Simulation Evaluation of the Combat Value of a Standoff Precision Airdrop Capability

This project is a simulation evaluation of the developmental standoff precision airdrop (SOPAD) capability. SOPAD is a new technology under consideration to deliver supplies to forward-deployed units using either a semi-rigid wing or a guided parafoil. These delivery systems allow airdrop of supplies from altitudes of 25,000 feet and distances 25 miles from the delivery point. Using global positioning system guidance, on board navigational computers, and automatic steering mechanisms, the delivery system flies to the target following a designated flight plan. The concept includes delivering supplies to remote and potentially hostile areas without endangering the supply aircraft. In addition, supplies can be delivered to multiple locations from a single aircraft. The Air Force\u27s THUNDER model was used to simulate the SOPAD capability and observe the impact in the simulated combat environment. The scenario places a light infantry brigade in a position where supply by ground is prohibited due to terrain limitations and it must hold its position until relief forces are available. The unit must fight for a one-week period being resupplied only through airdrop. The results of the simulation are measured through aircraft attrition, unit strength, forward line of troops movement, and the supplies delivered to the unit

An application of a proposed airdrop planning system

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2004.Includes bibliographical references (p. 117).The United States military has always had an increasing need for more accurate airdrops, whether the drops are being implemented for various special operations missions, or for basic humanitarian relief. Improving the delivery accuracy of airdrops will result in numerous benefits. In attempting to improve airdrop accuracy, it is helpful to know what errors will arise throughout the course of a drop. This information is effective in revealing to the airdrop personnel what steps can be taken to improve the airdrop, as well as what the expected landing accuracy of the airdrop will be. This research converges on tools to assist in the estimation and improvement of airdrop landing errors. Wind estimation was studied to better understand the landing errors that stem from different wind prediction methods, as well as from onboard wind measurement systems. Other uncertainties, throughout each phase of an airdrop, are also known to produce landing errors, such as uncertainties in release conditions and parachute dynamics. These errors were implemented in airdrop simulations, for both unguided air release planning systems and guided airdrop systems, to determine the effects of these uncertainties on landing error. Error in wind estimation was found to be the largest source of error in the airdrop simulations. Guided systems were hypothesized to have much smaller landing errors than the unguided systems, and that hypothesis was confirmed in this study. One major benefit of using guidance was the ability to implement onboard wind measurement systems. Using the data from the simulation results, this information was combined to produce an airdrop planning aid to assist airdrop personnel in their aerial deliveries.(cont.) While the tool developed in this study is not a complete product, it represents a template on which to base further airdrop planning aids.by Lucas Jonathan Fortier.S.M

An Object Oriented Simulation of the C-17 Wingtip Vortices in the Airdrop Environment

This thesis effort focuses on the development of an object-oriented simulation of C-17 personnel airdrop operations and provides a tool for risk assessment of jumper and wingtip vortex interaction. Using the initial modeling efforts of the Wright Laboratory, this model expands those efforts to include random aircraft, wind and jumper movement within the simulation using MODSIM III as its language. Once the model was built, verified, and calibrated, it helped perform a preliminary analysis of jumper risk with varying element spacing and no crosswind. The results of the simulation provided 15 data points with which linear and logistic regression provided an estimation of the marginal rate of change of jumper/vortex encounter rate. Using the third order model shows that the encounter rate levels off around 24,000 feet spacing between element leaders at 12%, and stays as high as 11% at 32,000 feet before dropping to 0.4% at 34,000 feet. Further research and model improvements may bring the encounter rate down at the more distant spacing but that is left for post thesis analysis efforts

Estimating Cargo Airdrop Collateral Damage Risk

The purpose of this research is to determine an appropriate method for estimating cargo airdrop collateral damage risk. Specifically, this thesis answers the question: How can mission planners accurately predict airdrop collateral damage risk? The question is answered through a literature review and a thorough examination of a data set of real world airdrop scoring data. The data were examined to determine critical factors that affect airdrop error risks as well as to determine the characteristics of airdrop error patterns. Through this research it was determined that bivariate normal distributions with parameters pairs determined by empirical data are appropriate for modeling cargo airdrop errors patterns. Collateral risk is estimated by summing numerical integrations of a fit bivariate normal distribution for each drop type across rectangular representations of drop field objects in the field of concern. Airdrop altitude and chute type are found to make a statistically significant difference in airdrop error patterns while airdrop aircraft type does not appear to have a significant effect. This research methodology is implemented in an EXCEL spreadsheet tool that can be easily used by airdrop mission planners including an extension, requested by the research sponsors, to handle bundled drops that fall in a linear spread

Performance, Control, and Simulation of the Affordable Guided Airdrop System

This paper addresses the development of an autonomous guidance, navigation and control system for a flat solid circular parachute. This effort is a part of the Affordable Guided Airdrop System (AGAS) that integrates a low-cost guidance and control system into fielded cargo air delivery systems. The paper describes the AGAS concept, its architecture and components. It then reviews the literature on circular parachute modeling and introduces a simplified model of a parachute. This model is used to develop and evaluate the performance of a modified bang-bang control system to steer the AGAS along a pre-specified trajectory towards a desired landing point. The synthesis of the optimal control strategy based on Pontryagin's principle of optimality is also presented. The paper is intended to be a summary of the current state of AGAS development. The paper ends with the summary of the future plans in this area

Effects of Automation on Aircrew Workload and Situation Awareness in Tactical Airlift Missions

In tactical aviation, decision superiority brought upon by high situation awareness remains the arbiter of combat effectiveness. The advancement of sophisticated avionics and highly automated cockpits has allowed for the reduction of aircrew size, and in certain platforms, removal of the crew from the aircraft entirely. However, these developments have not reduced the complex and dynamic interaction between situation awareness and crew workload. While many predictive and experimental methods of evaluating workload exist, situation awareness can only be measured by conducting trials with human operators in a functional prototype. This thesis proposes an innovative methodology to predicatively determine situation awareness potential with discrete-event simulation software. This methodology measures situation awareness as both a function of task accomplishment and workload experienced. Utilizing two common but complex tactical scenarios, this method and existing workload measurement techniques can derive a direct comparison between a reduced-crew highly automated cockpit and a less automated legacy aircraft. Finally, conclusions regarding the effectiveness of replacing human operators with automation in tactical events can be made and tested in future experiments with actual aircraft and aircrews

Inland Resupply without a Road or Runway: Airdrop Solutions Including High-Altitude Precision Systems

Given the variety of airdrop options now available, it may be difficult to determine the best mix of paradrop and aircraft types to employ, how the chosen types affect delivery weight capacity and what the least cost would be for the operation while still accomplishing the mission regarding drop zone weight, altitude, offset, and accuracy requirements. This research creates a planning tool to analyze these decisions and also identify trends regarding the best aircraft and paradrop types to use considering cost and capability in a strategic rather than tactical setting. This is accomplished through the formulation of a linear program implemented as a spreadsheet model for several different scenarios. This research indicates that new high-altitude precision airdrop (HAPAD) systems will make conventional airdrop obsolete due to both cost and performance and that C-5 aircraft, if used, have the potential to dramatically increase airdrop capacity at competitive cost, particularly when using 30,000 lb HAPAD. Also, regarding cost, this research suggests airdrop system design life needs to match life expectancy and that all relevant costs must be included to make an accurate comparison with alternative resupply methods

C-17/Paratrooper Risk Assessment Analysis

The C-17 test and evaluation community has been testing different aircraft formation geometries in search of a configuration which minimizes paratrooper encounter with the wake vortices of upstream aircraft. This thesis develops a simulation tool that the C-17 test and evaluation community can utilize as an advanced risk assessment model to use on proposed formation geometries prior to live testing. The model is developed under the architecture of object-oriented simulation using MODSIM III and parallels similar efforts by the Aerodynamic Decelerator Technology community in creating object-oriented counterparts to already developed trajectory models of various degrees of freedom. This thesis develops the paratrooper object portion of the simulation model while the Petry thesis (1997) develops the C-17 aircraft and vortex objects. Once integrated with the Petry C-17 aircraft and vortex objects, and after verification and validation, the simulation model is applied to a simplified airborne operation scenario using the mean distance of paratrooper impact location to assembly areas and DZ dispersal distribution as MOEs for different aircraft formation geometries. Lateral separation is shown to have the most influence on both MOEs, while trail distance has minimal effects. For the airborne commander, this translates into operational parameters applicable to the choice of assembly areas and formation geometries. Further operational parameters of any significance are gained when coupled with the results from Petry on encounter rates between paratroopers and wake vortices where trail distance has a significant impact

Personnel Airdrop Risk Assessment Using Bootstrap Sampling

Previous work on personnel airdrop problems involving jumpers has been (1) event-oriented entanglement rates, (2) number of canopy bumps, (3) landing injuries, and (4) deaths. The thesis expands this area of research by developing cumulative distribution functions of maximum possible chute entanglement risk for the C-17 using bootstrap techniques. By comparing the effects of various C-17 aircraft configurations on the entanglement CDF, this thesis shows that under certain configurations the risk of centerline entanglement for the C-17 is less than for the C-141