Red Emperor

Good Evening Lads,

On August 2003 Maynard Hill launched TAM5 (Spirit of Butts Farm) who went from Cape Spear to Ireland in 38 hours! 3000km with a single gallon!

Is it possible to do a Jet RC who could do the same flight but way faster? Something with a wingspan below 3m and total weight below 20kg (mostly fuel).

What's the most fuel-efficient turbine? Can it reach a cruise speed of 300 to 400km/h?
A flying wing design is the best option?

j.duncker

My Feedback: (2)

Just not possible with current model turbines in a small size such as 3 m and 20 kg.model would require something like a a Wren Supersport which is the smallest turbine that could flt a 20 kg model providing it was a glider type. It burns a litre of fuel every 4 minutes at full throttle. Burn rate at 1/2 throttle will be about 8 minutes per litre.

Assuming the flight takes 15 hrs [ it will take longer I think ] and you can fly at 1/2 throttle [you will need more power early on ] you need 112.5 litres of fuel.that weighs 90 kg.

Red Emperor

Thank you for replying.

Can you give me some tips on where to start? Doesn't have to be specific. What's a feasible setup for a small plane (below 50kg would be more realistic)?

-What kind of propulsion/engine should I look for? Ideally to reach 200km/h cruise speed.
-Is the flying wing design a good choice?

j.duncker

My Feedback: (2)

First of all a warning. At 50 kgs you are well into military/commercial drone territory and you require all sorts of permits. Proceeding without them will result in visits from the authorities.

At 50 kgs the design becomes much easier. Maynard had to stay below 5 kgs at launch to comply with FAI rules. If I was doing this I would look at the Shell Eco Marathon for ideas. A Honda 50cc 4 stroke motor cycle engine would be a good starting point. Many of the early participants used this as the base engine and achieved 1000 miles per gallon. Enlarge Maynards design and you would have something that would make it. Bear in mind Maynard made several attempts that just disappeared before succeeding.

200 km/h will be difficult to achieve though. Most drones capable of prolonged durations are essentially powered gliders with high aspect ratio wings. They would fly at about 100 km/h for maximum fuel efficiency. As the square law applies to get to 200 km/h needs 4 times the power.

Although many designers looked at flying wings for long distance efficient flight no one has really achieved much success. The military like the layout for stealth reasons but fast they are not.

Please make sure you comply with all government registration requirement and drone regulations. I am sure that somewhere someone trawls through these forums for people contemplating illegal activities.

Red Emperor

Didn't expect to have regulations if you're sending it in the middle of the ocean at low altitude. Ill look into laws/regulations to be sure about size restriction.
You pretty much answered all my questions.
Again, thank you for replying!

jester_s1

There may not be regulations for the ocean, but there are for the land sites you plan to takeoff and land from.