Help! Seeking prop/motor help breaking the world endurance record for UAVs <50kg with a prandtl wing

Keaton Hare

New member
Psel with a glider endorsement.. No need to explain wave, how to predict / find / use, just know it's harder than the books indicate from experience. Or I am a lousy pilot. Or both.

Otoh, once every so often, we get someone like you who wants to do a duration or altitude remote aircraft. Never get to see the result of their efforts come to fruition.. at least you don't need a pressure suit.
It’s definitely a hard problem to solve.. I have a lot of experienced people helping me (y’all included) so I hope I can manage it . My current model is predicting about 9 hours of battery endurance so we will see how it does. I wouldn’t even be trying without the help of Albion and a few others - our advantage seems to be the prandtl wing and the fact that we are starting simple and cheap - hopefully it’s enough but even if it isn’t it’ll be a fun project. I’ll be sure to update you all once I start building and testing
 

Keaton Hare

New member
Autonomous flying at 30.000+ft.
Surely you will need the authority from the FAA and have to meet stringent collision avoidance criteria for each and every flight if flown in the USA
we will be using some waivers for flight testing, and ideally we will be testing at the FAR site. The full size version will either be off the coast out of US airspace or flown over Mexico
 

Piotrsko

Master member
When I was gliding there was a zone marked out for flight into wave that was pretty much unrestricted, no comm, no transponder, BUT, it's CONUS iirc between MT Whitney and Ridgecrest. Just had to call FAA preflight for entry and they would keep the military iron aware for you. Unsure what the procedure is currently. Used to be marked on the sectionals with a border

There's wave lift out in the ocean? New one on me. Theoretically is possible.......
 

Keaton Hare

New member
When I was gliding there was a zone marked out for flight into wave that was pretty much unrestricted, no comm, no transponder, BUT, it's CONUS iirc between MT Whitney and Ridgecrest. Just had to call FAA preflight for entry and they would keep the military iron aware for you. Unsure what the procedure is currently. Used to be marked on the sectionals with a border

There's wave lift out in the ocean? New one on me. Theoretically is possible.......
We can fly with a smooth atmosphere ideally , so we won’t need wave over the ocean. However some of the super high altitude wave in Argentina that the Perlan project uses probably does extend into the pacific. At Williams in CA we have a local wave window that can be opened by the office on a good day
 

Piotrsko

Master member
You're a bit upwind from Reno. Did you have monster wave conditions yesterday? We had wave with 6 visible attached cirrus cloud streets, perhaps more visible behind the mountains to the east.

So 81 hours duration from 60k ft is 12.34 fpm down, sea level landing, calm air. Probably doable with cutting-edge, maybe not a flying wing but solid 40+ L/D design. State of the art a while back was 60+ L/D. You're hauling an 80ah battery which is good for perhaps ten plus hours continuous thrust on available motors. Not enough for duration, but enough to get you into lift.

Can't see where any of this is impossible or really even difficult
 
I've been building custom designs for the past 6 years myself, and its of my opinion that for a first pass design its probably best to use the simplest approach for the best results. Ambition has a way of getting in the way, and trying to solve too many innovations all at once can frustrate the mission. Using a conventional but optimized layout can offer a strong foundation for the real challenge: optimizing a power system to last for days long, and a flight control system to work smartly and predictably. Either way, if y'all are confident in your ability to built a prandlt flying wing don't let us stop you.
 

Keaton Hare

New member
You're a bit upwind from Reno. Did you have monster wave conditions yesterday? We had wave with 6 visible attached cirrus cloud streets, perhaps more visible behind the mountains to the east.

So 81 hours duration from 60k ft is 12.34 fpm down, sea level landing, calm air. Probably doable with cutting-edge, maybe not a flying wing but solid 40+ L/D design. State of the art a while back was 60+ L/D. You're hauling an 80ah battery which is good for perhaps ten plus hours continuous thrust on available motors. Not enough for duration, but enough to get you into lift.

Can't see where any of this is impossible or really even difficult
We have solar! So hopefully we won’t even need wave at all but will definitely be nice to have - ideally the battery will last the night and recharge during the day
 

Keaton Hare

New member
I've been building custom designs for the past 6 years myself, and its of my opinion that for a first pass design its probably best to use the simplest approach for the best results. Ambition has a way of getting in the way, and trying to solve too many innovations all at once can frustrate the mission. Using a conventional but optimized layout can offer a strong foundation for the real challenge: optimizing a power system to last for days long, and a flight control system to work smartly and predictably. Either way, if y'all are confident in your ability to built a prandlt flying wing don't let us stop you.
Thankfully l don’t have to design it I just have to build it - Albion sent me the design based on my parameters so I just have to cut and place the ribs, and design the elevons. Hopefully I can get it done in the next few months - I will definitely post updates on the build here
 
Thankfully l don’t have to design it I just have to build it - Albion sent me the design based on my parameters so I just have to cut and place the ribs, and design the elevons. Hopefully I can get it done in the next few months - I will definitely post updates on the build here
Thats pretty cool! Custom design from the expert themself.