Why would the treadmill runway need to be 3000trs long??? after all a treadmill at the gym is only 1.5 mts approx yet i can run 5k>. and still not reach the end....never seem to achieve t/o either although i have sufferd u/c failure once!!!!
so the time saved constucting 3000mtrs can be used to build a large fan for that much needed airspeed.