Ozone contamination in aircraft cabins: Objectives and approach

Three panels were developed to solve the problem of ozone contamination in aircraft cabins. The problem is defined from direct in-flight measurements of ozone concentrations inside and outside airliners in their normal operations. Solutions to the cabin ozone problem are discussed under two areas: (1) flight planning to avoid high ozone concentrations, and (2) ozone destruction techniques installed in the cabin air systems

Global measurements of gaseous and aerosol trace species in the upper troposphere and lower stratosphere from daily flights of 747 airliners

Extensive measurements include ozone, carbon monoxide, water vapor, and aerosol and condensation nuclei number density. Less extensive measurements include chlorofluoromethanes, sulfates and nitrates. Certain meteorological and flight information are also recorded at the time of these measurements. World routes range in latitude from about 60 deg N near North America to about 40 deg S over Australia and 23 deg S over South America. Typical data show significant changes in ozone, carbon monoxide, and water vapor when crossing the tropopause either during changes in altitude or at cruise altitude. These gases as well as light scattering particles and condensation nuclei exhibit considerable variability along a flight route

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Light weight plastic foam thermal insulation for cryogenic storag

Ozone Contamination in Aircraft Cabins. Appendix B: Overview papers. In-flight measurements

The NASA Global Atmospheric Sampling Program ozone measurements were obtained to establish to characteristics of the ambient ozone concentration during routine operations and to determine the attenuation of ambient concentrations of cabin air systems from simultaneous ambient and in cabin measurements. The characteristics of ambient ozone include: (1) maximum concentration; (2) duration of ozone encounters; (3) frequency of ozone during a flight; (4) variability of ozone during a flight; (5) in relation to routes, altitude, and meteorological conditions

Ozone Contamination in Aircraft Cabins: Summary of recommendations

Recommendations from the three panels on in-flight measurements, flight planning to avoid high ozone, and ozone destruction techniques are summarized

Simultaneous measurements of ozone outside and inside cabins of two B-747 airliners and a Gates Learjet business jet

The average amount of ozone measured in the cabins of two B-747 airliners varied from 40 percent to 80 percent of the atmospheric concentrations without special ozone destruction systems. A charcoal filter in the cabin air inlet system of one B-747 reduced the ozone to about 5 percent of the atmospheric concentration. A Learjet 23 was also instrumented with monitors to measure simultaneously the atmospheric and ozone concentrations. Results indicate that a significant portion of the atmospheric ozone is not destroyed in the pressurization system and remains in the aircraft cabin of the Learjet. For the two cabin configurations tested, the ozone retentions were 63 and 41 percent of the atmospheric ozone concentrations. Ozone concentrations measured in the cabin near the conditioned-air outlets were reduced only slightly from atmospheric ozone concentrations. It is concluded that a constant difference between ozone concentrations inside and outside the cabin does not exist

Ozone concentration in the cabin of a Gates Learjet measured simultaneously with atmospheric ozone concentrations

A Gates Learjet Model 23 was instrumented with monitors to measure simultaneously the atmospheric and the cabin concentrations of ozone at altitudes up to 13 kilometers. Six data flights were made in February 1978. Results indicated that only a small amount of the atmospheric ozone is destroyed in the cabin pressurization system. Ozone concentrations measured in the cabin near the conditioned-air outlets were only slightly lower than the atmospheric ozone concentration. For the two cabin configurations tested, the ozone retention in the cabin was 63 and 41 percent of the atmospheric ozone concentration. Maximum cabin ozone concentration measured during these flights was 410 parts per billion by volume

Low cost fabrication development for oxide dispersion strengthened alloy vanes

Viable processes were developed for secondary working of oxide dispersion strengthened (ODS) alloys to near-net shapes (NNS) for aircraft turbine vanes. These processes were shown capable of producing required microstructure and properties for vane applications. Material cost savings of 40 to 50% are projected for the NNS process over the current procedures which involve machining from rectangular bar. Additional machining cost savings are projected. Of three secondary working processes evaluated, directional forging and plate bending were determined to be viable NNS processes for ODS vanes. Directional forging was deemed most applicable to high pressure turbine (HPT) vanes with their large thickness variations while plate bending was determined to be most cost effective for low pressure turbine (LPT) vanes because of their limited thickness variations. Since the F101 LPT vane was selected for study in this program, development of plate bending was carried through to establishment of a preliminary process. Preparation of ODS alloy plate for bending was found to be a straight forward process using currently available bar stock, providing that the capability for reheating between roll passes is available. Advanced ODS-NiCrAl and ODS-FeCrAl alloys were utilized on this program. Workability of all alloys was adequate for directional forging and plate bending, but only the ODS-FeCrAl had adequate workability for shaped preform extrustion

Global sensing of gaseous and aerosol trace species using automated instrumentation on 747 airliners

The Global Atmospheric Sampling Program (GASP) by NASA is collecting and analyzing data on gaseous and aerosol trace species in the upper troposphere and lower stratosphere. Measurements are obtained from automated systems installed on four 747 airliners flying global air routes. Advances were made in airborne sampling instrumentation. Improved instruments and analysis techniques are providing an expanding data base for trace species including ozone, carbon monoxide, water vapor, condensation nuclei and mass concentrations of sulfates and nitrates. Simultaneous measurements of several trace species obtained frequently can be used to uniquely identify the source of the air mass as being typically tropospheric or stratospheric. A quantitative understanding of the tropospheric-stratospheric exchange processes leads to better knowledge of the atmospheric impact of pollution through the development of improved simulation models of the atmosphere

Atmospheric constituent measurements using commercial 747 airliners

NASA is implementing a Global Atmospheric Monitoring Program to measure the temporal and spatial distribution of particulate and gaseous constituents related to aircraft engine emissions in the upper troposphere and lower stratosphere (6 to 12 Km). Several 747 aircraft operated by different airlines flying routes selected for maximum world coverage will be instrumented. An instrumentation system is being assembled and tested and is scheduled for operation in airline service in late 1974. Specialized instrumentation and an electronic control unit are required for automatic unattended operation on commercial airliners. An ambient air sampling system was developed to provide undisturbed outside air to the instruments in the pressurized aircraft cabin