SAWE Technical Papers

@inproceedings{3737,

title = {3737. Use of Mass Growth Allowance to Dynamically Manage Mass Risk},

author = {Zaid Karajeh},

url = {https://www.sawe.org/product/paper-3737},

year  = {2020},

date = {2020-07-01},

booktitle = {2020 SAWE Tech Fair},

pages = {6},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Virtual Conference},

abstract = {Management of mass budgets and the associated risks in the aerospace industry has positive impacts that affect delivery and launch of spacecraft. This paper presents a novel feedback control method to manage mass risk over the course of spacecraft design and production. The control method uses a dynamic upper and lower boundary formed as a function of heritage spacecraft mass risk. Spacecraft that deviate above the upper bound fall out of compliance and should trigger action. By observing how the risk mass varies over time with respect to the boundaries, scheduling risks could be identified preserving launch date and potentially acting as a cost saving effort for the spacecraft manufacturer.},

keywords = {19. Weight Engineering - Spacecraft Estimation, 26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3543,

title = {3543. Development of a Concept for a Weight Estimation and Calculation Tool},

author = {Andreas Schmidt},

url = {https://www.sawe.org/product/paper-3543},

year  = {2012},

date = {2012-05-01},

booktitle = {71st Annual Conference, Bad Gögging, Germany},

pages = {20},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Bad Gögging, Germany},

abstract = {This paper includes first steps of developing a concept for a weight estimation and calcula- tion tool. 

This tool should allow estimation of detail masses and overall mass of an aircraft concept, as well as calculating the centre of gravity of the aircraft concept. Calculation of mass mo- ments of inertia should be enabled in the tool, too. This calculation is important for any flight control system (FCS). 

The module for mass moment of inertia calculation was programmed during the author's diploma dissertation. 

The integration of data bases with empiric mass data of already developed and built aircraft plays an important role for mass estimation of new aircraft concepts. During aircraft devel- opment actual CAD-data should be imported to the tool for control of mass evolution during development process. 

The tool should allow documentation of mass data from the beginning of the development process till series-production readiness and certification of the new developed aircraft. 

The motivation for this tool began within the cooperation between Assystem and Dr. Jost Seifert. The idea of Dr. Seifert was to develop a new Rotorcraft based on a new concept for a propulsion system. This new concept called hybrid-rotor required new access to mass estimation, because there are no mass data available for already developed aircraft using such a propulsion system. 

Similar tools for conventional flight concept already exist in companies, but they can't han- dle such a concept as the so called Hybro. The developed concept in this paper combines skills of existing tools to a new tool.},

keywords = {26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3495,

title = {3495. Using PHP/MySQL to Manage Potential Mass Impacts},

author = {I. Benjamin Hager},

url = {https://www.sawe.org/product/paper-3495},

year  = {2010},

date = {2010-05-01},

booktitle = {69th Annual Conference, Virginia Beach, Virginia},

pages = {20},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Virginia Beach, Virginia},

abstract = {This paper presents a new application using commercially available software to manage mass properties 

for spaceflight vehicles. PHP/MySQL (PHP: Hypertext Preprocessor and My Structured Query 

Language) are a web scripting language and a database language commonly used in concert with each 

other. They open up new opportunities to develop cutting edge mass properties tools, and tools for the 

management of potential mass impacts (threats and opportunities). The paper begins by providing an 

overview of the functions and capabilities of PHP/MySQL. The focus of this paper is on how 

PHP/MySQL are being used to develop an advanced 'web accessible' database system for identifying 

and managing mass impacts on NASA's Ares I Upper Stage program, managed by the Marshall Space 

Flight Center. To fully describe this application, examples of the data, search, and view pages are 

provided to show, not only the function, but the security, ease of use, and simplicity of this new 

application. 

The premise behind this paper is that PHP/MySQL are software tools that are easy to use and readily 

available for the development of cutting edge mass properties applications. These tools are capable of 

providing 'real-time' searching and status of an active database, automated report generation, and other 

capabilities to streamline and enhance mass properties management application. By using 

PHP/MySQL, proven existing methods for managing mass properties can be adapted to present-day 

information technology to accelerate mass properties data gathering, analysis, and reporting, allowing 

mass property engineers, and the management they support, to keep pace with today's fast-pace design 

and development processes.},

keywords = {12. Weight Engineering - Computer Applications, 26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3454,

title = {3454. Submarine Trim Dive Weight Growth},

author = {David Tellet},

url = {https://www.sawe.org/product/paper-3454},

year  = {2008},

date = {2008-05-01},

booktitle = {67th Annual Conference, Seattle, Washington},

pages = {15},

address = {Seattle, Washington},

abstract = {This paper examines recent data from SSN 688 Class submarine trim dives that were accomplished prior to and after ma jor overhauls. The trim dives are used to determine unaccounted-for weight change prior to and during the overhaul and to verify that the submarines are properly ballasted coming out of the overhaul. The data show that there is a trend toward negative UWC in both incoming and outgoing trim dives (though this may be due to outliers) and that in both cases the range of UWC is greater than the variable ballast system can absorb. There doesn't appear to be a pattern of weight growth by shipyard. The magnitude of excess outfit values used has increased in the past few years. The outgoing UWC appears to be influenced more by the experimental error of the trim dive than by the excess outfit value used in the reballasting calculations. However, there is a correlation between the outgoing UWC and the excess outfit values used; using a value of -10 to -20 tons appears to reduce the risk of large UWC from the outgoing trim dive.},

keywords = {26. Weight Growth, Marine},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3412,

title = {3412. Influence of Changing Aircraft Masses on Flight and Mission Performance},

author = {Wolfgang Längler and Mario Zimmerman},

url = {https://www.sawe.org/product/paper-3412},

year  = {2007},

date = {2007-05-01},

booktitle = {66th Annual Conference, Madrid, Spain},

pages = {18},

publisher = {Society of Allied Weight Engineers},

address = {Madrid, Spain},

organization = {Society of Allied Weight Engineers},

abstract = {The influence of changing aircraft masses on different flight and mission performances is to be demonstrated. In order to make the effects clear, all parameters (engine, fuel quantity, external stores, etc.) but mass are kept unchanged. Some fundamentals of flight mechanics are shown and compared to results of computer simulations of several modern fighters.},

keywords = {10. Weight Engineering - Aircraft Design, 26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3382,

title = {3382. ISS Mass Properties Analysis Process},

author = {Greg Ray},

url = {https://www.sawe.org/product/paper-3382},

year  = {2006},

date = {2006-05-01},

booktitle = {65th Annual Conference, Valencia, California},

pages = {18},

publisher = {Society of Allied Weight Engineers},

address = {Valencia, California},

organization = {Society of Allied Weight Engineers},

abstract = {Providing mass properties analysis of the International Space Station is one of the primary responsibilities of the Vehicle Integration & Performance (VIPER) team of Boeing IDS, Space Exploration, Program Integration. This task has evolved over the life of the ISS program to be a cooperative exchange of data between Boeing, NASA?s prime contractor for the United States On-Orbit Segment (USOS) and Energia, the Russian Federal Space Agency?s primary contractor for the Russian Segment (RS). The primary use of ISS mass properties data is for input to the Guidance, Navigation and Control (GN&C) System for both the US and Russian systems. The existence of dual GN&C systems demands that both systems are using the same set of mass properties data at all times. This duality of systems has led to the creation of Mass Properties Data Exchange Protocols between NASA and RSC-Energia. Other primary users of ISS mass properties data and analysis include Loads & Dynamics, Stowage Integration, and Logistics & Maintenance. This paper will present the process by which ISS mass properties analysis is generated and reported to the multiple users in the ISS Program.},

keywords = {26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3362,

title = {3362. Space Shuttle Orbiter Weight Growth Resulting from the Challenger and Columbia Accidents},

author = {Loren Simons},

url = {https://www.sawe.org/product/paper-3362},

year  = {2005},

date = {2005-05-01},

booktitle = {64th Annual Conference, Annapolis, Maryland},

pages = {17},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Annapolis, Maryland},

abstract = {A comparison of the weight growth due to the two Space Shuttle accidents will be presented. First an overview of the Space Shuttle Transportation System (STS) will be provided, followed by a quick weight growth history of the orbiter element and then the accident boards finding/recommendations and their impact to the weight of the orbiter element.},

keywords = {26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{3166,

title = {3166. SH-60R Helicopter Overview with an Investigation into In-service Weight Growth},

author = {James Wampach},

url = {https://www.sawe.org/product/paper-3166},

year  = {2001},

date = {2001-05-01},

booktitle = {60th Annual Conference, Arlington, Texas, May 19-23},

pages = {19},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Arlington, Texas},

abstract = {The SH-60R is a medium-sized ship-based naval helicopter designed to replace the aging SH-60B Seahawk. Like the SH-60B, the main mission of the SH-60R is to extend the sensor range of frigates for anti-submarine warfare, as well as performing anti-surface vessel surveillance and targeting. The SH-60R multi-mission helicopter has upgraded avionics including the Lockheed/Martin LAMPS MK III Block II Upgrade. In addition to the avionics upgrade, the SH-60R will have a strengthened airframe to allow for increased gross take-off weights and extended life. Improvements in avionics and airframe will allow the new SH-60R multi mission helicopter to provide increased battle group protection and add significant capability in coastal and regional conflicts. 

The SH-60R is a key part of the U.S. Navy's Helicopter Master Plan, which calls for the integration of all helicopter types and models. The SH-60R has been chosen to replace all of the SH-60B and SH-GOF aircraft currently in service. Replacing these models with one reconfigurable SH-60R will reduce costs associated with naval helicopter operations. 

As part of this cost reduction effort, the SH-60R will utilize components from existing SH-60B aircraft removed from the fleet. Thus, the SH-60R will be a 'remanufactured' aircraft as opposed to an all-new aircraft. The tail cone, vertical tail, dynamic system, and several hundred other components from the inducted GFE aircraft will be reused and reassembled into the new SH-60R cockpit/cabin sections. 

The reuse of a large number of parts previously in service presents a challenge for the weight control engineer which is unique to a remanufacture type program. Parts that have been fielded for years are likely to have experienced weight growth due to field repairs, moisture accumulation, dirt, paint, maintenance, etc. Quantifying the weight impact of this in-service growth when preparing a weight derivation for this type of program is not a well-documented process. Short of weighing every GFE part, how can a weight control engineer account for this expected variation? 

The first section of this paper will be an overview of the SH-60R helicopter remanufacturing program describing the basic aircraft configuration and primary missions. Emphasis will be placed on aircraft weight control history from design to initial production. 

The second section of this paper is an investigation into in-service weight growth. In-service weight growth is any unplanned increase in part weight as a result of field use. Various approaches to account for in-service weight growth will be discussed, as well as providing a method for estimating this weight growth based on results obtained from the SH-60R program. It is hoped that the lessons learned from work done on the SH-60R program will aid mass properties engineers efforts in the future.},

keywords = {26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{2451,

title = {2451. RS-86 Weight History and Predicted Flight Weight},

author = {T A White},

url = {https://www.sawe.org/product/paper-2451},

year  = {1999},

date = {1999-05-01},

booktitle = {58th Annual Conference, San Jose, California, May 24-26},

pages = {10},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {San Jose, California},

abstract = {The RS-68 engine is being designed and developed by Rocketdyne Propulsion and Power, The Boeing Company. Rocketdyne is located in Canoga Park, California. The engine is being developed as a part of the Boeing Delta IV launch vehicle for use by commercial customers as well as the United States Air Force Evolved Expendable Launch Vehicle (EELV) program. The first launch of the new EELV is scheduled in 2001. The Boeing RS-68 engine is a high thrust, very low cost liquid oxygen / liquid hydrogen booster engine. The weight growth is covered from the original engineering estimate to the start of the hot-fire development test program. The total engine growth, components of growth, and comparisons of weight increase/decrease are presented. The RS-68 engine weight growth is compared to the Apollo-era F-l and J-2 engines, and to the Space Shuttle main engine.},

keywords = {26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{2482,

title = {2482. F/A-18E Weight Management - A Retrospective (What We Did Right and What We Could Have Done Better)},

author = {K Bocam},

url = {https://www.sawe.org/product/paper-2482},

year  = {1999},

date = {1999-05-01},

booktitle = {58th Annual Conference, San Jose, California, May 24-26},

pages = {40},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {San Jose, California},

abstract = {(None - PRESENTATION)},

keywords = {26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{2414,

title = {2414. Mass Properties Engineering - An Overview},

author = {G Mathews},

url = {https://www.sawe.org/product/paper-2414},

year  = {1998},

date = {1998-05-01},

booktitle = {57th Annual Conference, Wichita, Kansas, May 18-20},

pages = {14},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Wichita, Kansas},

abstract = {This paper provides an overview of mass properties engineering as viewed from the perspective of satellite mass properties. Discussion includes the products of mass properties engineering, who uses them, expected knowledgeability, and involvement of the mass properties engineer (MPE) in a given program. Analysis, weight control, and verification are also discussed to provide visibility into the mass properties engineering activities.},

keywords = {26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{2294,

title = {2294. F-22 Weight Control Management},

author = {No Author},

year  = {1996},

date = {1996-06-01},

booktitle = {55th Annual Conference, Atlanta, Georgia, June 3-5},

pages = {-1},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Atlanta, Georgia},

abstract = {(None)},

note = {Paper Missing},

keywords = {26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{2319,

title = {2319. 40 Years of Rotary Wing Technology ''What Happened to Weight Empty''},

author = {R Gilliam},

url = {https://www.sawe.org/product/paper-2319},

year  = {1996},

date = {1996-06-01},

booktitle = {55th Annual Conference, Atlanta, Georgia, June 3-5},

pages = {27},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Atlanta, Georgia},

abstract = {(None)},

keywords = {26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{2240,

title = {2240. Weight Control in the Manufacturing Environment at Erda, Inc.},

author = {R. Alan Bird},

url = {https://www.sawe.org/product/paper-2240},

year  = {1995},

date = {1995-05-01},

booktitle = {54th Annual Conference, Huntsville, Alabama, May 22-24},

pages = {9},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Huntsville, Alabama},

abstract = {The aspect of weight control, to many individuals, seems to end with the completion of the design cycle. The potential for uncontrolled weight growth in an atmosphere where this thought pattern exists is unbelievably high. As a subcontractor to aircraft manufacturers and completion centers, we are very often given weight constraints for seating designs. It is our responsibility to manage our programs so that the not to exceed (NTE) weight values are indeed not exceeded. This paper shows several examples of how the weight of delivered chairs grew, and how process checks were utilized to control the weight growth. Starting with the Weight Engineer, probably the greatest contribution that can be made to a program, is to simply follow it. It does not take a great deal of time and/or effort to manage a weight control program compared to the extreme cost and aggravation associated with a weight reduction program. At ERDA, we are constantly faced with a variety of ?opportunities? that, if left unchecked, will result in unauthorized weight growth. With the average structural weight of our seats coming in at around 29.0 pounds, the addition of any weight is a large percentage of the total. Topics or areas that have been targeted are drawing/design revisions, cost saving procedures, assembly techniques, attitudes in manufacturing, and the lack of training and/or communications within the project team. In this paper, these topics are not listed in any particular order of priority.},

keywords = {26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{2241,

title = {2241. Weight Management/Ten Improvement Initiatives Applied to the F/A-18E},

author = {J F Conaway and D Nega},

url = {https://www.sawe.org/product/paper-2241},

year  = {1995},

date = {1995-05-01},

booktitle = {54th Annual Conference, Huntsville, Alabama, May 22-24},

pages = {26},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Huntsville, Alabama},

abstract = {(None - PRESENTATION)},

keywords = {26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{2242,

title = {2242. V-22 Weight Management},

author = {S W Harris and W Mikus},

url = {https://www.sawe.org/product/paper-2242},

year  = {1995},

date = {1995-05-01},

booktitle = {54th Annual Conference, Huntsville, Alabama, May 22-24},

pages = {37},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Huntsville, Alabama},

abstract = {(None - PRESENTATION)},

keywords = {26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{2284,

title = {2284. Mass Growth and Mass Control in UK Projects},

author = {J S Smith},

url = {https://www.sawe.org/product/paper-2284},

year  = {1995},

date = {1995-05-01},

booktitle = {54th Annual Conference, Huntsville, Alabama, May 22-24},

pages = {15},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Huntsville, Alabama},

abstract = {This paper discusses the mass growth of military aircraft during development from a UK perspective. The paper outlines the military aircraft procurement process as practiced in the UK, and draws attention to the importance of both International Collaboration and ?off-the-shelf? purchases in recent UK procurement projects. Some implications of the different procurement approaches on the control of mass growth are indicated, and the importance of the impact of the procurement process on the causes of mass growth, and the means of mass control, is stressed. The paper indicates the causes of aircraft mass growth during development, and describes some of the measures available to both Government and Industry to minimize development mass growth. The experience of development programs over the last twenty years or so is examined to show the effects of improvements in the mass prediction process. Finally, the current situation in the UK is examined, to identify lessons learned from the past projects, and to indicate the challenges which are considered to lie ahead.},

keywords = {26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{2188,

title = {2188. The Development of a Light Weight, Dynamically Certifed Chair for Cessna Citation Jets},

author = {R. Alan Bird},

url = {https://www.sawe.org/product/paper-2188},

year  = {1994},

date = {1994-05-01},

booktitle = {53rd Annual Conference, Long Beach, California, May 23-25},

pages = {11},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Long Beach, California},

abstract = {ERDA, inc., located in Peshtigo, Wisconsin, is a manufacturer of custom seating for business and executive aircraft, with worldwide markets. Although relatively small in size, (in the neighborhood of 150 people), weight control and weight reduction activities are very much a prime concern. My responsibilities involve the determination of structural weight during design and then concurrently with production. Every chair that leaves ERDA is weighed. The weight is then recorded along with the chairs' serial number for reference. In April of 1993, ERDA received a contract from Cessna Aircraft Corporation to design and construct an executive seat for their Citation Jet, model 525. (For ease of discussion, I will refer to the aircraft from this point on as the Cessna 525.) This was one of the most challenging programs that I have worked on. The requirements for this design were dictated by the Federal Aviation Administration (FAA), by invoking the Federal Aviation Regulation (FAR) part 23.562. This is a new regulation for aircraft interiors that go in new airframes. In general, all components are to be able to withstand 21g's of force in the forward direction, and 16g's in the down direction. It is an extremely demanding design challenge; so much that it took over 2000 engineering hours to complete the chair design. Cessna required that the seat structures weigh not more than 20 pounds each in order to keep the Cessna 525 within their weight allowance. This, as a starting point, was already eight pounds lighter than a typical ERDA chair that isn't dynamically certified. With the award of the contract ERDA management assembled a team of engineers and designers to focus completely on the design. The initial direction was to modify an existing seat design, making components as light as possible and then beef up the parts as they failed testing. This sounds great from a weight engineering standpoint, but for a stress engineer, the thought of chasing load paths around was unfathomable. Within the first day of the project it was obvious that this was not the correct approach. A full fledged effort began designing radically different, light weight components using a variety of glass/graphite composites, high strength aircraft aluminum alloys, and honeycomb panels. From a simple design stand point the typical base, or pedestal, is engineered to be a functional, structural platform for a seat to operate on. Up to this point, a pedestal did not need to absorb energy, but only transfer the energy into the aircraft's airframe. After several brainstorming sessions the decision was made to pursue a concept that would allow the pedestal to deform non-elastically, but not fail. The methodology was to utilize a ''legged'' pedestal that would lay over and deform as the energy shock went through the chair.},

keywords = {26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{2230,

title = {2230. Weight Growth: A Process and Its Utility},

author = {G S Mathews},

url = {https://www.sawe.org/product/paper-2230},

year  = {1994},

date = {1994-05-01},

booktitle = {53rd Annual Conference, Long Beach, California, May 23-25},

pages = {12},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Long Beach, California},

abstract = {This paper introduces a vocabulary, process, and process utility to deal with satellite weight growth. A vocabulary is developed to describe three major sources of growth: out-of-scope growth, in-scope allocated growth, and in-scope unallocated growth. A process is developed to utilize historical weight growth and its various sources, and the weight maturity of the satellite to compute and deplete the weight growth. And finally, discussion on the utility of the above process (minimizing weight, control weight development, specified weight, and the weight maturity index as a metric.},

keywords = {26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}

@inproceedings{2110,

title = {2110. A-12 Structural Target Weight Distribution Using the Finite Element Model (FEM)},

author = {S J Zaidel},

url = {https://www.sawe.org/product/paper-2110},

year  = {1992},

date = {1992-05-01},

booktitle = {51st Annual Conference, Hartford, Connecticut, May 18-20},

pages = {13},

publisher = {Society of Allied Weight Engineers, Inc.},

address = {Hartford, Connnecticut},

abstract = {The distribution of parametric weight estimates into detail structural component (target) weights is a difficult and time consuming process. Traditional methods use a high percentage of historical data and are not very responsive to advanced structural concepts. More accurate procedures are needed to establish better credibility as well as identify potential overweight areas earlier in an aircraft program. Use of the Finite Element Model (FEM) in distributing structural target weights was applied for the first time at McDonnell Aircraft (MCAIR) on the A-12 Project. The FEM contained the level of detail necessary to establish major structure target weights for the unique aircraft design and also provided traceability back to the strength analyses. Weight factors were derived to adjust the baseline stiffness model to represent detailed target weights. Additionally, the FEM was used as a check on the structural subsection weight distribution between MCAIR and its A-12 partner General Dynamics. The methodology developed has benefited related R&D projects and other aircraft programs (including the F/A-18E/F) which are using the FEM as a weight estimation and control tool. NOTE: Due to the sensitive nature of information related to the A-12 program, this paper has omitted data considered classified or which may give a competitive edge to any of the teams involved in the AX program.},

keywords = {26. Weight Growth},

pubstate = {published},

tppubtype = {inproceedings}

}