chief of Bureau of Aeronautics appear, in the light of subsequent events, to have been errors of judgment, but were arrived at after full and careful consideration by the most expert officers of the Navy in the operation and design of rigid airships, and do. not in any way involve negligence or culpability.
28. Although the disaster to the Shenandoah indicates that a rigid airship can probably be destroyed through external aerodynamic forces only, and that such forces can arise from air currents unaccompanied by visible signs recognizable by aerologists in the present state of knowledge, it is the opinion of the court that such conditions and combinations of circumstances are unusual, and such a conclusion docs not, therefore, throw doubt upon the safety and utility of rigid airships to a materially greater degree than does the fact that other types of craft for navigation in the air or on the water are likewise subject to destruction through unusual dangers which cannot invariably be foreseen and provided against.
VI. Loss of life.
Facts
42. The following officers and men lost their lives through the destruction of the Shenandoah:
- Lieutenant Commander Zachary Lansdowne
- Lieutenant Commander Lewis Hancock, Jr.
- Lieutenant John B. Lawrence
- Lieutenant Arthur B. Houghton
- Lieutenant Edgar W. Sheppard
- Everett P. Allen
- Charles H. Broom
- James W. Cullinan
- Ralph T. Joffray
- Celestino P. Mazzuco
- James Moore, Jr.
- Bartholomew O’Sullivan
- George C. Schnitzer
- William H. Spratley
43. Chief Gunner Raymond Cole received slight injuries and Aviation Chief Rigger John F. McCarthy was seriously injured.
44. Of those lost, eight were in the control car, four in power cars 4 and 5, and two in the body of the ship at the time of the disaster.
45. The control car broke away from the forward section of the ship after the main break in structure and this minor break was probably a direct consequence of the major break. The method of attachment of the control car to the main structure was the same in its general characteristics as that employed on practically all previous rigid airships, i.e., suspension cables for completely supporting its weight, combined with struts only sufficiently strong for steadying the car in flight and designed to collapse before injurious stresses could be transmitted to the main structure in case of contact with the ground when making landings. This general method of support is similar to that employed for the suspension of power cars. Two rigid airships designed and constructed since the Shenandoah embody a new and improved type of control car which is directly attached by structural members to the main frame work of the ship.
Opinions
29. The deaths of all personnel resulting from this accident were due to injuries received in the line of duty and were not the result of their own misconduct.
30. The injuries of all personnel were received in the line of duty and were not the result of their own misconduct.
31. Although the design of the control car and its method of suspension were in accordance with sound and well-established practice at the time of the building of the Shenandoah, the newer design as embodied in the Los Angeles is considered better and safer for future construction.
32. Although it is possible that some lives might have been saved had parachutes been carried and been actually worn by officers and crew at the time of the break-up of the ship, this does not affect or modify the opinion expressed in O-14 above, that the use of the present type of parachute in rigid airships is not advisable. The lesser danger must be accepted to avoid the greater risk.
VII. Loss of and damage to property.
Facts
46. The loss of the Shenandoah was complete. Steps for the recovery of salvage from the wreck have already been taken.
47. Minor damage was done to private property belonging to three residents in the vicinity of the disaster.
48. A board was appointed by the Secretary of the Navy immediately after the loss of the ship, which was charged with the duty, among others, of making report in regard to damage to private property.
Opinions
33. The report of the senior member of that board adequately covers the matter of damage to private property, and the recommendations contained therein arc sufficient to permit final decision and further action on the claims arising from this source.
VIII. General
Opinion
34. It may be accepted in the case of the loss of any craft at a certain place at a certain time that any change of action on the part of any individual directly or indirectly connected with the movement of such craft might have avoided such loss. In this sense, and in this sense only, can allegations of direct or indirect individual responsibility for the loss of the Shenandoah and the loss of life consequent thereon be supported. Such actions of individuals must be judged on the basis of the facts and established practices known and recognized at that time rather than on conclusions or deductions drawn after the event. Such actions of individuals as in light of subsequent events have been termed “errors of judgment,” were, in the opinion of this court, clearly without negligence or culpability. The disaster is part of the price which must inevitably be paid in the development of any new and hazardous art.
35. The court is of the opinion that the recommendations of Professor Hovgaard, technical adviser to the Judge Advocate, in his technical analysis of the evidence, and of Lieutenant Commander Rosendahl, senior surviving officer of the Shenandoah, in his summing up of the case on behalf of the survivors, both of which recommendations deal with future development of rigid airships, are worthy of the most careful consideration.
36. The court is of the opinion that competent technical and operating officers should be detailed to study the great mass of evidence and exhibits forming a part of the proceedings of this court in order to collate it in such form as to be most readily available and useful for future reference in any further development in the arts of construction and operation of rigid airships.
Recommendation
That no further proceedings be had in the matter