If the X-44 would have been stealthier than the F-22, it stands to reason that it was the impetus behind the NGAD program.
USAF/US NAVY 6G Fighter Programs - F/A-XX, F-X, NGAD, PCA, ASFS news, Page 105
X-44 MANTA The National Interest
6th Generation Fighter, Page 3
Mastering English Slang: English Terms Of Endearment, 50% OFF
The Air Force Is Only Building One NGAD: Secret Sixth-Gen Fighter
Finally: US Revealed Reborn X-44 Manta Sixth Generation Fighter Jet
Mastering English Slang: English Terms Of Endearment, 50% OFF
The National Interest: Blog
The National Interest: Blog
X-44 Manta Is This the Future of the US Air Force? After upgrading
The National Interest: Blog
Did America's next stealth fighter just get revealed on Instagram?