FLYING BOAT TRAGEDY.

Otago Witness, Issue 3954, 24 December 1929, Page 19

FLYING BOAT TRAGEDY.

EVIDENCE AT INQUIRY. CAPTAIN MAN’S THEORY. AUCKLAND, December IG. The theory that the fatal flight of the Dornier Libelle flying boat ’ ist Thursday was involuntary -as advanced at the Air Force Court of Inquiry which v.-as opened to consider the causes of the acci dent which resulted in the deaths of Cap tain D. Harkness and C. F. Goldsbro, off Milford Beach. The evidence was heard before Major L. M. Isitt and Captain S Wallingford, of the Hobsonville Air Base, an Flying Officer R. J. Copley, engineer to the Auckland Aero Club. Mr Seymour represented the Aerial Services Limited, the company operating the flying boat. There are some grounds for the belief that the stability of the machine was upset by the carrying of stone ballast, and Major Isitt wishes anyone who can throw light on the sugges tion to volunteer information. Captain W. Man, formerly of the Royal Naval Air Service, said he had acted as pilot of the Dornier Libelle since it commenced its tests on November 17. He had had SOO hours’ flying experience in seaplanes and flying boats, and 100 hours in aeroplanes. His permanent engagement as pilot was to be settled after the machine had passed its tests. The engine delivered only 1575 revolutions,’ and owing to lack of steerageway a slight collision with a moored launch occurred in St. George’s Bay. The pro peller was broken and the stabiliser damaged, but repairs were effected, and on November 19 witness and Major G. C. Cowper m..de a flight of -about 15 minutes. Neither the air speed nor the altimeter was working, and at no time subsequently had these instruments registered satisfactorily. On November 21 witness flew the machine for one and a-quartcr hours, and found the petrol pressure erratic. Adjustments were made, but only 1450 revolutions were obtained, and the machine would not rise with a pilot and two passengers. On November 22 an Austrian, known only as “ Rudolph,” commenced work as a mechanic. Further unsatisfactory engine tests followed, and on December 11 Goldsbro commenced work as a mechanic. The engine improved ami from 1775 to 1800 revolutions a minute were obtained. Witness made flights and Goldsbro and 11. R. Burrett were separately taken as passengers. The flying boat still would not leave the water with two passengers at a time. An auxiliary petrol tank was fitted without reference to witness, and during a flight Goldsbro suggested utilising it, but witness deferred any test in the air until lie had inspected the reserve installation. Witness detailed the engine tests, and said that the documents disclosed that the engine had run 1 hour 16 minutes on the ground and 2 hours 40 minutes in the air in Germany under witness’s care. In Auckland the testing periods had been 2 hours and 2 hours 30 minutes respectively. The normal petrol tank was under the pilot’s seat, and the fuel was fed by an

engine drive pump. There were 13 connections in suction pipe between the tank and the pump, and witness considered that this fact and the length of the suction pipe were the cause of the repeated failure to maintain a steady pressure. The pump was too weak to carry out the six feet lift required of it, and witness considered that this resulted in the “starving” of the engine and the consequent deficiency in power. An auxiliary petrol system had frequently been discussed. To Major Isitt, witness said that the flying boat had not been inspected by a licensed ground engineer. The only expel t available, Mr Copley, had his attention monopolised by the club machines. Witness had been informed that Rudolph ” had been an officer in an Austrian air force, and later a mechanic in the United States Air Force at Panama. He appeared to be a competent aero engine mechanic, and Goldsbro had a good reputation as a motor mechanic. Witness last flew the Dornier Libelle last Wednesday, and had no idea that Captain ‘ Harkness would fly it on the following day. Captain Harkness had never been in the machine when it was off water. It had been understood that after the flying boat had passed the tests pilots other than witness would fly it. In conversation the characteristics of the machine in flight had been fully discussed with Captain Harkness. “ Captain Harkncs*was a. very level-headed man, fully appreciating that the flying boat required handling different from that of an aero plane, and I am convinced that he had no intention of flying when he took the machine out on Thursday,” witness said “He had every respect for caut.on in flying, and he would have discussed it with me if he had had any plans regarding flying the machine. Mrs Harkness is also convinced that he did not intend to fly.” \\ itness said that his conviction was strengthened by the fact that Cap tain Harkness wore no flying kit when he took the flying boat on its fatal trip although he was very particular about such equipment. Major Isitt: Do you know anything about a stone which was found in the cockpit when the bodies were removed? Witness: I believe that it was carried for ballast and was intended to improv* the attitude of the machine for taxi ing tests on the water. To Mr Seymour, witness said the fact that the altimeter was out of order was not important. “ The trouble with the air speed indicator did not worry me either, as I was trained to fly without instruments,” said witness. “ Before anybody else flew the machine with my knowledge I would certainly have taken steps to see that the air speed indicator was working. After adjustments it worked up to 50 miles an hour, but would not respond to the movements of the machine.” Witness said that although the Dornier Libelle was thoroughly airworthy when he flew last Wednesday, at no time since its assembly had full efficiency bw-n obtained. “ The machine never let medown in the air through any failure,” he said. In his opinion the stone ballast was used to alter the trim of the ’’ying boat for taxi-ing. A pilot trained in aeroplanes and finding himself unexpectedly taking off fr» in the water in a flying boat would naturally treat the machine with respect. Once in the air the pilot would feel at home. The stalling risk was greater in a flying boat, and a pilot had to make sure that he had full fore-and-aft . control before shutting off the engine for the glide back to the water In examining the wreckage witness found both petrol taps in the “ on ” position, and he thought that the pilot must hav? resorted to the auxiliary tank. “ I think that the machine got tail heavy when down wind with a failing engine, and to get revolutions the pilot switched on the auxiliary petrol,” said witness. “ While the mechanic was trying to throw out the stone the machine may have stalled and gone into a spin.” Dr J. G. Stewart, a former Royal Air Force pilot, said that he noticed the flying boat flying erratically off shore. Captain H. 11. Sergeant, harbourmaster, said that the w flying boat was turning when it appeared to get out of control. He noticed no irregularity in the engine. The flying boat was righted before it sank, but the bodies could not be extricated. When raised to the surface the machine was still right side up, and witness considered that a stone from the sea bottom could not have found its way into the pit.

H. R. Burrett, shareholder in the Aerial Services, Limited, said that Captain Harkness asked him about noon on Thursday if he would assist with a boat in towing the flying boat out from where it had been moored on the previous evening. Witness offered to be at the boatsheds at about 4.30 p.m., and Captain Harkness said: “ Provided you dp not hear the machine over yonr office befo.e then.” Witness considered that remark was purely jocular. The machine was towed into the harbour, and* cast off with Captain Harkness and Goldsbro on board. Witness thought that the intention was merely to taxi on the water. The engine was started three or four times, and the machine taxi-ied short distances. Then the flying boat ran about half a mile across the surface, lifted slightly, and returned to the water three or four times, and finally took off and flew across the harbour until it was out of sight round the North Head. Witness was not aware if a stone was carried in the flying boat.

PRESENCE OF STONE BALLAST. «t i- AUCKLAND, December 17. n i 1 from the evidence we shall call later there is little doubt about the presence of stone ballast in the machine,” said Major L. M. Isitt, at the Air Force inquiry concerning the crashing of the Dornier Libelle flying boat off Miford Beach last Lhursday, involving the deaths of Pilot Captain D. E. Harkness and Mechanic C. F. Goldsboro. F. Better said he was in his garden on the point between Milford and Castor Bay when'he saw the flying boat. It was flying very low inland, and almost touched a group of macrocarpa trees. Witness thought for a moment that the machine would strike his house, but it deviated slightly and seemed to miss the ground by little more than a dozen feet. The machine then gained height and crashed over the water. After hitting the water, the flying boat turned slowly on its back. A. E. Ottley, an employee on the oil tanker Nucula, said he was present before the machine was salvaged, and lie assisted to release the bodies from the cockpit on the beach. There was no sign of a stone in the cockpit. Major Isitt said the stone could have been moved _ before the wreckage was beached. Evidence regarding the ballast would be called later. Recalled, Captain W. Man, pilot of the machine since its assembly, said he saw the stone and had the impression that it was removed in shallow water. Witness considered the flying boat was interesting rather than difficult to fly. A pilot inexperienced in its type would find it difficult until he had controlled it for about an hour. The flying position was quite different from that of a normal land machine. Captain Wallingford (to witness) : With the defective air ■ speed indicator would an inexperienced pilot stall very easily ? Witness: Yes. the flying boat was very light on controls and without an air speed indicator a strange pilot might get into trouble. Major Isitt: It is my theory that the stone had been carried in the back seat. When the machine turned over on the water it may have been dislodged and have thus fallen across the pilot’s knees where a previous witness found it. I think we can find out whether a similar stone was taken from the sheds near the moorings of the flying boat. If the stone had been in the front cockpit from the first I would have expected that the control column would have been damaged in tire crash. Mr Seymour said the petrol feed trouble experienced by Captain Man in the trials were interesting in view of the information just received from the Australian agent for the Dornier Libelle machines at Newcastle. The letter had beer adddressed to Captain Harkness and bore the dace of the day of the crash The iettei stated: “We have had similar experienced with a Libelle. I stated in my last letter that we had some trouble with petrol pump. My friends decided to install an Avro Windmill pump. Since then the feeding system has been working quite satistactorily. My friends have also come to the conclusion that the Libelle is slightly underpowered when taking off w.th two passengers. They are at the present moment experimenting by increasing the revolutions of the engine. With the propellor supplied by Dorniers the maximum revolutions are 1960, while the engine is built to do 2100 I nave taken up this matter with Uotniers and have recommended them to improve the ch sign of the Libelle. In any case 1 will recommend future clients t i have the boat equipped with a Cirrus Hermes cr a Siemens SH 14.” Captain Man said the flying boat had never failed him in the air, but he could not ge. the maximum engine revolutions and power to li.t a pilot and two passengers. » Major Isitt said the police were making further ir.'-cstigations and the inquiry would probably be resumed within a r ;' n ’ days. G’n the evidence already avai.able lie might make a report to Headquarters.