Simulator study of vortex encounters by a twin-engine, commercial, jet transport airplane

A simulator study of vortex encounters was conducted for a twin-engine, commercial, jet transport airplane encountering the vortex flow field of a heavy, four-engine, commercial, jet transport airplane in the final-approach configuration. The encounters were conducted with fixed controls and with a pilot using a state-of-the-art, manual-control system. Piloted encounters with the base-line vortex flow field out of ground effect (unattenuated) resulted in initial bank-angle excursions greater than 40 deg, coupled with initial sideslip-angle excursions greater than 10 deg. The severity of these initial upsets was significantly reduced when the vortex center was moved laterally or vertically away from the flight path of the encountering airplane. Smaller reductions occurred when the flow field was attenuated by the flight spoilers on the generating airplane. The largest reduction in the severity of the initial upsets, however, was from aging in ground effect. The severity of the initial upsets of the following airplane was relatively unaffected by the approach speed. Increasing the lift coefficient of the generating airplane resulted in an increase in the severity of the initial upsets

Effect on head-wind profiles and mean head-wind velocity on landing capacity flying constant-airspeed and constant-groundspeed approaches

A study was conducted to determine the effect of head-wind profiles and mean head-wind velocities on runway landing capacity for airplanes flying constant-airspeed and constant-groundspeed approaches. It was determined that when the wind profiles were encountered with the currently used constant airspeed approach method, the landing capacity was reduced. The severity of these reductions increased as the mean head-wind value of the profile increased. When constant-groundspeed approaches were made in the same wind profiles, there were no losses in landing capacity. In an analysis of mean head winds, it was determined that in a mean head wind of 35 knots, the landing capacity using constant-airspeed approaches was 13% less than for the no wind condition. There were no reductions in landing capacity with constant-groundspeed approaches for mean head winds less than 35 knots. This same result was observed when the separation intervals between airplanes was reduced

Preliminary results of simulated vortex encounters by a twin-engine, commercial aircraft during final landing approach

Piloted simulations of encounters with vortices of various ages and degrees of attenuation were performed with the Visual Motion Simulator. In the simulations, a twin engine, commercial transport on final approach, encountered the modeled vortices of a four engine, wide body, commercial transport. The data show the effect of vortex age and attenuation on the severity of the initial upset, as well as the effect of the vortex encounters on the landing capability

THE EFFECT OF AFLATOXIN B1 ON GROWTH RATE AND IRON METABOLISM IN JUVENILE MONGOLIAN GERBILS (Meriones unguiculatus)

The metabolic secretions from Aspergillus flavus, aflatoxins. are often found as contaminants of agricultural products used for human and animal consumption. Aflatoxin B1 is the most toxic and carcinogenic of the aflatoxins. A reduction in weight gain has been observed when juvenile animals are fed aflatoxin B1 over an extended period of time. This reduction in weight gain may possibly result from an anemic condition induced by an alteration of iron absorption and/or distribution. The effect of chronic sublethal levels of this hepatocarcinogen on weight gain and the uptake and distribution of 59Fe++ were studied in this investigation. An experimental group consisting of 12 male gerbils was fed an agar-based diet containing 10 ppm aflatoxin B1 and a control group consisting of 6 male gerbils was fed an identical diet which did not contain aflatoxin B1 for a 75-day period. The total mean aflatoxin B1 consumption of the experimental group amounted to 0.170 mg aflatoxin B1/kg of body weight. At the termination of the investigation the mean percent iron absorption of the control and experimental groups was determined. Values of 6.25 and 6.89, respectively, were calculated. The difference between these means was not determined to be significant. At the termination of the investigation the mean weight gain of the control group animals was 36.9 g as compared to 29.8 g for the aflatoxin group. The difference indicated that a significant reduction in weight gain was observed in the experimental group. lt was apparent that neither the physical activity nor diet consumption measured in the investigation affected the weight gain. Pathological analysis indicated that one-third of the experimental animals had liver injury and two of these had toxic hepatitis. The difference in the iron absorption between the aflatoxin group and the control group was not found to be significant but certain trends were observed. Animal number 13. the animal with the highest percent absorption, also had toxic hepatitis. However, contradictory evidence was also present with animal number 16 having toxic hepatitis and a very low percent iron absorption

Production of an English/Russian glossary of terminology for nuclear materials control and accounting

The program plans for Former Soviet Union National Nuclear Materials Control and Accounting (MC and A) Systems Enhancements call for the development of an English/Russian Glossary of MC and A terminology. This glossary was envisioned as an outgrowth of the many interactions, training sessions, and other talking and writing exercises that would transpire in the course of carrying out these programs. This report summarizes the status of the production of this glossary, the most recent copy of which is attached to this report. The glossary contains over 950 terms and acronyms associated with nuclear material control and accounting for safeguards and nonproliferation. This document is organized as follows: English/Russian glossary of terms and acronyms; Russian/English glossary of terms and acronyms; English/Russian glossary of acronyms; and Russian/English glossary of acronyms

Preliminary indications of water film distribution and thickness on an airfoil in a water spray

A sensor for measuring water film thickness is evaluated. The test is conducted in a small flow apparatus with a 1 ft chord model wing in a water spray. Photographic and visual observations are made of the upper wing surface and film thickness is measured on the upper and lower wing surfaces. The performance of the sensor appears highly satisfactory, and where valid comparisons can be made, repeatable results are obtained