Articles with tag: "Porter Perkins"

(Note: figures do not appear in the summaries below)

  1. Conclusions of the Porter Perkins Series

    "our knowledge of aircraft icing and the penalties associated with it has not changed substantially in the last forty to fifty years" 1

    Figure 1. Tunnel installation of hollow steel air-heated propeller for icing investigation. A tall, lean man with a distinctively tall nose inspects the propeller.

    From NACA-TN-1586. I believe that this is Porter Perkins, circa 1946.

    Summary

    The three areas of the many and varied contributions of Porter Perkins are reviewed.

    Discussion

    I will focus on three areas of Porter Perkins' publications:

    • Foresight about supercooled large drop (SLD) icing
    • A shift in instrument calibration
    • Contributions to the Appendix C icing regulation

    Foresight about supercooled large drop (SLD) icing

    I am not sure that I agree with the quote at the top (from 1993) now. A lot of things have happened in three decades.

    Perkins and Rieke 1 foreshadowed in 1993 the potential effects of large-size water-drop icing conditions, now commonly termed supercooled large drop (SLD) icing:

    [Emphasis added]

    Protection from "Severe" icing encounters is not possible by definition. Likewise, there is little …

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  2. Porter Perkins Flight Safety Publications

    "Most, if not all of the recent accidents on record having icing as the probable cause could have been prevented if the flight crews understood the serious nature of the situation and had applied appropriate corrective action." 2

    Summary

    Three publications on flight safety by Porter Perkins are reviewed.

    Discussion

    These publications are copyrighted. The first one, however, has a reuse license, and so much of the discussion will center on it.

    "Tailplane icing and aircraft performance degradation" 1992 1

    Ice on the tailplane (horizontal stabilizer) was identified as a risk on some aircraft:

    Although the sensitivity of airplanes to inflight icing has been recognized for many years and can be minimized by ice protection systems, the advent of the medium-altitude turboprop commuter transport aircraft has resulted in renewed attention to the icing problem. This review of icing has been prompted by several recent accidents that apparently were caused by …

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  3. Reproducing NACA-TN-2738 Calculations

    "In view of the number and complexity of the possible sources of error, it is not possible at this time to make a reliable estimate of the total accuracy" 3

    8-39 figure 10e. Calculations for Flight 8-39.

    Summary

    Calculations are made to assess the probability of encountering certain icing conditions.

    Introduction

    In Porter Perkins Ice Shapes and Ice Protection, references NASA TM 83564 1 and NASA TM 86906 2, the probability of encountering certain icing conditions was assessed, using methods from NACA-TN-2738 3. Here, we will attempt to reproduce those calculations.

    Discussion

    In NACA-TN-2738, data were divided by geographical region.

    Figure 1. Map of the United States showing approximate boundaries of areas used in the geographical classifications of icing data.

    The NASA Technical Memos did not state where the natural icing test flights were. However, as three of the authors were based out of the NASA Lewis Research Center, Cleveland, Ohio, I will assume that the flights operated out of there and were in the Eastern United States region.

    So, the appropriate chart to use is Figure …

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  4. Porter Perkins Ice Shapes and Ice Protection

    "An approach to characterizing the severity of an icing encounter is to relate that encounter to the frequency of its occurrence." 1

    Extract from Table I of NASA TM 86906. ICING CLOUD DATA AND ACCRETION PROPERTIES FOR ICING FLIGHTS.

    Introduction

    Three publications with Porter Perkins as an author are included here. Two publications are related, as they cover a flight test campaign to gather detailed ice shape data. The third publication describes a potential improvement to ice protection.

    There is much to see in these publications with multiple authors, and I will focus on what I believe to have been Perkins' contributions.

    Ice Shapes, NASA TM 83564 1 and NASA TM 86906 2

    NASA TM 83564:

    Summary

    This paper deals with the initial results of the NASA Lewis Research Center's flight research in quantifying the performance of an aircraft in various measured icing conditions. Flight research performed in natural icing conditions supports a number of major program elements at NASA. One of these elements is to develop …

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  5. Airships

    "a 2-hour flight in ... a mixture of wet snow and freezing rain ... produced no adverse effects on the operation of the airship."

    Figure 5a. Location of snow catch observed on airship envelope. (a) Snow distributed along top of envelope following 2-hour flight in light to moderate snow at -2 to -6 C.

    NACA-TN-4220, A Flight Evaluation and Analysis of the Effect of Icing Conditions on the PG-2 Airship

    Summary

    Icing threats to airships are assessed.

    Abstract

    SUMMARY

    A series of test flights was conducted by the U. S. Navy over a 3-year period to evaluate the effects of icing on the operation of the ZPG-2 airship. In supercooled. clouds, ice formed only on the forward edges of small protuberances and wires and presented no serious hazard to operation. Ice accretions of the glaze type which occurred in conditions described as freezing drizzle adversely affected various components to a somewhat greater extent. The results indicated, a need for protection of certain components such as antennas, propellers, and certain parts of the control system.

    The tests showed that icing of the large …

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  6. Meteorology publications by Porter Perkins

    "Statistical values that represent the meteorological and climatic variations, which are associated with icing, will indicate what to expect in normal flight operations." 6

    Figure 1. Location of ice-sensing probe on fighter-interceptor aircraft.
    From NACA-TN-4314.

    Summary

    Several publications by Porter Perkins were included in The Historical Selected Bibliography of NACA-NASA Icing Publications in the "Meteorology of Icing Clouds" section.

    Discussion

    The first several publications are only briefly described, as their major results are incorporated into the final publication, NASA Memo 1-19-59E, which will be reviewed at length.

    Note that NACA-RM-E52J06 outlines the need for data from broader sources, that is a theme in these publications:

    The majority of the research flights into icing conditions were made by attempting to select weather conditions, flight paths, and altitudes, which would yield heavy or continuous icing. Multiple traverses were often made when such conditions were found. It is impossible, therefore, to determine from this information the extent or frequency of specified icing …

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  7. Propeller publications by Porter Perkins

    "As the demand for all-weather protection on aircraft for unimpaired and continuous commercial and military service developed, the detrimental effects of propeller icing on airplane performance became increasingly important"

    1

    Figure 1. Tunnel installation of hollow steel air-heated propeller for icing investigation. A tall, lean man with a distinctively tall nose inspects the propeller.
    I believe that this is Porter Perkins, circa 1946.

    Summary

    Porter Perkins investigations of propeller icing are reviewed. These are the earliest investigations by him that I found.

    Discussion

    Two areas are discussed, the gas heating of propellers, and the measurement of thrust.

    Gas heating of propellers

    • Investigation of Effectiveness of Air-Heating a Hollow Steel Propeller for Protection against Icing, I - Unpartitioned Blades. NACA-TN-1586, 1948. 1
    • Investigation of Effectiveness of Air-Heating a Hollow Steel Propeller for Protection against Icing, II- 50-Percent Partitioned Blades. NACA-TN-1587, 1948. 2
    • Investigation of Effectiveness of Air-Heating a Hollow Steel Propeller for Protection against Icing, III - 25-Percent Partitioned Blades. NACA-TN-1588, 1948. 3

    SUMMARY

    An investigation to determine the effectiveness of icing protection afforded by air-heating hollow …

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  8. Porter Perkins

    "As the demand for all-weather protection on aircraft for unimpaired and continuous commercial and military service developed, the detrimental effects of ... icing on airplane performance became increasingly important" (1948)

    Figure 1. Tunnel installation of hollow steel air-heated propeller for icing investigation. A tall, lean man with a distinctively tall nose inspects the propeller.

    From NACA-TN-1586. I believe that this is Porter Perkins, circa 1946.

    Summary

    Porter Perkins published on icing topics for over 50 years while at NACA, NASA, and other groups.

    Biographies and Memorials

    Porter J. Perkins is a senior aerospace engineer working in aviation safety as manager of airworthiness of research flight activity at the Lewis Research Center of the U.S. National Aeronautics and Space Administration (NASA), Cleveland, Ohio, U.S. He has specialized in research on aircraft icing for more than 25 years. His in-flight measurements to characterize icing clouds were later incorporated into U.S. icing protection certification standards. He has authored or co-authored more than 25 reports in the field of aircraft icing, and continues to participate in …

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