Heading Meant Bearing In This Aircraft Warning Patent

Case: Honeywell Int'l, Inc. v. Universal Avionics Sys. Corp., No. 2006-1406, 2006-1435 (Fed. Cir. 7/3/07)

The One Sentence Summary: A judgment of infringement was affirmed where the district court correctly construed the claims as adopting terms used in non-standard ways by the patentee.


What They Were Fighting About: A jury had found that defendant's aircraft warning system infringed plaintiff's patent on an aircraft warning system that used proximity to the airport and angle of approach to determine whether an aircraft was on final approach.

Federal Circuit Holdings:

• District court did not err in determining that the patentee acted as his own lexicographer in using the term "heading of the aircraft" to refer to the bearing of the aircraft. The specification was clear that "heading" meant "bearing" as used in the specification and the claims.
• The district court properly rejected defendant's proposed construction of "enabling envelope" as requiring that the system turn on at that point.