KAKA INQUIRY EVIDENCE ENDED: BOARD NOW TO HEAR COUNCIL

Gisborne Herald, Volume LXXV, Issue 22817, 11 December 1948, Page 6

KAKA INQUIRY EVIDENCE ENDED: BOARD NOW TO HEAR COUNCIL

(P.A.) WELLINGTON, Dec. 10. A list of navigational aids nowin use in New Zealand and of aids projected for 1949 was produced by Mr. W. 11. Cunningham, appearing for the Air Department, when the fifth day’s proceedings before the board of inquiry into the Ruapehu air disaster on October 23 began this morning. The chairman of the board, Sir Harold Johnston, K.C., asked if Mr. Cunningham could also produce records of any similar inquiries in recent years from which it might be possible to find what steps had been taken as a. result of the findings of those inquiries to prevent a repetition of faults then discovered, if any.

Mr. Cunningham said that the only comparable previous crash was at Mount Richmond. Mr. D. W. Virtue, appearing for the N.A.C., undertook to obtain the records of that inquiry, which was in 1940.

The first witness today, Flight-Lieut. Harry Christian Salmon, engineer officer, R.N.Z.A.F.. produced the maintenance records of the Kaka which he had examined. The Kaka's engines had been changed in December. 1947, and in March, July and September, 1948. There had been quarterly compass swings, but not immediately after engine changes. He was not sure if the N.A.C. kept, or was required to keep, a compass log book, but the R.N.Z.A.F. regarded it as essential. There had been changes in the Kaka’s direction indicator and artificial horizon. The former had been in the machine for 880 hours at the time of the crash and the latter for 244 hours, after having previously been in another aircraft for 556 hours.

To Mr. Virtue, the witness said the last compass swing was five days after the last engine change in September. He had found no record of what correction, if any. was made to bring the compass back to standard.

Mr. Virtue: As far as we know the compass was behaving satisfactorily after that swing? The witness: Yes. No defects were reported. Check of Instruments The witness said he knew of no manufacturers’ standards for the check and overhaul of gyroscopic instruments. He thought the civil aviation requirements were for an annual check when the certificate of airworthiness was renewed.

John Irvine Joyce, chief surveyor of aircraft, Civil Aviation Branch of the Air Department, explained the system of records of performance, condition, maintenance and repair kept of all civil aircraft. He said he did not think a record of corrections of magnetic compasses was necessary. He knew of no special dispensation given to the N.A.C. with regard to compass swinging. His branch’s supervision extended to overhauls of civil aircraft and to records kept of overhauls. No limit of time was set for the periodical overhaul of civil aircraft instruments, but aircraft had an approved maintenance schedule. The instruments were not left in the machines between overhauls' without maintenance or checking. The R.N.Z.A.F. limit between instrument overhauls was 480 flying hours.

Maintenance Schedules

To Mr. Virtue, the witness said the N.A.C. had submitted maintenance schedules in regard to particular aircraft types and his department had approved of them. Aircraft logs such as those produced to the board were available to district inspectors on demand.

Mr. Virtue: I put it to you that matters such as a lack of compass swings immediately after a complete engine change should have been picked up by your inspectors long before this inquiry? The witness: They would take a snap check or check the log book as thoroughly as they think fit. It is probable that this partciular aircraft was not the subject of a snap check recently.

Mr. Virtue: Do you agree it is desirable to have a thorough check of all log books regularly?

The witness;

William Ronald Hunter, employed by the N.A.C. in charge of radio and instrument maintenance and overhaul, gave evidence of an arrangement to waive the requirement regarding compass swinging after engine changes in Electra aircraft because it was known that the deviation after such changes was negligible. Deviations Recorded.

The witness said he knew of nothing in writing regarding this arrangement. The N.A-C. kept a historv sheet of every compass. A note of individual deviations was kept unofficially. Reasons for compass changes would be recorded in the flight and station log and were supposed to be recorded on the history sheet There was a standard overhaul period for gyroscopic instruments at; 1100 flying hours with a check at 550 hours. He considered 1100 hours to be a safe operating period. The difference between this limit for civil aviation and the Air Force period of 480 hours was due to the higher utilisation of civil aircraft within a given period of time. It had been shown that this higher utilisation extended the safe operation period foi gyroscopic instruments on some overseas air lines to 3000 hours, provided those hours were flown within a period of one year. Failures in such instruments were usually gradual. A sudden failure was unlikely. To Mr. Virtue, the witness said his advice of the arrangement in regard to compass swinging came from the chief maintenance engineer’s department of the N.A.C. Inspection of Wreck.

Wing Commander R. C. Kean, inspector of aircraft accidents, said he v/ent with the first ground party to the scene of the wreckage, but was personally unable to get closer than 300 or 400 yards owing to the ‘'altitude angle of ascent and Anno Domini in wrong proportions.” However, from what he saw through binoculars, from what he was told by those who atcually reached the wreckage and from photographs, he considered the aircraft was on a course north, magnetic, when it hit the rock outcrop at 6000 ft. . All the indications were of a head-on impact at high speed. The radio control panel was less damaged than the main instrument panel and although, in the circumstances, complete reliance could not be placed on the readings found on the radio panel, it was unlikely that these settings were altered following the crash. Wing Commander Kean said as the cloud base did not rise above 4000ftfrom the time of the crash to the following Thursday afternoon, the wreckage was sighted at the earliest possible moment. He paid tribute to the pilot who picked out the wreckage against the snow background. Suggestion of Balloon.

To the chairman the witness said a number of suggestions for locating lost aircraft usually reached the department after an aircraft went missing. All were carefully considered. There was not the slightest doubt that the people making suggestions were trying to be helpful, but they were unacquainted with all the factors involved.

Commenting on a published suggestion of an automatically-released balloon which would be anchored over the wreckage in the event of a crash, Wing Commander Kean said that considerable weight would be involved in

carrying the necessary gas under high pressure. If an aircraft such as an Eiectra had to carry such apparatus there would be very little payload left.

There would be technical difficulties to an automatic release and the idea of release by the pilot, particularly in such sudden impacts as the Kaka met, would be wholly unreasonable. The suggestion also seemed to ignore the height of cloud encountered at such places as Mount Ruapehu. To be of any use the balloon would have to be at least 10 to 20ft. in diameter. In the Port Underwood and Mount Ruapehu accidents the wreckage was found as soon as the clouds lifted from it. In the recent Oxford crash in the Ruahines clouds had delayed the search for days. Kaka Seemed Airworthy

To Mr. Virtue. Wing Commander Kean said: “My investigations failed to disclose anything that would indicate the ZK-AGK was not in all respects airworthy . when she took off from Palmerston North on October 23. The fuel was adequate and the load was not excessive. The witness further said that it would be correct that the material recovered from the wrecked Kaka and put in to the board as exhibits had been in his possession for about a month. Mr. Virtue: You know that some of these papers, such as this alleged Norfolk Island roster, have been put to witnesses for the first time during this inquiry?

The witness: One paper only. Don’t you think it would assist the progress of the board if you had made a specific inquiry from the N.A.C. before the hearing began? The chairman: I don’t think the witness need answer that question. (To Mr. Virtue): You can develop that point in your submissions. This ended the evidence and the board adjourned until Monday when counsel will make their submissions.