Floatplane in the Trees
Moderators: sky's the limit, sepia, Sulako, lilfssister, North Shore
Re: Floatplane in the Trees
Accident report out. Unfortunately, another fuel related accident.
https://tsb.gc.ca/eng/rapports-reports/ ... 9q0146.pdf
It appears that the homemade dipstick(s) used were not accurate(there were two of them that were strangely latched together). I remember flying a couple of skydive planes that used homemade dipsticks as the fuel gauges were completely unreliable. One gets very used to the dipstick markings when they are fuelling up several times per day of flying. A couple of years later, someone decided to re-calibrate that dipstick and it was significantly different and had us using less fuel. But which one is correct. Of course, we were assured that the new one was more accurate but I just approximated what was being used previously as a precaution.
In the accident case, no one knew who made the dipstick. Is unusable fuel accounted for? Was the dipstick made when the aircraft was on wheels or floats? Was the aircraft level. Maybe best to just have a few extra gallons at least for homemade dipsticks that you are unfamiliar with. And in the case of this 206, the fuel selector cannot be selected to Both, so 30 minutes fuel reserve might be 2.5 gallons per side. Not a lot.
https://www.youtube.com/watch?v=ask3v9KfdBU
I found this video of someone making a dipstick for a taildragger. It seemed to get more interesting at 4:30. Not all usable fuel can be measured.
Meanwhile, this FuelHawk dipstick for a C-182(which I assume is fairly accurate) shows the first couple of gallons of measured fuel being unusable.
https://www.sportys.com/cessna-182-fuel ... tanks.html
https://tsb.gc.ca/eng/rapports-reports/ ... 9q0146.pdf
It appears that the homemade dipstick(s) used were not accurate(there were two of them that were strangely latched together). I remember flying a couple of skydive planes that used homemade dipsticks as the fuel gauges were completely unreliable. One gets very used to the dipstick markings when they are fuelling up several times per day of flying. A couple of years later, someone decided to re-calibrate that dipstick and it was significantly different and had us using less fuel. But which one is correct. Of course, we were assured that the new one was more accurate but I just approximated what was being used previously as a precaution.
In the accident case, no one knew who made the dipstick. Is unusable fuel accounted for? Was the dipstick made when the aircraft was on wheels or floats? Was the aircraft level. Maybe best to just have a few extra gallons at least for homemade dipsticks that you are unfamiliar with. And in the case of this 206, the fuel selector cannot be selected to Both, so 30 minutes fuel reserve might be 2.5 gallons per side. Not a lot.
https://www.youtube.com/watch?v=ask3v9KfdBU
I found this video of someone making a dipstick for a taildragger. It seemed to get more interesting at 4:30. Not all usable fuel can be measured.
Meanwhile, this FuelHawk dipstick for a C-182(which I assume is fairly accurate) shows the first couple of gallons of measured fuel being unusable.
https://www.sportys.com/cessna-182-fuel ... tanks.html
Last edited by pelmet on Sun Mar 22, 2020 7:39 am, edited 2 times in total.
Re: Floatplane in the Trees
It can get pretty interesting on a taildragger.
For fun I marked the fuel level in a pitts once. Blue markings for a wings level attitude, black markings for a 3 point - on - the ground attitude. There was up to an inch difference. Ground full indicated could be as low as only a 3/4 tank in the air. If you add a standard endurance of only 2 hours, losing a quarter of fuel reduces your allowed flying time by 40%.
Pretty obvious if you think about it, not always obvious for pilots new to the type if you don't expect such behaviour.
For fun I marked the fuel level in a pitts once. Blue markings for a wings level attitude, black markings for a 3 point - on - the ground attitude. There was up to an inch difference. Ground full indicated could be as low as only a 3/4 tank in the air. If you add a standard endurance of only 2 hours, losing a quarter of fuel reduces your allowed flying time by 40%.
Pretty obvious if you think about it, not always obvious for pilots new to the type if you don't expect such behaviour.
As an AvCanada discussion grows longer:
-the probability of 'entitlement' being mentioned, approaches 1
-one will be accused of using bad airmanship
-the probability of 'entitlement' being mentioned, approaches 1
-one will be accused of using bad airmanship
Re: Floatplane in the Trees
I believe you can increase the fuel quantity in some taildraggers by fueling them while they are in the level attitude. I haven't tried it and am not sure if fuel might be leaking out of a vent.digits_ wrote: ↑Fri Mar 20, 2020 9:55 am It can get pretty interesting on a taildragger.
For fun I marked the fuel level in a pitts once. Blue markings for a wings level attitude, black markings for a 3 point - on - the ground attitude. There was up to an inch difference. Ground full indicated could be as low as only a 3/4 tank in the air. If you add a standard endurance of only 2 hours, losing a quarter of fuel reduces your allowed flying time by 40%.
Re: Floatplane in the Trees
all tail draggers are fueled in the level attitude on floats
Black air has no lift - extra fuel has no weight
http://www.blackair.ca
http://www.blackair.ca
Re: Floatplane in the Trees
Only 2 times you can be absolutely certain of the fuel quantity.
Re: Floatplane in the Trees
Yup! 'Flown one regularly, the other onceOnly 2 times you can be absolutely certain of the fuel quantity.