Personal Log Book

Gisborne Herald, Volume LXXV, Issue 22816, 10 December 1948, Page 6

Personal Log Book

known Commander Hare break that instruction.

A pilot could refer to the Palmerston North operations office about the possible cancellation of a flight. He would be told that it was his responsibility. There had been occasions when the operations office had cancelled flights because of weather, or because a flight might last beyond daylight hours. Checks of Compass

Replving to Wing Commander J. W. IT. Bray, Captain Walker said that compass checks were carried out by the engineering department. If pilots detected any defects in the compass they would report them. He know of no "such report in respect to the AGK. Compasses in Electras would not deviate by more than two degrees plus or minus with a change of engine. Wing Commander Bray: I am going to put a question which the chairman directs that you need not answer: Can you make anv suggestion to help the board as to liow the Kaka got off its course?

Captain Walker: I cannot. I would just be theorising.

Asked by Captain K. C. Brownjohn how the route compared with others he know in and beyond New Zealand. Captain Walker said it was a reasonable route. There were days when, as mentioned by the pilots, the homers were of little value as an on-route guide, but they were still of great assistance as homing devices and for checking position when over them.

On days when homers were not helpful as on-route checks, due allowance must be made, either vertically or horizontally, for keeping clear of the mountains. The route was not more, or less, difficult than others he knew. If tire drift as indicated in the weather reports had been applied it should have kept the Kaka clear of Ruapehu. Weather Briefing

Replying to the chairman, the witness said that although lie had earlier stressed the need for pilots to have good weather briefing he thought lhat, on this occasion. Commander Hare, having just flown southward over the route, was in a position to know more about the weather on it than the forecaster at Paraparaumu. In this particular case it was not necessary for Commander Hare to spend much time with the forecaster at Paraparaumu as he was turning round on route within 15 minutes.

The Chairman: Assuming the flight plan at the time Commander Hare saw it at Paraparaumu showed drift calculations to port, instead of starboard. would that mislead him?

Captain Walker: I don’t think so. He would obviously be aware that there were strong westerlies blowing. Captain Walker said that the prime object of the flight plan was to obtain a clearance for the aircraft. It was not in a form suitable for use as a navigational document. The drifts shown on it referred to no specific route. The chairman: Then what use is it? Captain Walker: It is of no great use. He added that the essential computation of drift could be made by the pilot in about one minute. The chairman: It may be recognised that the only persons who take responsibility in these matters are the pilots, but if there are to be navigational aids given to pilots, one would like to know which are important and which are a mere matter of filling up forms. Captain Walker: I think it is essential for the pilot to keep a navigational log. Decisions on Cancellations Replying further to the chairman, Captain Walker said he did not think the decision on cancelling a flight was too difficult a one to ask of a pilot. The chairman: If a pilot cancelled a flight and another pilot decided to fly and did so successfully, would not the first pilot be discredited? Captain Walker: I don’t think so. If a pilot cancelled his flight, others would usually cancel theirs under the same conditions. Captain Walker agreed that an additional homer between Wanganui and Hamilton would be of assistance. There was no limit, as far as the pilots were concerned, to the number of aids they would like. The corporation had made proposals to the department and in every case where the recommendations were feasible they had been met. What the corporation wanted most was the quick installation of the aids that had been agreed to. The chairman: It is our duty to find out what aids are required. There are some aids required and the pilots want them?

Captain Walker: Yes, sir. Philip Ernest Hudson, a technical assistant in the Air Department, who said he had specialised in air navigation, said that in the north-bound instrument-flight plan for the AGK ho had found, in addition to an alteration of drift from port to starboard, that there were certain other errors and discrepancies. In the first place in the flight plan a true airspeed of 150 m.p.h. had been used whereas in the plan for the southbound flight a true airspeed of 145 m.p.h. was used. In the pilot's air log the. figure set out was 160 m.p.h., a fairly considerable discrepancy. “It does not appear that a standard figure for true airspeed is in common use for flight-planning, nor does it appear that the true airspeed is computed according to the engine power and temperature conditions at the lime,” said the witness. Errors in Calculations “There were certain errors in the calculation of drift and ground speed in the flight plan. For example, on the first stage the climb from Palmerston North followed by level flight to the Wanganui homer, the drift should have been half a degree to starboard and not two degrees or two and a half degrees to starboard. On fhe second stage, the climb from the Wanganui homer, the drift, if correctly calculated according to the forecast of wind velocity, should have been 15 degrees to starboard and the ground speed 87 m.p.h. and not 13 degrees to starboard and 75 m.p.h. “On the next stage the drift was slightly in error and the ground speed should have been 123 m.p.h. and no! 135 m.p.h. as shown.” These last figures could have been incorrectly obtained if the compute: was incorrectly manipulated, said the witness. He said he had examined another set of instrument-flight plans prepared at Paraparaumu on October 23. In addition again to the correction from port to starboard drift, there were other errors in calculations and alterations to the figures. They included errors in calculations of drift and ground speed and indicated some element of haste in the preparation of the flight plans. In a few cases they suggested that the person preparing the flight plans was not altogether familiar with the computer, continued the witness. Air Log Examined

“I examined the pilot’s air log which was found in thcwrecked aircraft and which apparently had been maintained by the co-pilot,” he proceeded. “I also examined the two navigation computers found in the aircraft.

“In the air log a number of pencil entries were partly illegible owing to the effect of the weather. Two entries for the south-bound flight included a record of a calculation of the true course, ground speed and drift, the drift being either seven or nine degrees to port.’’ The witness said it was noticeable that the first two lines in the body of the log related to the southward journey, the pilot’s final entry in these lines being the estimated time of arrival at Wanganui, 11.28. The last two lines related to the northward flight. It was noticeable that no calculations of ground speed for the northward flight were recorded. In the last line of the entries the Kaka was reported as being over Wanganui, presumably the Wanganui homer, at 1.37 p.m., having passed Ohakea at 1.26 p.m. A distance of 25 miles recorded in the log was evidently an approximation for the actual distance on the map between those points was 25 miles. The ground speed recorded was 150 m.p.h., which apparently was also an approximation, as there also appeared to be an elapsed time of 25 minutes to give an estimated time of arrival

over the New Plymouth cast reporting point of 2.2 p.m. The witness said lie had examined the computer found in Commander Hare's satchel. Had this been in use during the flight he would have expected to see a pencil mark on the computer recording the forecast wind velocity being used in the calculations. No such mark was visible. A pencil mark was found on Flight Officer Russell’s computer indicating a wind of 330 degrees at 40 knots, which was the forecast wind velocity used on the southward llight. The true course index on this computer was set to approximately a southerly heading. These two facts suggested that the computer was not used during the northward flight.