STALLING TEST

Wairarapa Times-Age, 18 April 1941, Page 3

STALLING TEST

SAFEGUARDS FOR PILOTS THRILLS FOR PASSENGER. PRECAUTIONS BEFORE FLIGHT. Describing his flight in an Airspeed Oxford, when the machine was put through a stalling test, Charles E. Wheeler mentions that leaving Woodbourne air station of the R.N.Z.A.F. the pilot, “observing the strict traffic rule,” climbed on a left bank, continuing the turn until the aeroplane was making straight for the heights which border the complicated maze of waters constituting Queen Charlotte and Pelorus Sounds.

This was a phase of a flight to demonstrate (Mr Wheeler goes on). It was shown that, given enough space in which to move, aircraft will fly on an even keel and an almost straight course if the controls are left alone. One of the engines was cut out, its air-screw revolving idly, windmill fashion. The Oxford continued its even course, with only a slight touch on the rudder to offset the drag of the idle engine. Had this process continued the complete course could have been made with a safe landing.

However, it was comforting for the passenger to hear again both engines running smoothly, till the pilot cut them both off, and speed dropped rapidly from over 150 miles an hour toward stalling point.

Stalling at low altitudes may be dangerous; therefore pupils of the R.N.Z.A.F. must be taught to recognise the symptoms and to lake action to avert a “stall” in good time. These symptoms were now to be demonstrated. Mr Wheeleor says that suddenly as the speed fell a strident horn began to sound. Surely something serious was about to happen. The cool young pilot, however, took no active steps, but asked his rather apprehensive passenger to •wait for the next signs of loss of speed. The instruments began to vibrate. Thus there was lively audible and visual warnings of the approaching “stall” in ample time to apply remedies. To the relief of the passenger, both engines resumed their healthy purr, the air speed picked up instantly, the horn obbligato ceased, instruments stopped dancing. They could check the altitude lost while all those exciting things had been happening—just a few hundred feet, with thousands to spare, the hills being still a comfortable distance below.

With the purpose of the flight achieved the machine returned to Woodbourne. An easy landing and the final formula associated with all flights. Details of the trip were logged by the pilot, noted by the duty pilot of the station, initialled by the pilot, and the passenger’s helmet and parachute were returned to store. The aircraft meanwhile was being given a good “runover” by the ground staff and refuelling squad. Referring to the beginning of the flight, Mr Wheeler indicates the precautionary measures to ensure that everything is in order. The flight first had to be authorised by the chief flying instructor. The station meteorologist, who provides three times a day a general report on weather conditions and the velocity of the wind at various altitudes, was consulted about visibility over the proposed route. Informed of the duration of the intended flight he gave the reassuring information that the excellent conditions would not change during that time. Had the route been a long cross-country one, he would have provided in a few minutes a complete picture of the weather throughout and also indicated possible developments. The Oxford Airspeed having been allocated for the flight, the pilot received its “ship’s papers” which travel with the aircraft. They give him a complete history of overhauls and inspection. He could see what had been last done and when the next inspection was due. The state of its oil and petrol tanks was indicated, certified by the initials of those who did the work. Satisfied that the aircraft' was fit for the journey and that weather conditions suited, the pilot signed a log in the duty pilot’s office, acknowledging receipt of the instructions for the flight, as detailed in the log, together with an estimate of the probable time to be taken. This log was completed when the pilot on return signed an entry that the flight had been satisfactory completed, and actual flying time was also reported.