Every Precaution To Make System Safe

Northern Advocate, 25 October 1947, Page 8

Every Precaution To Make System Safe

NORTHLAND AIR SERViCt

(By a Staff Corespondent) FEW passengers using the Northland air service can have any appreciation of the complex control system by which their safety is protected. These passengers weigh in with their baggage, enjoy the scenery while in the air and disembark at their destination possibly without knowing that in addition to the skill of the pilots, almost constant watch on their progress is maintained by ground radio installations.

Most of the Northland journey is under surveillance of the Air Department's aeradio station at Waipapakauri. while approach to and departure from the northern terminus at Kaitaia airfield is directed by a radioequipped control tower on the airfield itself. With these facilities it takes very oad weather indeed to close down the Kaitaia airfield. In fact, this airport has never yet been closed by bad weather. Within the next two or three weeks station ZLU. tire Waipapakauri aeradio. should be operating with newer and more powerful equipment. NEW KAITAIA TOWER In addition, it is understood, plans have already been approved for provision of a new control tower and metereological station at Kaitaia airport. These will greatly facilitate control of the expanded service which National Airways Corporation has undertaken to provide when additional aircraft are available. The most interesting stage of ground control from the/layman’s viewpoint is the procedure of operation at the airfield control tower, where station ZLU's superintendent (Mr E. N. Creelman) takes charge for the arrival and departure of the daily service aircraft. Fine weather reduces operations here to a routine. Approaching Kaitaia from the south after leaving Kaikohe, the aircraft makes radio contact with the control tower. HEIGHT SPEED, COURSE Details of height, speed and course are passed from the aircraft, which in turn receives information of ground wind direction and strength, and ultimately instructions and permission to land. On the ground the pilot receives a meteorological report for his southward journey and hands in his flight plan, showing his intended course to Kaikohe, Whangarei and Auckland. These messages are transmitted by land-line between the control tower and ZLU. and by radio-telegraph between Waipapakauri and the Auckland centre. Aeradio is used to transmit arrival and departure times at all Northland airports, and before leaving Kaitaia the aircraft must receive its departure authority from the control tower. Approaching Kaitaia the aircraftin this case registered ZK-ZGK sends a test call and establishes contact. "Electra Zebra George King to Kaitaia.” says the loudspeaker in the control tower. “Good morning. How do you receive me? Over.” "Kaitaia to Electra Zebra George King—Good morning,” tower responds affably. “I am receiving you loud and clear. Pass your message please. Over.” POSITION INDICATED With that the aircraft pilot indicates his position as, for example 12 miles south-east of Kaitaia airfield, and gives height and airspeed. He is. he says, flying at 150 m.p.h. and descending to approach the airfield. ,

Towei - responds with advice of altimeter setting, wind strength and direction at ground level, and nominates the runway on. which the Electra will land.

A few minutes later the aircraft is in sight, advises that it has commenced its final approach, and requests permission to land.

“Okay,” says tower, making a verbal check to ensure that the landing wheels are lowered, and the plane is down.

In cloudy conditions the radio telephone can bring an aircraft down without difficulty, provided the ceiling is no lower than from 350 to 500 ft.

Incoming pilots may set their course by radio compass on a “home beacon” at Waipapakauri, and their arrival over the beacon is indicated on the compass.

A pilot flying above cloud may then be advised of the flying time (a minute or so) required to clear the land so that he can come down through the cloud in safety over the sea. Once beneath the cloud the approach to the airfield is made in the normal manner, “HOMED” ON BEAM Under thicker conditions the aircraft is “homed” to Waipapakauri on the beacon and may by radio-telephone then be given a course and altitude to approach the airfield. The last phase of the approach to the runway is made by radio-telephone under visual direction. ZLU at Waipapakauri uses equipment installed and operated by .the RNZAF during the war years. Members of the staff are in the main Air Force personnel, and are acommodated in former Air Force station buildings. The transmitter is near the Waipapakauri airfield, where a small meteorological station is also placed, and alfhigh frequency direction finding unit also operates nearby. The medium frequency direction finding equipment and the installations for control of internal air traffic are

operated from Unnhi. on the Awanui Harbour shores some miles distant. The new and more powerful station to be taken over shortly is also at Unahi, but all these installations operate under the ZLU call-sign. Both high and medium frequency direction finders are used to plot bearings for overseas aircraft flying between New Zealand, the Pacific Islands, Australia and the United States. BUSY OPERATORS The two operators at Unahi arc busy | men while National Airways aircraft are in the Northland area. Every So minutes the aircraft send out position reports. These are- received by station ZLU and re-trans-mitted by radio-telegraph to Mangere, and to the Dominion's Air Traffic Control, which keeps a check on all internal service aircraft. Arrival and departure times at the three airports are signalled and relayed in the same manner. Through this station also passes the Northland service meteorological report which is passed to the aircraft through the Kaitaia control tower. Another service for National Airways passengers is the transmission of taxi requirements between the airport and the Kaitaia booking office by radio telegraph and landline. Passenger bookings may also be arranged by aeradio signal between various stations in New Zealand, acting in coopertyion with local booking offices. In a word, aeradio is a vital, if unspectacular. requirement to the smooth operation of New Zealand’s commer-" cial air service, and to the safety and comfort of its passengers. It is understood that arrangements are being made for the installation of control towers and radio facilities at Onerahi artd Kaikohe.

Bigger Prize Money

SYDNEY, Sat. (11 a.m.)— Next year's Doncaster Handicap and Sydney Cup will carry added prize-money. The Australian Jockey Club committee decided that these two events will also be governed by a stated maximum .weight, 9.10 and 9.7 respectively.

The Doncaster will now be worth £SOOO and the Sydney Cup £BOOO. The, Doncaster was formerly worth £3500 and the Sydney Cup £COOO. It is expected that there will be added prize-money for next year’s Epsom and Metropolitan Handicaps.