Alexander Lippisch's Aerodyne

Though renowned German aircraft designer Alexander Lippisch is better known for his delta wing designs and the tailless Messerschmitt Me 163 Komet rocket interceptor, one of his more innovative and unusual designs lacked wings altogether. At the end of the Second World War, Lippisch was one of many German engineers brought the United States under Operation Paperclip (rocket scientist Werner von Braun perhaps being one of the more famous engineers of Operation Paperclip). After spending several years consulting with Convair on his delta wing work that would result in the XF-92, the F-102 Delta Dagger, F-106 Delta Dart and B-58 Hustler, he joined American Collins Radio in 1950 to head its small aeronautical division in Iowa.

It was at Collins he was free to explore other aeronautical concepts and quite possibly his most unusual design was for the wingless Aerodyne. At the time in the early 1950s there was a profusion of VTOL designs, some even reaching the flight hardware state. Lippisch's Aerodyne consisted of an engine within a ducted shroud that exhausted through a pair of vectored cascades that provided both the propulsive lift when in VTOL mode and then shifted via a series of vanes to provide forward thrust while retaining enough of a downward thrust component to stay airborne without the use of wings. A conventional tail unit provided directional control while in forward flight.

As the engine thrust was used for both forward flight and for hovering flight, for an aircraft with similar thrust to weight ratios, the Collins Aerodyne would be faster and more efficient. And compared to the existing VTOL aircraft of the early 1950s that were tail sitters, the Aerodyne remained in a horizontal attitude and would have been much easier to land that the tail sitting designs of the day. Lippisch even claimed with the right amount of thrust, a modified Aerodyne might even be capable of supersonic flight.

Several subscale test models were flown before the full-scale Aerodyne was constructed. While it had provision for a cockpit, it would be flown unmanned to prove the concept full-scale. Co-axial propellers in the ducted shroud provided the thrust for the Aerodyne. In 1959 he received US patent No. 2,918,230 for the Aerodyne. While no documentation exists that the Aerodyne took flight, it was tested at NASA Ames Research Center's large 40 foot by 80 foot wind tunnel. In 1964, though, Lippisch contracted cancer and had to resign from his position at Collins Radio, ending work on the Aerodyne.

He eventually recovered in 1966 and formed his own aeronautical research company in West Germany to further pursue his wingless VTOL ideas and even developed some early wing-in-ground effect designs. In 1968 Dornier developed Lippisch's Aerodyne work into the small E1 drone and flight proved his ideas in 1972.

Source: Straight Up- A History of Vertical Flight by Steve Markman and Bill Holder. Schiffer Publishing, 2000, p72.

The Story of Los Angeles Airways

On 1 October 1947 Los Angeles Airways inaugurated the world's first scheduled helicopter air mail services on a loop route through the San Fernando Valley followed by additional routes to Newport Beach and San Bernadino within its first six months of operation. LAA was founded on 11 May 1944 by Clarence M. Belinn, the former head engineering superintendent of National Air Lines who was known at the time for having designed the fuel tank crossfeed system used on Amelia Earhart's Lockheed Electra. Though having established LAA during the Second World War, it wasn't until 1947 that the US Civil Aeronautics Board awarded LAA the route authorities to operate local air mail services in Southern California using the Sikorsky S-51. Before long, LAA was operating a twice-a-day mail service between the main downtown post office and Los Angeles International Airport along with a small package air express service.

With a fleet of five S-51s, LAA's first year of operations resulted in 700 tons of mail being carried with approximately 40,000 landings throughout the Los Angeles metropolitan area. The small operation maintained a 95% reliability rate and by the time it began its small package air express service in 1953, it was annually moving nearly 4,000 tons of mail a year.

In July 1951 the CAB awarded LAA's reliable helicopter operation the rights for passenger services which started in November 1954 with larger Sikorsky S-55 helicopters while the smaller S-51s continued the mail and small package services. While aviation history better has preserved the story of helicopter airline New York Airways, LAA began its passenger services only four months after New York Airways' first helicopter passenger services. In fact, on the inaugural New York Airways' inaugural helicopter service in July 1954 LAA founder and president Clarence M. Belinn was one of the invited guests.

In the summer of 1955 LAA added the new Disneyland resort and amusement park to its route network, using a dedicated Disney heliport in Anaheim. In that summer LAA had five passenger Sikorsky S-55s flying scheduled services between 25 destinations in the Los Angeles Basin from Hollywood in the north, Long Beach and Orange County in the south, and San Bernadino in the west. LAA even had interline agreements with major airlines at LAX, offering passengers connecting services on United Air Lines and later on, American Airlines. On 1 March 1962 Los Angeles Airways became the world's first scheduled operator of the turbine-powered Sikorsky S-61L with a 28-passenger capacity, having originally ordered four of the large helicopters derived from the Sikorsky Sea King for $650,00o each.

Despite having earned a permanent certificate from the Civil Aeronautics Board in July 1965, the CAB decided to end its subsidies of approximately $4.3 million/year to LAA having ruled that scheduled helicopter passenger services were not commercially viable. Though the loss of the federal subsidy was a significant blow to LAA, it was offset by investment by American and United for 23.8% control of LAA that allowed the airline to continue operations.

Tragedy struck LAA for the first time on 22 May 1968 when a main rotor blade separation from one of LAA's S-61Ls operating as Flight 841 caused a crash at Paramount City with the loss of all onboard. Then again, this time on 14 August 1968 another S-61L operating as Flight 417 was lost again due to a main rotor blade separation at Compton with the loss of all onboard including the 13-year old grandson of the founder of LAA, Clarence M. Belinn. The losses resulted in the grounding of the profitable Sikorsky S-61Ls and the temporary cessation of passenger services to Disneyland. With two helicopters lost, LAA had lost 1/3 of its S-61L fleet at that time in just the space of several months and the disruption even without the grounding would have been tremendous to LAA's services.

As a temporary stopgap, LAA ordered four De Havilland Canada DHC-6 Twin Otters in late 1968 and leased two further Twin Otters for use on routes to Riverside and San Bernadino from LAX Airport. The leased Twin Otters came from a small commuter airline based in Long Beach, Aero Commuter. In the following year, Aero Commuter rebranded itself as Golden West and took at 54% controlling interest in Los Angeles Airways. A year later, a pilots' strike lasting six months hit LAA further crippled its finances and a rescue deal was arranged with the Hughes Tool Company (Hughes Toolco) with Howard Hughes himself providing bridging financing pending the final deal. However, Hughes would pull the plug on the deal before it would be signed. As a result, on 26 September 1970, Los Angeles Airways ceased operations.

On July 1971 Golden West acquired LAA's operating certificate and two Sikorsky S-61Ls to restart helicopter services between Disneyland and LAX. The first services were flown by Golden West on 15 March 1972 but only lasted six months due to Golden West's own financial problems. The only reminder of LAA's historical legacy in Southern California is a memorial plaque near Gate 74 at Terminal 7 (United's terminal) of LAX where in its heyday, LAA's helicopters connected passengers from all over the metropolitan area with United's flights.

Source: Aviation News & Global Aerospace, May 2010. "US Airlines" feature by Maurice Wickstead, p53-54.

Despite an overall decline in accidents by airline operators in the last several decades, the general aviation accident rate has not changed as significantly. While it's obvious that those are two different worlds of flying that contribute to that difference, efforts to improve general aviation safety in the last several years haven't had the desired impact. The insurance company Avemco only insures piston aircraft and has embarked on a significant study to determine what can be done to improve general aviation safety. While admittedly that's financially self-serving for them, the preliminary results have lessons to be learned for the GA community.

Given that Avemco has very detailed information on the pilots they insure as well as on the exact nature of claims made, they are in a unique position of having a database that is more comprehensive than what the FAA and NTSB would otherwise have access to in any accident investigation. In addition, the FAA and NTSB databases only have information on accidents while Avemco's database also includes insured pilots who have not filed claims.

Their findings so far have been interesting. First of all, advanced ratings make no difference in the overall risk. It makes no difference in the accident rate by their data if the pilot has an IFR rating vs. VFR rating, or even an ATP certificate. Also, after several hundred flight hours, overall flight time doesn't make a difference either. While recent type experience does make a difference, the overall hours in a pilot's logbook have no influence on the accident rate either. It may be that what one gains in experience from advanced ratings is offset by new risk exposures. As a result, Avemco has focused on the psychology of the pilot as the primary difference between pilots who have accidents and those who don't.

Bill Rhodes, a human behavior specialist retired from the US Air Force Academy, is heading the research effort at the company. Though the work is far from complete, some overall patterns are starting to emerge from an exhaustive analysis of their database.

It seems that overall experience, skill, and level of training are important in preventing minor accidents. Usually these accidents don't meet the NTSB's criteria for reporting, so they don't appear in the federal safety investigation databases. But minor accidents are reported to the insurance company in the form of claims for a variety of incidents from fender-benders on the taxiway to a hard landing. These are typically accidents that are injury and fatality-free and more often than not, the more experienced the pilot regardless of ratings, the lower the minor accident rate.

In major accidents, however, involving injuries, fatalities or an aircraft write-off, the contributing factors are a bit less clear. Considering that on the average 500 people a year are killed in general aviation accidents in the United States means that finding a way to prevent major accidents doesn't just improve safety, it also helps the insurance company's bottom line as those accidents are its priciest claims. It seems that there's no difference between high-time and low-time pilots when it comes to the major accident rate.

Being a human behavior specialist, Rhodes has put a series of pilots through stressful simulator sessions that tax their abilities in an effort to understand the human factors in emergency and complex situations more clearly. It appears that one group of pilots is able to prioritize tasks quickly and effectively in such situations. He also measured physiologic parameters such as heart rate, breathing rate, and changes in speech patterns and this group of pilots were clearly under stress but adapted and handled the stress easily.

The other group of pilots it turns out don't handle stressful situations well. They unnecessarily try to multitask and are unable to filter out what is important and what's not in a given situation. It appears that this group of pilots may also be taking on additional risks that the first group of pilots won't because that first group will make conservative decisions at the outset to minimize their risk exposure.

While this information might seem intuitive, the key in improving general aviation safety lies in finding a way to identify those pilots who are more at risk as well as making risk assessment an important part of general aviation pilot training much in the same way it's universally applied in military flying which boasts a lower accident rate with low-hour pilots operating higher performance aircraft than most general aviation pilots will ever command.

Source: Flying, June 2010. "Left Seat- The Psychology of Safety" by J. Mac McClellan, p8-10.

The Centaur Upper Stage

During the early days of the American space program, there were two schools of thought in liquid-fueled rocket design. One group, represented by Werner von Braun and his team of NASA engineers at the Marshall Spaceflight Center, favored rockets with strong internal structures similar to that of monocoque aircraft. The other group, represented by the Atlas missile engineers at Convair, favored rockets with a thin aluminum shell that used pressurization of the tank and its propellants for structural integrity- what was called balloon skin construction.

The Atlas team had already proven their structural technique would work as the Atlas had already entered service as the first American ICBM and it was already being used for space launches from satellites to the manned Mercury program. The main engineers behind the Atlas, Charlie Bossart and Kraft Ehrlicke, were planning a high-energy liquid fueled upper stage that could be used on the Atlas to boost its orbital payload. This was the Centaur upper stage and it would use the first rocket engine to use liquid oxygen and liquid hydrogen- while liquid oxygen was commonly used as an oxidizer, the Centaur and its Pratt & Whitney RL10 rocket engines pioneered the use of liquid hydrogen- it was much colder and tricker to handle, but combined with liquid oxygen it offered a quantum leap in performance.

Early in the Centaur program the USAF was the main customer, but bureaucratic changes and shifts in mission funding requirements led the Centaur program to be transferred from the Air Force to NASA. As a result, the two main schools of thought in liquid-fueled rockets came to clash in 1962.

Von Braun's team offered a more conservative approach that was being incorporated in their work on the Saturn launch vehicle. Von Braun, now being placed in the position of overseeing the Centaur program, sent his structural engineering chief, Willie Mrazek, to San Diego to review the progress on the Centaur program. Convair's engineers by that point had already developed a reputation as being the "unruly wards" of the Marshall Spaceflight Center and while the USAF was willing to push the technological envelope, the safety-minded culture of NASA desired a less risky approach. Mrazek came to Convair in 1962 not terribly pleased with the balloon skin design of the Centaur.

The heads of Convair tried their best to keep Charlie Bossart and Kraft Ehrlicke clear of Mrazek during his visit. During a technical presentation on the Centaur's construction, unbeknown to Mrazek who was seated in the audience, Charlie Bossart managed to sneak into the presentation and took the seat right to Mrazek. As the presentation proceeded, Mrazek was constantly shaking his head and muttering to himself what he thought was wrong with the Centaur's design. By this point, Bossart had had enough despite his explanations to Mrazek (imagine these two men arguing in a loud whisper in the back of an auditorium) and took him outside. Deane Davis, Convair's deputy director for technical control and Ehrlicke's immediate superior, was convinced that Bossart was taking Mrazek outside to settle the score with fisticuffs.

Bossart took Mrazek to the outdoor factory yard where a brand-new Centaur upper stage sat, its polished thin aluminum skin gleaming in the sunlight. "What's inside it?" asked Mrazek. "Just nitrogen" replied Bossart, at which point he handed Mrazek a hammer and invited him to pound a hole into the side of the Centaur. Without the nitrogen pressurization, the Centaur would collapse under its own weight. Mrazek couldn't believe that gaseous nitrogen was keeping the Centaur's structure, so he took a swing at the rocket stage. The first hit was only a glancing blow and hardly scratched it. I can only picture Bossart at this point egging Mrazek on to hit it harder- which he did. The hammer rebounded off the skin and hit Mrazek in the face, knocking his glasses off. Again, the skin remained unscathed.

Bossart's point was made at the expense of Mrazek's ego and his glasses. The Centaur program proceeded onward from that day in 1962, and the Centaur is still in use today as a second stage on launch vehicles like the Atlas V. It was successfully used on the Titan series of launch vehicles and is currently under consideration as a high-energy upper stage on the new Delta IV rocket.

Source: To Reach the High Frontier- A History of US Launch Vehicles, edited by Roger D. Launius and Dennis Jenkins. The University Press of Kentucky, 2002, p344-345.

The AVE Mizar: The Flying Pinto

From yesterday's Taylor Aerocar to today's Terrafugia, designers and engineers have always dreamed of ways to combining the speed and convenience of flight with the ease and familiarity of automobile travel. Nearly all of the designs that have reached flight hardware status have involved custom-built cars combined with custom-built wings and empennages for flight. But one aeronautical engineer in 1968 dared to think differently and went with an off-the-shelf solution for both components that he was sure would make the flying car practical.

Henry Smolinksi earned his engineering degree from the Northrop Institute of Technology and had devoted a considerable part of his career working with North American Aviation and later, on Rocketdyne. In 1968 he founded his own design firm, Advanced Vehicle Engineers (AVE) based at Van Nuys Airport in southern California to bring his flying car ideas to the forefront. Rather than develop the car and aircraft components anew, Smolinksi thought it would be easier and more economical to use the wings, rear engine and twin tail booms from a Cessna 337 Skymaster mated to special fittings that could be adapted to just about any suitably light consumer automobile. For his prototype, Smolinski chose the Ford Pinto, a lightweight and inexpensive compact car.

Smolinski named his flying car the AVE Mizar, after the binary star in the handle of the Big Dipper. He forecast that it would be ready for the general sales by 1974 and would cost less than $30,000, much less than any general aviation single available in those days. Smolinski brought aboard Hal Blake as the VP of AVE and Bert Boeckmann, a lead salesman in a local southern California Ford dealership, to be responsible more the sale, marketing and distribution of the AVE Mizar via Ford dealers nationwide.

The Pinto had its dash modified to accommodate flight instrumentation and the steering column was also modified to also function as a control yoke as well as a conventional steering wheel. Retractable rudder pedals were also added that folded out of the way to provide access to the brake and gas pedal when in car mode. A set of self-guiding rails were installed on the roof of the Pinto and in effect, the car would be backed up into the the former Skymaster components. In the AVE Mizar prototype, the control linkages ran underneath the car and wing struts fitted into the slots on the lower door sill to support the wings. According to Smolinski, the Mizar would cruise at 13o mph with a maximum speed of 150 mph and a range of 500 miles. Take off roll was only 500 feet as was the landing roll- the car's engine could be used during takeoff to increase the acceleration of the Mizar and the car's brakes were used to shorten the landing run. He estimated that about 55 different production vehicles would be suitable for modification as the former Skymaster components could lift a car with a maximum weight of 3,800 pounds.

The AVE Mizar was formally unveiled at Van Nuys Airport on 9 May 1973. To demonstrate the ease of use, AVE's team planned to use women as test pilots. Taxi tests began in August at Oxnard Airport in Ventura County. By the time of its first flights, AVE had invested $2 million into the design and the first several flights were successful. On 11 September 1973, Smolinkski and Blake took off in the Mizar with Smolinski in the left seat. Climbing through 400 feet, the right wing strut broke free and the right wing folded on itself, sending the Mizar crashing to the ground, instantly killing AVE's president and vice-president. The NTSB's investigation revealed a faulty weld where the right wing strut joined its fitting in the lower right door sill.

The future of the Mizar died in that crash and the flying Pinto was faded into history as another aeronautical curiosity. There is a good website devoted the AVE Mizar at www.cookieboystoys.com/mizar.htm. Highly recommended for a full dose of avgeekiness!

Source: Air & Space Smithsonian, July 2010. "Oldies and Oddities- A Different Kind of Hybrid" by Peter Garrison, p18.

As early as 1957 NACA (NASA's predecessor) was already conducting lifting body research started by Dr. Alfred Eggers of the Ames Research Laboratory. His pioneering work on lifting body applications to re-entry vehicles for spacecraft and missiles led the US Air Force to initiate START- Spacecraft Technology and Advanced Reentry Test. By 1960 Dr. Eggers' work was taken up by several aerospace firms, most notably Martin Aircraft and Northrop to a lesser extent. Within two years, Martin's engineers had come up with their own designs for a reentry vehicle based on a lifting body design. The USAF considered the Martin designs to be possible foundations for either a maneuverable ICBM warhead that could evade Soviet anti-ballistic missile defenses or for a data/film return vehicle for a spy satellite that could maneuver on reentry to a more favorable recovery point. At the time, the first of the Corona spy satellites were operational and used a ballistic reentry capsule to return the film images to Earth. The timing of the return had to coincide with a point in the Corona's orbit that the capsule would hit a predesignated recovery point. A maneuverable lifting body capsule could be ejected on short notice from less favorable orbits and be maneuvered to a recovery point.

In August of 1964 Martin got the contract for the SV-5D PRIME (Precision Recovery Including Maneuvering Entry). Interestingly, it was assigned the X-23 designation after the completion of the program. Research work by USAF historians demonstrated that all contemporary documents of the day used the SV-5D designation.

Only about six and a half feet in length, the X-23/SV-5D had the same lifting body configuration as the later manned Martin X-24 aircraft. With a lightweight and high-temperature tolerant structure of titanium and beryllium, the craft with three types of ablative silcon and carbon-based heat shielding depending upon the expected maximum temperatures on various parts of the vehicle. The centrally-located equipment bay housed the guidance system, telemetry and data units and the recovery parachute system. The equipment bay was surrounded by a cold-wicking system- two plates surrounded a fluid-filled absorbent material. As the heat built up during reentry, the fluid slowly boiled off and was vented overboard as steam.

The only propulsion on the vehicle was a gas jet thruster system for exo-atmospheric maneuvering as well as body flaps for endo-atmospheric maneuvering. The X-23/SV-5D was carried aloft on an Atlas missile launched from Vandenberg AFB in California. Once the Atlas reached apogee, the nose shrouds were jettisoned and the X-23/SV-5D was released to begin its reentry maneuvers.

The first X-23/SV-5D was launched on 12 December 1966 but only pitch maneuvers were demonstrated. However, the recovery system failed at the end of the 30-minute mission and the first vehicle was lost in the Pacific. The second test took place on 5 March 1967 and during reentry at hypersonic speeds, the X-23/SV-5D maneuvered as much as 500 miles on each side of a ballistic reentry path, proving for the first time the work of Dr. Eggers and Martin Aircraft. Unfortunately, it too was lost in the Pacific when it came loose from its flotation collar and sank. The third and last flight took place on 18 April 1967 and the vehicle performed a full series of test maneuvers and was successfully recovered in midair near Kwajalein Island by a Lockheed JC-130B Hercules. The successful recovery of the third X-23/SV-5D allowed NASA and Martin engineers to study the effects of reentry on the different heat shield materials used on the craft. Due to the success of the third test and the partial results from the failed second test, the fourth X-23/SV-5D was never flown.

At one point there was discussion of using the design of the X-23/SV-5D as the basis for an unmanned hypersonic reconnaissance vehicle but the project never went forward. The third X-23/SV-5D is now on display at the National Museum of the United States Air Force in Dayton, Ohio. The data gleaned from the X-23 PRIME project proved immensely useful to NASA and Rockwell's engineers during the design of the Space Shuttle and the USAF used the data in its work on the reentry vehicles for its ICBM force.

Source: The X-Planes- X-1 to X-45 by Jay Miller. Midland Publishing, 2001, p256-259.

The Flamboyant Markings of VF-51's Phantoms in Vietnam

During Operation Linebacker over Vietnam in 1972, the two McDonnell Douglas F-4 Phantom II squadrons aboard the USS Coral Sea, VF-111 "Sundowners" and VF-51 "Screaming Eagles" each had their own obstacles to overcome to become some of the premier Phantom units in Southeast Asia. VF-51, in particular, had a double uphill climb as the squadron had just transitioned from the Vought F-8H Crusader AND their new Phantoms weren't so new- they were old F-4B models that had been rejected by the Marines as unairworthy and had been left in storage at MCAS El Toro in California for years.

Many of the senior cadre of pilots at VF-51 were ex-Crusader jocks who lamented the loss of their 20mm cannon and what they perceived the hassle of having a RIO (radar intercept officer) in the back seat. "I'd rather have 500 lbs of fuel than babysit an NFO (naval flight officer, the category of flight crew that were assigned as Phantom RIOs)." The pilots resented their transition training to the Phantom with VF-121 at NAS Miramar where they had veteran RIO instructors in the back seat. "About as fun as having your mother with you on a date" complained one pilot. VF-51's commander, Tom Tucker, ordered his pilots to "dummy up" and play nice with the RIOs to make the transition as smooth as possible.

Soon the ex-Crusader jocks fell in love with their new mounts. Having more power and a better radar than the Crusader was well-appreciated and a few of the former single-seat pilots also started to like having the extra set of eyeballs afforded by the RIOs. Before long, the pilots started to have preferences for certain RIOs but the RIOs themselves were an independent minded bunch. There's an anecdotal story of one RIO teaching his pilot a lesson on crew coordination when during a training mission the RIO shut down all the key radar and avionic systems and told his pilot "Okay, badass, see how well you can fly and fight now." Since the RIO had the switches for those systems, the pilot was left with little to do but keep from crashing. So an unspoken rule developed at VF-51 that RIOs also had say in which pilots they flew with. Many of the Phantom crews ended up flying with the same pilots and RIOs through much of the Coral Sea's 1972 combat cruise.

Having to get the elderly F-4Bs up and running proved to be VF-51's other difficulty in the run up to the 1972 combat cruise. The latest production model was the F-4J which rectified many of the problems with the F-4B, but as the rapid build-up of forces under President Nixon accelerated, any and all Phantoms that could be spared were snapped up by deploying squadrons. In VF-51's case, that meant a motley assortment of hangar queens from MCAS El Toro that hadn't flown since 1968. VF-51 was given free reign to press into service any maintenance crew from any squadron at NAS Miramar to form "Tiger Teams" that worked day and night to get the F-4Bs ready for combat.

With the pilots transitioned and finally working well with their RIOs and the F-4Bs ready to head to war, the only thing left was the come up with new squadron markings for VF-51's mounts. One of the squadron ensigns was sent to a corrosion control and painting course at NAS North Island and he had figured out which panels were opened up the most during routine combat operations. Squadron markings were devised that avoided these panels so they scheme stayed intact and it was one of the most flamboyant Phantom markings to go to sea- what rival squadrons called the "Supersonic Can Opener" was a bright eagle marking with tail feathers that splayed out on the rear fuselage. Even the main landing gear doors were painted with full color eagle talons.

Some of the Miramar command staff told VF-51 that the only thing their Phantoms were missing now were mudflaps and a raccoon tail attached to an aerial! One of the future MiG-killers of VF-51, CDR Jerry "Devil" Houston, recounted in an interview that while other squadrons were looking at ways to tone down their markings and even conceal their aircraft, for morale they wanted VF-51's markings "to be audacious; we wanted to be a magnet for MiGs...intruders in our airspace didn't have to speculate about who just whipped their ass."

Sister squadron VF-111 on the Coral Sea in response adopted an equally flamboyant sunburst tail marking for their 1972 combat cruise as well.

Source: Gray Ghosts: US Navy and Marine Corps F-4 Phantoms by Peter E. Davies. Schiffer Publishing, 2000, p151-153.

The Schweizer X-26 Frigate: The Longest Running X-Plane Program

In 1968 the US Naval Test Pilots School (NTPS) at NAS Patuxent River, Maryland, was struggling how to teach its test pilot students the phenomenon of inertia roll coupling, where the inertia of the heavier fuselage can potentially overcome the stabilizing effects of the wing and tail, particularly in high speed flight. Intertia roll coupling became more of an issue in the fighter aircraft of the day which often boasted long slender fuselages and relatively short span wings. The standard naval jet trainer of the day, the North American Rockwell T-2 Buckeye, despite its benign handling characteristics as a trainer, would react too quickly and at times dangerously to be an effective teaching tool on the phenomenon. The Navy needed an aircraft that had a unusually slow roll rate with a slow speed and good recovery characteristics to that the students of the NTPS could see and experience the evolution and recovery from inertia roll coupling.

The longer the wing span, the slower the roll rate. This made a long-span wing necessary and having a slow speed and good recovery characteristics made a glider aircraft the ideal platform. In an unprecedented move to quickly acquire the right aircraft for the NTPS, the Navy purchased two stock Schweizer SGS 2-32 two-seat sailplanes that could be towed aloft by another unusual aircraft in the NTPS inventory, De Havilland Canada DHC-2 Beavers which were in use to acquaint the NTPS students with tailwheel aircraft and STOL flight.

In order to circumvent the usual lengthy and bureaucratic procedures that come with aircraft acquisition, the Navy had the X-plane designation X-26A assigned to the gliders. They later would be christened "Frigate" after the frigate sea bird. The two X-26A Frigates entered service with the NTPS in August 1968. As the Navy's pilots were inexperienced in glider operations, the NTPS instructors were trained at Schweizer's factory in Elmira, New York. The first two X-26A Frigates were lost in fatal accidents in 1971 and 1972. A third X-26A was procured and unfortunately it, too, was lost in a fatal accident in 1980. Two more X-26A Frigates were purchased to replace the losses that year and to this day they still fly with the NTPS. With two classes going through the rigorous NTPS course each year with an average class size of 30-36, the two Frigate gliders are kept busy.

At one point there was an X-26B. Lockheed and DARPA had a concurrent program that wasn't part of the X-plane program to develop a quiet sensor platform for the Vietnam War. Two Schweizer SGS 2-32 gliders were used in the Project Prize Crew and when they became redundant to the the program, they were passed on to the NTPS as a powered gliders and designated X-26B. One was kept as a spares source for the other which flew, but the X-26B had to be withdrawn from the NTPS due to maintenance problems with its unique modifications for the Project Prize Crew.

This year marks the 42nd consecutive year of X-26A flight operations at NAS Patuxent River, making the Frigate glider the longest-running X-plane program in history, beating out the second longest program, the Bell X-14 VTOL testbed, by a substantial margin.

Source: The X-Planes- X-1 to X-45 by Jay Miller. Midland Publishing, 2001, p282-283.

Convair's Lenticular Defense Missile: Pye Wacket

Pye Wacket high speed wind tunnel model

In 1947 researchers at Wright-Patterson AFB in Dayton began investigations into the possibility of using missiles for bomber defense as the speed of jets and the weight of gun turrets made existing systems for bomber defense impractical. General Electric was the first to receive a USAF contract to pursue such studies, but soon transferred the work to Hughes where the missile developed didn't end up on bombers but on interceptors as the Falcon missile. McDonnell was next in 1952 to try and develop a jet-vane controlled defensive missile for the Convair B-58 Hustler, but the work was canceled in 1956. By that time, however, work began on the WS-110A project that would result in the North American XB-70 Valkyrie and more contracts were issued to study what the Air Force was calling DAMS- Defense Anti-Missile Subsystem, a system that fired a stream of pellets at inbound missiles. Again, those studies ended in 1959 despite some encouraging tests.

The USAF wasn't deterred, though, starting a program in 1958 in cooperation with North American and Convair called Pye Wacket for a defensive missile for the XB-70 Valkyrie. Three basic shapes were first evaluated by North American and Convair- a standard but modified version of the AIM-47 designed for the F-108 Rapier, a cylindrical missile using jet vane directional control, and an unusual saucer-shaped missile called a "lenticular defense missile". Studies showed the lenticular design the most promising as its shape allowed it to be pointed in any direction and fired, not wasting kinetic energy on turning towards the incoming threat.

By 1959 the USAF did a considerable amount of wind tunnel work at the Arnold Engineering Development Center in Tennessee of the lenticular Pye Wacket design. It was stable all the way to Mach 6. It had a diameter of 70 inches, was 9 inches deep at its thickest portion and weighed only 510 lbs. One end of the saucer shape housed the infrared seeker and two rocket motors were on the opposite end to give the Pye Wacket a range of approximately 72 nautical miles. A set of spoilers built into the curved surfaces of the missile provide directional control.

North American began to seriously consider the Pye Wacket missile for the XB-70 Valkyrie- posts were mounted vertically in the forward section of the weapons bay and the missiles were mounted on the posts via a screw thread that ran through the center of the missile. This way the saucer-shaped missiles could be threaded on the post and stacked. Two stacks of five missiles each would fit in the Valkyrie's weapons bay. When needed, the post rotated to point the lowest missile in the stack in the direction of the inbound target. The missile was then dropped out of the bay already pointed at the target at which point the rocket motors fired.

In the summer of 1959 Convair was awarded a design contract to further study the lenticular Pye Wacket design and modified the saucer shape to incorporate a blunt trailing end where the rocket exhaust was located. This improved the supersonic drag as well as the controllability of the missile. Roll reaction thrusters were added along with small lateral vanes as well as the original spoilers used on the original design. With over 80 hours of wind tunnel testing from speeds as low as Mach 0.6 to Mach 5, sled tests then took place at Edwards AFB on a full-scale article powered by three Thiokol solid rocket motors, the same type used singly on the AIM-4 Falcon air-to-air missile.

The tests reported accelerations on the order of 60G with the ability to make sharp high-G turns at supersonic speed without loss of control. An operational version of the Pye Wacket arming the Valkyrie would be 48 inches in diameter, carry a 50 lb warhead and be capable of extreme maneuvers up to Mach 6. Convair recommended that the Air Force procure 12 missiles for continued testing, but no documentation has been found that further details work done from that point on on the lenticular defense missile.

Convair also had proposed a strike version of the Pye Wacket that would allow a bomber to easily strike targets on each side of its flight path without having to overfly enemy defenses. A version was also suggested by the company to use as a highly maneuverable re-entry warhead for ballistic missiles.

It's always been a point of curiosity to me as an aviation geek why a weapon as promising as the Pye Wacket never got developed further. Or did it? Conspiracy theorists might think the Pye Wacket was classified and modern versions of the lenticular defense missile moving at speeds unattainable by manned aircraft might account for a good portion of the UFO sightings pointing to a super-maneuverable vehicle. Considering that the basic layout was stable at hypersonic speeds, it certainly would make a very capable rapid-strike weapon.

Now if you'll excuse me, I have to go fetch my tinfoil hat.

Source: Valkyrie: North American's Mach 3 Superbomber by Dennis Jenkins and Tony Landis. Specialty Press, 2005, p220-226. Photo: NASA

In the early morning hours of 29 August 2005, Hurricane Katrina made landfall near New Orleans as a Category 4 storm. In addition to the widespread flooding and destruction, the storm also destroyed much of the area's communications infrastructure from cellular towers to air traffic control systems. As an integral part of Joint Task Force-Katrina (JTF-Katrina), the US military, civilian agencies, and those nations who came to assist needed airspace coordination with as many as 80 helicopters alone airborne throughout the area rescuing survivors and inbound relief flights and outbound evacuation flights.

Two Navy E-2 Hawkeye squadrons provided air traffic control and coordination as well as a detachment of P-3 AWACS aircraft from the US Customs Service. The two Hawkeye squadrons involved were the reserve unit VAW-77 "Nightwolves" (call sign WOLF) from NAS Atlanta and VAW-126 "Seahawks" (call signs SEAHAWK and CLOSEOUT) from Carrier Air Wing Three embarked on the USS Harry S Truman which was sailing in the Gulf of Mexico assisting with relief efforts. In addition, the US Customs P-3 AWACS (which use a similar radar system as the E-2) from their home base in Corpus Christi (call sign OMAHA) also assisted the Navy Hawkeyes.

The E-2's radar and extensive communications suite allowed the crews to monitor the airspace, assist in location of stranded survivors, direct rescues, air traffic control and even identify with the radar safe landing areas and locations of tall obstructions. The two squadrons adopted the same system used for directing close air support for the New Orleans environment, using a grid and keypad system overlaying the area to coordinate and direct rescue aircraft and deconflict the airspace much in the same way fighters and strike aircraft might be directed to targets. At times a single E-2 might be controlling as many as 80-90 helicopters operating over the metropolitan area.

The E-2 Hawkeye has a crew of five- two pilots up front and three NFOs (naval flight officers) in the back who provide the airborne control and communication. The center seat is usually occupied by the commander or combat information officer who directs the efforts of the two NFOs on each side. Many of the helicopter pilots involved in the relief preferred working with the E-2 Hawkeyes as the smaller number of crew aboard made decision-making quick compared to the larger platforms like the P-3 AWACs. All one of the NFOs would have to do to direct a rescue effort was to turn to his commander and ask for clearance.

Source: Flying the World's Greatest Aircraft: Superlative Military Machines from Sabre to Raptor, James Bennett, editor. Fall River Press, 2009, p81.