Patrick Stoliker

Deputy Director 
NASA Dryden Flight Research Center

I left off begging a question in my last blog: despite 60 years of modernity that include six trips to the moon and back, the advent of the internet, and in the field of medicine things like magnetic resonance imaging and nano technology, not to mention Voyager leaving our solar system, we are still flying at virtually the same speed and altitude as did passengers on the first commercial jet service in 1952. Why? Has aeronautical technology peaked? Is aerospace a “mature technology” the same way that dirigibles are? Are there no more questions to ask in this field? Or are we on the cusp of the next golden era of aircraft development.

When the Germans asked General Anthony McAuliffe to surrender at the Battle of the Bulge in 1944, he reportedly said: “Nuts!” That’s my answer to the rhetorical question I posed.

First of all, there are plenty of aeronautical questions left to ask and answer, which is why, after more than 60 years, we’re still here at the same desert outpost those 13 people came to in 1946.

 Here’s some questions: can we make aircraft fly supersonically—over land—and suppress the shock wave that goes with it enough so that the noise is acceptable to the people on the ground? Can we do this and also improve the fuel efficiency of the same aircraft?

Here’s another question: can we actually reduce the cost of putting a pound of something—anything—into space? It’s run close to $10,000 per pound since I’ve been alive, and since I’ve been alive the quest has been to reduce that figure. There have been different plans, and Dryden has been involved in several of them, and we’re involved in another as I write this now. This is especially relevant since NASA’s mission has shifted from delivering goods to Low Earth Orbit (LEO) to exploring deep space; now the delivery job is going to private industry and our job—NASA’s job—is to nurture industry in this new venture. Finding ways to reduce the cost of access to space is serious business, not pie-in-the-sky stuff. These are questions that need answers.

Meanwhile, we at Dryden haven’t been sitting still these past 60 years, even if it might seem that way because we’re still traveling at the same speed as the folks who flew on Yoke Peter. While there are more of us in an airliner fuselage then ever, the range of the aircraft has increased dramatically and fuel consumption improved. That’s because the engines have become more efficient. They are also far quieter than before. If you don’t believe me, go find a Boeing 737-200 and get close to it when it takes off; when--and if--your hearing comes back we’ll go find a Boeing 737-800 and compare its takeoff noise level. On top of that, you can watch the -200 for a long, long time after it flies away because of its exhaust plume; the current crop of jet engines operate more efficiently and leave far less pollution in the atmosphere than did the previous generation. These are improvements most people tend not to notice—they’re qualitative not quantitative jumps—but NASA has had a hand in all this. Every time passengers get on an airliner that has winglets they should think two things: better fuel efficiency and NASA. (Think: Whitcomb and a KC-135 flown here at Dryden)

The seats passengers sit in, the way they are anchored to the floor, the fabric the seats are made of, the lighting on the floor that leads to an exit--these things and more are safety features that NASA Dryden has directly affected but which passengers are completely unaware of while they sip their sodas at 35,000 feet—they can’t even get snacks anymore—and don’t think about messing with your electronic device on the runway!! (Remember the Boeing 720 and the Controlled Impact Demonstration?) Life is better because of the continued questions we ask here.

There was a brief moment when it looked like we were all going to fly a bit faster as airline passengers. In 1972 engineers at Dryden began flying a Vought F-8 Crusader with a new wing on it. Designed by Richard Whitcomb of NASA Langley, the Supercritical Wing was expected to delay the onset of pre-Mach buffet and the dramatic jump in drag that accompanies an aircraft as it approaches Mach. Whitcomb’s radical new wing design did both, and the airlines were keen on getting planes with the new airfoil so they could fly faster. It would take a while for the manufacturers to get a plane to the market—it always does, but the airlines would be ready; and then the first gas peacetime gas crisis in American history hit (ca. 1974-). After that the airlines still wanted the supercritical wing—and they got them—but they never flew any faster then they ever did.

We continue to make incremental improvements in all classes of aircraft from micro-UAVS through general aviation, commercial, and high performance. But we still seem to be living in the shadow of the last golden age of aeronautics development.

So when you look around and say “we aren’t going any faster,” you could be saying “we are going the same as we did but doing it so much more cleanly, so much more quietly, so much more efficiently, so much more safely, at far less risk than ever before, and NASA and Dryden has had an enormous role in all of this, every step of the way!”

I’ll finish one more question, “What is going to trigger the next golden era of aeronautics?”

Patrick Stoliker

On May 2, 1952—virtually 60 years ago—36 people boarded BOAC’s De Havilland Comet DH 106, known as “Yoke Peter” to its crew for last letters of its registration G-ALYP, took their seats and readied for a long journey. These were the first paying passengers of the modern jet age, departing London for a 7,000-mile trip to Johannesburg, South Africa. Powered by four Ghost jet engines (also made by De Havilland) and with a cruise speed listed at about 500 mph, the passengers rode in pressurized comfort. About the only significant difference between that day and now was the legroom and the ratio of passengers to fight attendants. But if we pay too much attention to the similarities we’ll miss what is remarkable about the span of time involved. It’s been 60 years since the first passengers rode on a jet airliner and we’re still flying at the same speeds and the same altitudes.

There was a brief interval during which the wealthy could travel at Mach 2 on the Concorde (slightly faster if they wanted to fly the Soviet Tu-144), but neither airplane was ever a commercial success: both were just items of national prestige.

If it seems as though little has changed in the last 60 years—I said seems—consider how much changed between 1903 and 1952: call it the first 50 years of flight. It was on a wintry day in 1903 that two brothers from Dayton, Ohio, succeeded where no one else had, on the sand dunes of Kill Devil, North Carolina. Wilbur and Orville Wright were hardly the only ones trying to figure out flight at that time; there were quite a few in the US and in Europe, and most were further along than the two brothers. Even worse for the brothers, their competitors seemed to be better educated or better funded, as in the case of Samuel P. Langley of the Smithsonian Institution, or at least further along in the quest. 

The brothers made up for this with an intellect that the made their lack of a high school diplomas irrelevant. They learned the value of a wind tunnel by building their own, and they were smart enough to figure out that everyone before them had been wrong about the relationship of lift, wing area, and velocity, to say nothing of airfoils shapes. They had that rarest of talents, what Eugene Ferguson called “engineering in the mind’s eye,” the ability to move back and forth between the abstract and the concrete when trying to solve an engineering problem. They recognized propellers as rotating wings in the process. They understood wing warping and, more importantly, figured out the vertical stabilizer as the solution to adverse yaw, which they encountered on their glider, and they managed to do so largely because of how they mingled the abstract and the concrete. With Charlie Taylor, they put together a 180 pound, 12 horsepower engine with a good enough thrust to weight ratio to fly. It was an ungainly airplane, unstable in all axes, and I’m certain that only the hours of practice with the gliders gave them the skills needed to control the airplane. Then again, the same goes for riding a bicycle: it too, is unstable and takes time to learn how to ride, but you are then rewarded with a contraption that is nimble as can be, as opposed to a four-wheeled wagon. Progress came quickly. Although canard configurations have returned, the Wright’s pursued their original aircraft configuration until 1909, when they added an elevator and larger vertical tails. The 1910 Wright Model B had no canard and engines with 28-42 hp (with a production run of about 100 airplanes).

Their competitors settled into the more conventional wing/rudder/elevator configurations and everywhere advancements in capabilities and performance quickly followed (ditching wing warping in favor of ailerons was a way to control the airplane and try and avoid the Wright’s patent). Aircraft manufacturers proliferated across Europe and the United States. Although we think of this as the era of the biplanes (and triplanes), monoplanes like the Nieuport 2 were being built by 1910! The Loughead Brothers (later Lockheed) formed their first aircraft company in 1912 in Santa Barbara. The first aviation meet in America was held in Los Angeles (Dominguez Hills) January 1910 and airplanes were still so relatively new enough that dirigibles were a huge draw even then.

The speed with which aeronautical technology developed is astonishing and I consider this first decade one of the golden eras of aeronautics. We made big steps from the first ‘practicable’ airplane to modern aircraft. War had much to do with this, as it often does--in this case it was WWI. That war brought the first monococque fuselage, the interrupter gear, vastly improved flight instruments, the first UAV (the Kettering Aerial Torpedo, whose flight was made possible by Lawrence Sperry’s autopilot of 1914), the first all metal aircraft (Junkers J1, J2, and finally, the truly functional J4), just to name a few. The rapidity of the developments and their dramatic appearances likely makes us think war is the prime driver in such changes. But if we look at the bigger picture, this seems to be less the case.

After all, the Wrights achieved flight in a period of peace and were themselves not driven by any war, even if their first customer was the US Army Signal Corps. The first four-engine aircraft, Igor Sikorsky’s Ilya Mourometz appeared in 1914 in Russia, before The War. It was during the interwar years, the period between WWI and WWII, that NASA’s predecessor agency, the NACA (National Advisory Committee for Aeronautics) developed or assisted in developing some of the most fundamental changes to aeronautics, including retractable landing gear, the variable pitch propeller, deicing boots, engine cowlings, and the world famous NACA airfoils. It was in this same era that the first superchargers were developed to allow piston engines to gain higher altitudes (and speeds), and we saw the first genuine pressurized fuselages. It was in 1928—long before WWII began—that Englishman Frank Whittle conceived of the turbojet, and still before WWII that German Hans von Ohain succeeded in flying the world’s first turbojet, developed independently of Whittle. And while people first paid to travel by air before the War, it was in the interwar years that commercial aviation actually took off, so to speak.

WWII drove more aeronautical developments, of course, one of the subtler ones being the abandonment of seaplanes as the preferred way to carry passengers on long routes. The war resulted in plenty of new runways all over the world as well as an abundance of multi-engine aircraft with long range, making the big seaplanes a dying breed. It also helped that long-range navigation and radar approaches were improved and created, respectively, because of WWII. Piston engine/propeller aircraft had been having trouble with the transonic realm before WWII; figuring out supersonic flight was the next big challenge, and while folks in the Army Air Corps and the NACA expected it to be a big challenge, I don’t think they realized just how big the leap into the unknown would be. Getting to Mach 1 could be done with a turbojet engine, but if you were in a hurry to do it—and the AAF was—you were going to need a rocket plane. Jet engines of the era simply weren’t powerful or reliable enough to do the job-yet. This led to the Bell X-1, two X-1s actually, and the quest for supersonic flight. This was dawn of the golden age of flight research and X-planes, of almost infinite questions and purpose-designed aircraft like the X-3, the X-4, and the X-5.

Change came fast.

In 1961 TWA introduced in-flight movies on its Boeing 707s. By 1964 we had gone Mach 3 in a jet powered aircraft (A-12/SR-71), faster in rocket planes; we’d been to space and back in capsules and a space plane (the X-15), and supersonic flight was routine, at least for the military. In 1970 Boeing introduced first the “jumbo” airliner, the 747, and we’ve been packing in more and more passengers ever since. Yet we’re still flying at virtually the same speed and altitude as those 36 passengers on “Yoke Peter” in 1952. Have things really not changed? Are we in the doldrums, and if so, why?

By David McBride

Director, NASA Dryden Flight Research Center

Over the last several months, I have read many news stories and web accounts about rising and falling fuel prices and how some companies are rediscovering efficiencies by making trucks more aerodynamically efficient. These make me smile as it reminds me of the early aerodynamic truck studies conducted almost 40 years ago at NASA's Dryden Flight Research Center on Edwards Air Force Base. Fuel efficiency in long haul trucks was never much of an issue until the first peacetime gas crisis, in the early 1970s. In 1973 an aeronautical engineer at NASA Dryden began musing over ways to cut the aerodynamic drag of over-the-road trucks. He led a small team of researchers whose results had an extraordinary, if little recognized, impact.

The center’s first experiment involved a passenger van modified into a driving laboratory. We attached an aluminum rectangular box to the vehicle—hence the nickname Shoebox—and over successive experiments, changed elements of the box. We rounded the vertical and horizontal corners, sealed the entire underbody including the wheel wells, and even added a "boat tail" to the rear of the vehicle, finding out what benefits each had on the overall aerodynamic drag. Road tests of the Shoebox, with rounded vertical and horizontal corners front and back, lowered the vehicle's aerodynamic drag by 54 percent. Sealing the van’s underbody and wheel wells reduced drag another 15 percent. Road test showed a mileage increase of between 15 and 25%. Mileage may vary, of course, depending on conditions and styles, which is why Dryden's engineers were fond of testing outside of wind tunnels.

Image at right: 1970s van fitted with square corners, top image, and round corners bottom. Tufts of yarn attached to the sides of the van indicate air flow around the vehicle.

Our second experiment was conducted on a cab-over-engine tractor-trailer, again modified by rounding all of its front corners and edges. In addition, technicians attached sheet metal fairings over the cab's roof and sides, reaching as far back as the trailer; this completely closed the open space between the cab and trailer. While still looking like a tractor-trailer, it was a radical departure from anything on the road in the 1970s. Researchers found that in highway driving at 55 miles per hour, these changes resulted in 20 to 24 percent lower fuel consumption over an identical but unmodified tractor-trailer they tested against it.

At the time of NASA Dryden’s research, which extended off-and-on until 1982, the majority of long-haul tractors were cab-overs. This was because the Federal Aid Highway Act of 1956 – formally known as the National System of Interstate and Defense Highways Act – placed a limit on the length on the total vehicle.

Image to the left: As depicted by this 1975 image, sheet metal is attached to a heavy haul truck rounding the front corners of the truck and adding a fairing between the cab and the trailer of the truck.

The Surface Transportation Assistance Act (1982), which came primarily in response to the impact of the gas crisis on the trucking industry, required states to permit trucks with trailers as long as 48 feet on both interstate and intrastate highways, and effectively ignored the tractor altogether. This small detail of the bill was responsible for the shift from cab-overs to conventional engine-in-front tractors, a much more fuel-efficient design because of its shape.

In 1985 Kenworth introduced the T600, the first tractor manufactured with factory-built fairings that reflected the empirical research done at NASA Dryden. It is encouraging to see the continuing improvements to the shapes of both tractors and trailers today, all of which reflect research conducted at Dryden at the time or performed at three universities under Dryden’s guidance.

Hence, when you see fairings that narrow the gap between tractor and trailer, side skirts on the trailer, or boat tails on the back of trailers, you’re looking at the results, in part, of NASA and NASA-sponsored empirical research whose benefits have a tangible impact on our daily lives. It is especially gratifying when I think of the very real increases in fuel efficiency these trucks have realized, and the benefits we all derive as a result

By Patrick C. Stoliker

Deputy Director of NASA's Dryden Flight Research Center

It’s springtime again at Dryden. You can tell by the wild fluctuations in weather: cold and dreary, gale force winds, or sunny and balmy -  sometimes all in one day! The wild flowers start blooming, sometimes spectacularly; but this year not so much. I was at the Antelope Valley California Poppy Reserve, west of Lancaster, two weeks ago and the poppies were few and far between. 

Another principal indicator of springtime is the leap into the Planning, Programming, Budgeting and Execution (PPBE) cycle for the Agency's budget. For those not familiar with the process, let me explain.

We start off with PPBE guidance trickling out of Washington (stamped Draft, of course). This is followed by Strategic Program Guidance (SPG) – Draft 2. These documents provide the ground rules for each of the Centers and the Agency Mission Directorates to input their budget information into various databases. The budget information includes workforce numbers, procurement expenses and travel. It provides a top-level description of the Agency's activities for the next five years. Why is this important? Because it helps set the strategic direction and constraints in which we must complete our research priorities.

This is followed by the Program and Resource Guidance (PRG) from each Mission Directorate. The PRG is a more detailed description of the work the Mission Directorates plan to accomplish. We spend the rest of early spring revising inputs based on project plans, getting revised instructions, and revising timelines.

In reality this is a critical effort. What are the staffing and resource requirements for the Center to successfully operate the SOFIA aircraft for 1,000 hours of science flights? What are the implementation plans for the Aeronautics Research Directorate and how do we utilize our workforce to accomplish them? What is the schedule and what are the appropriate resources to support launch abort system testing for MPCV? Working with all the organizations at the Center, we will develop our best answers to these questions, and effectively use the resources to execute these missions.

All the while we are using a very blurry crystal ball to extend this guidance five years into the future. So these are the things keeping us busy: building spreadsheets, attending Budget Control Boards, and chasing shifting time lines every spring.

For me, one of the best parts of spring is driving onto the Center at sunrise after the time change and Hangar 4802 is lit up and lined with airplanes. That sight never disappoints me.

Two days ago it started bright and sunny, a week ago I shoveled a foot of snow off my driveway, and another storm is coming in this weekend. I’m certain it is going to snow, my apple trees all started blooming this week…it’s springtime at Dryden again.