ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard...

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Mission statement from Program Executive Office Carriers •“To support and operate aircraft to engage in attacks on targets afloat and ashore which threaten our use of the sea and to engage in sustained operations in support of other forces.” • In order to do this we must be able to launch a wide variety of aircraft while at sea. •The current steam catapults cannot launch the proposed future aircraft, particularly the next generation of
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Transcript of ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard...

Page 1: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

Mission statement from Program Executive Office Carriers

• “To support and operate aircraft to engage in attacks on targets afloat and ashore which threaten our use of the sea and to engage in sustained operations in support of other forces.”

• In order to do this we must be able to launch a wide variety of aircraft while at sea.

• The current steam catapults cannot launch the proposed future aircraft, particularly the next generation of unmanned vehicles.

Page 2: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

What is needed to resolve this?

• The C13-2 catapults steam catapults on the existing Nimitz Class aircraft carriers have to be substantially upgraded in their capabilities to be able to carry out the mission statement of the Carrier Program Executive Office.

• This requires conversion to closed loop control of the launch and an increase in launch power.

• This can be accomplished by integration of the ICCALS technology into the existing C13 steam catapults.

• This also requires a reduction in required manpower to operate and maintain the catapults.

Page 3: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

The Internal Combustion CatapultThe Early Days

The C14 Internal Combustion Catapult (ICCALS) was developed in the 1950s and successfully launched planes in 1959. See C14 and History on “about us” page of web site http://launch-services.com

Used the same launch engine as the steam catapult. Was more powerful than the steam catapult. Used JP5 and compressed air burned in a single

large combustor to develop pressurized launch gas.

Page 4: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

C14 Catapult Operational in 1959 at NAWC Lakehurst

Page 5: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

C14 Catapult History (continued)

Inability of C14 catapult to deliver consistent end speeds to launched aircraft and “manmade reliability issues” removed it from consideration for USS Enterprise. Replaced by the C13 steam catapult aboard the USS Enterprise at new construction.

Bank of large air compressors intended to supply the C14 catapult still aboard the Enterprise.

1950’s technology ready to support the ICCALS catapult technology in spite of “reliability issues” and 2010’s technology is ready to support an internal combustion catapult superior to either the steam catapult or EMALS

Page 6: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

ICCALS Technology Updates

Technology changes made to improve the technical viability and performance of the Internal Combustion Catapult:• More efficient oxidizer and oxidizer management• Subdivision of the combustion event into multiple

combustors which average out combustion instabilities to deliver a smooth and controllable highly variable mass flow of combustion gas and steam from the combustor assembly to the launch engine.

• A controlled constant or increasing launch acceleration pressure during the launch event over the length of the launch stroke

Page 7: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

• Updated control system to incorporate a technological quantum leap in computer control of the combustion event.

• Use of modern combustion technology as used by automotive technology and NASA technology.

• Use of modern ignition, combustion control and injection technology.

• Rising acceleration rather than falling acceleration during the launch stroke like the C13 steam catapult.

ICCALS Update Requirement (continued)

Page 8: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

What is needed for Carriers? Our catapult fleet requires a backfit capable catapult

technology that provides EMALS-like capabilities for existing carrier catapults

The ICCALS catapult modification meets and exceeds all of the capabilities that EMALS claims.

With full closed loop control, peak to mean acceleration will be minimized just as EMALS

The ICCALS catapult is lighter, cheaper, more powerful, more space efficient, is based upon current technology and requires little development.

Page 9: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

ICCALS Benefits

Relative to the C13-2 steam catapult the ICCALS catapult:• Uses less ship internal volume than the C13-2

catapults.• Costs and weighs less than the C13-2 catapult.• Is more powerful than any of the alternatives.• Can maintain low peak to mean acceleration and

control of the launch event similar to EMALS• Can launch a wide range of planes from UAVs or

UCAVs to fighter-bombers and sled launched TLAM and TASM cruise missiles, ATACMs and self defense missiles such as Sea Sparrow

Page 10: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

ICCALS Benefits

• Costs less than either of the alternative catapult.• More efficient use of ship volume.• Is current technology with almost all of the

components off the shelf. The system can operate with all COTS hardware, but would be more efficient with optimized hardware.

• Makes little demand on the propulsion plant and reduces reactor fuel burn-up. Only need spray water for cooling and steam which is less than 3% of the 1320 pounds of water per launch required for the C13-2 steam catapult.

• Removes significant topside weight which aids ship stability.

Page 11: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

ICCALS Benefits

• Steam delivers 75 Megajoules of energy, EMALS delivers 122 Megajoules of energy. ICCALS delivers more than 792 Megajoules of energy, based upon 6 gallons of JP5 (Kerosene) per launch

• Total power developed for ICCALS is a function of the number of combustor modules deployed and fuel burned per unit time.

• Operation at a higher pressure provides even more launch energy.

• The system can be built and tested NOW.

Page 12: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

What Needs To be Done?

Initial system architecture definition. Initial design studies and hardware tests. Demonstration of concept feasibility and

continuation of technology development. Preliminary ship integration studies. Prototype construction and test of the combustor

assemblies. Assembly and test of ICCALS at land based or

existing (mothballed) carrier C13 catapult.

Page 13: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

Technology alternatives

• Allows alternative ship concepts and ship types to function as aircraft launch and recovery platforms like the baby flat-tops of WWII.

• Allows backfit of ICCALS system into the existing Nimitz Class Carriers providing catapults that exceed the capability of the present or planned catapults while providing ¾ of a million pounds topside weight reduction over 50 ft above waterline and eliminating the “launch box” wind over deck requirement.

• EMALS cannot be backfit into the Nimitz Class Carriers

Page 14: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

Proposed ICCALS Team Members

NAVSEA PEO CARRIERS NAVAIR PMA 251 Huntington Ingalls Industries Inc Stallard Associates NAWC Lakehurst Old Dominion University NASA ATK

Page 15: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

Plan Of Action

Set up proposed team. Determine schedule constraints and funding

requirements. Brief appropriate officials as requested Conduct presentations as required to other NAVAIR

and NAVSEA activities. Seek funding to backfit one selected carrier at

refueling overhaul or at Selected Restricted Availability (120 days)

Page 16: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

Plan Of Action (Cont.)

Identify construction need dates for critical hardware. Identify availability of C13-2 existing launch hardware. Construct test bench, then build and test combustors. Demonstrate a combustor assembly producing launch

pressure gasses to duplicate launch requirements for gas production for the lightest and heaviest anticipated launch vehicle.

Page 17: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

ICCALS INTEGRATED PRODUCT TEAM

PEO CVN 78 - Program Lead Management PMA 251 and Stallard Associates – Technical

development and production schedule lead. NSWC Lakehurst catapult engineering. Design of

optimized control system for the ICCALS catapult and conduct ICCALS assembly and qualification testing.

Old Dominion University. Engineering support and systems and engineering review. Participate in technology development of new catapult capabilities.

Page 18: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

ICCALS INTEGRATED PRODUCT TEAM

HII for shipboard system integration, appropriate systems engineering, integration drawing production schedule and catapult modification/installationTiger Team .

NASA – Support combustor and feed system design and igniter lead or support.

Page 19: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

ICCALS INTEGRATED PRODUCT TEAM

Team with NSWC Indian Head for Naval shipboard integration of oxidizer technology as applicable.

Team with NASA, Stallard Associates and ATK for liquid propellant combustor and fuel/oxidizer feed design.

Team with HII for shipboard system integration, hardware need dates, shipboard integration into construction schedule and appropriate systems engineering.

Page 20: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

ICCALS INTEGRATED PRODUCT TEAM

PEO CVN78 Program Office (PMA 378) provide program management for ICCALS Internal Combustion Catapult technology development.

PMA 251 and Stallard Associates to support program management and provide development, design and engineering oversight.

NAWC Engineering, Lakehurst test facility• Provide catapult requirements and integration

engineering to integrate C13-2 launch engine with ICCALS catapult combustor modules and control system.

• Provide engineering/assembly services to temporarily remove C13-2 launch valve and mount ICCALS manifold and combustors for qualification testing at ground based catapult.

Page 21: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

NAWC Test Site Management

NAWC will accomplish the following:• Modify a C13 land based catapult using team supplied

manifolds to accept the prototype ICCALS steam and combustion gas generators.

• Manage temporary trailer mounted fuel and oxidizer delivery systems provided by team

• Provide temporary modifications to the C13 control system as appropriate to accommodate the ICCALS control system.

• Conduct test launch program as required to prove technology viability as soon as feasible.

Page 22: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

ICCALS 1990s Clint StallardSignificant Events

Numerous meetings with PMA 251 and team members 1995-1998

Visited NAWC, Lakehurst, NJ several times to site check the ground based C13 Mod 0 and C13 Mod 2 launchers. Determined that temporary backfit of the ICCALS system is feasible for the C13-0 catapult or the C13-2 catapult

Hosted a carrier tour for team personnel. Inspected catapults, control rooms, accumulators and steam piping areas of ship.

Constructed and successfully tested combustors jointly with Thiokol (ATK).

Page 23: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

ICCALS 1990sSignificant Events

Presentations to Captains Vandenberg, N885 and O’Hare, PEO CVN 77

Captain O’Hare indicated a desire to have one of the ICCALS cats as cat 4 on his ship• Drop-dead dates and installation strategies were

discussed for CVN 77• Ship-wide benefits of the ICCALS catapult were

discussed by both Captains.

Page 24: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

ICCALS Program Termination

In May of 1998, NNS management decided that it would be more desirable to the Navy for NNS to support EMALS, thus NNS terminated my ICCALS program and clarified the NNS role of systems integrator and not technology competitor.

The ICCALS program was producing and testing hardware when it was terminated, leaving only the General Atomics electromagnetic catapult in competition as a systems supplier in place of the C13-2 steam catapult

Page 25: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

Initial Task Goals FOR 2011

Provide rationale to NAVSEA and Congress for acceptance and funding of the ICCALS program. An additional benefit of the ICCALS technology is that it can act as a fall-back option if EMALS slips further on CVN78 (it was originally supposed to have gone on CVN77)

Provide to NAVSEA and Congress the urgency for ICCALS program funding to insure meeting the current CVN78 build schedule.

Page 26: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

Initial Task Goals FOR 2011

Provide the programmatic and technical basis for ICCALS design and development.

Start production of test hardware and control system design update.

Page 27: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

Task DeliverablesFor The ICCALS Catapult

Technology development team identified. System preliminary design and component

identification. Produce supporting analysis for verification of design performance

Produce concept drawings, construction drawings and interface drawings for catapult construction and insertion into CVN78.

Support Navy PMA 251-Stallard Associates position as technical lead

Design, construct, test and deliver prototype hardware to NAWC Lakehurst for integration into the ground based C13 catapult launch engine for qualification testing.

Page 28: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

Where We Are Now

The ICCALS catapult offers a better fall-back option for CVN78 if the EMALS catapult has developmental delay causing slip to CVN79. Compared to the steam catapult, it has a much lower installed cost, lower installed weight, lower in-hull volume consumption and lower impact to ship design, stability and ship construction.

The ICCALS catapult provides a more affordable, more powerful, more capable and easily installed catapult launch option for CVN78 than the steam catapult if EMALS has to slip to CVN79.

Page 29: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

Budgeting for the future

Current additional projected CVN78 budget over-runs driven by catapult technology are estimated to be up to $560 million.

Total costs for an ICCALS system installed are estimated to be less than $25 million for the first catapult and less than $10 Million each for following installations. Could install ICCALS on 10 operating carriers for $415 million.

Installation of EMALS hardware into land based

prototype starts no later than 7 months after funding.

Page 30: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

Why Do We Need To Do This?

We need this technology to be built and qualified so as to allow the existing carrier fleet to have the launch capabilities defined as needed for the future Naval Air fleet and currently intended to be met on future carriers by EMALS which is not backfittable to the current Nimitz Class carriers

Page 31: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

Why DO WE NEED TO DO THIS (cont)

7 months is sufficient time to build and start testing an ICCALS prototype system, using existing Naval catapult assets. This rather ambitious schedule is based upon almost all of the hardware being off the shelf with developmental effort being at a minimum.

The greatest effort will be in updating and validating the current FY1998 control system design.

Page 32: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

In Conclusion, The ICCALS Benefits

Relative to both the C13-2 steam catapult and the EMALS catapult, the ICCALS catapult:• Is basically off the shelf • Very little development required• Uses less ship internal volume• Weighs less and costs much less• Is more powerful than either of the alternatives.• Can maintain low peak to mean acceleration• Can launch a wide range of planes from UAVs to

fighter-bombers and cruise missiles and ATACMs using a special launch sled.

• Can be installed on other platforms

Page 33: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

Additional ICCALS Benefits

Reduces the required Tavg for the reactor/core burn-up by elimination of ship-produced catapult steam and 1320 lbs of distilled water required per C13-2 launch.

Eliminates the requirement to do high speed runs within the launch box for aircraft launch

Eliminating either/both will extend core life.

Page 34: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

Additional ICCALS Benefits

Maintaining a constant or increasing acceleration of the plane being launched reduces or eliminates the wind over deck requirement and the launch box

Saves over 760,000 pounds topside weight compared to the C13-2 steam catapult.

Page 35: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

Additional ICCALS Information

ICCALS is backfittable at low cost to all of the C13-1 and C13-2 operational carriers, providing a great increase to the fleet in capability, both offensive and defensive and range of vehicles launched.

EMALS is not backfittable to the Nimitz Class cariers.

Additional combustion catapult information is available at Bob Holland_com

Page 36: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

ICCALS Cost and Savings

The ICCALS upgrade should much more than pay for itself just in reduction of replacement costs of air wing aircraft due to airframe life extension and in the shipboard manpower reduction for operation and maintenance of the simplified C-13-2 catapult, particularly as these savings continue post-installation for the remaining 25 year life of the ship. 

    costs such as an EMALS-like system (1.29 billion up front costs and estimated 50 million per catapult per the Queen Elizabeth EMALS bid, not counting the additional generating capacity required to gain the capability provided by the ICCALS upgrade to launch a wider range of vehicle weights and end speeds at a highly controlled rate of acceleration

Page 37: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

ICCALS Cost and Savings

A savings of 170 personnel (11% of 1550 support air crew) at $30,000 each per year over half the life of the ship (25 years) equals $127.5 million dollars which is more than ten times the cost of the ICCALS upgrade per catapult. 

Page 38: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

ICCALS Cost and Savings

For an air wing of 58 planes at an average procurement cost of $58 million, the aircraft investment is $3,306 million. Therefore, a 10% life extension over 25 years due to airframe launch stress reduction is worth $330.6 million or a total savings of (330.6+127.5)/25= $18.3 million savings per year.

 

Page 39: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

ICCALS Cost and Savings

Given this number, an ICCALS upgrade should have a payback period of 2.84 years and a savings of $405 million over the remaining 22 years of of the remaining 25 year life of the carrier. 

Page 40: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

ICCALS Cost and Savings

For 12 carriers, that is a net operating savings of more than 4.866 billion dollars over an average operating life of 25 years after refueling.  If installed at new construction, the ICCALS savings would be $9.736 billion dollars compared to steam launch over the 50 year life of the carriers.

Page 41: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

Contact Information

For additional information please contact Clint Stallard [email protected] [email protected] Stallard Associates

757-325-8298 Office

757-846-4814 Cell

http://launch-services.com

Page 42: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

Lakehurst Naval Air Warfare Ctr1959 with C14 catapult installed

Page 43: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

http://www.bobholland.com/me/reaction3.htm.com

After the X-15 project I was transferred to the Internal Combustion Catapult project. (1950s).Ok, You say "What is that?". First let me explain the catapult.

Planes that require flying speed are launched from an aircraft carrier by a catapult using high pressure steam. The problems with this are:

• Fresh water is needed to generate the steam • As the catapult moves the pressure drops. The initial

"kick" is very high and then the acceleration drops off. The plane and pilot may be subjected to as much as 5G's at the start to get enough speed to get airborne.

This is why aircraft carriers always turn into the wind and increase speed to launch planes. To conserve fresh water and reduce stress to pilots and planes.

Page 44: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

From Bob Holland.com (continued)

Reaction Motors designed a system with a rocket engine that burned jet fuel and added salt water to generate the steam.

Both jet fuel and salt water are readily available at sea. The engine produced constant pressure throughout the launch and a plane could be launched with as little as 2G's of constant acceleration.

This means that aircraft could be launched with less stress and even at flying speed downwind.

Page 45: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

From Bob Holland.com (continued)

I was transfered to Lakehurst New Jersey. The left catapult is steam, the center was the Reaction Motors catapult and the large building to the right is the steam house required to generate the steam for the steam catapult.

Right about now you are probably wondering "if this thing was so great then why are we still using steam catapults?

Page 46: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

From Bob Holland.com (continued)

The answer is very simple. In the latter stage of the project we turned the

catapult operations over to Navy personnel. The arrangement was that if there were any problems the Navy personnel could go home while we fixed it.

DUH

Page 47: ICCALS INTERNAL COMBUSTION CATAPULT AIRCRAFT LAUNCHER Presented By: Clint Stallard Stallard Associates 10-21-2011.

From Bob Holland.com (continued)

Yup, we had problems. Leaks, cut wires, loose fittings, water in the hydraulics, you name it. Anything the sailors could think of so they could get off work.

The boys in Washington looked at the numbers and in their infinite wisdom decided that the system was too unreliable.

I worked on both catapult systems and believe me, the Reaction Motors system was far superior, less expensive and more effective.