A century of launch and recovery: from flywheels to magnets.
Naval Aviation began on 14 November 1910, when Eugene Ely launched his Curtiss Model D biplane from USS Birmingham (CL 2) without the aid of any launching device--and barely made it into the air. Much has changed since Ely's day: aircraft size, weight, and speed have grown inexorably larger, heavier, and faster. Launch systems have defined and limited the realm of the possible not only for the dimensions of aircraft, but by extension the duration, range, and lethality of sorties as well as the variety of missions that can be flown.
In the next several issues of Naval Aviation News, we'll revisit the technologies that have launched and recovered Navy and Marine pilots for nearly a century, while spotlighting EMALS and AAG.
Early Years (1912-1954)
Before the advent of the steam catapult, the U.S. Navy tinkered with multiple technologies for the launching of aircraft from a wide variety of different ships. Early experimentation focused on catapults intended for cruisers and battleships. On 31 July 1912, using a land-based catapult powered by compressed air, Lt. Theodore G. Ellyson conducted the first test of a catapult using an A-1 in Annapolis, Md. The test was unsuccessful; the aircraft was not completely secured to the catapult and became caught in a cross-wind, crashing into the water. On 12 November 1912, Ellyson tried again with an altered catapult, this time successfully. Three years later, on 5 November 1915, history was made when the first Navy aircraft, an AB-2 flying boat, piloted by Lt. Cmdr. Henry Mustin made the first catapulted launch from a ship while under way, when it flew off the stern of USS North Carolina (ACR 12).
The Navy also experimented with other power sources and models, including catapults that utilized gunpowder and flywheel variations. On 14 December 1924, a Martin MO-1 observation plane flown by Lt. L. C. Hayden was launched from USS Langley (CV 1) using a catapult powered by gunpowder. Following this launch, "powder power" was used aboard both cruisers and battleships, although Langley's catapults were removed in 1928 because of infrequent use.
The Navy continued to rely on compressed air, gunpowder, and flywheel designs as their mainstay catapult systems, although research was well under way to design a system capable of launching greater numbers of heavier aircraft into the skies. In 1934, the Navy announced plans for a flush-deck hydraulic system (Type H, Mark 4-1) capable of launching planes from the decks of aircraft carriers. Shortly thereafter, the Bureau of Aeronautics announced that space aboard the carriers USS Yorktown (CV 5) and USS Enterprise (CV 6) would be reserved for these hydraulic catapults: two for the flight deck and one athwartships on the hangar deck.
Following several years of catapult testing, Yorktown and Enterprise launched SBC-3 and 03U-3 aircraft from the flight and hangar deck catapults on 4 August 1939. On 16 November 1940, the Bureau of Aeronautics established a catapult procurement program for the entire Essex-class of carriers.
After war began in December 1941, hydraulic catapults were little used on the fleet carriers because of the small load capacities of the early designs. According to Lee Pearson in the May-June 1995 Naval Aviation News, "In April 1943 Enterprise recommended her catapults be removed because they were so limited to small, slow airplanes that they were of no use. Instead, they were replaced with updated H2-1 catapults capable of accelerating an 11,000-pound airplane to 70 mph in a 73-foot run."
Hydraulic catapults were essential, however, for the Navy's smaller carriers during the war. Escort and light carriers (CVEs and CVLs) needed them to launch aircraft from their shorter decks and to carry the many Army Air Forces aircraft they shuttled to bases throughout the Pacific.
The catapult proved to be an essential piece of the war against the Japanese in the Pacific. As Navy aircraft--such as the mighty Grumman TBF/TBM Avenger torpedo-bomber--grew in size throughout the war, the extra "oomph" of the catapult became necessary to get aircraft into the air with more effective payloads and range. Using the entire deck and the 18 knots of wind, according to an article in the February 1954 edition of Naval Aviation News, the TBF was lucky to get airborne without its torpedo. Using the catapult, the TBF could carry its torpedo plus a full tank of gas.
Following the end of World War II, the Navy looked to improve on all aspects of its current catapult system. While their catapult design was fine for launching aircraft such as the Avenger, Grumman F6F Hellcat, and Curtiss SB2C Helldiver, the future of aviation warfare hinged on effectively launching a higher sortie rate of increasingly larger propeller-driven and jet-powered aircraft. The Navy devoted both time and energy into the study of upgrading its catapult system with varying success. Across the sea in Great Britain, however, came the answer.
Steam Catapults (1945-Present)
Following the war, the Royal Navy was hard at work developing a new catapult system for their fleet of carriers. Cmdr. Colin C. Mitchell, a reservist, recommended a steam-based system as an effective and efficient means to launch the next generation of naval aircraft. According to reminiscences of U.S. Navy Rear Adm. D. K. Weitzenfeld, who served as the assistant director of the ship installations division of the Bureau of Aeronautics in the 1950s, Mitchell's work on a steam-based catapult system led the way to the U.S. adopting this new technology.
"After the war Mr. Mitchell returned to his shop," wrote Weitzenfeld. "Using what he called 'shop assisted engineering' techniques he worked out in a wood model a design which allowed the slot to open and close without losing any significant energy. He then duplicated this in full scale metal, making and testing one 12-inch cylinder, coverplate and associated hardware. It worked. With this design in hand the Royal Navy went ahead with a full scale catapult to be installed in HMS Perseus [R 51]."
The U.S. Navy knew that for carriers to maintain their capabilities, they had to adapt to the size and weight needs of new aircraft. Soon after the installation of an experimental steam catapult aboard Perseus in 1950, the U.S. Navy saw the potential for its own carriers and began a program of its own.
"On 6 August 1951, the CNO accepted an offer from the Royal Navy to send HMS Perseus to the U.S. for our test program," wrote Weitzenfeld. "At that time, the BXS-1 steam catapult in Perseus had 890 launches, 105 with live aircraft. At the same time we were in the process of planning the installation of our XC-10 powder catapult (to be replaced by a gas generator) for March 1952."
Perseus arrived in Philadelphia on 20 January 1952 for calibration of its BXS-1 catapult, a developmental model that required 20-minute intervals between aircraft launches. The carrier arrived at Norfolk on 11 February 1952, and went right to work as the steam catapult launched F3Ds, F9F-2s, and F2Hs in succession during the next few days. USS Eugene A. Greene (DD 711) supplied steam to the catapult at pressures greater than those used by the British to test the weight limits of the system.
At the end of the testing, more than 140 test launches of dead loads and varying carrier aircraft types were made, further cementing the status of steam as the catapult of choice for U.S. carriers.
According to Weitzenfeld, who was on the carrier at the time of the test launches, the catapult had an immediate impact on those in attendance. "[Commander, Naval Air Force U.S. Atlantic Fleet] Vice Adm. John J Ballentine, a spectator along with many others turned to Capt. (then Lt.) Russ Reiserer, myself, and the rest of his staff and said 'I want that steam catapult!' This thought was carried directly to the CNO by Ballentine when he returned to the office."
So on 28 April 1952, a few months after the demonstration, the U.S. Navy announced that the British-developed steam catapult would be adopted for U.S. aircraft carriers, with the first installation to be aboard USS Hancock (CV 19). Hancock was decommissioned after the war but was reclassified as CVA 19 on 1 October 1952. It was recommissioned on 15 February 1954, and became the first carrier in the Navy outfitted with steam catapults capable of launching high-performance jets.
Several months later, the Project Steam test program commenced on Hancock as Cmdr. Henry J. Jackson, in an S2F-1 Tracker, was catapulted in the first operational test of the C-11 steam catapult. A total of 254 launchings were made in June with the S2F, AD-5, F2H-3, F2H-4, FJ-2, F7U-3, and F3D-2 aircraft. With only one aircraft lost during the tests, the experiments proved that the steam catapult was the most effective technology yet to maximize aircraft fuel and ordnance payloads.
Pilots immediately recognized the importance of the new catapult system. "There's a tremendous difference between the steam catapult and others I've been shot off of," said Lt. Cmdr. Edward L. Feightner, a development officer with VX-3 and World War II ace, in a February 1954 interview with Naval Aviation News following the first public demonstration of the steam catapult on 3 December 1953 at the Naval Air Material Center in Philadelphia, Pa. "It's much better for the pilot. I have never been shot off [a steam] catapult before, so I braced for the shock which never came. I wouldn't have had to brace my head at all, so easy was the shot."
With the approval of the fleet and the blessings of its pilots, steam was in. Since then, it has seen duty on every postwar class of U.S. aircraft carrier, from USS Forrestal (CV/CVA 59) to USS George H. W Bush (CVN 77), while launching aircraft from Avengers to F-14 Tomcats, F/A-18 Super Hornets, and S-3 Vikings. As the size and weight of naval aircraft continue to increase, however, the Navy believes it sees the future in magnets.
To paraphrase Yogi Berra, it is deja vu all over again for the Navy. Aircraft with a wider range of sizes, weights, and launching needs are entering the fleet. The F-35 Lightning II will soon replace the venerable F/A-18E/F Super Hornet, both heavy and light unmanned aerial systems such as the X-47B and ScanEagle will occupy space on the flight deck, and a catapult is needed to operate flexibly around these aircraft's launch requirements while continuing to increase sortie rates.
"Currently, steam catapults are capable of launching today's carrier aircraft as well as the fixture F-35C Lightning II and X-47B unmanned aircraft that are not yet operational in the fleet," said Capt. James Donnelly, program manager for the Navy's Aircraft Launch and Recovery Equipment program. "EMALS is designed to launch today's current air wing as well as all future carrier aircraft platforms in the Navy's inventory through 2030 with reduced wind-over-the-deck requirements when compared to steam catapults, and additional capability for aircraft growth during the 50-year life of the carrier."
To that end, the Navy is betting all their chips on EMALS.
EMALS is composed of an energy storage unit, a power conditioning system, and a closed-loop control system. The catapult will also use linear induction motors, which directly produce motion in a straight line, to allow the aircraft to launch at speeds ranging from 55 to 200 knots.
"The Navy has been considering electromagnetic technology since the World War II era," said George Sulich, the integrated product team lead for EMALS. "It wasn't until 1982 that a concept feasibility study determined an electromagnetic launcher could successfully be used to launch aircraft from a carrier that research and development began on technologies that have evolved into the current EMALS program."
According to Sulich, EMALS will provide several distinct benefits over its steam predecessor, including a wider energy range that expands the carrier's capability envelope to accommodate heavier aircraft as well as lighter unmanned air vehicles. EMALS will also allow: increased operational availability because of its electrical and electronic components; a health monitoring system that prevents the catapult from launching if something is wrong; linear motors to launch, brake, and retract the shuttle (instead of the multiple systems used on a steam catapult); and a 10-fold increase in efficiency when compared to steam catapults.
EMALS will also generate higher sortie rates, reduce overall maintenance to the system and aircraft, and require fewer Sailors to operate.
"As the steam catapult system ages, it frequently requires additional personnel to monitor a gauge or tend to maintenance issues," said Donnelly. "EMALS will monitor its own condition and keep the operator informed of system status, providing information on, and criticality of, any compromised components as well as aid maintainers in troubleshooting down to low-level components. This will permit a significant reduction in the manpower workload required to operate and maintain the system."
The Navy began technical demonstration contracts with General Atomics and Northrop Grumman Marine Systems in 1999, in an effort to develop potential prototypes for a catapult using electromagnetic energy to replace steam. By 2004, the Navy offered a $145.6-million systems design and development contract to General Atomics for a full-scale prototype at Joint Base McGuire-Dix-Lakehurst, N.J.
General Atomics was subsequently awarded a not-to-exceed $6-million
contract modification in March 2006 for the incorporation of two engineering change proposals for the EMALS center deck display and a revision to the launch control system motor controller, a harbinger of increased cost issues that would become synonymous with the early test and development of EMALS.
A Government Accountability Office report issued on 30 March 2009 stated that problems during EMALS development resulted in unforeseen cost growth and schedule delays. Just four months later, during the 16 July 2009 U.S. House Armed Services Seapower and Expeditionary Forces Subcommittee oversight briefing on EMALS, committee chairman Gene Taylor (D-MS) voiced his growing concerns with the future catapult system.
"I have been briefed, as I believe other members of this subcommittee have been briefed, that the issues in completing and delivering the [EMALS] components were a result of the contractor's inexperience managing a major production effort," he said. "I find that answer unsettling because it is the Navy's responsibility to oversee what their contractors are doing and to identify problems before they become problems."
Taylor also had scolded the Navy and General Atomics in 2008 committee hearings, noting that "the Navy requested an additional $40 million dollars for continued development of EMALS because, and I quote, 'the contractor underestimated design and production cost.' The cynic in me would say the contractor purposefully low-balled the bid to get the contract knowing full well the Navy would be forced to pay whatever the true costs of the system turned out to be. Perhaps we should have built another Nimitz-class carrier until the research and design for EMALS was complete."
Although the program was under scrutiny, construction of the full-scale test site continued, testing was well under way, and progress was made. On 3 September 2008, EMALS reached the phase 1 milestone at the General Atomics test facility in Tupelo, Miss. This testing was performed to ensure that EMALS's motor technology would operate efficiently and reliably once it reaches the carrier. On 28 September 2009, EMALS completed the first phase of its highly accelerated life testing, which tested the catapult launch motors ability to operate in simulated "at-sea" environmental conditions while aboard the carrier.
The early cost overruns of the system were typical of the trial-and-error nature of developing any new technology. While the use of electromagnetic energy itself is not new, supplying the launching needs for entire carrier air wings is certainly one of the most ambitious uses of this science to date. Donnelly notes that the design, capability, and internal monitoring system of this technology is less manpower intensive than steam, which will ultimately lead to a more efficient and less costly method of launching aircraft.
"Actual EMALS operation and sustainment costs are still being determined, but given the fiscal climate facing the Navy now and in the future, EMALS technologies must be affordable and reduce the total life-cycle cost over the existing systems," he said. "These reductions in cost are directly related to the 30-percent reduction goal in the number of operators and maintainers required for the EMALS. Depot-level maintenance associated with EMALS is also expected to be reduced over the life-cycle of the carrier."
With these tests complete, the full-scale catapult was deemed operational on 13 November 2009 at a ceremony at Lakehurst, and the system began dead-load launching shortly thereafter. On 18 December 2010 the program reached its most meaningful milestone with the historic first launch of an aircraft using an electromagnetic aircraft catapult. An F/A-18E Super Hornet piloted by Lt. Daniel Radocaj of VX-23 took to the skies of eastern New Jersey following EMALS maiden launch. "I thought the launch went great," said Radocaj, echoing the statements of Edward Feightner more than 50 years before. "I got excited once I was on the catapult but I went through the same procedures as on a steam catapult. The catapult stroke felt similar to a steam catapult and EMALS met all of the expectations I had."
Since then, EMALS has launched a variety of aircraft from the older C-2A Greyhound to the F-35C, and its components are being delivered to Gerald R. Ford for installation.
More than a century has passed since Lt. Theodore G. Ellyson and his A-1 were launched into the brackish waters of Annapolis after the Navy's first unsuccessful catapult launch. Gunpowder, flywheels, and steam all took center stage in the long drama of launching aircraft during times of both war and peace. With the commissioning of Gerald R. Ford in 2016, EMALS will look to improve on the job of its siblings and ensure the skies above the oceans are kept full of winged sovereignty.
Caption: Engineers at Joint Base McGuire-Dix-Lakehurst, N.J., work on the EMALS trough at the System Functional Display site.
Caption: The Navy's first (unsuccessful) attempt to launch an airplane by catapult came in 1912, when Lt. Theodore G. Ellyson and his A-1 aircraft were thrown into the water at a test facility in Annapolis, Md.
Caption: A powder catapult was successfully demonstrated in the launching of an MO-1 observation plane from the forward turret of the battleship USS Mississippi (BB 41) in Bremerton, Wash., on 24 December 1924.
Caption: Lt. Cmdr. Henry Mustin, piloting an AB-2 flying boat, makes the first successful catapult launch from a ship while aboard USS North Carolina (ACR 12) in Pensacola Bay, Fla., on 5 November 1915
Caption: First tested in 1939, hydraulic catapults were installed on the Yorktown- and Essex-class carriers, as well as on all escort carriers. Many of the fleet carriers had hangar-deck catapults, as seen here, that were largely novelties and not widely used.
Caption: Catapults made it possible for the weighty Avenger, such as this TBM, to join the fleet during World War II when the torpedo-bomber's great size would have otherwise relegated it to land bases.
Caption: In the early 1950s, the U.S. Navy took advantage of British advancements in steam catapults to conduct their own tests of the new technology. Here, an F7U Cutlass tests a steam catapult at a facility in Philadelphia in 1953.
Caption: An E-2D Advanced Hawkeye launches using the Electromagnetic Aircraft Launch System at the full-size shipboard-representative test site at Joint Base McGuire-Dix-Lakehurst, N.J., on 27 September 2011. (Photo by Kelly Schindler)
Caption: An F/A-18E Super Hornet makes the maiden launch from the Electromagnetic Aircraft Launch System at Joint Base McGuire-Dix-Lakehurst, N.J., on 18 December 2010.
|Printer friendly Cite/link Email Feedback|
|Publication:||Naval Aviation News|
|Date:||Jun 22, 2013|
|Previous Article:||Warlords assist with Operation Guardian.|
|Next Article:||The day my maintainers saved my life.|