BASS STRAIT TRIP
Name Withheld
My private VFR flight from Tasmania to Victoria in my own aircraft was proceeding normally. I was a relatively low hour pilot and I was busy flying, navigating, and monitoring radio frequencies 126.7 MHz (the CTAF of the local airport) and 126.5 MHz (area freq.) by intermittently flipping between the two frequencies on the single radio in my aeroplane.
Approximately 50 minutes into the flight at 5,500 ft and about 10 nm north of Tasmania over Bass Straight the engine began to run roughly. The engine had not misfired once since its purchase in 90 hours of operation. The engine did not clear immediately and I was a long way out to sea, so I elected to turn sharply to the right towards the Tasmanian coast as a precautionary measure. Shortly after completing the turn the engine stopped running and with a gear box fitted to this engine the propeller also stopped. Looking at a stationary propeller blade in front of you 10 nm out to sea is not an enviable position.
Following this my thought pattern and a sequence of events went something like this;
BUGGER.
I setup a best glide with a 15 kt tailwind and visually checked my trajectory and decided that I should be able to reach the beach and land crosswind. I did a quick mental mathematical check to confirm that I should just make the beach. 5,500 ft at 9:1 = a bit less than 9 nm plus the advantage of a 15 kt tailwind for the ten minute glide at 65 kt......15 kt for 10 min = a bit over 2 nm. 9 + 2 = more than 10 nm. In the air, in that situation, that calculation took me less than 3 seconds.
Get on the radio and make a Mayday call.
Check the instrument panel and find BOTH fuel taps OFF.
I quietly ask myself "Who turned the fuel off" I look at the dog and decide that it probably wasn't her.
I turned both fuel taps on, and commenced a short wait for the carbys to fill. Turn avionics and strobes off to protect them from any power surge on start. Then the thought occurs that three or four seconds is a long time to sit and do nothing waiting for fuel to fill the carby bowls in this particular situation.
I hit the starter and decide that the throttle should have been closed first as the engine went instantly to cruise power. I resumed normal flight and switched the avionics and strobes on.
I then turned to resume track for Flinders Island. I called to cancel the Mayday call with Melbourne Centre and realised that I had made the Mayday call on 126.7 MHz instead of 126.5 MHz, the area frequency. It took a few minutes to sort that out and normal operations were resumed.
What I learned from this was..
Lesson 1. Fuel management in high wing aircraft with two fuel tanks.
This aircraft type tends to siphon fuel from one tank to the other. When both tanks are full, the tank being filled will vent fuel overboard from the fuel tank breather. This problem is managed simply by turning off the tank with the lower fuel level after climb-out. When 5 or 10 litres of fuel have been used from the full tank, turn both tanks on. This is a simple effective fuel management strategy. When I moved to turn the isolated tank on, the tank in use was inadvertently turned off instead through lack of care and attention. I am unlikely to do this again.
A new fuel management strategy is now used.
1. Both fuel on for take-off.
2. Draw one tank to about half empty.
3. Change tanks and draw the second tank to empty.
4. Change back to the half empty tank and to ALL of the remaining fuel on board.
This strategy removes any doubt about which tank should be selected in the event of a low fuel situation occurring.
Inputs to the aircraft should be careful, deliberate, considered and double checked.
Lesson 2. Radio Management
The Mayday call was made on frequency 126.7MHz. Immediately after the incident, I called on 126.7 to check if anyone had heard the call and was acting on it. No reply was received. I then called Melbourne Centre on area frequency 126.5 MHz, cancelled the Mayday and advised them of the frequency error.
126.7 is widely used along the north coast of Tasmania by private pilots and probably should be monitored in flight. 126.5 is the area frequency and probably should also be monitored in flight. My aircraft has only one radio.
I now stay on area frequency over water with 15 min skeds over water and over the tiger country in the western area of Tasmania.
