Small UAS Detect and Avoid Requirements Necessary for Limited Beyond Visual Line of Sight (BVLOS) Operations

Potential small Unmanned Aircraft Systems (sUAS) beyond visual line of sight (BVLOS) operational scenarios/use cases and Detect And Avoid (DAA) approaches were collected through a number of industry wide data calls. Every 333 Exemption holder was solicited for this same information. Summary information from more than 5,000 exemption holders is documented, and the information received had varied level of detail but has given relevant experiential information to generalize use cases. A plan was developed and testing completed to assess Radio Line Of Sight (RLOS), a potential key limiting factors for safe BVLOS ops. Details of the equipment used, flight test area, test payload, and fixtures for testing at different altitudes is presented and the resulting comparison of a simplified mathematical model, an online modeling tool, and flight data are provided. An Operational Framework that defines the environment, conditions, constraints, and limitations under which the recommended requirements will enable sUAS operations BVLOS is presented. The framework includes strategies that can build upon Federal Aviation Administration (FAA) and industry actions that should result in an increase in BVLOS flights in the near term. Evaluating approaches to sUAS DAA was accomplished through five subtasks: literature review of pilot and ground observer see and avoid performance, survey of DAA criteria and recommended baseline performance, survey of existing/developing DAA technologies and performance, assessment of risks of selected DAA approaches, and flight testing. Pilot and ground observer see and avoid performance were evaluated through a literature review. Development of DAA criteria—the emphasis here being well clear— was accomplished through working with the Science And Research Panel (SARP) and through simulations of manned and unmanned aircraft interactions. Information regarding sUAS DAA approaches was collected through a literature review, requests for information, and direct interactions. These were analyzed through delineation of system type and definition of metrics and metric values. Risks associated with sUAS DAA systems were assessed by focusing on the Safety Risk Management (SRM) pillar of the SMS (Safety Management System) process. This effort (1) identified hazards related to the operation of sUAS in BVLOS, (2) offered a preliminary risk assessment considering existing controls, and (3) recommended additional controls and mitigations to further reduce risk to the lowest practical level. Finally, flight tests were conducted to collect preliminary data regarding well clear and DAA system hazards

Kinematic, dynamic, and thermodynamic impacts of hook-echo hydrometeors, including explorations into the utilization of polarimetric radar data.

The role hook-echo hydrometeors play in driving RFDs is investigated by estimating hook-echo hydrometeor types and amounts from polarimetric radar data and by using that information to drive a relatively simple downdraft model. Soundings for the individual cases are used to initialize the downdraft model in order to replicate the environments of the storms as closely as possible.Simulations of hydrometeor driven RFDs show that hydrometeor fields inferred from radar data are able to drive significant downdrafts without the influence of vertical perturbation pressure gradients. Moreover, they reveal that above the boundary layer supercell environments are relatively resistant to downdrafts whereas within the boundary layer they are generally supportive of downdrafts. It appears that in many supercell environments relatively large hail (≥ 1 cm in diameter) or vertical perturbation pressure gradients may be needed to drive deep midlevel downdrafts that penetrate into the boundary layer. Because the boundary layer is an important downdraft generation/intensification layer, its thetae profile appears to be important to the surface RFD thetae deficit and, consequently, to tornadogenesis. To further examine these issues, analyses using idealized soundings that represent multiple possible RFD environments and analyses of the complete set of VORTEX cases are planned.Recent studies have revealed that the thermodynamic properties of the rear flank downdraft (RFD) may dictate whether or not a supercell becomes tornadic. Since hydrometeors are thought to be an important driving force for the RFD, it is postulated that they may be important to its thermodynamic properties and, possibly, to tornadogenesis.Since this effort and others like it require the quantitative utilization of radar data, issues pertaining to this are explored. In addition to analyses of coordinate transformation equations and an innovative objective analysis technique for weather radar data, the difficult problem of response functions for arbitrary weight functions and data distributions was considered. A novel approach to this problem revealed that the local response function for distance dependent weighted averaging schemes is the complex conjugate of the normalized Fourier transform of the effective weight function. This facilitates new research avenues, especially regarding analyses of irregularly spaced data

A Multi-Platform, In-Situ Kinematic and Microphysical Analysis of a Parallel Stratiform-Mesoscale-Convective System

The North Dakota Citation Research Aircraft obtained measurements of stratiform precipitation clouds within mesoscale convective systems over Oklahoma during the spring of 2011 (MC3E) in conjunction with a multitude of ground- and airborne-based remote sensing instruments. The Citation was used to take measurements of base atmospheric variables as well as cloud and precipitation properties. Cloud droplet properties were measured by the Cloud Imaging Probe (CIP), Two-Dimensional Cloud probe (2D-C), the High-Volume Precipitation Spectrometer Version 3 (HVPS3) probe, with the spectra from these probes combined to create a single drop size distribution. The Atmospheric Radiation Measurement (ARM) program ran three X-Band Scanning ARM Precipitation Radars (XSAPRs) and launched balloon-borne sounding systems (radiosondes) in support of the Citation research flights. NASA\u27s S-band Dual Polarimetric Radar (NPOL) was also used to collect volumetric and range height indicator (RHI) scans during these flights. The ARM Convective Vertical Velocity (CONVV) evaluation Value-Added Product (VAP) is a derived product that combines reflectivity and Doppler velocity data from three XSAPRs and the National Weather Service (NWS) Vance, OK Weather Surveillance Radar 1988-Doppler (WSR-88D) radar to produce a three-dimensional wind retrieval field to a height of 16 km within a 100-km2 horizontal plane. Datasets included in this collection come from the CIP, 2D-C, and HVPS3 (at 1 Hz) aboard one Citation flight occurring on 11 May 2011; two NPOL RHI scans; five CONVV VAP products; one ARM radiosonde; and six volume scans from each of six NWS WSR-88D radars operating in the vicinity of the MC3E field project

Adjuvant nivolumab versus ipilimumab (CheckMate 238 trial): Reassessment of 4-year efficacy outcomes in patients with stage III melanoma per AJCC-8 staging criteria.

Nivolumab was approved as adjuvant therapy for melanoma based on data from CheckMate 238, which enrolled patients per American Joint Committee on Cancer version 7 (AJCC-7) criteria. Here, we analyse long-term outcomes per AJCC-8 staging criteria compared with AJCC-7 results to inform clinical decisions for patients diagnosed per AJCC-8. In a double-blind, phase 3 trial (NCT02388906), patients aged ≥15 years with resected, histologically confirmed AJCC-7 stage IIIB, IIIC, or IV melanoma were randomised to receive nivolumab 3 mg/kg every 2 weeks or ipilimumab 10 mg/kg every 3 weeks for 4 doses and then every 12 weeks, both intravenously ≤1 year. Recurrence-free survival (RFS) and distant metastasis-free survival (DMFS) were assessed in patients with stage III disease, per AJCC-7 and AJCC-8. Per AJCC-7 staging, 42.4% and 57.3% of patients were in substage IIIB and IIIC, respectively; per AJCC-8, 1.1%, 30.4%, 62.8%, and 5.0% were in IIIA, IIIB, IIIC, and IIID. After 4 years' minimum follow-up, the AJCC-7 superior efficacy of nivolumab over ipilimumab in patients with resected stage III melanoma was preserved per AJCC-8 analysis. No statistically significant difference in RFS between stage III substage hazard ratios was observed per AJCC-7 or -8 staging criteria (interaction test: AJCC-7, P = 0.8115; AJCC-8, P = 0.1051; P = 0.8392 ((AJCC-7) and P = 0.8678 (AJCC-8) for DMFS). CheckMate 238 4-year RFS and DMFS outcomes are consistent per AJCC-7 and AJCC-8 staging criteria. Outcome benefits can therefore be translated for patients diagnosed per AJCC-8