Finding that the prior art did not enable anyone to actually make and use the claimed invention, the Federal Circuit reversed a Patent Trial and Appeal Board (PTAB) finding of obviousness on Friday. The Raytheon v. GE decision emphasized that a prior art reference must either (1) give an enabling disclosure, or else (2) be enabled by other prior art or other evidence.

In this case, Raytheon’s patent claimed a gas turbine engine, having a certain power density. GE challenged the patent in inter partes review, based on a 1987 NASA memo. The NASA memo provided some aggressive turbofan engine performance parameters. According to GE and the PTAB, the skilled artisan could calculate a power density from these parameters, to render Raytheon’s claims obvious.

However, Raytheon argued that these parameters from the NASA memo presupposed the use of certain composite materials in the turbofan engine. Raytheon further showed that these types of composite materials from the NASA memo would not have actually been available. GE did not directly dispute this point. Instead, GE simply said that the power density could be calculated from the information in the NASA memo. GE therefore said that the materials were irrelevant. The PTAB ruled in favor of GE, deciding that the information in the NASA memo enabled the power density limitation, regardless of the composite materials.

The Federal Circuit disagreed. A prior art reference does not necessarily need to provide all details needed for making and using its subject matter. However, for any such prior art references that are not “self-enabling,” enablement must be possible from other prior art references or other evidence. If not, then the invention cannot be obvious. In this case, because GE gave no reason why the NASA memo would have been enabled, even after Raytheon showed extensively that the necessary composite materials would have been unavailable, the Federal Circuit found the claims not to be obvious.

As an alternative, GE argued that the power density would have been a “result-effective variable” that was obvious to optimize. However, the Federal Circuit stated that “If a skilled artisan cannot make [the NASA memo’s] engine, a skilled artisan necessarily cannot optimize its power density.”

Typically, questions of obviousness focus on missing elements, or on the basis to modify or combine the prior art. The Federal Circuit even pointed this out, in the outset of their decision on Friday. Still, applicants and patentees have other options, such as the possibility to demonstrate that the prior art was not enabled. On the other hand, for other parties looking to challenge patent validity, obviousness arguments may sometimes need to account for whether the skilled artisan could have actually made and used the invention, based on the prior art.