Gas, Spark and Air.
This incident got a fair bit of consideration from a few of us – (darts practice). Not the full on kind, more of the ruminative, speculative sort of thing. Pointless try to nut it out without a full report on the outstanding items the ATSB has retained for further examination. However, whilst this type of discussion always ends up with more questions than answers, some of those questions can be and should be answered in the initial report. For example – the weather conditions that day have not been mentioned; they were not good. Low freezing level, rain, turbulence etc. Not an ideal day for flying – if you didn’t have to, certainly not for fun or very far from the circuit. When turbulence and moisture combine with a low freezing level the possibility of some kind of icing is always on the cards. Carburettor ice would have been a potential hazard; but, this C172 engine was fuel injected. Fuel does not seem to have been in short supply, the early engineering report leaves you with impression that ‘spark’ was not an issue, which leaves with only ‘air’ to wonder about. This leads us to the engine air intake. Is there an alternate air source? Seems not:-
"4. Watch for signs of engine icing related icing conditions. An unexplained loss of engine speed could be caused by ice blocking the air intake filter. Adjust the throttle position to obtain maximum RPM, this may require advancing or retarding of the throttle depending on where the ice has accumulated. Adjust mixture, as required for maximum RPM."
Furry muff – but throttled back for approach, changing runway, watching for traffic, with wind and turbulence to divert the attention – the advice above is fatuous to say the least. The small adjustments required to maintain profile at a low power setting almost precludes any indication of inlet air icing being noted, let alone dealt with.
One of the more intriguing aspects is the left turn made toward the end of the flight – strange until you drag out the satellite photographs – then it all becomes clear. There is a large, tempting football field in a handy position – which, it could be argued, the pilot saw as a viable alternate to landing on some house. Hobsons choice but with speed and height – in all probability do-able. We don’t know the configuration of the aircraft – ATSB fail to mention this important element. Given the wind on the day and a glide ratio published as approximately 9:1 (at ::68 KIAS) with flap out, the aircraft was battling the odds – retracting the flap may have bought a precious few feet of airspace.
The altitude needed to make a successful glide approach is compromised by the approach procedures in place. 9000 feet travelled for each 1000 ft of height is pretty close in. Call it (for sake of a number) a 1.5 nm final; or, a requirement to be at 2000 ft at 3 nm. This does not fit the airspace model. When an area is as extensively built up as the approach to 35 at Moorabbin, a dead stick landing should be a consideration in the design of airspace. Indeed, it is a rare event, very rare, as is a King Air smacking into a DFO – but accidents on take off and landing rate where on the grand scale of occurrence?
We shall have wait and see what the ATSB eventually come up with – but for my money, this pilot was only a few feet short of walking away and telling the tale over a beer. Which leaves you to wonder about fate and ‘if only’. Take care out there – Murphy flies with everyone; for a Reason.....
Toot – toot.
Just a final thought – when I learnt almost every landing was a ‘forced landing’ with the odd engine clearing throttle up – glide approach, every time, making allowance for wind and other considerations. I wonder if the long powered approaches we see today and the extended circuits are helpful to the single engine ‘thinking’. Fair enough for multi-engine training – but,,,,
This incident got a fair bit of consideration from a few of us – (darts practice). Not the full on kind, more of the ruminative, speculative sort of thing. Pointless try to nut it out without a full report on the outstanding items the ATSB has retained for further examination. However, whilst this type of discussion always ends up with more questions than answers, some of those questions can be and should be answered in the initial report. For example – the weather conditions that day have not been mentioned; they were not good. Low freezing level, rain, turbulence etc. Not an ideal day for flying – if you didn’t have to, certainly not for fun or very far from the circuit. When turbulence and moisture combine with a low freezing level the possibility of some kind of icing is always on the cards. Carburettor ice would have been a potential hazard; but, this C172 engine was fuel injected. Fuel does not seem to have been in short supply, the early engineering report leaves you with impression that ‘spark’ was not an issue, which leaves with only ‘air’ to wonder about. This leads us to the engine air intake. Is there an alternate air source? Seems not:-
"4. Watch for signs of engine icing related icing conditions. An unexplained loss of engine speed could be caused by ice blocking the air intake filter. Adjust the throttle position to obtain maximum RPM, this may require advancing or retarding of the throttle depending on where the ice has accumulated. Adjust mixture, as required for maximum RPM."
Furry muff – but throttled back for approach, changing runway, watching for traffic, with wind and turbulence to divert the attention – the advice above is fatuous to say the least. The small adjustments required to maintain profile at a low power setting almost precludes any indication of inlet air icing being noted, let alone dealt with.
One of the more intriguing aspects is the left turn made toward the end of the flight – strange until you drag out the satellite photographs – then it all becomes clear. There is a large, tempting football field in a handy position – which, it could be argued, the pilot saw as a viable alternate to landing on some house. Hobsons choice but with speed and height – in all probability do-able. We don’t know the configuration of the aircraft – ATSB fail to mention this important element. Given the wind on the day and a glide ratio published as approximately 9:1 (at ::68 KIAS) with flap out, the aircraft was battling the odds – retracting the flap may have bought a precious few feet of airspace.
The altitude needed to make a successful glide approach is compromised by the approach procedures in place. 9000 feet travelled for each 1000 ft of height is pretty close in. Call it (for sake of a number) a 1.5 nm final; or, a requirement to be at 2000 ft at 3 nm. This does not fit the airspace model. When an area is as extensively built up as the approach to 35 at Moorabbin, a dead stick landing should be a consideration in the design of airspace. Indeed, it is a rare event, very rare, as is a King Air smacking into a DFO – but accidents on take off and landing rate where on the grand scale of occurrence?
We shall have wait and see what the ATSB eventually come up with – but for my money, this pilot was only a few feet short of walking away and telling the tale over a beer. Which leaves you to wonder about fate and ‘if only’. Take care out there – Murphy flies with everyone; for a Reason.....
Toot – toot.
Just a final thought – when I learnt almost every landing was a ‘forced landing’ with the odd engine clearing throttle up – glide approach, every time, making allowance for wind and other considerations. I wonder if the long powered approaches we see today and the extended circuits are helpful to the single engine ‘thinking’. Fair enough for multi-engine training – but,,,,