Dale McLeod 

I have many memories of Walt Evans since I first met him in1951. Then he was a group leader in the Auto Control Section of Dept. 93, in the Aerophysics Lab, Downey, North American Aviation Co. Along with Bob Osborne, Bruce Horsfall, Bob Brown, John Slater, Jesse Bowman, and others, he reported to John Moore who was Section Chief. 

To a young engineer then, Walt Evans seemed to me so far ahead of the pack in technical insight and creative ability, as to be regarded only with awe and great respect. Later, as I got to know him better and on a more personal level, my respect for him only increased. It has been a privilege to know him, to have been associated with him professionally, and to share in celebrating his official retirement from Rockwell.

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John R. Moore

I understand from Dee Lyon that you retired from Rockwell at the end of January. This is to let you know how much I am thinking of you and remembering all of the great times that we had together, both in St. Louis and California

You must know how much I have always admired your creativity, engineering expertise and sense of humor, plus your personal warmth and friendship. I think that one of the great desecrations of modern times was the removal of the historic inscription in concrete near the Downey main strip, with its deathless lines that, as I remember, went! 

"From this point in Euclidean space

Man first attempted to brace 

His path through the heavens 

And in spite of Walt Evans 

Safely returned to this place.”

As I recall, this was the first flight of the XN-1; and an air bump threw you against a power switch on one of the racks, thereby summarily terminating the experiment, of course you, must take a lot of pride and satisfaction root locus method (and spirule) from knowing that has helped many, many thousands of engineers to design better automatic control systems,

I understand that you are swimming quite a bit, making beautiful colored drawings and pioneering new approaches to computerized chess. No doubt, with your remarkable creativity and intelligence, you have become a real software expert.

Walt, please know that I think of you often and you and Arline (with whom you must share my great admiration and affection).

I wish the very best for you.
 

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Sam Carlson

It seems only a very short time ago that we met in your office at North American in Downey. That was in September of 1952. Six months earlier I had been interviewed at Purdue University by Ray Hamada, who was on a recruiting trip for North American. I told Ray that if I could work for Walt Evans, I would accept North American's offer.

I consider myself most fortunate to have had the opportunity to get started in my career in the Aerospace Industry working for you, Walt. All of us who worked with you learned so much - pride in technical excellence, respect for absolute integrity, and satisfaction in accomplishing extremely challenging goals through dedicated individual and team efforts.

Walt, I thank you for these lessons. They have been important to me throughout my career and are still today.

Aside from the career association, Dot and I have cherished our friendship. with you and Arline, and your children. We remember fondly the Group 64 picnics that were so much family fun. Also, the parties that you gave and the other occasions for getting together. We hope to see you and Arline more in the future.

With best wishes and fondest memories upon your retirement, and looking forward to many more years of warm friendship, I remain

Your friend,Sam Carlson

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Norman F. Parker

Dear Walt and Arline-

Carol and I wish you the very best in retirement. As the saying goes, "you've earned it". Looking back on the days at Autonetics, there was an awful lot of hard work involved but it was enjoyable work because of the people who shared the effort. It was an unusual group, unusually talented but equally important, a team of individuals more interested in the performance of the organization than in their own welfare or progress. I hope when you reminisce you get the same warm feeling that I do with pride in the character and capabilities of your associates as individuals and pride in their accomplishments as a team.

It's fun too to remember the humor the honey used as damping fluid in the leveling cells, the Red Star product that covered us when we worked in the C-47, the fresh jokes brought by every visitor from Washington, the arguments in the carpool, trying to convince visitors that we really were tracking stars, etc.

Sharing, whether work or humor or support, is an important part of life and you both have given more than your share and God bless you for it.

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Marge and Bruce Horsfall

Dear Walt:

I'm glad that De Lyon took the initiative to give some of us a chance to express our best wishes on your retirement, belated though they may be. It immediately reminded me of the course you gave a number of us at the NAA Inglewood plant soon after you joined us. Those were days when it seemed that we were getting paid just for having fun. Johnny Moore put together quite a team to develop principals and precision instruments for navigation a couple of orders of magnitude better than previous state of the art, much of which is still fundamental to present equipment, and you were an important member of that team.

I could wish that you had not been cut down as you were, I am happy to know that you are making progress in fields new to you which make use of talents previously hidden. More power to you, and may you continue to improve and enjoy your retirement! Best wishes to you and Arline from both of us.

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Ray Brands

Dear Walt:

Just a short note to let you know how much I appreciated working for NAA/Autonetics and with before "Science during the "glory days" of But Down to Business". My admiration for you goes back to the D.C. Machinery class at Washington University,1947.

Your fresh and innovative approach to that subject stimulated my mind, and turned what could have been a dull course into one for which I still have fond memories. You were most instrumental in my coming to work at NAA in June of 1951, after I received my M.S.E.E. from the University of Illinois. I look back on my decision as one of my better ones. 

At the time I thought that defense work would last about another five years and then collapse. but it's been almost 34 years. and it looks like the military-industrial complex is here to stay.

I want to thank you and Arline for shepherding me through my first year in California as a not too mature young man really his own for the first time.

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Dear Arline & Walt,

I very much enjoyed reading the booklet you sent me, personal experience, I can think of no one more deserving than you Walt.

In 1948, I was in New Mexico as part of the "Native" missile test crew. As the program wound down, many of the NAA crew were joining other companies with ongoing work in field testing. Jobs back in Downey didn't seem too plentiful at that particular moment and it looked like my days in the Aerophysics lab would soon be over. Ray Curci used to come to New Mexico every so often to work on the autopilot and he said he thought he could get me into the servo unit. He told me of a new dynamic leader named John Moore that Dr Edlefson had hired and of a guy named Walt Evans who was teaching a servo course that made sense. This sounded pretty good to me, so I asked him to try and get me a spot. Your course and in particular the root locus method finally pulled all the parts together for me.

I remember the early root locus days when everyone was inventing a way to make plots. I'll never forget the large rubber sheet which when made into a second order system looked like Sally.

Then there were the engineers from Hughes. I demonstrated using spirule at John Moore's UCLA course and they wanted the drawings. They had a 100 made in their machine shop and the assembler glued all the parts solidly together in the position shown in the assembly drawing!

Bob Cannon's comments on Goddard's First Law reminded me of "The Big Guns Law of Project Estimation'. We were working on an autopilot program for the Navy and the program manager wanted to reduce cost, so he asked each unit supervisor how much could be saved if we had 18 months instead of 12. All the hardware guys came back with savings (no overtime needed, no rush orders for parts, less redundancy, etc. Cannon, who had the analysis unit came back with a 50% increase. He said he needed the following:

One engineer to analyze the pitch loop

One engineer to analyze roll yaw

One engineer to interface with aerodynamics

One engineer to interface with hydraulics 

One engineer to interface with electronics

Two REAC technicians

The above crew was required for the life of the program. The quality of the final product would improve with time. However, I guess Ruth and Dale have told you about our ranch life. We are enjoying it very much.

Again, my congratulations and best wishes.

Jeff

Robert Nease

We were sorry to hear of Walt's death and terribly disappointed that we could not come to the service celebrating his life with you, family and friends. Walt was truly one of a kind----not sure they make guys like him anymore. Although I never worked directly for Walt, he was one of the first of the "old timers" that I met in Downey (Mitz was a friend from school and instrumental in my coming to work for Autonetics). We had lots of good times in Downey, a few years together in Newport Beach, and then quite a while in Anaheim. We shared an interest in (very amateurish) athletics ---- seemed to have something going most of the time, with lots of that while we were at Ford.

But the big hero in this story is Arline. You meant so much to him and have spent most of your life taking care of him/family, without a lot of fanfare and praise. Walt was so proud (and rightly so) of his family and always told me that you were responsible for anything good which happened---- even later when he had difficulty communicating.

Since we were expecting to attend the service I had planned to bring along some messages from the old gang, and Greg has promised to do this for us on Saturday. Also, I promised Mitz that I would tell you that he was not up to the emotional experience of the service, and that he would be in touch with you. I likewise told Norm Parker that I would pass along his best wishes to you--- he was in the Bay Area with a daughter who was in the hospital.

Our thoughts and prayers are with you and your family in this time of sorrow and change----really big changes for you. If we can help, please let us know. We hope things go really well for you and will keep you on the Group 69 Reunion list in case you are interested in coming.

Love to all,  Delight and Bob Nease

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Hal Engebretson

Sam Carlson

Bob

Thanks for informing us about Waly. I had not heard about it. Sorry that we will not be able to attend the service on Thursday. We will want to make a charitable donation in his memory. If you learn of a charity that the family would prefer, please let us know. 

Walt Evans was the reason I went to work in North American after graduate work at Purdue University, I had learned of Walt's work in servomechanisms and had read his published papers. When Ray Hamada was recruiting for North American Aviation at Purdue shortly before I completed my graduate studies, I told him I would like to work at North American if I could work with Walt Evans. I reported to work at North American in September 1952, in Walt's group. My immediate supervisor was Walt Pondrom. The two Walts were two brilliant stars. 

After about six or eight months, Walt Evans launched me on my management career by appointing me supervisor of the Instrumentation Unit, and he was a great person to work for. 

I have never known anyone more brilliant or of higher personal integrity than Walt Evans.

Regards to you and Delight. Sam Carlson

Jeff Schmidt 

How about some good news?

I was shocked to read your report on Dave Friest and his wife. Your next note on Walt Evans makes me think I should cancel my Email. I would like to attend Walt’s funeral but won't be able to make it. We are snowed under with grand parenting duties all week. Shari came down on the 6th and left Melissa. Steve came home for the weekend and he and Melissa went with us on Sunday to the Harris ranch where we met Sue. We returned with James and Matt. Every day has been filled with horseback riding, 4 wheeler riding, swimming etc. Have also had lots of neighbor kids swimming and horseback riding with them. Tomorrow we are going to Santa Cruz for some cooler weather and a few roller coaster rides. As you can see the grandkids have us busy almost to the time we leave for Turkey and Greece.

Would you please give Arline Evans our condolences. I always thought Walt was one of the best. Many of us can claim a minor role in winning the cold war but Walt alone took the black art out of servo analysis. He made it into an understandable procedure for college students worldwide. To top things off he had a great sense of humor.

Thanks for keeping us posted.

Jeff and Jean

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Frank Pelteson

I just got a Fax from Ken Gow relating that Walt Evans died yesterday. The obituary, probably from the OC Register (and maybe from a Whittier paper) describes his life and career. Call Ken Gow at (562) 699-3501 for further details.

Walt hired me personally in 1952. He was interviewing Sam Carlson and me simultaneously at his home while watching football. He was informed that way.

I worked in his Auto controls department under Harry Newman and Tom Curtis in the Test Equipment section in Building 1 at Lakewood and Clark. Walt was my Group Leader at the time. Those were the XN-5 and XN-6 days at Aerophysics Labs. Navaho and Snark were being equipped with the N-6 and N-2 respectively. Remember?

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Hal Engebretson

I was sorry to hear that Walt had died. I regret that I will be unable to attend the services for him. We are now in Washington for the summer. Walt was the Group Leader for Group 64 when I started to work for North American in 1954. Sam Carlson was my supervisor. 

Many people respect Walt for his outstanding technical ability. I also respect him as an outstanding manager of people. When I started to work, it became obvious that if you worked in Walt's group, he supported you. The message was that one did not have to worry about trying to do a good job, if you did your best, Walt would support you. That management attitude resulted in some very good people developing to do some very good work. It is too bad that more managers do not have that faith in their people and ability to motivate them.

Regards, Hal

Frank Pelteson

Walt Evans, of Root Locus and Control System Dynamics fame passed away at 79 on July 10. One of his design tools, the Spirule, was used by every Servo Loop designer before computerization made the problem elementary. 

Walt interviewed Dr. Sam Carlson and me simultaneously at his Whittier, CA home in late 1952 during a football game on TV. During the break he invited us out into the street to lateral some footballs. He asked, during a run-by, "Do you want the job?" I said, "Yes." That was the start of my nineteen year career at North American. Walt was a simple, straight forward man. He used to disconcert me by solving a problem in five minutes that used to take me four hours to analyze to come to the same conclusion.

My immediate boss, Tom Curtis, who was under Walt, on-board serviced and monitored the inertial navigator on the Nautilus North project.

The passing of a great genius. And an era, I might add.

_____________________________________________________________________________JJoseph Portney

To: Frank Pelteson

Frank:

I was sorry to hear that Walt Evans passed away. I had never known him but through the ION.

I met Nichols (Nichol’s Plot fame) at a local ION section meeting one evening in the late 80's when I was the guest speaker. You described in Walt his genius of seeing the answer or approach immediately where the rest of us falter. This is the unique attribute that many famous scientists possess. Enrico Fermi was said to be able to see the simple approach where others sought out a more complex path that frequently ended nowhere. We live in a great era where both of us have met the great people of our discipline. I was fortunate enough to meet the last of the great navigation practitioners and many aviation pioneers. My colleague, Norm Emmott, and I were editors of the Litton Avionics Newsletter 1989-71 and published 8 thick volumes (100+ pages per issue) which included interviews with famous aviation exponents such as: Major Alexander Seversky, General Curtis Lemay, Dr. Cleminshaw (Griffith Observatory director), Capt. P.V.H. Weems (taught Lindbergh and Earhart navigation), Ed Sharkey (Rand scientist) and Charles Draper. It was always a thrill to meet these great people and hear more about their achievements and interesting anecdotes. 

I found some more information on the unipolar coordinate system from Cedric O'Donnell's book on Principles of Analysis and Design of Inertial Navigation Systems. The book resides in a storage annex of the UCLA library and I was permitted to copy some pages. This mechanization was apparently used on the Skate when it went to the North Pole. I like to believe that since it required only three direction cosine transformations as opposed to the other coordinate systems (displaced poles to the equator's intersection with Greenwich and the international date line meridians) which requires 9 (reducible to direction cosine transformations it was preferred owing to the limitations of the Verdan computer. The unipolar intuitively appears to be simpler because the polar axis and the spin axis are coincident whereas the other coordinate system is displaced 90 degrees.

Best regards, Joe

2003 April 2

Robert H Cannon – Interview Notes

4:30 to 6:30 pm, 844 Hill Avenue, Stanford, CA

Professor of Aeronautics at Stanford University

Bob Cannon was a graduate student at MIT when his mentor, Den Hartog, introduced him to John Moore from NAA. Cannon graduated in 1950 but did not join NAA until 1951. John Moore was “quite a salesman”, and got Cannon interested in moving to California. Den Hartog knew Bill Bollay, director of the Aerophysics lab. From Hartog Cannon had learned to rely more on the roots of the characteristic equation as more important indicators of a system's behavior than was its frequency response. Hence, the foundations for his receptiveness to root locus were laid at MIT.

Bob Cannon’s wife (Bev?) had a cousin who lived in Whittier – Seth Pickering, whose father was a former orange farmer and for whom Pickering Avenue is probably named.

Cannon reported to work – a grid of desks (40 x 40) referred to as the “bullpen”. He knew who Dad was but was not sure how to introduce himself. He decided to write a letter from a fictitious town of “Stinky Poo, Long Island”, and wrote that he had been reading in a Barbershop there about a new “root locust” method. Dad traced down the source of the letter in a couple of hours.

Cannon was assigned to the auto-pilot group, whereas Dad reported to Fred Eyestone in the Inertial Guidance group. Cannon reported to Bill Mullins. Mullins and Eyestone reported to John Moore. 

The airplane guys had moved to Downey from Inglewood and had a completely different culture than the control group. Their idea of stability was different from that held by the control group. This difference led to many debates over the parameters of the control systems.

Root locus, within Aerophysics Group, spread like wildfire. Four or five guys were running with it. Most of them were assigned to the Navaho missile program. The main applications at the time for root locus were on the Navaho and the F-86D aircraft. Later, when Cannon transferred to the Inertial Guidance group, he shared an office with Dad and Mullins. 

About that time, Fred Eyestone installed a two-way intercom to all the group leader offices. Upon first spotting it, Dad pushed the button and shouted, “can you hear me Fred!” into the microphone, blasting Eyestone’s office speaker.

At NAA, carpools could park closer to the entrance. Cannon came up behind Dad and beeped his horn. Dad did not turn around or step to the side, he jumped onto the back of whoever was walking in front of him.

According to the Cannon, Dad’s ideas on how to control NAA’s inertial guidance system for the XN- were used in its final design. This guidance system was used in the Nautilus to make it to the North Pole.

Regarding Gordon Brown’s review of the root locus paper, it is important to know that Brown (and Campbell) had just published a book that purported to be the new bible for servomechanisms. Its use of frequency response techniques was central to its approach, and Brown did not want to entertain the thought that a new idea had significant merit.

How did the root locus method disseminate? At NAA, Cannon said it was “the language we talked.” Cannon and others attended committees, such as the SAE Committer A-18 and IAS where the latest ideas and future of the field were discussed. The root locus method spread in part through such meetings, as well as papers in nationally distributed journals, and Bill Bollay’s December 1951 Wright Brothers lecture.*[1]

At MIT, Cannon said there were many “fiefdoms.” For example, Draper Labs and Servo-mechanism Labs had little interaction. They were separate entities. It was not a collegial environment. Gordon Brown was in the EE department; Charles Draper was not. Cannon suspected Draper “would” have picked up the Root Locus early on, as Draper Labs was designing and building things, whereas Brown’s EE department was not. Cannon recalled, however, as late as 1957 bidding on a contract and learning that the Draper Labs approach did not propose using root locus. He was unsure of dates.

Cannon left NAA in 1957, having worked there since 1951. NAA’s Harry Singleton had gotten crosswise with someone at NAA and left, taking his own different ideas with him. “I’m going out that door and I’m going to make a million dollars,” he proclaimed when he left. He missed by about a factor of 5,000 according to Cannon, as Singleton went on to form Teledyne and then bought Ryan Aircraft to form Teledyne Ryan.