Zunum Aero, Inc. v. The Boeing Company

Procedural Issue

Appellate jurisdiction — Federal Circuit's exclusive jurisdiction under 28 U.S.C. § 1295(a)(1) turns on whether a patent counterclaim is compulsory under FRCP 13(a); scope of supplemental jurisdiction under 28 U.S.C. § 1367(a) over state-law claims tied to a permissive federal counterclaim

Holding

On a petition for panel rehearing raising subject-matter jurisdiction for the first time, the Ninth Circuit held it had appellate jurisdiction despite patent-law counterclaims below. The Federal Circuit's jurisdiction under 28 U.S.C. § 1295(a)(1) is exclusive whenever a party asserted a compulsory patent counterclaim in the action — regardless of whether that counterclaim is itself before the appellate court — so the threshold question is always whether the patent counterclaim was compulsory or merely permissive under Federal Rule of Civil Procedure 13(a)'s 'transaction or occurrence' test. Applying the Ninth Circuit's two-part 'logical relationship' framework from Mattel v. MGA Entertainment (do the same operative facts underlie both claim and counterclaim, or does the claim's aggregate facts activate an otherwise-dormant right to bring the counterclaim), the panel held the patent-inventorship counterclaims here were permissive, not compulsory — reaching the identical result under the Federal Circuit's own three-factor test in the alternative — so jurisdiction over the appeal was proper in the Ninth Circuit. The panel also held, joining the First, Second, and Seventh Circuits with no contrary authority in any circuit, that a district court's supplemental jurisdiction under 28 U.S.C. § 1367(a) over related state-law claims is broader than the compulsory-counterclaim standard: it reaches claims sharing only a 'common nucleus of operative fact' — a looser 'loose factual connection' — with a permissive federal counterclaim that supplied removal jurisdiction. Petition for panel rehearing denied. Judge Bade concurred in the jurisdictional outcome on different grounds, arguing the majority's reliance on Mattel's 'logical relationship' synthesis substitutes for Rule 13(a)'s actual 'transaction or occurrence' text, and flagged possible tension with the circuit's own Pochiro decision that may warrant en banc resolution.

Why It Matters

Essential reading before filing or opposing any appeal in a case involving a patent-law counterclaim: get the compulsory/permissive characterization wrong and the appeal may belong in the wrong circuit entirely, since § 1295(a)(1)'s Federal Circuit exclusive-jurisdiction hook applies whenever a compulsory patent counterclaim was asserted below, even if patent issues aren't what's being appealed. A counterclaim seeking a declaratory judgment on patent inventorship or validity is not automatically compulsory just because it arose in the same lawsuit — ask whether the same operative facts prove both the claim and counterclaim, and whether the claim's facts affirmatively activated a previously dormant right to bring the counterclaim; a claim and counterclaim can be logically compatible (both sides can win) and still be separate transactions. On the removal side, this confirms that a permissive federal counterclaim is enough to anchor supplemental jurisdiction over related state-law claims under § 1367(a) — the 'common nucleus of operative fact' standard is looser than the compulsory-counterclaim test, so removing on the strength of a permissive patent counterclaim doesn't strand the state claims that came along with it. Judge Bade's concurrence previews a live doctrinal fault line — whether Mattel's two-prong gloss should be the operative test at all, versus Rule 13(a)'s bare text — worth flagging if this question recurs, since she suggests the tension with Pochiro may warrant en banc review.

About This Entry

Court: United States Court of Appeals for the Ninth Circuit
Topic: Jurisdiction
Month: September 2026
Publication status: Published
Last verified: 2026-09-02

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