How Lockheed's Skunk Works Gotinto the Stealth Fighter Business

Lt. Col. William B. O'Connor USAF (ret.)

Filed to: WAR 4/17/12 10:00pm

How do you hide an airplane behind a bird? Very skillfully. Lt. Col. William

B. O'Connor (ret.) flew the F-117 Nighthawk during the Bosnia Conflict,

and in Stealth Fighter, he explains the history, operation, and soul

America's most advanced stealth jet.

While the United States had never embraced a defensive mindset and

had only fielded one strategic SAM system to that point, the Nike-

Hercules dating from the 1950s, and one real medium-range tactical

system, the HAWK (homing all the way killer), the Soviets had

fielded over fifteen different systems. One Soviet SAM system was

even armed with nuclear warheads.

It had become clear that there had to be a better way. So in 1974, the

U.S. Defense Advanced Research Projects Agency (DARPA) initiated a

program known as Project Harvey (named after the 6 feet 3 1/2

inches tall invisible white rabbit from the play of the same name).

The ultimate goal was to develop a combat aircraft with as low a

radar signature as possible. Five aerospace corporations had been

contracted a million dollars each to give it their best shot.

Surprisingly, Lockheed hadn't been among them. It was only an

accidental tip-off that allowed Lockheed's Ben Rich to lobby for

inclusion. Rich had been an engineer on the secret U-2 and SR-71

reconnaissance aircraft and had by then advanced to become

Lockheed's successor to the famous Kelly Johnson as director of the

Skunk Works. The "Skunk Works" is the official alias for the

department responsible for all of Lockheed's highly secret advanced

development projects. It was formed in 1943 to build America's first

jet fighter, the P-80, and numerous other projects that belong to the

shadow world of military operations.

By the time Rich had gotten wind of Project Harvey, there was no

money left for another developmental contract. So Lockheed was

offered a shot-for a dollar. But Rich wanted in and wisely turned

down the token dollar. He knew that any new technologies developed

with company funds would then be proprietary. Lockheed was

famous for building small fleets of extremely advanced aircraft-

often used for highly secretive missions. During World War II, they

had built the United States' first operational subsonic jet fighter, the

P-80. They skipped the Mach-1 era altogether and jumped right to

fielding the United States' first fighter capable of speeds in excess of

Mach 2, the F-104 Star Fighter. Along the way came the high-flying

U-2, the higher-flying SR-71, the hypersonic D-21 drone (which

would ride piggyback on an SR-71 until released), and other things

not yet named.

In Rich's own words, the unsung hero of Lockheed's effort was an

anonymous staff mathematician and electrical engineer named

Denys Overholser. Overholser and his mentor, another

mathematician named Bill Schroeder, had discussed the possibilities

of utilizing some of the equations associated with optical scattering

(how electromagnetic waves bounce off variously shaped objects) on

this project. Both had the rather odd hobby of reading obscure

Russian mathematics papers and had made the ultimate "nerd's

nerd" discovery. They had stumbled across a paper published in

Moscow a decade earlier titled "Method of Edge Waves in the

Physical Theory of Diffraction." It had been written by Pyotr

Ufimtsev, the Soviet's chief scientist at the Moscow Institute of

Radio Engineering and the last in a long line of scientists developing

a long series of wave equations originally derived centuries ago by

the Scottish physicist James Clerk Maxwell.

The U.S. intelligence community had helped translate this research

and brought it to the West. The paper was in no way classified or

related to weapons development at all. It was purely theoretical

math. Years later, Ufimtsev immigrated to the United States to teach

at the University of California, Los Angeles, and only then discovered

his inadvertent contribution to the development of stealth aircraft.

The equations that Ufimtsev had developed made the reflections of

radio waves off hard surfaces predictable. Not invisible, transparent,

or tactical in any way-just predictable. The problem for Lockheed

was that the calculations were so ferociously difficult that the most

advanced supercomputers in the world at the time could only

compute results for flat surfaces. Any attempt to perform the

calculations for the curved surfaces you would find on a conventional

aircraft-well, those machines would still be grinding away toward a

solution today.

Schroeder recognized how these equations could be applied to

Lockheed's current project. The solution was not even to attempt to

design an aircraft with any curved surfaces, but to build one with

dozens, or perhaps hundreds, of individual flat triangular and

rectangular plates. Then the challenge was to compute the reflection

from each and every flat surface before adding them all together to

build a picture of the aircraft's total radar signature. Once you knew

where every bit of radar reflection was coming from, you could then

reorient those individual plates so that the reflection would go off in

a direction away from the radar looking at it.

The process became known as "faceting." And that became the real

secret-not to absorb all the radar or make the plane somehow

transparent, but to make the plane's signature predictable. That

predictability could then be used to shape a tactically useful aircraft.

The jet would also be covered in thin sheets of RAM, but the bulk of

the stealth effect was achieved by its shape.

Traditionally, a single engineering specialty will take the lead during

the design of a new aircraft. An aerodynamicist may be in charge of

pushing through a new wing or fuselage shape, as happened with the

early delta wings and area-ruled fuselages of the "Century Series" of

interceptors. Sometimes it may be the power-plant guy: "Here's the

engine we're going to use, build us a jet fighter for it." This is how

the P-80 came about. Occasionally it may be the armaments people-

the A-10 is fundamentally a massive 30mm Gatling cannon with a

plane built around it. In this particular case, this was the first time

the lead was owned by an electrical engineer.

The computer program designed by Overholser's team to make these

calculations was called Echo- 1. Armed with that tool, the first test

subject, the Hopeless Diamond, was built. It was described as a

diamond for obvious reasons and "hopeless" for its aerodynamic

qualities (or rather, its complete lack thereof).

Early radar testing of the Hopeless Diamond turned out to be

staggeringly successful. The White Sands experimental radar range

near Holloman AFB was used. When the radar was fired up for the

initial testing, the only thing that showed up was the reflection of

the pole on which the test model was supposed to be mounted.

Assuming that the model had fallen off the pole, the radar operators

sent technicians downrange to fix the problem. To their surprise, the

ten-foot model was still in place.

To test the model at all, Lockheed then had to design an invisible

"stealth pole" to mount the model utilizing the same technology as

the proposed fighter. The results were once again astounding, and

incredulous USAF officials were called in to witness and verify the

data.

The first opportunity to impress these officials almost resulted in

embarrassment. When the radars were turned on, the reflections,

while still very small by airplane standards, were orders of

magnitude larger than what the USAF officials had been led to

expect. They could still clearly see a small radar return from where

the model was mounted.

While the Lockheed engineers were trying to explain this

discrepancy, a radio call came in from a technician downrange. He

reported that a bird was perched on the ten-foot model. The quick

reply was an order to blow the horn of the pickup truck the guy was

sitting in. As the startled bird flew away, the radar reflection on the

test scope disappeared.

The very idea that a combat aircraft could be made so invisible as to

hide behind a bird was an opportunity that couldn't be passed up.

Everything associated with the program became classified at the

highest levels. The program was transferred from DARPA to the

USAF special projects office. The word "stealth" was forbidden to be

mentioned in any unclassified document. And in April 1976, the Ford

administration gave Lockheed the go-ahead for a full-scale aircraft.

The Skunk Works was officially in the stealth fighter business.

Stealth Fighter: A Year in the Life of an F-117 Pilot by Lt. Col. William B.

O'Connor USAF (ret.) is reprinted with permission from Zenith Press. All

Rights Reserved

Stealth Fighter: A Year in the Life of an F-117 Pilot by Lt. Col. William

B. O'Connor USAF (ret.) is available from Amazon.

 Stealth Fighter: A Year in the Life of an F-117 Pilot

5 purchased by readers

Buckeye_Fan Lt. Col. William B. O'Connor USAF (ret.)

4/17/12 10:39pm

Actually the F-22 is the most advanced stealth fighter. It has a

smaller radar signature than the F-117

slaw Buckeye_Fan

4/18/12 12:46am

Technically the term "fighter" shouldn't even be brought up

when discussing the F-117 because it was designed primarily as

a ground-attack aircraft, with barely any air-to-air combat

capability.

nachobel TOTORO! slaw

4/18/12 6:04am

If by "barely any" you mean "literally no", then yes.

chris209 Buckeye_Fan

4/18/12 10:42am

The F-22 is also decades newer and more advanced (the F-117

is also technically a bomber).

slaw nachobel TOTORO!

4/18/12 4:55pm

I've been told that the F-117 was theoretically capable of

mounting a single AAM for the purposes of sneaking up on and

taking out high-value aircraft like the Soviet Mainstay.

I suppose I Lt. Col. William B. O'Connor USAF (ret.)

4/17/12 10:30pm

"America's most advanced stealth jet"

While the F-117 is amazing, its successor, the Northrop

Grumman B-2 is definitely the most advanced (and sexiest)

stealth fighter that we know about.

Buckeye_Fan I suppose I

4/17/12 10:39pm

The B-2 is a bomber....... not a fighter

Roen Buckeye_Fan

4/17/12 10:44pm

Agreed. The F-22 with its litany of problems is the world's most

advanced hypersonic cruise capable stealth fighter -well when

its functional that is. ^^

DingoJunior I suppose I

4/17/12 10:44pm

Er... Except that the B-2 isn't the F-117's successor.

I suppose I DingoJunior

4/17/12 10:50pm

That's true. I recognized that as soon as I posted that but didn't

want to edit. B!=F lol.

AND they were developed at around the same time so it

couldn't have been the successor.

nurflugel9 Lt. Col. William B. O'Connor USAF (ret.)

4/17/12 10:18pm

Correction: America's first subsonic jet fighter was the Bell P-

59 Aircomet. The Lockheed P-80 Shooting Star was the second.

wagnerrp nurflugel9

4/17/12 10:43pm

That's debatable. It was intended as a fighter, but was an utter

failure, and ended up cancelled, with what planes that had

already been built being delegated as jet trainers.

OttoMaddox wagnerrp

4/18/12 4:08pm

The P-59 wasn't exactly an utter failure. Bell did produce 50

examples, even as the USAAF gave up on it as an operational

fighter, which were used to familiarize pilots with the

performance and handling characteristics of jet aircraft. The

USAAF realized that America was behind the curve in jet aircraft

development and didn't have high expectations anyway. But the

Airacomet program created the nucleus of jet aviation in the US,

from engine development, airframe design, maintenance and

support as well as pilot training. The fact that the plane itself

wasn't great was almost beside the point. By the time the P-80

entered service as America's first OPERATIONAL jet fighter

there were pilots who could fly them and ground crews that

could maintain them. [www.joebaugher.com]

wagnerrp OttoMaddox

4/18/12 4:51pm

The Brit's tried it, and found it lacking compared to even the

Meteor. The Navy tried it, and couldn't use it for carrier

operations. It wasn't even competitive compared to modern

piston fighters in anything but very high altitude operation.

First jet aircraft, sure. It no doubt gave the pilots and ground

crews valuable experience on the use and maintenance of jet

aircraft during the transition from older piston aircraft, but as a

jet fighter, it was a failure.

dpoles64 Lt. Col. William B. O'Connor USAF (ret.)

4/18/12 9:16am

Why was is designated a fighter with an F designation? I have

always wondered. It is a bomber, no guns or missiles. It

essentially snuck in, opened a bomb bay door and dropped a

smart bomb. I assume there is some pentagon procurement

subterfuge going on there.

Dabamash dpoles64

4/18/12 1:31pm

A higher up comment suggested that it was to attract pilots to

the program. Makes sense. Why fly a bomber, when you can fly

a fighter!

duodsg Dabamash

4/19/12 3:22am

Going to the National Museum of the USAF multiple times per

year for nearly two decades, and being around lots of USAF

personnel, I've heard something altogether different.

The "F" designation was to mislead any foreign espionage as to

the real purpose of the aircraft. After all, you wouldn't expect a

fighter to go into enemy airspace to bomb sensitive locations,

would you?

Dabamash duodsg

4/19/12 1:49pm

That makes a lot of sense as well :)

HammerheadFistpunch Lt. Col. William B. O'Connor USAF (ret.)

4/17/12 10:15pm

skunkworks by Ben E. Rich is also a great read on the subject.

driggity HammerheadFistpunch

4/17/12 10:19pm

Came here to post this. I read the book about 4 or 5 years ago

and it's really good.

DingoJunior HammerheadFistpunch

4/17/12 10:39pm

Yep, totally loved that book.

MrCrash HammerheadFistpunch

4/17/12 10:42pm

That's one of my favorite books!

rds2431 HammerheadFistpunch

4/17/12 11:02pm

Read that book in college. Years later I mentioned it to my dad,

turns out he worked on the A7's with the "stealth" pods

mentioned in the book

chiggerfruit Lt. Col. William B. O'Connor USAF (ret.)

4/18/12 12:18am

Ah yes, my favorite airplane of all time. I would kill to

fly/own(hah!) one of these things. I just think they're the best

looking aircraft ever created. The stealth bit was also made it

pretty bad ass to me. A lot of people don't think they look great,

but I think those people are crazy. I also love how the P90 looks

for a gun, so that might explain my tastes more...

bugstomper2 chiggerfruit

4/18/12 2:59am

AND you can! LOL!

chiggerfruit bugstomper2

4/18/12 3:18am

Oh. My. God. You just made my childhood. This will be mine by

the end of the year.

Sprzout chiggerfruit

4/18/12 3:46am

I've heard they're incredibly hard to fly, that they want to roll

over because of the design of the body.

Then again, that seems to be common for spy planes - I seem

to remember that the U-2 had such a narrow window for lift

that pilots had to make a really wide, sweeping turn in them.

But you're right, they're awesome looking!

Turbineguy aka Will Alibrandi Sprzout

4/18/12 9:42am

They'd be impossible to fly if it weren't for the flight control

computer keeping the shiny side up. (if there was a shiny side,

that is) The plane is so aerodynamically unstable the FCC

continually makes many flight control inputs to keep the plane

in the air. It's a fly-by-wire setup where pilot control inputs to

the FCC are translated into flight control surface movements.

IIRC that FCC is triply redundant because a failure would result

in the loss of the aircraft.

chris209 Lt. Col. William B. O'Connor USAF (ret.)

4/18/12 10:43am

Another interesting fact is the F-117 was technically a stealth

bomber, not fighter. They used the 'F' designation to attract

pilots to the program.

SpainIsInYurp chris209

4/19/12 4:07pm

And to misinform the Soviets.

phimuskapsi Lt. Col. William B. O'Connor USAF (ret.)

9/13/15 9:34pm

I also highly recommend ‘Skunk Works’ as a great read. It’s all

about the F117’s development.

MrvinTheMarshn Lt. Col. William B. O'Connor USAF (ret.)

4/18/12 9:42am

My wireless network at my old appt was named Skunk Works...

Good article

Unicorn_Turdz Lt. Col. William B. O'Connor USAF (ret.)

4/17/12 10:27pm

Load More

Awesome.

DingoJunior Unicorn_Turdz

4/17/12 10:45pm

Heh, nice and stealthy :)

Picklehaube Unicorn_Turdz

4/18/12 10:35am

'MMMMMMerica!

-Nibbles chewing comments and spitting them out since 2011