United States Court of Appeals 

for the Federal Circuit ______________________ 

MAG AEROSPACE INDUSTRIES, INC., NKA MAG 

AEROSPACE INDUSTRIES, LLC,

Plaintiff-Appellant 

v.

B/E AEROSPACE, INC.,

Defendant-Cross-Appellant

______________________ 

2015-1370, 2015-1426

______________________ 

Appeals from the United States District Court for the 

Central District of California in No. 2:13-cv-06089-SJOFFM, Judge James S. Otero.

______________________ 

Decided: March 23, 2016

______________________ 

STEVEN MOORE, Kilpatrick Townsend & Stockton 

LLP, San Francisco, CA, argued for plaintiff-appellant. 

Also represented by ERWIN CENA, San Diego, CA; ADAM 

HOWARD CHARNES, Winston-Salem, NC; CANDICE C.

DECAIRE, ALYSON L. WOOTEN, Atlanta, GA; MATTHEW 

CHRISTIAN HOLOHAN, Denver, CO; WILLIAM E. MOSLEY, 

Menlo Park, CA.

ANDREI IANCU, Irell & Manella LLP, Los Angeles, CA, 

argued for defendant-cross-appellant. Also represented by 
2 MAG AEROSPACE INDUSTRIES, INC. v. B/E AEROSPACE, INC. 

RICHARD BIRNHOLZ, MORGAN CHU, BENJAMIN HABER,

HARRY MITTLEMAN, MELISSA SEDRISH RABBANI. 

______________________ 

Before PROST, Chief Judge, MAYER and REYNA, Circuit 

Judges.

PROST, Chief Judge. 

These appeals concern vacuum toilets, such as those 

that are commonly found on commercial aircrafts. Plaintiff-Appellant MAG Aerospace Industries, LLC (“MAG”) 

sued B/E Aerospace (“B/E”), alleging infringement of U.S. 

Patent Nos. 6,536,054 (“’054 patent”), 6,536,055 (“’055 

patent”), and 6,353,942 (“’942 patent”) in the United 

States District Court for the Central District of California. 

The district court granted summary judgment of noninfringement on all patents, from which MAG timely appeals. The district court also ruled that the doctrine of 

assignor estoppel barred B/E from arguing that the asserted patents are invalid, and B/E cross-appeals from 

that ruling. For the reasons stated below, we affirm the 

district court’s rulings. 

BACKGROUND

The patents-in-suit relate to the quick repair of vacuum toilets such as those used in commercial aircraft. 

They describe technology that facilitates maintenance and 

service of vacuum toilets and minimizes vehicle downtime 

through the use of toilet components that are “line replaceable units” (“LRUs”)—single modules that are targeted for easy replacement in the field. The ’054 patent 

describes a vacuum toilet that includes a “waste receptacle” (i.e., toilet bowl) that is “toollessly inserted into and 

removed from the installed position independent of the 

frame,” and thus can be easily and quickly replaced. ’054 

patent col. 4 ll. 47–67. The ’055 and ’942 patents claim 

the use and repair of LRUs within vacuum toilets. Specifically, the ’055 patent requires two LRUs: (1) a waste 
MAG AEROSPACE INDUSTRIES, INC v. B/E AEROSPACE, INC. 3

receptacle, and (2) a “valve set” that includes “at least two 

of the discharge valve, rinse fluid valve, and flush control 

unit.” ’055 patent col. 11 ll. 30–33. The ’942 patent, 

which is the parent of the ’055 patent, discloses a modular 

vacuum toilet in which the toilet bowl is supported on top 

of a structural support frame by an “out-turned flange” 

around the opening of the toilet bowl. ’942 patent col. 11 

ll. 6–7. 

MAG sued B/E, alleging direct and indirect infringement of the claims of the asserted patents. On November 

21, 2013, B/E counterclaimed on the basis of noninfringement and invalidity. In response to B/E’s invalidity 

counterclaim, MAG asserted the affirmative defense of 

assignor estoppel. 

On July 24, 2014, the district court issued a Markman

order construing several terms of the asserted patents. 

Relevant here, from the ’054 patent, the district court 

construed the term “toollessly” to mean “without the use 

of any tools.” J.A. 38. From the ’055 patent, the district 

court construed the term “line replaceable unit” to mean 

“a single module targeted for easy replacement in the 

field.” J.A. 41. Finally, from the ’942 patent, the district 

court construed “an out-turned flange supported by the 

top of the support structure” to mean an “outside rim or 

edge turned away from the sidewall, transferring loads to 

the top of the support structure.” J.A. 34.

On December 8, 2014, B/E moved for summary judgment of noninfringement, and MAG moved for summary 

judgment of no invalidity on the basis of assignor estoppel. On January 23, 2015, the district court granted B/E’s 

motion for summary judgment of noninfringement. The 

district court also granted MAG’s motion for summary 

judgment of no invalidity due to assignor estoppel. 

Both parties timely appeal. We have jurisdiction under 28 U.S.C. § 1295(a)(1).
4 MAG AEROSPACE INDUSTRIES, INC. v. B/E AEROSPACE, INC. 

DISCUSSION

We review a district court’s grant of summary judgment under the law of the regional circuit, which here is

the Ninth Circuit. Memorylink Corp. v. Motorola Sols., 

Inc., 773 F.3d 1266, 1270 (Fed. Cir. 2014). The Ninth 

Circuit reviews the grant of summary judgment de novo. 

Greater Yellowstone Coal. v. Lewis, 628 F.3d 1143, 1148 

(9th Cir. 2010). We review a district court’s ruling of 

assignor estoppel for abuse of discretion. Pandrol USA, 

LP v. Airboss Ry. Prods., Inc., 424 F.3d 1161, 1165 

(Fed. Cir. 2005).

MAG argues that the district court erred in granting 

summary judgment of noninfringement of the asserted 

patents. B/E argues that the district court erred in ruling 

that it was barred from asserting invalidity under the 

doctrine of assignor estoppel. We address each of these 

arguments in turn. 

I. SUMMARY JUDGMENT OF NONINFRINGEMENT 

The district court granted B/E’s motion for summary 

judgment of noninfringement of the ’054, ’055, and ’942 

patents, holding that (1) the toilet bowls in B/E’s toilets 

cannot be “toollessly” replaced; (2) the “valve set” in B/E’s 

vacuum toilets is not an LRU; and (3) B/E’s toilet bowl 

does not include an “out-turned flange supported by the 

top of the support structure.” For the reasons discussed 

below, we affirm the district court’s rulings.

A. The ’054 Patent

MAG argues that the district court erred in ruling on 

summary judgment that B/E’s toilet bowl cannot be 

replaced “toollessly” as required by the ’054 patent. MAG 

points to B/E’s technical documents and the testimony of 

B/E’s former Director of Sales and Marketing, Paul 

Neary, which it says show that B/E’s toilet bowls can be 

replaced either manually or with the use of a coin. For

example, B/E’s documents state, “The toilet is designed to 
MAG AEROSPACE INDUSTRIES, INC v. B/E AEROSPACE, INC. 5

be dis-assembled, assembled, maintained, and serviced 

without tools.” J.A. 3110 (emphasis added). MAG points 

out that, in fact, twenty-nine of B/E’s technical documents 

provided to customers make that assertion. Moreover, 

MAG relies on Mr. Neary’s testimony that he “definitely” 

informed B/E’s customers that the toilet bowl is designed 

to be replaced and serviced without tools. J.A. 3083. 

Thus, MAG contends that there is a genuine issue of 

material fact as to whether B/E’s toilet bowls meet the 

“toollessly” replaceable limitation of the ’054 patent. 

MAG is incorrect. There is no dispute that B/E’s toilet 

bowl is attached to its frame with two screw fasteners. 

And the record evidence showed that to release the screws 

and remove the bowl, some kind of tool is necessary. In 

fact, MAG presented no evidence that the screw fasteners 

could be turned using only one’s hands (e.g., using a 

fingernail). Indeed, B/E points out that every fact witness 

who was asked testified that a tool, such as a coin or a 

screwdriver, is necessary to release the screws. The B/E 

documents on which MAG relies do not create a genuine 

issue of material fact on this point. Instead, as the district court properly determined, those promotional and 

non-technical documents were simply “using a definition 

of ‘tools’ that excludes coins.” J.A. 16. The unrebutted 

evidence shows that the reference to “without tools” was a 

typographical error. Moreover, MAG’s reliance on an outof-context snippet of Mr. Neary’s testimony is unpersuasive. When Mr. Neary was asked more directly about 

whether the toilet bowl could be removed manually, he

clearly stated that a tool (like a coin) is required. 

The question then remains whether a coin is a tool. 

In its Markman order, the district court construed “toollessly” to mean “without the use of any tools.” J.A. 39, 41. 

The district court made clear that even unconventional 

tools would be considered tools in the context of the ’054 

patent, stating that “the claims and specification never 

describe the types of tools that could or could not be used 
6 MAG AEROSPACE INDUSTRIES, INC. v. B/E AEROSPACE, INC. 

to remove or install the toilet, nor does the patent make

any reference to mechanics.” J.A. 39. Importantly, as 

B/E points out, MAG does not challenge the district 

court’s claim construction. Although MAG devotes a 

paragraph under its standard of review section to claim 

construction, MAG does not clearly advocate for review of 

the construction of “toollessly.” MAG instead argues that 

the district court never fully resolved the question of 

whether a coin qualifies as a tool within the meaning of 

the ’054 patent and that a genuine issue of material fact 

remains. 

MAG is again incorrect. As MAG has framed the issue, the question is not whether the district court properly determined that “toollessly” means “without the use of 

any tools,” but instead is whether that construction leaves 

open the question of whether a coin is a tool. It is clear 

based on the back and forth at the claim construction

hearing that the district court did fully resolve that 

question. The district court specifically rejected MAG’s 

proposed construction that “toollessly” means “without 

the use of conventional mechanics’ tools” and instead 

stated that the specification clearly indicates that the 

invention of the patent is that no tools of any kind are 

necessary. Thus, the district court previously determined 

that a coin is a tool and, because MAG is not challenging 

the construction itself, the district court did not err in 

granting summary judgment of noninfringement.

B. The ’055 Patent

MAG next argues that the district court erred in 

granting summary judgment of noninfringement of the 

’055 patent on the basis that the “valve set” in the accused 

B/E toilets is not an LRU. MAG points to B/E technical 

documents that it contends show that B/E designed its 

“valve set” to address the problem of complicated valve 

replacement by making the valve set easy to remove from 

the toilet. MAG also notes that a B/E video further con-
MAG AEROSPACE INDUSTRIES, INC v. B/E AEROSPACE, INC. 7

firms that the valve set consisting of the discharge valve 

and the flush control unit is designed to be easily removed 

and replaced. Thus, MAG contends that summary judgment was inappropriate. 

The district court previously construed LRU to be “a 

single module targeted for easy replacement in the field.” 

J.A. 41. MAG says that the “discharge valve” and the 

“flush control unit” comprise the valve set in B/E’s toilets. 

The question is thus whether the discharge valve and the 

flush control unit together act as a “single module targeted for easy replacement in the field.” J.A. 41. In support 

of its position, MAG only identifies the B/E video; but, as 

the district court noted, that video does not clearly identify the flush control unit. In contrast, B/E presented 

significant evidence that the discharge valve and the 

flush control unit are removed separately, with the flush 

control unit being removed before the discharge valve. 

Indeed, MAG admits that B/E’s maintenance manuals do 

not provide instructions for removing and replacing the 

discharge valve and the flush control unit as a single 

module. MAG also presented no evidence that the two 

components have ever been removed at the same time by 

a customer. Thus, the district court properly concluded 

that there was no genuine material dispute as to whether 

the discharge valve and the flush control unit operated as 

a single module targeted for easy replacement. The grant 

of summary judgment of noninfringement of the ’055 

patent was thus correct.

C. The ’942 Patent

Finally, MAG contends that the district court erred in 

granting summary judgment of noninfringement of the 

’942 patent, arguing that the district court incorrectly 

found that B/E’s toilets do not have the claimed “outturned flange.” The court previously construed “outturned flange supported by the top of the support structure” to mean “outside rim or edge turned away from the 
8 MAG AEROSPACE INDUSTRIES, INC. v. B/E AEROSPACE, INC. 

sidewall, transferring loads to the top of the support 

structure.” J.A. 34. Again, MAG does not appear to be 

challenging this construction, but instead argues that the 

district court applied a different construction at summary 

judgment and that, under the proper construction, there 

is a genuine material dispute as to whether B/E’s toilets 

infringe. 

MAG identified two structures that it claims are outturned flanges on B/E’s toilet bowl: (1) a first edge located 

at the base of the vertical columns on the sidewall of B/E’s 

toilet bowl (called “ribs”); and (2) a second edge located 

within a groove machined into these vertical columns. 

Using finite element analysis, MAG’s expert testified 

that the identified edges contact and transfer loads to the 

top of the support structure of the B/E toilet. MAG also 

relies on other B/E documents, including a computeraided design (“CAD”) depicting an “edge” at which load 

was transferred from the bowl to the frame. MAG’s 

expert thus explained that both the first and second edges 

enable B/E’s toilet bowl to mate with and transfer loads to 

the top of the support structure. 

As the district court concluded, however, neither edge 

meets the out-turned flange limitation of the ’942 patent. 

The “first edge” identified by MAG is merely the bottom of 

the vertical columns and not a flange. As to the CAD 

drawing, there is no evidence that it represented the 

actual product marketed and sold. Instead, B/E provided 

evidence that its toilet contains a gap of approximately 

1/8th of an inch between the vertical column and the 

frame; thus, the “first edge” does not actually touch the 

top of the support structure and cannot transfer load to 

the top of the support structure. 

As for the second edge, it is merely a slot within the 

vertical columns and not an “outside rim or edge turned 

away from the side wall” as required by the district 
MAG AEROSPACE INDUSTRIES, INC v. B/E AEROSPACE, INC. 9

court’s claim construction. J.A. 34. Thus, the second edge 

also does not meet the claimed limitation. 

MAG also argues that the district court improperly 

revised its construction at summary judgment by requiring that the flange be a “flat horizontal piece” and that 

the “top of the support structure” be limited to a horizontally flat structure with uniform elevation. Those arguments are without merit. The district court said nothing 

about uniform elevation; instead, it merely concluded that 

the edges identified by MAG did not touch the top of the

support structure. Similarly, although the district court 

referenced the lack of a flat horizontal piece, the court 

was not requiring that the flange be such a piece; instead, 

the court properly compared the slot in the ribs (the 

“second edge”) to the construction of “out-turned flange” 

and found that the limitation was not met. The district 

court thus did not improperly revise its constructions at 

summary judgment and, instead, correctly concluded that 

B/E’s toilets did not infringe the ’942 patent.

Because the district court properly determined that 

there were no genuine issues of material fact as to noninfringement of any of the asserted patents, we affirm the 

district court’s grant of summary judgment of noninfringement.

II. ASSIGNOR ESTOPPEL

In addition to granting B/E’s motion for summary 

judgment of noninfringement, the district court also 

granted MAG’s motion for summary judgment of no 

invalidity. B/E cross-appeals from that ruling, contending 

that the district court improperly applied assignor estoppel to bar it from asserting that the patents-in-suit are 

invalid. 

Assignor estoppel is an equitable remedy that prohibits an assignor of a patent, or one in privity with an 

assignor, from attacking the validity of that patent when 
10 MAG AEROSPACE INDUSTRIES, INC. v. B/E AEROSPACE, INC. 

he is sued for infringement by the assignee. Diamond Sci. 

Co. v. Ambico, Inc., 848 F.2d 1220, 1224 (Fed. Cir. 1988). 

“Privity, like the doctrine of assignor estoppel itself, is 

determined upon a balance of the equities.” Shamrock 

Techs., Inc. v. Med. Sterilization, Inc., 903 F.2d 789, 793 

(Fed. Cir. 1990). As we previously said in Shamrock 

Technologies, 

If an inventor assigns his invention to his employer company A and leaves to join company B, 

whether company B is in privity and thus bound 

by the doctrine will depend on the equities dictated by the relationship between the inventor and 

company B in light of the act of infringement. The 

closer that relationship, the more the equities will 

favor applying the doctrine to company B.

Id. Here, one of the inventors of the patents-in-suit, Mark 

Pondelick, now works for B/E. Mr. Pondelick assigned the 

patents to his former employer, who in turn assigned 

them to MAG. The district court concluded that Mr. 

Pondelick was in privity with B/E and thus that assignor 

estoppel applies to bar B/E from attacking the validity of 

the patents. The district court did not clearly err in its 

determination. 

The district court analyzed a number of factors identified in Shamrock Technologies to determine whether a 

finding of privity was appropriate: (1) the assignor’s 

leadership role at the new employer; (2) the assignor’s 

ownership stake in the defendant company; (3) whether 

the defendant company changed course from manufacturing non-infringing goods to infringing activity after the 

inventor was hired; (4) the assignor’s role in the infringing activities; (5) whether the inventor was hired to start 

the infringing operations; (6) whether the decision to 

manufacture the infringing product was made partly by 

the inventor; (7) whether the defendant company began 

manufacturing the accused product shortly after hiring 
MAG AEROSPACE INDUSTRIES, INC v. B/E AEROSPACE, INC. 11

the assignor; and (8) whether the inventor was in charge 

of the infringing operation. B/E argues that many of 

these factors support its position that assignor estoppel 

should not apply. For example, B/E notes that Mr. Pondelick joined B/E after the decision to develop the accused 

toilet was made and that there was never a plan to conduct infringing activities; in fact, the point of hiring Mr. 

Pondelick was to avoid infringement. B/E also points out

that this case is unlike the others where privity was found 

because Mr. Pondelick has a negligible financial interest 

in B/E. Finally, B/E says that the district court should 

not have disregarded the fact that Mr. Pondelick was 

making good faith efforts to avoid infringement. 

The district court acknowledged all of B/E’s arguments but found on balance that assignor estoppel was 

appropriate. The district court’s conclusion is not clearly 

erroneous. As the district court found, many of the

Shamrock factors weigh in favor of finding privity. For 

example, the district court noted that B/E used Mr. Pondelick’s knowledge to conduct the activities that are now 

alleged to be infringing; that he was hired specifically to 

develop the toilets that are accused of infringement; and 

that he was the Director of Engineering for B/E during his 

time as a consultant and later became Vice President and 

General Manager of B/E EcoSystems, the division that 

manufactured the accused toilets. Based on the extent of 

Mr. Pondelick’s involvement in the alleged infringing 

activity and the fact that B/E “availed itself of [Mr. Pondelick’s] knowledge and assistance” to conduct the alleged 

infringement, Intel Corp. v. U.S. Int’l Trade Comm’n, 946 

F.2d 821, 839 (Fed. Cir. 1991), we cannot say that the 

district court abused its discretion in finding that assignor 

estoppel applies. We therefore affirm the district court’s 

ruling that B/E is barred under the doctrine of assignor 

estoppel from arguing that the patents-in-suit are invalid. 
12 MAG AEROSPACE INDUSTRIES, INC. v. B/E AEROSPACE, INC. 

CONCLUSION

For the foregoing reasons, we affirm the district 

court’s rulings. 

AFFIRMED

COSTS

Each party shall bear its own costs.