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Thruster88

First day back at work

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First day back for a Cessna 172 and this happens

 

https://www.atsb.gov.au/publications/investigation_reports/2018/aair/ao-2018-005/

 

I sympathise for the pilot. If casa was to introduce just one more rule it should be that all old or new aircraft with crap fuel gauges must have a dip stick calibrated in litres, the repeatability of this simple piece of aluminium is truly amazing.

 

20190111_142627.thumb.jpg.e834865908a36e674d1bf475026e32aa.jpg

 

 

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I never rely on fuel gauges. Fuel tanks in wings are very wide and shallow so any slight parking angle will give erroneous results even on the dipstick let alone the gauge.

 

I set my fuel sender float arm length according to the VDO manual for the depth of my main tank when I installed it. All well & good but the gauge read is based on the linear value provided by the float position. The problem is that most fuel tanks are not perfect cubes or rectangles so the reading will only be perfectly accurate at empty and full. This is why you should have a placard with the actual fuel amounts and the gauge reading on the panel. When you are flying it isn't much use having the placard in the manual as it was in this case.

 

I also sympathise with the pilot as he would have got back if he had 182 litres on board instead of 144. The only issue was that he'd have used about half of his reserve getting back. As he was using a higher power setting than normal running in the engine at 2500rpm  fuel consumption would have been higher than at a standard cruise of around 2350rpm. At that rpm he would most likely have got back with 144 litres and with 182 litres with the 45 minute reserve intact

 

Now of course the reserve has been lowered to 30 minutes & the controversial Fuel Mayday introduced. Stupid rule IMHO. I still stick with the 45 min reserve.

 

 

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Better to have more fuel, that extra 8liters will save a life

 

 

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Notwithstanding the pilot seeing the different calibration marks on the dipstick,  but missing the new fuel tank quantity placards on top of the wing - while refuelling the aircraft, he missed a couple of other really important differences.

 

1.  The new engine was a Lycoming 0-360 of 180 HP, and has a fuel consumption quite a few L/hr higher than the previous 150/160 HP engine. Probably around 4-5 LPH more at 65% power. 

 

2. When running in a 180 HP engine, (@ 2500rpm/ 75% pwr), you'd expect to use around 40 LPH - which was exactly what was used up to fuel exhaustion. (3hrs 38mins into 144L). Running in an engine on the job does have some risks - because you are a long way from home should it begin to misbehave! It's probably OK if over wheatbelt terrain - but over bush??  Also, it's desirable not to run the engine with long descents, (unless you can hold the 75% power) - which happened here on 2 occasions, ( from 7500, 8500).

 

Was account taken of the larger engine, and it being 'run in'?  Unknown. The flight planning was for 4 hrs flight fuel + 45mins reserve, or, 30.3 LPH. This is below what would be normal flight planned fuel burn for an 0-320 engine (32 LPH). Had it been planned on 32 LPH, then there would have necessarily been only 3 hrs 45 mins flight fuel. They might have just squeaked home?

 

It does show that aircraft can differ within the model, and in a fleet, it's common for a pilot to fly 2 or 3 different aircraft on any one day.  It's prudent to understand the 'differences' of each one of the fleet if you are a line pilot, but management should have had a better advisory system as standard practice.

 

Sensible flying saved the day in the end, but it could have been much worse over some of the tiger country in the Goldfields.

 

happy days,

 

 

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Reminds me of the oft-repeated quote from an interview of Ernest K Gann - "The only time you can have too much fuel in an aircraft, is when you're on fire!"

 

He was darned lucky he found a patch of scrubby ground to land on - there's some pretty heavy timber in a lot of that area around Burra Rock. W.A Goldfields trees are quite unforgiving, if you have no choice but to land in them.

 

Burra-Rock-landing.thumb.jpg.4eeb834b3141d6ab40d14c86df842895.jpg

 

 

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There is no mention of the installation of a new O360 engine. The engine was bulk stripped according to the report and presumably new rings etc installed requiring a run in. Only the propeller & both wings were replaced. I don't know where the placard was located but it was not on the wings The useable fuel of 72.2 litres was written on the wing in the photo though.

 

 

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There is no mention of the installation of a new O360 engine. The engine was bulk stripped according to the report and presumably new rings etc installed requiring a run in. Only the propeller & both wings were replaced. I don't know where the placard was located but it was not on the wings The useable fuel of 72.2 litres was written on the wing in the photo though.

 

Penn Yan conversions are almost always 180HP 0-360 engines AFAIK. The shiny new fuel placard is just aft of the fuel filler cap, (see pic in atsb rept), and staring the refueller 'in-the-face'.   If the engine had been installed well prior to the wing damage accident, then the pilot would have been familiar with its' fuel consumption - but this is invariably far lower than the 'running-in' fuel consumption for the same engine. The LAMEs also noted the changes in the POH, though this would have been less likely seen without notification from them to 'all pilots'

 

So, regardless of what HP/capacity the engine was - it used 144L avgas over a 3 hr 38 min period, ie, 40 LPH.  For a flight involving 2 quite high climbs, plus some circling of fire zones,  I'd think this would be about correct for the 0-360, but very high if it was an 0-320.

 

Again, a real heads up for pilots flying any aircraft which has been in maintenance for major work.

 

happy days,

 

 

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Well, No. If a new engine was installed the report would have said so. Bulk stripping and new rings etc does not produce a new 180 HP engine. The picture of the fuel placard on the left of the picture showing the filler cap on the wing is the placard for both tanks. It is also on a black background. The wing is white.

 

 

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My O-360 drinks about 35 LPH when properly leaned at 65% power. At 75% about 38, so I plan on 40.

 

 

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I don't know where the placard was located but it was not on the wings

 

About two lines above the photo in the report, it says it was "affixed the centre of the instrument panel".

 

 

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