Special Ops: Four Accounts of the Military's Elite Forces

by Orr Kelly

  George Rapp, who has since retired but was involved in the development of the F-404 from the time it was just a paper engine until it powered the navy’s new strike-fighter, knew from the beginning that GE’s new engine would have to be designed to avoid the stalls and failures common to other jet engines. One of the reasons GE lost to Pratt & Whitney in the competition for the engine for the F-15, he believes, is that they were unable to convince the air force they had done as good a job as they had in designing a fool-proof engine. As it turned out, the Pratt & Whitney engine chosen by the air force was plagued for years by the problem of compressor stalls.

  Even before the navy made operability its number one priority, GE had put a small team of some of its best engineers to work on that very problem. Other designers had focused their efforts on the inlet through which air comes into the engine, hoping to avoid turbulence that way. The GE engineers did their best on the inlet design, but they concentrated most of their attention on the design of the fan, the first moving part the air encounters as it enters the engine. They succeeded in designing a fan that, in a fraction of a second, smooths out the air before it goes into the compressor.

  “The fan takes junk in and attenuates it before it goes into the high-pressure compressor,” Rapp says. This made the F-404 the first fighter plane engine in which there are no restrictions on how the pilot flies the plane or moves his throttle. “Under the worst conditions, if the pilot makes the worst possible throttle movements, the engine will not stall.”

  Well before the navy came along with its new priorities in engine design, General Electric had begun to concentrate, on its own, on two of the things that turned out to be among the most important to the navy: reliability and maintainability, plus cost.

  “GE was the first company to really adopt internally the commitment to do the right kind of job in the design,” Lenox says. “Northrop was next, then McDonnell Douglas. Hughes finally came around under pressure from the navy and McDonnell.”

  In his evangelizing tours of the plants that built planes and their components for the navy, Will Willoughby was at first met by stiff opposition. To build in reliability, they argued, would cost far too much. But he won over many in the industry by convincing them that a well-designed airplane, engine, or radar would mean greater efficiency—and thus greater profits—for the companies involved.

  General Electric was, on its own, one of the first to recognize the value of worrying, early in the design phase, about the cost of building and maintaining an engine. Although this seems a commonsense approach, it runs contrary to the natural inclinations of most engineers. One McDonnell Douglas manager summed up the problem this way: “From years of training, all engineers possess inordinate amounts of ‘technical greed,’ the desire to do a perfect job, to wring the last bit of performance out of a design whether or not it is required or cost effective.” Officials at General Electric also noted that engineers like to start from scratch and create their own new design when, from a business sense, it is much better to adapt a design already in production to new uses.

  Frederick A. Larson, who was put in charge of the cost-cutting effort in the early 1970s, had to counter both these natural tendencies of engineers. Larson and his boss, Paul Setts, the general manager for combat aircraft, set two goals: The new engine would be much smaller than the engines then being made for the F-4 Phantom, but provide at least as much thrust. And two engines would cost about the same as the air force was spending for one engine for the F-16.

  Once the general structure of the engine had been determined, the drawings were turned over to the company’s design organizations. One group of engineers worked on the turbine, another on the compressor, a third on the overall structure of the engine, a fourth on lubrication systems, and so on for each part of the engine. Their drawings were then turned over to manufacturing engineers who thought through the problems of producing each component.

  A value engineer or an advanced manufacturing engineer would determine, for example, how long it would take to drill each hole and calculate the cost. This forced the designers to consider whether they could reduce the number of bolts in a major component such as the compressor if the bolts were made slightly larger.

  In some cases, the designers even let the weight creep upward—something they instinctively fight against—because they could save money by eliminating some of the expensive machining required to cut away excess metal.

  Through this whole process, the designers faced the challenge to reduce the cost of each component of the engine by fifteen percent. If they fell short, they had to give their reasons in writing, including a list of the alternatives they had considered.

  One result of this meticulous attention to detail in the early design of the engine can be seen by comparing it to the J-79 engine, which was developed by GE in the 1950s to power the F-4 Phantom. The J-79, a highly successful engine, was the yardstick against which GE measured its design for the F-404. The new engine is a little over thirteen feet long, slightly less than three feet in diameter, weighs 2,180 pounds, and produces 16,000 pounds of thrust. The older engine produces about the same power, but it is four feet longer and five inches wider in diameter, weighs 1,165 pounds more, and has half again as many parts.

  When the engine moved from development into production, GE had none of the kinds of problems that Hughes faced when it began to produce its new radar. The design-to-cost effort had forced the GE engineers to think ahead to the question of how to produce the engine most efficiently.

  The early emphasis on holding down costs also had a spin-off in greater ease of maintenance when the engine reached the fleet. In the past, many of the bolts in an aircraft engine were wired in place to prevent them from vibrating loose and causing damage inside the engine. Wiring all the bolts ran up the cost of production, and it was a constant nuisance and frustration for maintenance mechanics. Every time they repaired an engine, they had to remove the wires and then, when they were finished, put new wires back in place. Bloody fingers were a normal hazard of the trade. In the F-404 engine, the wires have been eliminated from all of the bolts mechanics normally have to remove. Each bolt is locked in place and held there—even if it should happen to vibrate loose—by a little pin.

  The maintenance men were also kept in mind in other aspects of the engine’s design. The directions for maintenance of engines in some earlier planes read like a bad joke. The first step involved in replacing the engine in an A-4 Skyhawk, for example, is to remove the plane’s tail. The engine in the F/A-18 is attached at only three points. One engine can be lowered through a hatch on the bottom of the fuselage and another inserted in a matter of minutes. The navy set two goals: it wanted to be able to change the engine “within the shadow of the airplane,” and it wanted to change an engine in twenty-one minutes. Mechanics have been able to do it in less than seventeen minutes.

  In previous engines, many of the controls were built into the plane. This meant that mechanics had to spend hours tuning a new engine. On the F-404 engine, the controls come with the engine, so no tuning is required. Once the engine is installed and checked for leaks, it is ready to fly.

  Unlike earlier jet engines, the F-404 is not routinely taken out of service for an overhaul after a certain number of hours in use. The designers decided this was wasteful because the wear on an engine can vary dramatically depending on how it is used. The engines in a plane used routinely for aerial combat take much more of a beating than those in a plane that spends much of its time in straight and level cross-country flight. For example, at Lemoore Naval Air Station in California’s Central Valley, pilots fly across the Sierra Nevada mountains to ranges in Nevada or Arizona for most of their training. But pilots at Fallon, Nevada, or Canadian fliers at Cold Lake reach their bombing and air combat ranges soon after takeoff. Instead of being packed off for a scheduled overhaul, each F-404 engine is individually monitored and pulled out for maintenance only when work is needed.

  The life of the engine is
monitored in two ways. Each engine has thirteen borescope ports through which mechanics can peek inside to see if there is any sign of damage. It also has an automatic system that constantly monitors the condition of the engine. If something serious happens, a voice in the pilot’s earphones intones: “Engine left” or “Engine right.” He immediately cuts power to that engine. Earlier warning systems told the pilot when something was wrong with an engine—but left him to figure out which engine was acting up.

  Information about performance of the engine—and many other parts of the plane—is also recorded automatically on a device in the nose wheel bay. A quick look tells the mechanic where to search for signs of trouble. The system also keeps a record of the performance of the engine over its lifetime.

  The engine monitoring system uses thirteen sensors that check temperatures, air velocity, and vibration and speed of the moving parts. All but one of the sensors is needed to help control the engine, so the system adds little to the weight or cost of the plane. The measurements from inside the engine are flashed to the mission computer ten times each second and compared with numbers for normal performance in the computer’s memory.

  The system has one feature that seems almost magical. Whenever anything goes wrong, a record is preserved showing the engine’s performance, beginning five seconds before the malfunction and continuing thirty-five seconds afterward. This makes it possible to turn the clock back and, in effect, watch the problem occur. This feat of legerdemain is accomplished by having the computer constantly erase data from the sensors—but waiting forty seconds before beginning to erase. If anything goes wrong, the tape is not erased, so it preserves the record of the engine’s operations just before and after the malfunction.

  The value of the engine monitoring system was demonstrated early in the flight tests of the F/A-18 when an engine destroyed itself in flight. Normally, it might take months or even years of tests to try to duplicate such a failure, determine what had gone wrong, and find a way to fix it. In this case, the system quickly pinpointed a tiny sensor about the size of a person’s index finger as the source of the trouble. The sensor, consisting of a platinum wire in a metal case, is attached at the front of the engine. As the temperature of the air coming into the engine changes, the electrical resistance of the platinum wire changes. This tells the engine the temperature of the air, so it can adjust the speed of the fan and the angle of the vanes that both guide the air into the engine and control the tail pipe temperature. All of this is critical to the proper running of the engine.

  Tests showed that the platinum wire had come in contact with the metal casing and shorted out. This sent a signal to the engine that it was receiving air that was very, very cold. As the engine adjusted to this false information, it ran out of control, came apart and destroyed itself. With the clues provided by the monitoring system, it was possible to understand the problem, work out a modification of the faulty device, and install new sensors in the fleet, all within six months.

  The investigation of the engine failure was aided immeasurably, of course, by the fact that the other engine continued to operate, and the pilot was therefore able to bring the plane back to be examined. In a plane with only one engine, such a failure would have forced the investigators to begin their work with a pile of scrap metal.

  In the course of their investigation, the engineers found that a similar failure had occurred once before. In that case, the pilot recalled hearing a “pop,” but the engine continued to operate and he completed his mission. Later, when mechanics looked inside the engine with a borescope, they found that a turbine blade had broken loose and careened through the rear of the engine without causing further harm.

  This was one of the early bits of evidence demonstrating that the F-404 is often capable of shrugging off damage that would destroy another engine. Mechanics report a number of occasions when engines continued to operate even after suffering major damage.

  Master Chief Don Leap, a mechanic with VFA-125, the training squadron at Lemoore, speaks with awe of the damaged engines he has seen: “They’ll eat damn near anything and keep running. On one plane, the motor ate a forty-pound piece of copper and kept running with a hole in the side. One ate a landing gear pin. You find a pilot flying with a motor that’s all torn up, and not know about it.”

  In these cases, the monitoring system may not even alert the pilot because the temperatures, rotation speeds, and vibrations it checks ten times every second all remain within normal limits, despite severe damage. The ability of the engine to keep operating, despite these peacetime accidents, is an encouraging sign that the plane would be able to withstand severe battle damage and continue to fly.

  Throughout the development of the F/A-18 and its F-404 engine, both McDonnell Douglas and General Electric often found themselves in an awkward political position.

  McDonnell Douglas had a vital business interest in sales of the F/A-18, not only to the U.S. Navy, but to other countries as well. But it also had a very special relationship with the U.S. Air Force. It produced the F-15 Eagle for the air force, and it was important to maintain cordial relations with this major customer. On the other hand, McDonnell Douglas, as manufacturer of the F/A-18, produced the chief rival to the air force F-16 fighter in international sales. While the companies involved with the F/A-18 pooled their resources and met for strategy sessions to coordinate their lobbying on Capitol Hill, Lenox and other navy officers noted that McDonnell Douglas was more reticent than the others—especially if there was a danger of stepping on air force toes.

  McDonnell Douglas also had a complex relationship with the nation’s two major jet engine makers. It dealt with Pratt & Whitney for engines for its F-15 and with GE for F/A-18 engines. The aircraft manufacturer had to be careful not to openly favor either of the two engine makers. But there is no question that the McDonnell Douglas engineers and managers were at that time much more comfortable in their dealings with GE than they were with Pratt & Whitney. As one McDonnell Douglas official put it:

  “Pratt & Whitney was ‘king of the hill.’ It was not responsive to problems. The Pratt & Whitney practice was to confuse the situation until the problem was so severe that the government put a lot of money into solving it. GE was second to Pratt & Whitney, and their management knew they had to be better to be number one. They worked the engineering on the F-404 very hard. They worked their problems, and they solved their problems. When you worked with the GE guys, you planned on working late. When you worked with the PW guys, when it came time to go home, they went home.”

  The problem, it seemed to the people at McDonnell Douglas, was that Pratt & Whitney, in those days, was part of a conglomerate run by lawyers and accountants, while GE was run by its engineers.

  Pratt & Whitney suffered two stunning reversals. In one case, Japan Airlines, a longtime customer, dropped Pratt and Whitney and switched to GE engines. In the other instance, the air force awarded GE a contract to provide a new engine, based on the design of the engine in the F/A-18, for use in its F-16 and F-15 fighters. It was not until these incidents that Pratt & Whitney brought a new emphasis on quality production and service to its customers. “Pratt & Whitney has come a long way since then,” a McDonnell Douglas official says.

  For General Electric, the fact that its engines were used in a variety of planes, some of which were direct rivals, caused some awkward moments.

  “We consciously and religiously do not favor one aircraft company over another,” says Burton A. Riemer, who was general manager for the engine chosen to power the F/A-18. “Our job is to sell engines. If we’re not in an airplane, we don’t sell engines.”

  The company’s policy of not favoring one company over another was put to the test in the late 1970s when Grumman officials, who were continuing to lead the opposition to the F/A-18, came up with a novel idea. They quietly enlisted GE’s cooperation in designing a new model of the A-7 attack plane made by LTV—the big loser in the earlier competition for the new navy strike-fighter. Inste
ad of a single engine, the new A-7 would be powered by two of the new engines GE designed for the F/A-18.

  The beauty of this plan was that it would allow for the death of the F/A-18 but still provide for continued production of the new jet engines at Lynn. And this, Grumman hoped, would deprive the F/A-18 of two of its most powerful backers on Capitol Hill: House Speaker Thomas (“Tip”) O’Neill, Jr., whose district was next door to that in which the Lynn plant is located, and Senator Edward Kennedy, the Massachusetts Democrat. The assumption was that the two legislators cared more about engines—and jobs—than they did about the F/A-18.

  A top Grumman official hand-carried the proposal to the Pentagon to the office of Russell Murray II, a key aide to Defense Secretary Harold Brown. Murray, who began as a strong critic of the F/A-18 program but later became one of its most influential supporters, says: “It was a most wonderfully ingenious proposal. It was pure political engineering. I’ve never seen one as ingenious as that.”

  The twin-engined A-7 didn’t fly, either politically or in the air. But LTV and, even more, Grumman, continued nipping at the F/A-18 at every opportunity. At one point, Grumman hired a public relations firm to visit news offices to spread bad news about the F/A-18. Both Lenox and his boss, Forrest Petersen, felt compelled on several occasions to call officials of the two companies and tell them to lay off.

  Petersen considered the opposition to the plane unjustified and wrong. He told company officials in scathing language that it was not their responsibility to their stockholders to criticize a major navy program that was approved and underway; they should not try to sell their product by killing someone else’s product. The open sniping stopped, but Petersen was never convinced the behind-the-scenes attack had ended.