Utilization of a fixed base simulator to study the stall and spin characteristics of fighter airplanes

Feasibility of using fixed simulator to determine stall and spin characteristics of fighter aircraf

Flight investigation of a vertical-velocity command system for VTOL aircraft

A flight investigation was undertaken to assess the potential benefits afforded by a vertical-velocity command system (VVCS) for VTOL (vertical take-off and landing) aircraft. This augmentation system was conceived primarily as a means of lowering pilot workload during decelerating approaches to a hover and/or landing under category III instrument meteorological conditions. The scope of the investigation included a determination of acceptable system parameters, a visual flight evaluation, and an instrument flight evaluation which employed a 10 deg, decelerating, simulated instrument approach task. The results indicated that the VVCS, which decouples the pitch and vertical degrees of freedom, provides more accurate glide-path tracking and a lower pilot workload than does the unaugmented system

A piloted-simulation evaluation of two electronic display formats for approach and landing

The results of a piloted-simulation evaluation of the benefits of adding runway symbology and track information to a baseline electronic-attitude-director-indicator (EADI) format for the approach-to-landing task were presented. The evaluation was conducted for the baseline format and for the baseline format with the added symbology during 3 deg straight-in approaches with calm, cross-wind, and turbulence conditions. Flight-path performance data and pilot subjective comments were examined with regard to the pilot's tracking performance and mental workload for both display formats. The results show that the addition of a perspective runway image and relative track information to a basic situation-information EADI format improve the tracking performance both laterally and vertically during an approach-to-landing task and that the mental workload required to assess the approach situation was thus reduced as a result of integration of information

Bonding machine for forming a solar array strip

A machine is described for attaching solar cells to a flexable substrate on which printed circuitry has been deposited. The strip is fed through: (1) a station in which solar cells are elevated into engagement with solder pads for the printed circuitry and thereafter heated by an infrared lamp; (2) a station at which flux and solder residue is removed; (3) a station at which electrical performance of the soldered cells is determined; (4) a station at which an encapsulating resin is deposited on the cells; (5) a station at which the encapsulated solar cells are examined for electrical performance; and (6) a final station at which the resulting array is wound on a takeup drum

Flight investigation of cockpit-displayed traffic information utilizing coded symbology in an advanced operational environment

Traffic symbology was encoded to provide additional information concerning the traffic, which was displayed on the pilot's electronic horizontal situation indicators (EHSI). A research airplane representing an advanced operational environment was used to assess the benefit of coded traffic symbology in a realistic work-load environment. Traffic scenarios, involving both conflict-free and conflict situations, were employed. Subjective pilot commentary was obtained through the use of a questionnaire and extensive pilot debriefings. These results grouped conveniently under two categories: display factors and task performance. A major item under the display factor category was the problem of display clutter. The primary contributors to clutter were the use of large map-scale factors, the use of traffic data blocks, and the presentation of more than a few airplanes. In terms of task performance, the cockpit-displayed traffic information was found to provide excellent overall situation awareness. Additionally, mile separation prescribed during these tests

Buoyancy waves in Pluto's high atmosphere: Implications for stellar occultations

We apply scintillation theory to stellar signal fluctuations in the high-resolution, high signal/noise, dual-wavelength data from the MMT observation of the 2007 March 18 occultation of P445.3 by Pluto. A well-defined high wavenumber cutoff in the fluctuations is consistent with viscous-thermal dissipation of buoyancy waves (internal gravity waves) in Pluto's high atmosphere, and provides strong evidence that the underlying density fluctuations are governed by the gravity-wave dispersion relation.Comment: Accepted 18 June 2009 for publication in Icaru

Le suivi pratique des patients sous pression positive continue

The therapeutic follow-up is a decisive factor of the success of a long course treatment by continuous positive airway pressure (CPAP). The effectiveness of this treatment on both symptoms and complications must be regularly verified. Polysomnography with CPAP could be necessary in order to check out the efficacy of this treatment and/or to find an associated diagnosis when symptoms persist, particularly a diurnal drowsiness, which is the main therapeutic target in obstructive sleep apnea syndrome (OSAS). The secondary effects that are likely to compromise the compliance of CPAP treatment must be resolved, particularly the nasal intolerance, which are enhanced by mask leakages and often corrected by using heated humidity with CPAP delivery systems. The efficacy of CPAP on both diurnal drowsiness and hypertension is related to the compliance of this treatment which must be regularly verified, at the same time that the clinical evaluation. The data obtained from the device\u27s memory give information concerning the number of hours day to day, in which the CPAP device was running at the prescribed pressure. The first months with CPAP are decisive to avoid a failure of the treatment at long term. This period must be closely monitored by both the physician and the home care provider. Patients should use the CPAP at least 3–4 h by night and all possible means should be used to obtain a maximal compliance. Therapeutic educational programs could help to reach this goal

Risk analysis to support operation and maintenance of an ageing dock-gate for the Port of Marseille Authority

The dry dock n°10 is a strategic infrastructure of the Port of Marseille Authority: its dimensions (465 x 85 m) place it among the biggest dry docks in Europe. Built in the seventies, it is isolated from the sea by a dock-gate in prestressed concrete. Faced to the ageing of this dock-gate, the Port of Marseille Authority wished to make the most of its knowledge in order to assess the feasibility of two considered operation scenarios: use the dry dock for ship repair or for building new civil engineering structures. In this context, OXAND and the Port of Marseille Authority worked together so as to obtain formal and objective decision-making indicators. These indicators took into account the different operation stakes of the dry dock (security, availability), the condition diagnosis and the ageing prognosis of components and facilities of the dock-gate, along with adapted maintenance actions and related costs. The risk analysis methodology used for this study allowed (1) to characterize the risks linked to each foreseen operation scenario, (2) to identify the most appropriate actions to control these risks, integrating operation constraints (e.g.: need to put the dock-gate in dry dock), (3) to rank these actions regarding their cost/benefit ratio and thus (4), to build a maintenance plan