Originally Posted by
Tourist
This is what I thought until I had a bit of a think.
Why outrun anything?
What about if you just turned the engines off and drifted with the wind?
Ummm, you hit the ground, someplace slightly downwind of where you shut off your engines. I don't think you quite grasp the concept of what they're building here. The fundamental concept of this is that it's not a pure aerostat, but a hybrid, which is completely dependent on forward motion and/or directed thrust to stay airborne. That is *THE* thing which makes it different than blimps which already exist, and have very limited application. The underlying concept here (which you seem to have missed) is that it is claimed to have better lifting capabilities than blimp, is because of lift and thrust. So if you're using it to carry the loads advertised, if you shut off the engines, you come down out of the sky.
Free ballooning would certainly be an option if you were operating empty, but it's hard to make money flying around empty.
Originally Posted by Tourist
I would say that a blimp with a planned endurance of weeks has ...
But it doesn't have a planed endurance of weeks, or even one week, they suggest a loiter time of five days, but that is a max loiter time, not cruise time and not cruise time with a payload. Completely aside from the fuel/payload issue, do you really think that a heavy lift airship will also have provisioned accommodation for the crew for "weeks" ? you're drifting dangerously into Jules Verne fantasy land here.
This aircraft, like all powered aircraft is going to to be fuel and load limited. I think that you are misled by the payload and endurance figures the salesmen are slinging about somewhat carelessly. I wouldn't go as far as to say they're being
dishonest, but the claims need to be taken in context. The aircraft I fly has a cruising endurance of 12-13ish hours. It also has a payload capability or about 48,000 lb. However, it does
not cruise for 12 hours with a 48,000 lb payload, not even close. Payload would be less than 10,000 lb with a max fuel load. Conversely, cruise endurance with a max payload and reasonable reserves is in the neighborhood of 3 hours.
If you're using this contraption for heavylift operations you're not going be able to free balloon, and you're going to be fuel limited. You can plan on it. So you're not going to simply be able to wander off 10 hours in a new direction when bad weather is approaching, you're going to have to get yourself, and your blimp, and your heavy-lift payload on the ground, and not just on the ground anyplace, but on the ground at a location which has an airship hangar.