In his fascinating interview with Hush-Kit in May 2012, supercar designer Peter Stevens theorised on the often close relationship between aircraft and automobile design: “In aircraft terms all cars can be described as being reliant on ‘low speed aerodynamics’, but the actual shapes are often taken from very high speed aircraft”.
One of the most blatant examples of this idea at work was American car designer Harley Earl’s astonishing Firebird series of concept cars for General Motors (GM) during the 1950s. Powered by gas-turbine engines developed by Emmett Conklin and bristling with fins, bubble canopies and other aeronautically-inspired refinements, the Firebirds represented the high-point of America’s obsession with the jet age.
Earl was no stranger to using aircraft as inspiration — his Le Sabre concept car of 1951 was, as the name suggests, directly influenced by North American’s F-86 Sabre jet fighter, then fighting it out with Soviet MiGs over Korea. He had also long admired the unorthodox twin-boom layout of Lockheed’s World War Two-vintage P-38 Lightning, reflected in the designer’s fishtail fenders for later GM products. Earl was fascinated by the impression of speed that aircraft imparted, fighter aircraft in particular adhering to his concept of cars looking long and low, alert, ready to pounce.
Having introduced sharply-swept fins and wraparound windshields, both a prevalent part of contemporary fighter design, on the Le Sabre, Earl felt compelled to push further into the realms of the fantastic, often making almost impossible demands on his long-suffering technical team in the interests of pushing the envelope of American automobile design.
Reportedly, Earl was aboard an airliner during one of his frequent trips across the USA in the early 1950s when he read a short article in an in-flight magazine on the futuristic Douglas A4D Skyray, which made its first flight in January 1951. Earl was fascinated by the new Navy fighter and stared at the photographs in the article for more than an hour. Remarking that it was “a striking ship”, he tore the page from the magazine and put it in his inside pocket before settling into deep thought. When his travelling companion asked whether he was thinking of next year’s model and what it might be, Earl paused for a moment before slapping his breast pocket and saying “I have it right here”. Earl later recalled: “I was only answering the banter in kind. Then bingo, I decided I had kidded myself into something”.
Design and construction of the first Firebird began in 1953, the idea being to create a complete rolling laboratory in which state-of-the-art technology could be tested in real road conditions. It was also a clear opportunity for GM to showcase the extremes in technology and design that it was capable of. Given the company designation XP-21, the single-seat Firebird I was the first American car to be powered by a gas turbine engine, in the form of the 370 h.p. Whirlfire GT-302. Arguably the single most impractical car ever devised, the Firebird I comprised a bullet-shaped fibreglass fuselage with a single fin and short rounded delta “wings” (as on the Skyray), the driver being accommodated in a fighter-style cockpit with a bubble canopy. Flaps were also incorporated for braking purposes — another lift from aeronautical design. The car was driven by Conklin and racing driver Mauri Rose and found to be largely satisfactory, despite issues with noise, exhaust overheating and, unsurprisingly, extremely high fuel consumption.
Earl’s second Firebird, designated XP-43, was intended to parlay the lessons learned with the Firebird I into a more practical four-seat family car. With its distinctive double air intakes at the front, high bubble canopy and fin, the Firebird II was intended to be a component of GM’s “Safety Autoway of Tomorrow”, a rapid transit system which would take advantage of an “electronic brain” in the car, which received signals from a metallic conductor buried in the road, the magnetic device creating a form of autopilot for cars. The boffins at GM worked hard to get the system working and eventually conducted successful tests of what the company dubbed the “dream highway”. The Firebird II was the first car to have its entire exterior bodywork constructed from titanium, then being used in the construction of the USA’s state-of-the-art fighters such as the McDonnell F-101 Voodoo and Lockheed’s F-104 Starfighter — another of Earl’s appropriations of contemporary aeronautical techniques.
If the Firebird II reflected fighter aircraft design in the mid-1950s, the last — and most extravagant — of the Firebirds anticipated the cutting edge of the next generation of American warplanes, typified by Republic’s super-sleek F-105 Thunderchief, which entered US Air Force service in mid-1958. While GM’s engineers were perfecting the “electronic chauffeur”, Earl and his team were going for broke with a design that incorporated no fewer than seven wings and fins protruding from a science-fictionesque wedge-shaped main body.
Promotional material of the time dispensed with any pretence of subtlety and announced that the new Firebird would be “an entirely different kind of car, in which a person may drive to the launching site of a rocket to the moon”, the aeronautical terminology being supercharged to include the rapidly escalating space race. The new car, which incorporated double bubble canopies, cruise control and air-conditioning, was to be fitted with an extension of the Firebird II’s “ping-pong ball” control system, known as Unicontrol, in which steering, acceleration and braking would be performed by means of a single control stick, again echoing fighter cockpit design.
The initial tests of all three Firebirds were referred to as “first flights”, that of the Firebird III taking place at GM’s Desert Proving Ground in Phoenix, Arizona, in August 1958, the machine subsequently undergoing extensive trials in a windtunnel, as used for testing aircraft.
Publicly unveiled at GM’s 1959 Motorama show in New York City and Boston (actually held in October 1958), the Firebird III was a hit; the two-seat rocket-ship of the road fired the imaginations of the young and old alike. As on the Firebird II, Earl had sought to exploit aerodynamic braking in the form of air brakes, which emerged from flat panels in the Firebird III’s main body. The 225 h.p. Whirlfire GT-305 engine provided propulsion power only, a separate 10 h.p. two-cylinder powerplant being installed to drive the electrical and hydraulic accessories.
The Firebird III was not just a hit at the car shows; in April 1959 it was exhibited at the World Congress of Flight in Las Vegas, its space-age looks fitting right in with the highly advanced military hardware on view at nearby Nellis AFB.
The Firebirds were never seriously intended to be put into production, however earnest the brochures of the time were in suggesting otherwise, and although a Firebird IV ground-effect machine was built in mock-up form, GM decided that the III was the end of the line for the ambitious space-age Firebirds. The name, however, lived on in a series of Pontiac “ponycars” from 1967.
All three Firebirds still survive and have been acquired by GM, which aims to restore them to roadworthy status and possibly tour them at some stage. Happily, car designers are still very much taking cues from aeronautical developments, as Peter Stevens explained in his Hush-Kit interview: “I do think that designers are looking at things like the F-117 stealth fighter for inspiration; the Lamborghini Aventador is a good example of this trend”. Long may it continue.
By Nick Stroud, Editor of The Aviation Historian
The interview of Peter Stevens by Joe Coles can be found here:
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Peter Stevens designed the beautiful curves of the Mclaren F1, which has been described as the finest car in history. The F1 was the fastest production car for an incredible twelve years (1993-2005) and clocked an insane 231 mph in 1993 (seventy years earlier, the Nieuport-Delage aircraft had surpassed the 230 mph barrier in the air). As visiting professor of car design for the Royal College of Art and a lover of aviation, Hush-kit decided to grill Stevens on planes, beauty… and flying-cars!
From where does your love of aviation stem?
Principally from my Godfather who was a Wing Commander in a Lancaster squadron, I built him an Airfix model of one when I was about 12 years old, and as a scientist he then built a scale wind tunnel at Birkbeck College so that he could demonstrate the principals of flight to me. He lived just at the back of Duxford air field and we would often sneak in there.
What was your most notable flying experience?
When I first discovered what ‘wake turbulence’ meant! Not long after qualifying for my PPL I was taking off from Leavesden air strip near Watford and was instructed by the tower to depart right after an HS 125, at about 250 feet the little Grumman Tiger that I was flying, just about fell out of the sky. I will be forever grateful to my instructor Keith who had drilled in to me ‘lower the nose, level the wings and then regain control’, it worked, hence these replies to your questions. Or maybe the idiot who flew in on finals at Elstree beneath me and never even saw me. He was excellently roasted by the tower after I had gone round again!
What is your favourite aircraft and why?
No question, the SR-71 Blackbird! When you consider that the project was underway back in 1955 and that part of the brief was to make an aircraft that would be almost impossible to describe in conventional terms at that time, in order to protect the secret nature of the project, it put all forward thinking into perspective. For any designer this is a crucial thing, the ability to think beyond contemporary norms is very difficult but it is what you have to do if you want to make progress.
What do you consider the most beautiful aircraft (if different from above)?
It sounds so easy to say the Spitfire but for me it’s true. Most summer weekends a couple of Spitfires fly low over our house, either on their way to or from air displays. They come from a strip just a bit North of where we live in Suffolk. And the reason they still look (and sound!) so beautiful is part of a personal theory that I have. The Hurricane is a fabulous aircraft but I suspect that the draughtsmen who would have drawn the full-size lines of the ‘plane would have been local to Hatfield and would most probably have had amongst their drawing kit ‘railway curves’. These are very large radius curves used during the laying out of railway tracks. If you then connect these very big radius lines, often almost straight lines, with regular corner radii you get a Hurricane. The Spitfire, on the other hand was drawn up in Southampton where the draughtsmen would have come from the boat building industry, and they would have amongst their drawing kit ‘ships curves’, these are transitional curves that slowly tighten or flatten over their lengths. Hence the more sensuous lines of the Spitfire. Despite the arrival of CAD I still use ships curves for the most important lines on a car. These curves are sometimes call ‘French curves’ and are some of my most valued studio possessions.
The architect Norman Foster has a model of the Northrop YB-49 flying wing in his studio, do you have a model aircraft in yours?
Two little models, a Gee Bee (such outrageous proportions), a DC-3 (first plane I flew in with my Godfather), and a BIG model of a Bleriot Monoplane (those first days of flight were just so romantic).
What effect has aviation had on car design, if any? For instance has the faceted, angular stealth shape of modern aircraft influenced any designs?
In aircraft term all cars can be described as being reliant on ‘low speed aerodynamics’ but the actual shapes are often taken from very high speed aircraft. This could be considered dishonest but designers are so often looking for the ‘next new thing’. When designing a fast road-car the whole aero thing is so different from that to be considered when designing a race car. On a road car you do not want lift but you also do not want much downforce at all, otherwise the springs will need to be so stiff to avoid scraping the ground at high speeds that the thing will ride like a truck at low speeds. I do think that designers are looking at things like the F-117 stealth fighter for inspiration, the Lamborghini Aventador is a good example of this trend.
What was the most beautiful era for aircraft design?
It’s easy to get carried away with the romantic notions of early aircraft and see Golden Eras in the past, or to use the daft old adage used in race car design that ‘if it works well and wins it’s automatically beautiful’, but that is just not true. There are aircraft from all eras that are beautiful and many that are not.
Do you have any thoughts about the crossover (if any) between the purely aesthetic design fields and that of applied design (like in aviation).
I suppose that in the past designer were more inclined to be just surface decorators, this was particularly true in the Victorian age. But as popular ideas of design focused on simpler forms the designer took charge of both the form and the surface decoration. Whether this time line followed or preceded that of painters and sculptors, I am not sure (subject by a PhD I think). What I have observed is that some pure engineers have a very real sensitivity towards the difference between a ‘good line’ and a ‘poor line’, Both Patrick Head and John Barnard, ex Formula One designers, were very aware of the importance of a ‘good line’ to them. This comes back to the Spitfire and Hurricane debate.
A related point – cars and aircraft that are designed apparently for purely aerodynamic concerns are often very beautiful, indeed often the most beautiful examples of their kind. Why should this be?
I think that a sensitivity for what airflow wants to do is an unusual trait, these days CFD (Computational fluid dynamics) can produce technically correct solutions that lack any degree of harmony in the resultant forms. You can push the airflow around but you cannot force it to do what it does not want to do, I see the air as being lazy and wanting to take the least stressful path and it is the same for your hand when passing over a form. Natural transitions as seen in nature almost always have something to tell us about the best aerodynamic shapes. A good example in car design is the Jaguar XJ 13 of 1966/67; Designer Malcolm Sayer was an aerodynamicist at Jaguar but also a superb designer and the car exudes style.
What will be the next technology to move from aviation to motoring or vice versa, for example have F1 drivers used helmet mounted displays or have any advanced materials recently passed into cars from the aerospace world?
I think that more specialised carbon composites, particularly penetration resistant ones could find their way into race cars. The head-up display thing (the HUD) or the much more complex Apache helmet mounted system is now not needed in F1 cars because (unfortunately) there is an army of guys monitoring all the systems in the car and making strategy calls from the back of the pit garage, or even in some cases monitoring stuff back at the factory.
What will aeroplanes look like in 100 or even 1000 years time?
In 100 years I suspect that military aircraft will be pilotless but I think that private flying will remain popular but the machines will be so much more efficient and ‘drama’ proof. The huge amount of progress made in automated systems for cars, like stability control etc will find their way into aircraft in the near future. In a 1000 years we will without doubt travel virtually or maybe in person, very rarely, using our rare and expensive carbon/energy credits that we will have to earn by our ultra low energy personal lifestyles. How grim is that!
Will flying cars ever become popular?
As popular as amphibious cars. Who would want a crap car that is also a very poor aircraft? Just like who wants a miserable car that is also a thoroughly poor boat?
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