Ken Szalai, left, and Bill Burcham gave some advice to engineers on beginning a project, citing relationships with people at the center and outside it, knowledge of the topic and persistence as keys to success. (NASA Photo / Tom Tschida) If anyone knows what it takes to get a new research project going at Dryden, it's Al Bowers, Bill Burcham and Kenneth Szalai. A Code R all-hands meeting June 4 brought the three Dryden notables together to inspire engineers and give them an advantage in pursuing their ideas.
All three touched on the need to develop partnerships throughout the center, at NASA and beyond to gain support for ideas. Also of importance, they noted, is to keep up on the state of the art and know the political and national trends that might make it easier to present an idea.
Al Bowers, project manager of the Environmentally Responsible Aviation project at Dryden, explained how a small project was an education for him. The Eclipse project consisted of a C-141 towing an F-106. The flight research was intended to investigate elements of a concept developed by Kelly Space and Technology. It involved towing a reusable launch vehicle to an altitude, releasing it, and then firing a rocket on the spaceship during a second stage. Although a tow launch is common for a sailplane, researchers found no technical information on the dynamics of a tethered flight, Bowers explained.
From the beginning of the project, Bowers said, "nothing was easy." Bill Lokos told Bowers that structure of the F-106 would require study before anything could be added, such as hardware to which a rope could be attached. Further study confirmed that the F-106 forebody needed to be reinforced. That wasn't the last surprise. During Jim Murray's qualification testing of the rope it was determined that the rope was like a cannon shot when it was released. Anything in front of rope was at risk. The rope went through a steel wall after one test, Bowers said.
Other assumptions were disproven.
"We assumed the rope would be straight in flight. There were pretty considerable differences in what we saw in flight and simulation and we were missing large chunks of something. Later we found out it was the rope. We had to go back and model [what the rope was doing]. It's the things you don't anticipate that will catch you," Bowers added.
Bill Burcham, a current Tybrin Corp. employee at Dryden and a former Propulsion Branch chief, explained how an event could provide an environment for research. With perseverance, that research idea can be taken to flight.
Al Bowers offered insights from his experiences at Dryden. (NASA Photo / Tom Tschida) In July 1989 a United Airlines DC-10 suffered an explosive decompression of a center engine, and the debris from it severed the hydraulics and the flight controls were rendered useless. However, a pilot on board as a passenger had the idea to manipulate the throttles to use the engine's thrust for control to enable the aircraft to land in Sioux City, Iowa, saving 181 lives.
On a flight with Jim Stewart to St. Louis later that year, Burcham sketched on a napkin a closed-loop control system in which the digital flight computer could use engine thrust to control the aircraft, just as flight controls had been used to deflect aircraft surfaces to maneuver the United aircraft. Stewart was program manager for the F-15 Highly Integrated Digital Electronic Control project at Dryden.
Stewart encouraged Burcham, and offered to look into flying the concept on the F-15 HiDEC simulator. Research pilot Bill Dana flew the simulation first and called the idea the Propulsion-Controlled Aircraft, a name that has stuck. Tom McMurtry, then Dryden chief pilot, had other research pilots fly the concept and he decided to assign new research pilot Gordon Fullerton as well, "an innovative guy and an excellent engineer and pilot," Burcham said. Then-new engineer Jeanette Le put the propulsion-controlled aircraft on the Boeing 720 simulator as part of a probationary project, and it worked well.
Luck was with Burcham and his team, but relationships had to be developed outside of Dryden to help the concept take flight. At a flight safety meeting in Singapore, that began to happen, Burcham recalled. He presented a paper at that meeting and generated a lot of interest in his ideas. Next, NASA centers were briefed. Ames Research Center, Moffett Field, Calif., was interested in running the idea on their simulators, but had no funding to do so. Dryden came up with funding and Ames researchers were fired up. Soon the concept was ready to fly on the Ames simulators, and airline pilots, aerospace companies and others tried it out.
"Not everybody was enthusiastic. There were skeptics around. A program manager at headquarters(tm) said it was the stupidest idea he had ever heard of and told our director to stop wasting time, and the center director at the time - who shall remain nameless - 'forgot' to tell me that," Burcham said.
Boeing officials said their planes were safe enough, and Dryden rejected a propulsion-controlled aircraft patent because it was interesting, but lacked "practical value." However, "after a year we had the patent approved and it was finalist for invention of the year," Burcham said.
Meanwhile, Stewart had the HiDEC project extended, at no cost, for propulsion-controlled aircraft research, but the initial results were discouraging.
"It was terrible," Burcham said. "It became very difficult [to fly] and a full-time job keeping the aircraft wings level. It was way worse than the simulator. Then we decided to use a computer in the loop to stabilize the aircraft."
That led to an MD-11 experiment, in large part thanks to involving Ames and developing relationships with private industry, the National Transportation Safety Board, the Air Force and others who agreed that flights on the MD-11 to test a propulsion-control aircraft system on a commercial-type aircraft were necessary. The conclusion: "With a total loss of hydraulics, there are only a few areas of flight from which the pilot could not recover," Burcham said.
Former Dryden director Ken Szalai, who was the project manager of the F-8 Digital Fly-By-Wire project, said getting concepts to flight requires an engineer know his stuff and develop relationships at all levels while solving a customer's problem or meeting their goals. Windows of opportunity may be available, he said, especially if "you have a track record to prove you can carry out the work."
The F-8 DFBW project is a perfect example of how Szalai learned these lessons. Dryden's Cal Jarvis and Mel Burke made a pitch at NASA Headquarters for a new aircraft called the Unstable Control Configured Vehicle.
"It had no horizontal tail, it did have horizontal and vertical canards, and an analog control fly-by-wire. Rockwell had done a study on it and it was well beyond the state of the art," Szalai said.
Analog fly-by-wire was within reach and interest had been generated among those in private industry. However, Dryden was not fully aware of the state of the art in digital flight controls; it was Neil Armstrong who reminded Dryden representatives such controls had been used on the lunar lander. The Dryden proposal was rejected. But NASA officials were interested in the idea of pursuing digital fly-by-wire. So, the Dryden team started looking at the lunar module flight control system and digital computer.
"We went back and proposed F-8 DFBW control system with an Apollo lunar module digital fly-by-wire control system, and the rest is history," said Szalai. "The airplane flew within a year and a half after that, and had a single, full-authority, full-time flight control system with a single computer. Four years later, we flew the first fault-tolerant digital fly-by-wire control system and that airplane - along with the F-8 supercritical wing that sits in front of Dryden - changed the course of history in aircraft design."
In the current environment, Bowers said researchers must focus on the research and sell ideas as the best and most economical path to answers. And once an engineer is involved in a project, he said, "If something doesn't look right, say so. If it looks bad, say something."
Dryden Research and Engineering Director Brad Flick added, "Don't guess how much risk we are willing to take. If you know what you are talking about, we might do it. Don't be afraid to ask."
Established engineers can provide ways to think about engineering challenges.
"Old-timers can tell you how they would solve a problem, but you won't learn anything. They will ask you a bunch of questions and it's going to infuriate you. What we are tying to do is make you think about the problem, because ultimately it's not us who are going to make you figure it out. We are going to leave it to you," Bowers said.