4 ms·

Yes, in VTOL mode you are generally going to want to land into the wind or wheel the aircraft into the wind for takeoff. I think that would probably be possible

by lambda 4y ago

Yes, in VTOL mode you are generally going to want to land into the wind or wheel the aircraft into the wind for takeoff. I think that would probably be possible. But we are also concerned with CTOL performance; in order to add more flexibility, CTOL performance is something that we are focusing on heavily, as if a runway is available you can do a takeoff and/or landing with lower energy use and thus get more range, so we're designing to be able to takoff and land either CTOL or VTOL. For example, one of our use cases is cargo, such as UPS getting packages from an airplane at the airport, to its distribution center. At an airport, you have a runway available for takeoff, so you might do a CTOL takeoff, and then a VTOL landing at the distribution center, and vice versa for the return trip. And what I'm saying is that our aircraft, at least, won't have crosswind capabilities that are terribly high when doing CTOL takeoff and landing. It's pretty light and floaty and has a strong weathervaning tendency, and control surface sizes are kept limited in order to save weight and drag. It will be able to handle the minimum and maybe a bit more, but I wouldn't expect it to do well significantly above what the demonstrated crosswind velocity is. Ours is designed more as a glider that happens to have electric propulsion and lift capabilities, rather than a conventional powered aircraft, in order to be able to eke more range out of our batteries and provide a greater safety margin in the event of loss of propulsion power, but there are some tradeoffs to that design. Also, I should say that I'm a software guy, this is my first aviation related job, and I only have about 2 hours in my logbook for dual received, and our certified design is not finalized and we are still doing some trades on things like control surface sizes, so anything I say here might be wrong now or in the future. But right now, we have a fairly limited crosswind envelope.

sokoloff 4y ago
That might not be as big of a concern as it first appears. You’re rarely more than 50 miles from an airport with either a crossing runway or a taxiway better aligned to the unusual wind (naturally, airports tend to have a primary runway aligned with the prevailing winds when terrain permits). In an emergency, landing on an aligned taxiway is probably not materially different in risk profile from a VTOL landing on an uncontrolled ramp or parking lot under those same wind conditions.
- lambda 4y ago
  Yep, I'm not saying it's a big limitation, given the VTOL capabilities and availability of airports. Just that there will be few windy days in which we might not be able to fly, but that's the case for pretty much all small aircraft.

by lambda 4y ago

sokoloff 4y ago

That might not be as big of a concern as it first appears. You’re rarely more than 50 miles from an airport with either a crossing runway or a taxiway better aligned to the unusual wind (naturally, airports tend to have a primary runway aligned with the prevailing winds when terrain permits). In an emergency, landing on an aligned taxiway is probably not materially different in risk profile from a VTOL landing on an uncontrolled ramp or parking lot under those same wind conditions.

lambda 4y ago
Yep, I'm not saying it's a big limitation, given the VTOL capabilities and availability of airports. Just that there will be few windy days in which we might not be able to fly, but that's the case for pretty much all small aircraft.