'it is so exhilarating to fly because it has such large control surfaces - its delta wings,' he said. 'it is a bomber but it handles like a fighter.'

The wreckage in Abbottabad appeared to have exotic coatings and distinct surfaces and edges reminiscent of stealth aircraft such as the B-2 bomber and the F-22 fighter, aviation experts say.

The Integrity operating system is used today in mission-critical environment such as the B1 bomber and various other fighter jets and commercial airlines.