HD1962MM12

Events between 1959 and 1965 during MM I and II

Fly Wheel for Minuteman Proposal: : Some time ago visiting Buxton, when helping with his computer, we talked about MM I, and Buck brought up the idea of using fly wheel methods. I chuckled remembering the origins of that idea and of test work Art Greer, Ron Frazinni and Clarence Ashe did on that. It began when I first learned there was such a thing as Minuteman. Art Greer had sat down by me at the cafeteria in Downey. Art & I often talked of how to do things. He’d confessed to how dumb they’d been thinking they could study hydraulic system dynamics with movie film recording pressure gage readings on a big Navaho Iron Bird. In the Bomb Shelter we used Sanborn recorders for such tests, the same as used by Dr’s for EKG tests. This time Art asked if I had any ideas on how to power pumps at the back of a solid propellant motor – it had been decided to use four tilting nozzles. So I went through the full litany of all I knew about starting aircraft engines from shotgun shells to small motors that ran up fly weights to electric motors such as on B-29s where the armature also served as fly weight – spinning up before engagement. Jokingly I said you could even spin one motor stage with respect to the other to drive a generator, even giving it spin stability as if rifling in a gun barrel. Brainstorming always included dry humor. When he left to go back to the proposal task he was convinced a fly wheel was a candidate. Thus I was not surprise when they showed up with a mechanism to test. After repeated tests it was soon established that the flywheel idea would not work for our application. Not because it was a bad idea, but because of the nature of the demand. Servo valve leakage was a constant power drain, magnified because it was at a pumps lowest efficiency, considerable energy was consumed before any flight control activity. Buck enjoyed this back ground story.

Minuteman I: As work expanded Lou Purpura and Art Greer went to the Project office and I was made lead engineer for Minuteman I servos and pumps. Ron Frazinini and Clarence Ashe, newly hired, were assigned to work with me and we began a design review from scratch. We found that servo valve leakage, necessary to achieve hydraulic gain, had been omitted when sizing the pumps, also forgotten was the condition when both servos are commanded to work at the same time. We needed to go from a 5 gpm pump to a 7 gpm pump. As these were battery powered this also changed the battery size. I could not get anyone to listen to me, few knew who I was anyway as I’d worked in Bomb Shelter isolation. So I wrote a note to Ray Curci, then in the project office, and whom I knew from Navaho work. I wrote, “there is a strong possibility first flight will fail – the actuators and pumps are undersized.” He was busy so I left it with his secretary and went back to my desk. About 15 minutes later Ray was at my desk asking, “now what the hell is this about?” It only took moments to show him our calculations – he’d worked in hydraulics and readily followed the numbers. He didn’t say a thing and turned to walked away, then looked back saying, let me know what is required and how long it will take to implement. We had a complete redesign and hardware on hand in 90 days.

[Lou Purpura was our hydraulic pump expert on the Navaho, and was in charge of Minuteman pump procurement prior to moving to MM Project office. He became a part of the Program Managers staff, and was a significant player through and after the MM program. We had adjacent desks when I hired in and were close friends, often exchanging ideas and pooling efforts. Attends annual Christmas party.]

[Art Greer was one of the brightest in our unit, and worked with Lou in launching MM I and moved to the Project office at the same time. Art and I were close friends, then lost contact when he moved to another site. Nobody seems to know what happened to him.]

[Ron Frazinni: Was one of our most capable engineers who later went to work for Honeywell, keeping in contact with Clarence Ashe. We still exchange Christmas cards.]

[Clarence Ashe: Was a very talented engineer who was assigned difficult problems, he was liked by all he worked with, later becoming a Director (I believe) of Honeywell. ]

Digital Hydraulics: At the beginning there was a belief we should have “digital” servo valves and digital actuators to go with the digital electronics. Fritz Gardner was head of our IR&D and Jim Jewel built a digital servo valve. Ling Temco Vaught and Cadalac Gage build digital actuators in response to this assumed need. Later following MM III, while experimenting with how to replace analog electronics with digital electronics, I found I could command analog 8ma servo valve coil with a simple 4 CMOS transistor device (then new RCA 4016). With this, existing analog servo valves became “digital valves”.

[Jim Jewel was an artist by instinct and an excellent design engineer, often coming up with innovative solutions to problems. He contributed significantly to the MM I and MM II Nozzle Control Unit designs, status unk.]

Digital Actuator Idea Disclosure: While preparing this I came across an idea I submitted in 1961 on how to step motion of a hydraulic actuator by step porting pairs of pressure and return ports causing the actuator to advance or retract one step. The figure to the left shows shaft lands and groves and a “rolled out” porting collar with pairs of holes. Fluid ported to step 2 causes the piston to move until the land cuts off flow. If fluid porting is move to position 3 it causes a one step motion in one direction and in the opposite direction if applied to position 1. By digitally stepping the ports it would digitally step actuator stroke. There are many things wrong with the idea even if it worked – but it’s not worth the effort to go into such details. (If I convert this to HTML format for browser use, I’ll permit calling up the submittal plus it’s in house response by patent department and in house R&D review.) Looking back it was an admirable effort sustained by my own ignorance – much time and money was wasted by the hydraulics community chasing the then magic word DIGITAL – what applied to electronics did not have an equivalent value to hydraulics.

MM I Reliability: Once I was lead engineer on Minuteman actuators and pumps I became involved in the Reliability issue. Bill Yetter was made head or our Reliability effort and they set up a failure report system – and were soon dealing with lots of paper, with no real method for making sense of it. [Bill Yetter Navy WW II would go on to selling securities after retirement, attends annual Christmas party.] We had evolved a method of monthly meetings with LTV (servos) and Vickers (pumps) in which we would do severe experimental qualification testing, send failed items back to the supplier, then have failure analysis and solution presentations at the periodic meetings. As lead engineer I was keeping notes on failures and fixes, on all items delivered and tested. Aware Yetter was having trouble accounting for progress he was making, I provided him a copy of each periodic data upgrade – which he reported as Reliability Program progress. There were about a dozen failure modes uncovered on both servos and pumps, however once a failure mode was fixed it did not fail in that mode again. We had gone to gausian random vibration testing – testing had become very sophisticated – much better than we’d done on prior equipment. In this way we developed very reliable Power Elements. Later Bill Strobel remarked , we did too good a job, no follow on work is required.

Wiping Oil with Feet: In the Bomb Shelter CD I’d compiled was a photo of Larry Hein, [Larry Hein was an energetic very capable Hydraulics technician, always in demand. Larry suffered a stroke and died about 1970?.] I asked Buck if he recognized Larry? He did not. I said, that’s too bad, you see Larry suffered a stroke after you did, and Larry said you had been very helpful to him by lending encouragement. I continued, you and Larry had been a team at Boeing in the first Minuteman design review. The stage I nozzle control unit on display was leaking oil from the actuator shaft. You and Larry were taking turns wiping up the oil with the soles of your shoes so the leak wasn’t noticed. We had a call from Larry and I immediately contacted LTV Ling Tempco Vaught who supplied the actuators. LTV began an intensive study on how to prevent leakage when the oil pressure drops to about 10 psi, that applied by the reservoir bellows spring force. They came up with a combination tefflon rubber seal, where rubber sustained pressure on the tefflon at low hydraulic pressure – we never had a problem after that.

Burying a naked pump inside the reservoir, saving weight and seals, was a brilliant idea – as was placing the position transducer inside the actuator. Navaho servos had transducers on the outside and trouble with binding independent shafts. Burying the pump was a Purpura-Greer idea, it saved weight and oil seals.

Production stage I NCU, experimental unit such as this had shaft seal leak at Boeing

Time Constant: Several years later I was assigned to work for Bill on the then new Minuteman II. One day Bill came to me with a problem he was having. He’d bought a cabin in the mountains and had a need to map elevations on the lot for future improvements. He knew I’d done surveying and wanted to know how to do it. He was short on funds so I told him how he could rig a carpenters level and binoculars to make horizontal sightings to a multi-yard stick pole and map the lot relative to a base elevation. He asked if that’s what I did when I recently added on to my house. I said no I used water, I filled the foundation ditch with water, then set stakes at water level periodically for base line elevation. He thought that was great but couldn’t dig a ditch as I’d done. I said well you don’t need a ditch, you can use a garden hose with visible open device at each end, fix one end at the high spot and lift the other end until the water is at the same height. He thought that was a great idea. Next day he came by and said he finally had it worked out. He said he bought some plastic tubing like you use to pump air into fish tanks, that he could carry in his pocket as he didn’t have a garden hose. He continued, I’ve worked out the time constant for how long I need to hold the end to make sure the water has indeed found it’s own level. Bill thought in mathematics terms – making him very special and different from us not that skilled.

Bill meets his match: I happened to be present when Bill Stobel and Dave Biles got into a mathematic discussion. [Dave Biles had worked at an atomic energy lab prior to working for NAA. Several persons have told me Dave was one of the brightest people they had ever known. Dave disappeared about 1965 and nobody’s heard of him since.] Dave had been working in the Sim Lab when it was found the MM I servos and pumps were undersized and I knew him only by looks. I learned the calculations for sizing the MM I servos and pumps had not been done by Lou Purpura & Art Greer but by Bill Stobel, as Bill had come by to talk with me about it. Bill felt very bad about having made the mistake, which was very easy for any one to do if you didn’t happen to know the hidden inner workings of a servo valve – that they leaked. Bill became comfortable trying ideas out on me. It was at such a time I was present when Dave Biles walked in. Dave listened to what Bill was telling me, then said, no Bill that’s not right it goes this way, taking a place at the black board. I was amazed at how Dave handled Bill – as if Dave was the professor and Bill the student! Bill took pride in his work and persons respected his talent – at the same time he had the utmost respect for Dave’s ability – it was important to Bill to prove himself to Dave, where Dave could care less – it was only mathematics, something Dave handled with even more ease and confidence than Bill. It was my pleasure to later work with and know Dave as a close friend. Dave and Bob Averil were good friends. Long before I knew Averil Dave told me Averil was a good engineer, which coming from Dave was a real complement. Bob Averil played a key roll in the development of the Post Boost Propulsion System, the first to use our new digital computer. I worked closely with Bob during that period. Bob later became a department head – then tragically contacted a disease that makes it almost impossible to control his body motions.]

Square Wave Noise: While still in the Bomb Shelter test facility Bob Kelley had solved the square wave noise problem. We had used linear transducers designed by Gary Collins a former Navaho Radar-Radio engineer. Gary patterned these after an IF Transformer with a tuning slug. He’d been playing cards with the flight control guys complaining about vibration ruining variable resistor wipers used to measure position. Collin’s transducers had worked fine on Navaho using 400 cycle ac. [Gary Collins left the Navaho program and set up him own company where he manufactured position transducers. These were soon on every missile and aircraft in the US inventory, most built in a house in Downey he converted into his shop and laboratory. Gary died about 1970.] For Minuteman we didn’t have a source of AC and had to chop DC with transistors to make square wave AC. The fellows were having problems finding then new transistors that would hold up. This 6000 kcycles, now called hertz, was creating lots of noise in the servo loop electronics, making the valve current look ratty. I had gone to Odel Taylor supervisor of our servo electronics for help with our Bomb Shelter electronics. [Odel Taylor was later assigned to special electronic manufacturing operations and I lost track of him.] He sent Bob Kelley an old Ham Radio designer, skilled but without an engineering degree. Odel wanted only fellows with engineering degrees working on the Minuteman electronics design. Bob was a godsend to us and I soon became aware the engineers with degrees were frequenting the bomb shelter to discuss their problems with Bob. Bob had a good friend in another unit who had a degree and an expert on transistors – Bob went to him when he sought advice. They were having trouble finding quality power transistors and we needed quality square wave generators for testing position transducers. Bob solved our test equipment problem with commercial HiFi MacIntosh Amplifiers of the kind his friends on Mt Wilson used for commercial broad casts. Bob ignored the high frequency noise seen on scope images of servo valve amplifier outputs saying, “don’t’ worry about that noise, the servo valve will average it’s effect, valves cannot respond to the high frequency.” I remembered this in later when commanding an analog valve with digital signals, I knew the coil would average the high frequency commands – this was a key element in proceeding with that later experiment. I also made use of his explanation that it is necessary to have large output transformers on HiFi vacuum tube amplifiers to sustain quality – that large transformers would not be required if transistors were used to drive a hi-fi speaker – transistors are current amplifiers and speaker coils operate on ampere turns.

Johns Hopkins had used 400 cycle for their accelerating switching valve, and that frequency would rattle the hydraulic lines. Thus years later when coming up with a way to run an analog valve with a digital signal I knew I needed to be above 400 cycles and that at 6000 hz feedback excitation could also be used for command iterations – the valve coil would average the “noise”.

Piranha Proposal: Dr Stone had collected people to work an a proposal, Dave Biles, Rogel Van Wyke, Jim Jewel, Ken Nichols of Space division and I were on that team. The proposition was to fire a missile out of a 5 inch gun on a main battle tank to hit a spot of light placed by a forward observer on a target. Some one gave it the name Cerebra (sp?), another name for the South American Piranha fish. I was asked to work on the solid propellant motor, so I made an end grain burning design and sent it off as a specification to McGrego TX from which to make a proposal design. Their message back to Dr Stone was to use what they had received, as it was what they would propose. In the mean time Dr Stone assigned me to come up with servo actuators for the four pop up control fins when the missile came out of the barrel. Jim Jewel worked on the fin design, Nichols on the aerodynamics and Biles/Van Wyke on the flight dynamics. I got out text books and papers on how to make pneumatic servo controls to operate off a bottle of pressurized nitrogen. This was new territory for me, I knew pneumatic attributes were much different than hydraulics. However I’d found some excellent information on operating systems and felt comfortable with the result. Once that was done Dr Stone asked me to design electronics for the servo controls. They already had in mind an existing system they could use as for a Cyclops eye for seeing the target spot and issuing guidance commands. I objected telling Stone I was not an electronics expert. Stone just smiled said that’s what you said about the solid propellant job – just give it your best shot. So I came up with an electronics design which they used as is for the proposal. During this, as a means of taking a break, I’d go by where Biles was running analog computer simulations. During these discussions he explained that the problem was not in reaching the target but the last phase large swings in which they could over shoot or under shoot the target. I appreciated what they were doing.

We did not win this unsolicited proposal initiated by Dr Stone – however the customer liked the idea. A short time later Dr Stone went to work for a company in San Diego who did win such a contract.

While working on the MM III post boost system head hunters made repeated efforts to talk with me. I didn’t know why they were interested in me, but they knew things about me and said just name your price. I said there are lots of other people, you don’t need me. They said, we’ve been asked to get you. I said I can’t tell you what I’m working on – just accept my saying thanks but no. After thinking about it I came to believe the offer came from Dr Stone.

Not long after Dave Biles disappeared, no one hearing from him again. I like to think he went to a job of his choice. The last I saw him was in the parking lot, the woman he’d been living with had died of cancer and he was very broken up about that. He’d been working on how to back track to a mortar location using radar traces of shell trajectory. I’ve regretted we were so busy and lost track. Bob Averil also wondered what happened to him. Dave was a rare kind, very special as friend and working partner.

Our MM raceway wiring included heavy power cables, running the length of the vehicle, to drive pumps during ground checkout. If we could power pumps using solid propellant, we could significantly reduce weight. For ground check out we could power pumps with air – it was worth looking into.

Solid Propellant Driven Pumps: After MM II began to slow down I decided to look into ways to drive hydraulic pumps using solid propellants. I knew Vickers was providing such a pump to Douglas for the Skybolt missile. I had a visit with Jack Leopold at Vickers who showed me their set up for running tests as well as the Motor-Pump mechanism. [Jack Leopold was one of the lead engineers at Vickers, status unk.] The solid propellant generated “warm gas” 2000 F derived from an end burning chunk of Ammonium Nitrate solid propellant. This warm gas drive a hydraulic pump as a motor direct connected to a pump. I discussed the idea of them attaching such a motor to one of the Minuteman pumps? Jack said there was no reason why it would not work. With the support of Jim Anderson we arranged to fund such a purchase. Since I had graduated as a mechanical engineer I still had my books on thermo dynamics and decided to do an analysis on flow of warm gas through such a warm gas hydraulic motor. It took some time as I had to relearn things I’d forgotten but I finally completed the analysis. I was pleased with the results except for the size of the input port on the “pump”. By my calculations it should be at least twice the present size. So I drove to the Vickers plant in Torrance for a talk with Leopold. I waited while he finished notes on a paper he then handed to a person to implement. I told him I’d done an analysis and all looked well except the inlet port should be doubled in size. He looked at me in silence, a long pause, then asked how I came to that conclusion? I told him and he just shook his head. I was puzzled?. Then he smiled and said, that piece of paper I just sent out was to do just that – we had come to the same conclusion from our tests results!

Solid Propellant Gas Generators: I made arrangements to meet with a Dr Stutenbruck at Rocketdyne to learn something about solid propellant gas generators. I knew they used these to power the liquid oxygen pumps to dump the equivalent of a tank wagon of fuel or oxygen in one minute! This was a good meeting in which they told me about how to build a gas generator and use squibs to ignite the propellant. I learned a squib was propellant attached to heater elements at the end of long wires. Electrical current fires the squib propellant which in turn ignites the main propellant. I next arranged to make a trip to McGregor TX to a Rocketdyne solid propellant plant where, to learned more about propellants and how to handle them. They gave me design hand books on burn rates and various options for burn surface shapes. When I returned I obtained permission to run such test in our Bomb Shelter, and placed an order for a Berrilium cross cut saw for cutting solid propellant slices. I had used this information when working for Dr Stone.

The parts were delivered but in the mean time I’d been sent off to another assignment.

B-1A Pre 1^st Flight Design Review: I received a call from someone saying I’d been selected to go to NAA to participate in a Design review of the B-1A before it’s first flight. I reported as directed and was taken to a large area in which they had set up rows and rows of panels on which aircraft wiring drawings had been place. There I met others from other divisions of the company and subcontractors. This is where I met and teamed up with Ed Olive from Sperry in Arizona. Ed was about 6’ 4” and could see and reach up to the top of the large drawings. I was too short to see let alone reach that high without a stool or ladder of which there were none. Ed was very capable and bright as well as a nice guy to work with. Ed was frustrated because NAA would not fund them to support a systems integration effort. I was well aware from talking with Autonetics people who had been transferred to that division, that NAA was operating on a bare bones budget. Ed was aware of this but he was facing a similar problem at home while being caused to support for free what he considered to be NAA’s responsibility. (Later, on loan to Douglas, I found this was common practice for aircraft companies to place a heavy support burden on subcontractors.) These drawings represented the installation of Sperry Flight control equipment, thus he was one of the few who knew how to check the wiring. My contribution was negligible as I was struggling just to figure out what the system was about and what I was looking at. By the time the design review was over I had learned enough to be of help. All I could do was validate what Ed was finding. He could see high enough to follow the wiring and I could validate what wires had traced to what. From this he found several instances where controls wiring, defined by the drawings, was reversed. This review was held because during final check out were repeatedly encountering problems with improper wiring.

I’d not dealt with aircraft wiring since B-29’s and was immediately impressed by what I was trying to review. Our Minuteman wiring was a toy by comparison. Our boxes were complex but few. The B-1A had a range of boxes from simple to very complex, some 200 of them dispersed throughout. The defensive avionics used emitter coupled logic to achieve maximum speed and had to be liquid cooled. I became aware the EMUX system reporting aircraft status and SITS system for checking out the redundant systems, both threaded though out the entire airplane.

While there I was told to see Guinevere, the secretary, I was to call Autonetics. I envisioned seeing a blond Guinevere and was surprised to find a nice looking very black girl! That evening when I got home I was shown a new black kitten the kids wanted to keep. Asking what they should name it, without hesitation I said Guinevere – they were delighted with the name saying it was very clever of me. So Guinevere joined our black rabbit Riley, whom I’d also named after finding he only had one ball.

DoffleMen & Boundry Layer Control: The AF had contracted MIT’s Diamond Ordnance Test Lab to study the possibilities to us “Fluidics” for making computers impervious to radiation interference. They came up with designs that could be etched in glass and interconnected. The working elements looked like little men, with head input, arm control ports and output legs. Fluid pressure entering the head could be cause to latch to flow down one leg vs the other by applying an on or off control to the arms. Corning Glass was contracted to make experimental models of this. We and LTV (Ling Tempco Vaught) our MM I servo actuator subcontractor contract looked into this for possible applications. The advent of smaller and smaller digital electronics soon cause such studies to be discontinued.

I had checked out a book on Boundary Layer Control by Schlicten, a German documenting their research during WW II. His book showed how upstream air flow effect boundary layer “dead air” on a surface. I had also read a book written by one of the Rocketdyne engineers which provided the equations on flow through a rocket engine nozzle. This provided the means of determining the amount of thrust achieved for various parameters.

A mix of what if ideas

While brainstorming for ideas I decided to draw a rocket engine nozzle inside out. This placed the throat of the nozzle on the outside and the “expansion nozzle” growing smaller at the tail. I wondered if we could apply the “dofflemen” effect and control the boundry layer flow down stream of the outside bump, which was the “nozzle throat”, causing external air to be laminar or turbulent, applying push pull attitude control on the desired side? We could create an attitude control torque couple with a bumps at front and back? I called it aerodynamic bump control. I visited with Bill Stobel about this & he said, even if it worked we could not use it, as missiles are soon out of the atmosphere. I said yeah but perhaps it could be used to guide a gravity bomb. Or we would cast the shape in the form of a trash barrel and use it to drop supplies to a desired place – lift it’s nose for landing?

I began some calculations on how much control one could achieve by modifying the boundary layer but hit a snag with Schlicten’s equations. He was placing decimal points midway and I was reading them as multiply. It took a while before I found their real meaning and by then my attentions had been drawn elsewhere. I made a number of sketches of these ideas with some crude equations – I was gone on an assignment for about a week and when I came back my sketches were gone?? I never went back to this domain as it would involve supersonic flow, more calculating power than my slide rule and much more brainpower than I could muster.