Engineering topics

Morris, G. J.

Publications and source records attributed to Morris, G. J..

13 records

NASA NTRS1988

The effect of low temperature on Antarctic endolithic green algae

Laboratory experiments show that undercooling to about -5 degrees C occurs in colonized Beacon sandstones of the Ross Desert, Antarctica. High-frequency temperature oscillations between 5 degrees C and -5 degrees C or -10 degrees C (which occur in nature on the rock surface) did not damage Hemichloris antarctica. In a cryomicroscope, H. antarctica appeared to be undamaged after slow or rapid cooling to -50 degrees C. 14CO2 incorporation after freezing to -20 degrees C was unaffected in H. antarctica or in Trebouxia sp. but slightly depressed in Stichococcus sp. (isolated from a less extreme Antarctic habitat). These results suggest that the freezing regime in the Antarctic desert is not injurious to endolithic algae. It is likely that the freezing-point depression inside the rock makes available liquid water for metabolic activity at subzero temperatures. Freezing may occur more frequently on the rock surface and contribute to the abiotic nature of the surface.

NASA Discipline Number 52-30↗

NASA NTRS1981

The NASA digital VGH program, early results

Data from airline digital flight data recorders provides relevant statistical data for estimating fatigue life consumption of the current airliner fleet and for design criteria updating for future designs. The data indicates real operating effects due to the autopilot, i.e., gust response frequency peak increase by 2 or 3 times, and the existence of the low frequency low amplitude limit cycle motion in altitude hold. The extension of more data types for ground operations is considered. Onboard processing of simple data types is also considered.

Crabill, N. L.↗

NASA NTRS1980

Air transport flight parameter measurements program - Concepts and benefits

A program is described in which statistical flight loads and operating practice data for both narrow- and wide-body airline transport aircraft, intended primarily for use by manufacturers in updating design criteria, are obtained from existing, on-board digital flight data recorders. Procedures for editing and processing the data are explained, and differences between these and past NACA/NASA analog data are discussed. One major such difference is the automatic bandpass filtering of normal acceleration data to separate high-frequency gust response from low-frequency maneuver response. Plans and preliminary efforts for the development of an on-board data processing system, able to derive statistical aircraft operating parameters directly from real-time data, are also reviewed.

Morris, G. J.↗

NASA NTRS1977

Comparison of VGH data from wide-body and narrow-body long-haul turbine-powered transports

Data are presented on incremental normal accelerations due to gusts, operational maneuvers, and check flight maneuvers, derived gust velocities, and the airspeed and altitude operating practices of one type of wide body, long haul transport airplane flown by five airlines on international routes. These data are compared with VGH data obtained from long haul, narrow body transport airplanes also flown over international routes.

Zalovcik, J. A.↗

NASA NTRS1975

A review of the NASA V-G/VGH general aviation program

The V-G and VGH data collected from a wide variety of general aviation airplanes since the inception of the NASA V-G/VGH General Aviation Program in 1962 are presented. These data were analyzed to obtain information on the gust and maneuver loads, on the operating practices, and on the effects of different types of operations on these parameters.

Jewel, J. W., Jr.↗

NASA NTRS1974

Operating experiences of retardant bombers during firefighting operations

Data are presented on operational practices and maneuver accelerations experienced by two Douglas DC-6B airplanes converted to retardant bombers and used in firefighting operations. The data cover two fire seasons in the mountainous regions of the northwestern United States.

Jewel, J. W., Jr.↗

NASA NTRS1971