[00:00:50] Speaker 01:
May it please the court, Mike Vellake on behalf of United Technologies Corporation and I have with me Patrick Coyne from the Finnegan to Henderson.

[00:01:01] Speaker 01:
The board erred here below in construing the term stability margin which is a term of art in the aerospace industry and we asked this court to give stability margin its ordinary and customary meaning which is

[00:01:15] Speaker 01:
the meaning that the term would have to a person of ordinary skill in the art.

[00:01:20] Speaker 01:
In a sense, this appeal is unique in that it's undisputed.

[00:01:25] Speaker 01:
GE agrees that stability margin means exactly what UTC says.

[00:01:31] Speaker 03:
That's right.

[00:01:32] Speaker 03:
So that's not really the issue about what stability margin means.

[00:01:35] Speaker 03:
I think what the issue is, you can tell me why I'm wrong, is whether or not you have to do, whether it requires a calculation.

[00:01:45] Speaker 01:
And that is the issue, Your Honor.

[00:01:49] Speaker 01:
And if we construe stability margin, if we give it meaning, you have to do a calculation.

[00:01:55] Speaker 01:
You have to make a determination.

[00:01:57] Speaker 01:
Because the industry standard definition for stability margin is you have this on a FAMMAP, a stability limit line.

[00:02:08] Speaker 01:
And then stability margin is defined as the pressure ratio on this stability limit line.

[00:02:14] Speaker 01:
down to the fan pressure ratio at the operating point.

[00:02:19] Speaker 03:
And so it's a subtraction.

[00:02:23] Speaker 03:
The term itself talks about determining the undesired stability margin, right?

[00:02:29] Speaker 01:
Yes, your honor.

[00:02:30] Speaker 03:
We're talking about an undesired stability margin.

[00:02:33] Speaker 03:
So the question is, what does detecting that mean?

[00:02:37] Speaker 03:
And the board said, well, detecting it means whether conditions that may lead to instability are present.

[00:02:44] Speaker 03:
So taking everything you say about this industry understood definition of stability margin, et cetera, et cetera.

[00:02:52] Speaker 03:
Why is the board wrong in the context of this claim?

[00:02:57] Speaker 03:
to not construe the undesired stability margin in kind of broader, more fluid way.

[00:03:04] Speaker 01:
Because that's indeed one of the board's errors in particularly with respect to claim 15.

[00:03:11] Speaker 01:
We'd submit they rewrote the claim.

[00:03:14] Speaker 01:
Quoting the board, it says, quote, the claims are similarly devoid of any express language requiring that a stability margin be numerically calculated.

[00:03:25] Speaker 01:
Isn't that true?

[00:03:26] Speaker 01:
The claims themselves don't literally say it needs to be numerically calculated.

[00:03:31] Speaker 01:
If we construe stability margin though, consistent with figure three in the specification, it does need to be numerically calculated.

[00:03:39] Speaker 01:
But then the board went on to say rather they simply require detecting conditions

[00:03:45] Speaker 01:
that may lead to instability are present.

[00:03:48] Speaker 01:
We submit, Your Honors... Isn't that exactly what the claim says?

[00:03:52] Speaker 00:
I mean, it says detect from these four different things, at least one of which doesn't require any kind of calculation, and then determine the undesired margin from that detecting step.

[00:04:06] Speaker 00:
I mean, if you're determining the undesired margin from that detecting step, then several of those don't require a calculation.

[00:04:14] Speaker 01:
If you take from the detecting step, which is the... Well, that's what the claim language says, right?

[00:04:20] Speaker 00:
That's exactly what it's... You determine the undesired margin from the steps outlined in the detecting step.

[00:04:27] Speaker 00:
And the detecting step doesn't necessarily require calculation.

[00:04:30] Speaker 01:
The detecting step says detecting at least one of a turbofan pressure ratio, low spool speed, airflow direction, and throttle position, and that's inclusive.

[00:04:42] Speaker 01:
It needs to have one of those to meet the first part of the method claim limitation here in detecting.

[00:04:50] Speaker 01:
But just using that information alone, you can't determine what the stability margin is

[00:04:56] Speaker 01:
Indeed, both experts, when they were asked... Well, wait, what does it mean?

[00:05:02] Speaker 03:
I mean, maybe I'm looking at the wrong site.

[00:05:04] Speaker 03:
Doesn't the determining step mean, say, determining the undesired stability margin from the detecting step?

[00:05:11] Speaker 03:
So, the only answer to how do you determine it is the detecting step.

[00:05:20] Speaker 03:
And the detecting step says at least one.

[00:05:23] Speaker 03:
I guess I'm having the same confusion or problem that Judge Hughes seems to be having.

[00:05:27] Speaker 03:
I think the language is quite precise and clear.

[00:05:30] Speaker 01:
Focusing on Claim 15 alone and to meet that specific limitation, you would need one of those.

[00:05:39] Speaker 01:
But you have to look at the specification to give this meaning.

[00:05:43] Speaker 01:
The reason that those parameters there in the first step of Claim 15 are important and why one of those might affect your stability margin is they're going to move your operating point.

[00:05:57] Speaker 01:
And what your operating point is, is where that fan is in flight.

[00:06:03] Speaker 01:
And so we submit, Your Honor, focusing solely on just claim 15, that it doesn't mean that based on one of those conditions alone, aha, you would have stability margin.

[00:06:17] Speaker 01:
Indeed, we ask each of the experts here, if you simply know airflow direction, just airflow direction, do you know what the stability margin is?

[00:06:26] Speaker 01:
And the answer is no.

[00:06:28] Speaker 01:
You have no idea what the stability margin is.

[00:06:30] Speaker 03:
So you think claim 15 means

[00:06:33] Speaker 03:
Determining step means determining from the detecting step or from other information not recited in this claim.

[00:06:46] Speaker 01:
From other information that is not specifically recited in the first step.

[00:06:51] Speaker 03:
So that's what from the detecting step means from the detecting step except predominantly from something other than what's listed in the detecting step.

[00:07:00] Speaker 01:
Well, if you look at the detecting step, the first thing is the turbofan pressure ratio.

[00:07:06] Speaker 01:
And so if you know the turbofan pressure ratio and you combine it with looking at the fan map that's shown in Figure 3 in the specification, then you can look exactly where your operating point is.

[00:07:22] Speaker 01:
You can look at it in relation to the stability limit line, and you can calculate your stability margin.

[00:07:29] Speaker 03:
Fair enough.

[00:07:30] Speaker 03:
But the claim says detecting at least one.

[00:07:35] Speaker 03:
So that's one, but that's not required by the detecting step, right?

[00:07:39] Speaker 03:
It could be any of the four.

[00:07:41] Speaker 01:
It could be any of the four.

[00:07:43] Speaker 03:
So it's not limited by any means to the pressure ratio.

[00:07:47] Speaker 01:
But Your Honor, the person of ordinary skill in looking at Claim 15 would read that claim along with the specification.

[00:07:57] Speaker 01:
The person of ordinary skill would know full well exactly what stability margin means because it's shown very consistently with what's an industry standard definition in Figure 3 with that vertical line, that fan stability margin.

[00:08:15] Speaker 01:
So when the person of ordinary skill has that understanding and knows full well what stability margin is, when that person reads claim 15, not reading it literally as we're reading it right now from the detecting step alone, that doesn't alter the definition to a person of ordinary skill.

[00:08:35] Speaker 01:
They understand that what the controller's doing is using one of those parameters

[00:08:42] Speaker 01:
in its calculation of the stability margin, along with what else is required to determine what a stability margin is.

[00:08:51] Speaker 01:
So if we look at Claim 15 simply in a vacuum, I understand Your Honor's questions of why from the detecting step could literally mean just one of these things.

[00:09:02] Speaker 01:
But again, that's why we asked the experts who knew full well exactly what stability margin means consistent with the specification, as well as they know one of those parameters alone is not enough.

[00:09:17] Speaker 02:
Well, is it one thing to look at the parameter and other parameters, or that may be one thing?

[00:09:27] Speaker 02:
The only way you can look at those require a numerical calculation, which is essentially what you're asking for.

[00:09:37] Speaker 01:
Part and parcel to each one of those, it would be a numeric, that would be a number if you will.

[00:09:45] Speaker 01:
The patent is clear that you have these sensors, you have a throttle position sensor, you have a low speed spool sensor.

[00:09:53] Speaker 01:
And so those parameters there in claim 15, that's feeding information into that controller.

[00:10:01] Speaker 01:
The controller also has other information

[00:10:05] Speaker 01:
Therefore, using all of that information, it can go ahead and calculate a stability margin.

[00:10:13] Speaker 01:
The other part of Claim 15, we should also look at Claim 15, we were focused solely on from the detecting step.

[00:10:21] Speaker 01:
But what's important as well is the following limitations that come after from the detecting step.

[00:10:29] Speaker 01:
It says next in the method that you infectively increase a nozzle exit area and what that does is relieve back pressure on the fan and it lowers the operating line to increase

[00:10:46] Speaker 01:
your stability margin.

[00:10:48] Speaker 01:
That's a correcting step there.

[00:10:50] Speaker 01:
And what is it correcting for?

[00:10:52] Speaker 01:
It's determined you have an undesired stability margin, and then the claim goes on and corrects for it.

[00:11:00] Speaker 01:
Well, you have to do a calculation in order to make

[00:11:04] Speaker 01:
the correction as the patent explains these turbo fans operate which you're talking about the lowering portion of it yes yes you're saying you can't do this without a calculation

[00:11:18] Speaker 01:
correct your honor because what you've determined in that second step is an undesired stability margin then what the controller is going to do is tell the nozzle exit area go ahead and increase release the back pressure on the fan and

[00:11:37] Speaker 01:
What that will do is lower the turbofan operating line, increasing the turbofan stability margin.

[00:11:45] Speaker 01:
So it's restoring the stability margin so that it's sufficient.

[00:11:50] Speaker 01:
The way these fans work in flight, they're obviously highly sophisticated instruments.

[00:11:57] Speaker 01:
You have supersonic airflow coming into the fan.

[00:12:01] Speaker 01:
Fundamentally, you have to know where that operating point is.

[00:12:05] Speaker 01:
Then you calculate a stability margin.

[00:12:08] Speaker 01:
If you determine it's undesired, the rest of claim 15 goes through and says, make that correction.

[00:12:16] Speaker 01:
And we submit that when this controller is making such a correction, it's doing

[00:12:24] Speaker 01:
quite precisely.

[00:12:26] Speaker 01:
It's not doing it simply, I detected a condition that may lead to instability and I simply react.

[00:12:35] Speaker 01:
It has to know how to correct and it's very precise when it makes that.

[00:12:40] Speaker 02:
You're saying it necessarily calculates the difference between the pressure ratio at the fan stability limit line and the pressure ratio at the fan operating point.

[00:12:51] Speaker 01:
That's what you're saying.

[00:12:52] Speaker 01:
It has to be done.

[00:12:53] Speaker 01:
It has to be done fundamentally, and then if it is straight, if you have an undesired or insufficient stability margin, it's going to correct precisely.

[00:13:05] Speaker 02:
That would have been easy enough to write into the patent, wouldn't it?

[00:13:09] Speaker 01:
We submit, Your Honor, at least in Figure 3, the specification, it's clearly shown, and the person of ordinary skill in the art would understand exactly that lowering that fan operating line, you lower your operating point, you're restoring your stability margin.

[00:13:25] Speaker 01:
I see that I'm in my rebuttal time now.

[00:13:27] Speaker 03:
Why don't we hear from the other side?

[00:13:28] Speaker 03:
Thank you.

[00:13:44] Speaker 04:
The entire argument the UTC is making is based on a non-existent claim.

[00:13:54] Speaker 04:
There is no claim, there is no claim language that requires calculating a stability margin.

[00:14:02] Speaker 04:
If there was,

[00:14:03] Speaker 04:
This would be a different story.

[00:14:05] Speaker 00:
But I gather that their argument is that this is the only way possible to do any of this is to do that calculation and went throughout when they're talking about the controller and the various inputs and things like that.

[00:14:18] Speaker 00:
It necessarily means when you're talking about an undesirable stability margin that it relies on a calculation to get there.

[00:14:27] Speaker 00:
What's wrong with that argument?

[00:14:28] Speaker 04:
The problem with that argument, Your Honor, is that that is not what is taught in the patent itself.

[00:14:33] Speaker 04:
The patent very clearly teaches that undesired stability margins can occur simply from the result of air entering the engine at an angle that is not in line with the engine axis.

[00:14:51] Speaker 04:
This is

[00:14:53] Speaker 00:
So how do they know that that angle of air will create an undesirable stability margin without knowing what the desirable one is and then calculating the difference?

[00:15:04] Speaker 04:
That is exactly what this patent is attempting to overcome, is that it was known in the art, as taught in the background of the invention, it was known in the art that if the air comes into the engine,

[00:15:18] Speaker 04:
at an undesirable angle, it causes unwanted pressure gradients on the fan.

[00:15:23] Speaker 04:
And that alone can cause an undesired stability margin.

[00:15:28] Speaker 04:
So there is an embodiment in this patent that teaches all you do, all you need to do is detect that the air is coming into the engine.

[00:15:38] Speaker 03:
Absolutely, Your Honor.

[00:15:40] Speaker 04:
There are several spots in the patent, but I will start with column one at line 24.

[00:15:52] Speaker 04:
And this says, one of the important performance limitations for the fan is the loss in fan stability margin that occurs during aircraft maneuvers and crosswind operating conditions.

[00:16:09] Speaker 04:
During those maneuvers or crosswind conditions, the inlet flow, that's the inlet flow of the air, approaches the aircraft inlet in a direction that's not in line with the axis of the engine.

[00:16:21] Speaker 04:
That can cause pressure gradients that result in significant pressure distortion entering the fan.

[00:16:29] Speaker 04:
That right there talks about this problem of air entering the engine at a direction that is not in line with the axis, which can cause pressure gradients on the fan, which causes loss in fan stability margin.

[00:16:43] Speaker 04:
Then, in the summary of the invention, they say, this is how we're going to solve this problem.

[00:16:51] Speaker 04:
And this is at line 52, 53.

[00:16:54] Speaker 04:
In one example, the physical nozzle exit area, that's the exhaust nozzle, is increased at the undesired stability condition in which the airflow into the engine creates this destabilizing pressure gradient.

[00:17:11] Speaker 04:
Air comes into the engine in a direction that is not parallel to the axis.

[00:17:15] Speaker 04:
It causes pressure gradients on the fan.

[00:17:18] Speaker 04:
That results in an undesired stability margin.

[00:17:21] Speaker 04:
All you need to do is to detect that and then open the nozzle, which automatically increases your stability margin.

[00:17:29] Speaker 03:
What about Figure 3?

[00:17:31] Speaker 04:
Certainly, Your Honor.

[00:17:34] Speaker 04:
Figure 3, first of all, as the Board correctly found,

[00:17:39] Speaker 04:
Фигur 3 показывает, no, es ist nicht quantifizierlich.

[00:17:45] Speaker 04:
Es ist nichts in diesem Patent, es ist nichts in Figur 3, das sagt, wie viel Margen es benötigt, um einen genannten Stabilitätsmargen zu behalten.

[00:17:59] Speaker 04:
Und wenn man auf Figur 3 schaut, es zeigt einen operativen Punkt, ja.

[00:18:03] Speaker 04:
But nowhere does the specification ever state that in order to determine an undesired stability margin, you have to first calculate the fan operating point.

[00:18:12] Speaker 04:
Because what's shown here in figure three is that the nominal fan operating line, which was the one in the middle of the graph, the operating line moves downward when the nozzle area is increased.

[00:18:28] Speaker 04:
The whole line moves, not just a point.

[00:18:31] Speaker 04:
And that's the whole point of this, is that when that air is coming in into the engine at that undesired angle, you want a better safe than sorry situation.

[00:18:42] Speaker 04:
If you know the air is coming in at an angle that's not in line, you want to automatically open the nozzle because that releases the back pressure and lowers that entire line.

[00:18:53] Speaker 04:
Not just the point.

[00:18:54] Speaker 04:
And when you lower that operating line,

[00:18:57] Speaker 04:
You necessarily increase the stability margin because that is determined by the fan stability limit line, which is the line at which the fan should never operate above.

[00:19:09] Speaker 04:
So you're here.

[00:19:13] Speaker 04:
This is your stability limit line, the one on top.

[00:19:16] Speaker 04:
This is your fan operating line, where the fan actually is.

[00:19:20] Speaker 04:
You determine the air is coming into the engine at a wrong angle.

[00:19:25] Speaker 04:
Uh-oh, my stability margin

[00:19:27] Speaker 04:
can now will be decreased, so I better open the nozzle and lower this line.

[00:19:34] Speaker 04:
That's what the invention is.

[00:19:36] Speaker 04:
That is what claim 15 covers to a T. Claim 15 is very clear.

[00:19:45] Speaker 03:
That's exactly what your friend was referring to, lowering limitation.

[00:19:50] Speaker 03:
Is that what you're talking about?

[00:19:52] Speaker 04:
That's exactly what it teaches.

[00:19:53] Speaker 04:
It teaches that, in fact, if you look at claim, if you look at Figure 3, Your Honor, at the upper right of Figure 3, it says that the fan stability limit decreases with increasing inlet flow distortion and reduces the stability margin.

[00:20:09] Speaker 04:
Well, that, that is,

[00:20:12] Speaker 04:
Increasing inlet flow distortion is what's caused by that airflow entering the engine at an improper direction.

[00:20:18] Speaker 04:
All you need to do is detect that.

[00:20:20] Speaker 04:
When that is detected, you know that the stability margin has now lessened because of the pressure gradient on the fan.

[00:20:28] Speaker 04:
So you just open up the nozzle.

[00:20:29] Speaker 04:
Release the back pressure, down goes the line.

[00:20:31] Speaker 02:
But the detecting process is that the pilot doesn't do that by looking at the airflow.

[00:20:38] Speaker 02:
It's all done by some sort of technology.

[00:20:40] Speaker 04:
Correct, it's a controller.

[00:20:42] Speaker 02:
So you have to have sensors.

[00:20:45] Speaker 02:
You do.

[00:20:45] Speaker 02:
And so those sensors have to tell the controller specific numbers of what's going on so that the controller knows or is set to say when the number goes this way,

[00:20:59] Speaker 02:
I've got to go that way, right?

[00:21:01] Speaker 04:
Well, Your Honor.

[00:21:03] Speaker 02:
Otherwise, how does the machine know?

[00:21:05] Speaker 04:
Because there is a sensor located, in fact, this is at column 3 to the top of column 4.

[00:21:11] Speaker 04:
In one example, a sensing device is used to determine the direction of the airflow into the engine relative to the axis.

[00:21:20] Speaker 04:
The sensing device is located on the airframe and is used by the controller to determine the angle of attack.

[00:21:27] Speaker 04:
So that's only detecting that the air that's coming into the engine is at an improper angle.

[00:21:33] Speaker 04:
That's all.

[00:21:33] Speaker 04:
It's not calculating a fan operating point.

[00:21:36] Speaker 04:
It doesn't need to do that.

[00:21:37] Speaker 04:
That's the whole point of the invention.

[00:21:40] Speaker 04:
They wanted to cover the situation where it's better safe than sorry

[00:21:46] Speaker 04:
If you know the air is coming into the engine at an improper angle, you don't need to take those precious milliseconds to then calculate what the actual operating point is, determine if your stability margin is enough, and only then open up the nozzle to increase the margin.

[00:22:01] Speaker 04:
You just detect that the air is coming in at the wrong angle.

[00:22:04] Speaker 04:
We're in a situation that could cause unstable operating conditions, so we're going to lower the line, period.

[00:22:11] Speaker 04:
Claim 15 says specifically,

[00:22:17] Speaker 04:
that you detect the undesired stability margin from the detecting step, determinant from the detecting step.

[00:22:29] Speaker 04:
So undesired stability margin is determined by detecting at least one of, and that lists those four things.

[00:22:39] Speaker 04:
And one of those things is the airflow direction.

[00:22:43] Speaker 04:
So, as the board properly said, the plain language of this claim says

[00:22:48] Speaker 04:
That you can determine the undesired stability margin from detecting the airflow direction, period.

[00:22:55] Speaker 02:
Now it may be the case that for other parameters some calculation may be necessary.

[00:23:00] Speaker 04:
It may be your honor, but the way that this claim is written

[00:23:06] Speaker 04:
If they were asserting this claim in court, all they would need to show is that somebody was determining or detecting the airflow direction and then opening the fan nozzle to increase the stability margin.

[00:23:20] Speaker 04:
That would infringe that claim.

[00:23:21] Speaker 04:
Well, then they're also stuck with that will be proven invalid, that claim, if we can show in the prior art that such an invention had already existed, and that's exactly

[00:23:33] Speaker 04:
Harner and Harloff, the two primary references, both teach operating the fan, opening the fan nozzle in order to lower your operating line.

[00:23:44] Speaker 04:
So if the way that UTC reads claim 15 is to rewrite it by requiring first calculating a stability margin based on at least one of those, and according to my colleague, perhaps more things, but that's not the way claim 15 is written.

[00:24:02] Speaker 04:
Their claim construction just cannot be reconciled with Claim 15.

[00:24:10] Speaker 04:
Unless, I know it's been a long morning for everybody, unless you have any further questions, I'm happy to see the rest of my time.

[00:24:16] Speaker 03:
I think you're fine, thank you.

[00:24:17] Speaker 04:
Thank you, Your Honor.

[00:24:27] Speaker 01:
I want to pick up exactly where Council left off, and GE wrote this in their brief.

[00:24:33] Speaker 01:
They framed the question, quote, in other words, do the claims require determining the fan operating point and calculating the stability margin, as UTC argues, or do the claims reasonably cover embodiments

[00:24:47] Speaker 01:
where it's not necessary to calculate the actual stability margin.

[00:24:51] Speaker 01:
Claim 15 doesn't cover those embodiments.

[00:24:56] Speaker 01:
This is GE's brief, bottom of 40 and top of 41.

[00:25:03] Speaker 01:
And Claim 15 doesn't cover those embodiments.

[00:25:07] Speaker 01:
It very clearly says you determine the undesired turbofan stability margin.

[00:25:14] Speaker 01:
You have to make that determination.

[00:25:18] Speaker 01:
We're left at a claim construction and an argument that is tantamount to if you don't know what the stability margin is,

[00:25:27] Speaker 01:
How can you determine that it's undesired?

[00:25:30] Speaker 01:
Because in their construction, no one's ever even determined or calculated what the stability margin is.

[00:25:38] Speaker 01:
The second and last point I want to address is this argument that the board used as purposes for their construction and that GE makes here, which is simply basing Claim 15 and its determination on airflow direction alone.

[00:25:54] Speaker 01:
And council said, if the airflow is coming in not parallel to the inlet axis, you have an undesired stability margin.

[00:26:02] Speaker 01:
They frame this in their brief simply as these if-then scenarios.

[00:26:06] Speaker 01:
And that simply can't be the case when an airplane is inclined.

[00:26:12] Speaker 01:
And it's ascending.

[00:26:14] Speaker 01:
Obviously, the air's not entering parallel to the inlet axis.

[00:26:19] Speaker 01:
That's what the board relied on.

[00:26:20] Speaker 01:
That's what GE argues here.

[00:26:23] Speaker 01:
And that's just a sensing device that is, as counsel said, at the bottom of column three, top of column four, that goes into the controller.

[00:26:34] Speaker 01:
The controller makes a calculation.

[00:26:36] Speaker 01:
It's a computer.

[00:26:37] Speaker 01:
It calculates stability margin.

[00:26:40] Speaker 01:
Are there any further questions?

[00:26:43] Speaker 03:
Thank you.