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No doubt that skiing sports is great especialy when your weight is the main force which speed up your motion in snow.

I was asking myself, why we don't use the same concept for huge planes & reduce some of fuel consumption during takeoff stage on runway.

Typical Boeing 747 jet burns about 5000 Gallons in takeoff until reach cruise speed. It's about 10% of their fuel capaccity.

Is it possible in constructional side to build slopped runway like what we see in right corner photo OR it has some risks ??

Is it worth it or there are tradeoff with other considerations?

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Miracle Airfoil
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    Most of that 5000 gallons must be climbing to cruise and unaffected by the runway. Closer to 850 gallons for takeoff roll and climb to 3000 feet. – BowlOfRed Nov 29 '21 at 10:30
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    Does this answer your question? Why don't short runways use (downhill) ramps for takeoff? –  Nov 29 '21 at 10:50
  • What would you recommend to stop an aircraft on a descending runway? Snow plow or parallel? – mins Nov 29 '21 at 13:31
  • The main reason is a bit different from what is mentioned in the “duplicate” question: it would not reduce the energy required, so it would not reduce the fuel consumption. By rolling downhill, the aircraft exchanges potential energy for kinetic energy. But then it has to climb back up, and further to the flight level, which means it has to gain the potential energy again, and it's the engines that have to provide it. So in the end the engines have to provide the same energy and there are no savings to be had. – Jan Hudec Nov 29 '21 at 14:49
  • … it does allow shorter runway, which helps in places like Courchevel or Lukla where there isn't room for create a longer nor flatter runway. But it comes with its own challenges, making flat runway preferable where possible. – Jan Hudec Nov 29 '21 at 14:52
  • @mins land uphill. Except of course we can't usually assume still air so we can't do that. Airfield that have one-way runways or similar constraints have a lot of unplanned downtime as at Tenzing-Hilary – Chris H Nov 29 '21 at 16:08
  • @ChrisH: I believe the context is takeoff only, I was referring to aborted takeoffs, e.g. because there is an engine failure before V1. – mins Nov 29 '21 at 16:12
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    @mins Ah OK. I was thinking about the planes having to arrive before they could depart. Certainly Courchevel looks like you might be getting in a bit more skiing than you'd planned if an engine fails on departure – Chris H Nov 29 '21 at 16:15
  • Believe it or not, the ramp would lead to a shorter take-off but would burn more fuel. A climbing aircraft (to regain altitude) must also burn fuel against lift drag as well as angle of climb. A rolling aircraft only burns fuel against the grade with minimal axle friction. If the runway was 3 miles long and 300 feet up hill, a light aircraft could save fuel by taxiing up the first 2 miles, then taking off uphill! – Robert DiGiovanni Nov 30 '21 at 21:54

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