Remaining Fuel - Range Calculations

[rianmonnahan]

Hi All,

I have a new Arcus 2.0 M and am pouring over the manual.

I have query on expected range, say, for 14l of fuel. I find the sawtooth method range figures in the manual (p. 5.3.2.3) fairly optimistic.

They work out to about 20 time remaining fuel. So, approximately 280km for 14l. That might work for the flat lands.

BUT I fly in the Alps. I think perhaps 10 times the remaining fuel would be a more conservative estimate given the terrain you have to overfly here and the passes you have to cross.

I recently had to divert to Grenoble on my way back to Sisteron after getting stuck in Chambery. I did not have enough fuel to climb over 2500 m, not enough to cross safely from Grenoble to Gap. So, I turned around at around 2000m near the Taille Fer, landed in Grenoble and got a tow home. 

I am going to take off with more fuel or get a tow to begin the day. I am also going to carry about 500ml of 2T oil and the filling tube on-board from now on. Still I am looking for a good rule of thumb regarding the range one might expect.

Feedback based on personal experience would be much appreciated.

Cheers,

Rian Monnahan

Arcus 2.0 M #304

D-KTKL

[bucc...@gmail.com]

From flying with multiple french professional mountain gliding instructors since 25 years, the rule is 20:1 glide ratio to your next safety landmark, being it a col, a mountain at sufficiant height to climb again, or a landable field.  Calculate accordingly.  BTW, if you are pulling the engine out to start when you are in trouble, do not pull out the engine if you are in sinking air.  Glide to the next field for a landing.  The published distance to travel with sawtooth engine runs is based on flat terrain, no obstructions whatsoever and landable fields everywhere.  That is far from reality in the Alps