The U.S. commercial space launch industry has changed considerably since the enactment of the Commercial Space Launch Amendments Act of 2004. FAA is required to license or permit commercial space launches, but to allow the space tourism industry to develop, the act prohibited FAA from regulating crew and spaceflight participant safety before 2012—a moratorium that was later extended but will now expire on September 30, 2015. Since October 2014, there have been three mishaps involving FAA licensed or permitted launches.

美聯邦航空廳(Federal Aviation Administration)의 航空機 製作檢査 制度의 現況

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Scaling Constraints for Urban Air Mobility Operations: Air Traffic Control, Ground Infrastructure, and Noise

The continuous-descent approach is among the key concepts of the Next Generation Air Transportation System. Although a considerable number of researchers have been devoted to the estimation of potential fuel savings of the continuous-descent approach, few have attempted to explain the fuel savings observed in field tests from an analytical point of view. This paper focuses on the evaluation of the continuous-descent approach as a fuel-reduction procedure. This research gives insights into the reasons why the continuous-descent approach saves fuel, and design guidelines for the continuous-descent-approach procedures are derived. The analytical relationship between speed, altitude, and fuel burn is derived based on the base of aircraft data total-energy model. A theoretical analysis implies that speed profile has an impact as substantial as, if not more than, vertical profile on the fuel consumption in the terminal area. In addition, the continuous-descent approach is not intrinsically a fuel-saving procedu...

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Investigation of Potential Fuel Savings Due to Continuous-Descent Approach

Optimized profile descent (OPD) is an operating procedure being used by airlines to improve fuel and environmental efficiency during arrival operations at airports. In this study, we develop a stochastic dynamic programming framework to manage the sequencing and separation of flights during OPD operations. We find that simple calculation based measures can be used as optimal decision rules, and that the expected annual savings can be around $29 million if such implementations are adapted by major airports in the United States. Of these savings, $24 million are direct savings for airlines due to reduced fuel usage, corresponding to a potential savings of 10%–15% in fuel consumption over current practice. We also find that most of these savings will be due to the optimal spacing of OPD flights, as opposed to the optimal sequencing policies which contribute only 14% to the total savings. Hence, optimal spacing of OPD flights is much more important than optimal sequencing of these flights. We also conclude that there is not much difference between the environmental costs of fuel-optimal and sustainably-optimal spacing policies. Hence, an airline-centric approach in improving OPD operations is likely to be not in conflict with objectives that might be prioritized by other stakeholders.

Lower Cost Arrivals for Airlines: Optimal Policies for Managing Runway Operations under Optimized Profile Descent

The current research focuses on predictability, variability and operational feasibility aspect of Continuous Descent Arrival/Approach (CDA), which is among the key concepts of the Next Generation Air Transportation System (NextGen). The idle-thrust CDA is a fuel economical, noise and emission abatement procedure, but requires increased separation to accommodate for variability and uncertainties in vertical and speed profiles of arriving aircraft. Although a considerable amount of researches have been devoted to the estimation of potential benefits of the CDA, only few have attempted to explain the predictability, variability and operational feasibility aspect of CDA. The analytical equations derived using flight dynamics and Base of Aircraft Data (BADA) Total Energy Model (TEM) in this research gives insight into dependency of vertical profile of CDA on various factors like wind speed and gradient, weight, aircraft type and configuration, thrust settings, atmospheric factors (deviation from ISA (DISA), pressure and density of air) and descent speed profile. Application of the derived equations to idle-thrust CDA gives an insight into sensitivity of its vertical profile to multiple factors. This suggests fixed geometric flight path angle (FPA) CDA has a higher degree of predictability and lesser variability at the cost of non-idle and low thrust engine settings. However, with optimized design this impact can be overall minimized. The CDA simulations were performed using Future ATM Concept Evaluation Tool (FACET) based on radar-track and aircraft type data of the real air-traffic to some of the busiest airports in the USA (ATL, SFO and New York Metroplex (JFK and EWR)). The statistical analysis of the vertical profiles of CDA shows 1) mean geometric FPAs derived from various simulated vertical profiles are consistently shallower than 3° glideslope angle and 2) high level of variability in vertical profiles of idle-thrust CDA even in absence of uncertainties in external factors. The present investigation also suggests that prediction and guidance of fixed FPA descent trajectory by the performance based Flight Management System (FMS) would help in reduction of unpredictability and variability associated with vertical profile of aircraft guided by the FMS coupled with auto-pilot (AP) and auto-throttle (AT). The statistical analysis of the vertical profiles of CDA also suggests that for procedure design; ‘AT or above’, ‘AT or below’ and ‘Window’ type altitude constraints and FPA constraints are more realistic and useful compared to obsolete ‘AT’ type altitude constraint because of variability in vertical profiles.

Predictability, variability and operational feasibility aspect of CDA

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Flight Trials of CDA with Time-Based Metering at Atlanta International Airport

The initial spacing applied between departing aircraft is a major factor affecting the efficiency of departure operations at an airport. When departure operations are conducted under Instrument Flight Rules (IFR), successive in-trail departures must be provided a minimum of 3 nautical miles (NM) radar separation unless visual separation is applied. However, if the departure paths diverge by 15 degrees or more immediately after takeoff, reduced initial spacing can often be applied: separation is provided by the increasing lateral distance between the aircraft rather than by a fixed in-trail distance. The smaller initial spacing when diverging departures can be conducted leads to more departures per hour. This paper explores options for application of efficiency-enhancing reduced departure spacing and presents the concept of a single separation rule, the Unified Departure Operation Spacing (UDOS) concept, where the same reduced initial spacing is generally applied whether or not the departure paths diverge. The paper reviews the currently applicable standards, describes the analysis and simulation approaches taken to assess longitudinal spacing observed in actual operations, and provides estimates of potential operational benefits.

Concept and benefits of a unified departure operation spacing standard

Reinventing High Density Area Departure Traffic Management

The advent of Required Navigation Performance (RNP) capabilities enabled the development of the Established-on-RNP (EoR) approach concept. Flight validations of the concept are currently being conducted at Denver International Airport (KDEN) to demonstrate the operational viability of independent parallel EoR approaches to widelyspaced runways. The validations complement ongoing studies to determine the acceptability of routine EoR operations from a safety aspect. Broader application of EoR operations and the ability to realize associated benefits throughout the National Airspace System (NAS) largely hinge on aircraft RNP equipage levels and achieved navigational performance to safely support approaches to runways with closer centerline spacing. This paper explores options to leverage Performance-Based Navigation (PBN) capabilities commonly available on modern transport category aircraft to enable NAS-wide use of curved flight paths and same-altitude turns to independent final approaches for landing on parallel runways. Initial findings suggest that leveraging design flexibilities to increase the lateral spacing between turns to angled approach paths may facilitate PBN-based approach applications and enhance operational safety. The paper reviews the separation standards and air traffic control requirements currently applicable to parallel approach operations, presents procedure design concepts that capitalize on PBN-enabled design flexibility, outlines key benefits of associated operational changes, and identifies potential applications.

Concept and Benefits of PBN-Enabled Parallel Approach Operations

The advent of radar surveillance over half a century ago enabled numerous Air Traffic Control (ATC) standards that continue to be in use today to safely separate aircraft. In the case of departure operations, the discrete increase of spacing requirements that applies when transitioning from terminal to en route control hampers Next Generation Air Transportation System (NextGen) goals of improving operational efficiencies. This paper proposes the concept of the Established-on-Departure Operation, or EDO, standard that capitalizes on improved navigational precision of Performance Based Navigation (PBN) operations. The concept incorporates current diverging procedures permitted in the terminal area as well as the concept of reduced divergence. The paper describes the requirements for its application and presents the analysis carried out to extend the applicability of a previously proposed standard for reduced-divergence operations. For Area Navigation (RNAV) Standard Instrument Departure (SID) operations, the analysis conservatively quantified a reduced divergence angle of 9 degrees, a 40-percent reduction in angular divergence when compared to today's 15-degree requirement. In order to illustrate implementation examples and estimate potential benefits, the concepts were applied to the RNAV SID structure at The Hartsfield-Jackson Atlanta International Airport (ATL). For ATL alone, the estimates show a potential annual benefit of approximately $1.6 million per year. The standard concepts offer a suite of additional procedure design options not currently available to better accommodate airspace constraints and to increase the efficiency of departure operations transitioning from terminal to en route control.

Dennis J. Zondervan

Papers

Flight Trials of CDA with Time-Based Metering at Atlanta International Airport

Concept and benefits of a unified departure operation spacing standard

Reinventing High Density Area Departure Traffic Management

Concept and Benefits of PBN-Enabled Parallel Approach Operations

A separation standard for departures transitioning from terminal to en route control