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Thread: The EAA needs an Atmosphere Dude Ranch

  1. #1

    Wink The EAA needs an Atmosphere Dude Ranch

    First Flight of the Ingenuity Mars Helicopter: Live from Mission Control - YouTube I got brought up short in my understanding of the usefulness of Mathematics and Measurement sometime in 1968 when I had done what I considered a major milestone. I had fitted an equation to a pattern of human behavior. My later attempt at trying to fit an overall mathematical construct to the behavior of a guided missile finally showed I was no better at describing the relation between humans and flight than I had been earlier with humans and horses.

    Yesterday, I went in Microsoft Flight Simulator to a place I had been in my earliest looks at this new version of code I have interacted with since I stopped making my own code in 2002. My father had made jokes about a private pilot he knew who had a broken altimeter. This pilot would take off and then tap at the broken glass in the indicator dial. I had approached this fuss in 1968 when trying to choose an atmosphere for global military use. Along with this choice I needed to mechanize in code or hand calculations the height above the terrain. Another engineer who had recently come to our operations analysis had collected information and literature on radar, and aneroid altimeters. In an airplane you could also look out the windscreen or the out the side windows and see over the fuselage panels how far up one is.

    Yesterday, I was at a grass field in Central America looking again at the difference in sea level between the Atlantic and Pacific sides of the isthmus. I landed at 1000 feet below sea level. This was the Pacific side. The nearest airfield on the Atlantic side is far North in mountains and clouds where earlier lightning ran me off.

    In the literature collected by the other engineer, who transferred from Long Beach to Missouri with a group identified by Bob Eberhard, the Operations Analysis Manager for MACAIR, was error data for devices that showed the radar altimeter at +/- 10 % of the actual value generally up to 1000 feet. The aneroid altimeter was estimated at +/- 200 feet at any altitude.

    My personal experience with measurement of errors in constructing mathematical function representation of physical phenomena was with apparatus for measuring the black body radiation of a cavity in a metal (platinum) tube as presented at a hole in that tube. Kind of thin experience for a young analyst, who needed to describe a Boost Glide Standoff Missile for the purpose of creating a boundary and parametric contours of exploration in a test range.

    The major interest was in the inflight instrumentation aircraft size and flight characteristics to collect this information. Unlike my earlier chastisement for making a mathematical fit to the grading of Navigators in Training which escaped the negative mathematical behavior near the origin of a cubic, this time a competitor had not just finished a study for the military. This time I was reaching into a flight regime where the concept of gliding was negated by vanishing atmospheric pressure. The only humans involved at the time of measurement were to be in an air plane. It wasn't just to be a measurement onboard telemetered to earth or a line of sight optical theodolite and radar tracked. But then I sublimed to more scientific questions like, "What is the speed of sound on Mars?" and how does the sea surface height vary on the moon Titan? Basic stuff to an analyst looking forward to ?? 2021
    Last edited by 2ndsegment; 04-19-2021 at 03:44 AM. Reason: look again today

  2. #2
    This is not right on the atmosphere which was difficult to access as a individual. One of the members of the Aerodynamics Research Group at Douglas Aircraft had gotten a copy of the Computer Aided Design Evaluation (CADE) program from MCAIR after that group had won the F-X Concept Formulation USAF competition. He was working with two younger engineers to make the code usable on designs at Long Beach which would have futuristic design features. The program made parametric mashups of various features and output "carpet plots" of the performance variables and expected values of pilot operating handbook kind of data like ceiling, takeoff field length and landing field length, and maximum speed.

    He came to me because we both were working for an Advanced Design Manager on a program called High Performance Advanced Attack Aircraft (HIPAAS) and I had been tasked with assisting Huntington Beach MACASTRO-WEST in getting another computer code accepted by Navy pilots for a missile. "Do you think you can get a 15% thick supercritical airfoil section accepted by Navy Attack or Fighter pilots?" This was a level of detail deeper than I had worked with.

    Those of you who know Aerodynamics much better than I did at the time would say, "Ridiculous!" 6 % or maybe 8 % thick still has a chance to be acceptable for a tactical design based on the current designs made in the 50's. 13% might be a bit fat for a commercial wing. The Whitcomb wing was not yet on a DC-10 and the roof airfoil was not on the Airbus.

    On my own in the late 1990's I flew unknowingly on a twin turboprop SAAB 340 with a supercritical airfoil from Houston to Shreveport, Louisiana to visit a friend. I also was shocked with "horn", "shaker", "pusher" by a new member of the marketing staff who was pushed into our analytic group. He flew Dassault Falcon 20's for discrete charters. Sidestick controllers and "LAW" were things coming. Angle of Attack vanes were for landing on aircraft carriers.

  3. #3
    The NAVY was not totally committed to advanced air and a study by a Captain Meeks came to the fore called Advanced Navy Vehicle Concepts Evaluation (ANVCE). This study tried to go across all kinds of vehicle concepts including ships, surface effect craft, ground effects machines, and -- yes aircraft for a whole plethora of missions. The ANVCE I was asked to study was a four engine turboprop. Now you might say, the 15 % Supercritical wing refocused? No, the burden was put on creating scenarios with threats and in all the potential theaters of conflict. So, my world of tools still included a Handbook of Chemistry and Physics that had an atmosphere in cgs standards. It was from winning a science fair prize in the late 1950's.

  4. #4
    Where did reality go? First thing I found was a Swissair brochure that presented a double-decker, commercial transport with four bypass ratio 6 engines in an artist's concept and a performance engineer's charts with other data. That showed up in the new mockup area as a wooden full-size construction of a section of fuselage. Walked down to look at it as I puzzled about the CX-HLS team that had occupied the offices in building 13 near my drafting board for A/RIA. It was becoming time to go to the moon but no one was telling me anything about that except on commercial television.

    Don Brimley had briefed me on the pressurization turbo-compressors and their water separators and bootstrap compressors that were obvious in ducts in the nose of the DC-8 but more subtle in the tips of each pylon on the Boeing 707. I did not walk up a ramp into the mockup. That concept did not take hold in the market as a big dip in traffic made such ambitious concepts unreality. It was only material for a moment.

    Later, in the mockup area a truly wildly torqued arching wing section over what was to be the nacelle for a DC-10 and a short section wing airfoil appeared in aluminum. It was quite thin compared to an advertising picture and description of the C-5 upper wing slab and how it was milled. I commented to my boss and he send me down to look at the mockup. While there, I looked at the perforated ducts and noise treatments. Engine acoustics was going to be beyond the bypass air and tubular noise arrestors of the JT-3D and JT-3B of the DC-8 and 707.

    Now I had three atmosphere models to keep track of. The general universal global one, the onboard passenger compartment and the noise field of the engine energy.

    I'd like to jump ahead here to the Engine Based Oxygen System (EBOGS) to cover the oxygen masks in the emergency aspect of the passenger compartment, but there are none coming beyond tactical air and trainers.
    Last edited by 2ndsegment; 02-14-2021 at 11:09 AM.

  5. #5
    One has to be careful of over projections of rules of thumb like every increase in English unit altitude of 1000 feet has a temperature decrease of 3 degrees Fahrenheit. Knowing the liquid air temperature or the individual values for Nitrogen, Oxygen and Argon misses the triple point where gas, liquid and solid coexist, and the supersaturation effects of quickness. High enough and the molecules dissociate and have longer mean paths so it seems the gas is increasing in temperature up high enough as space approaches.

  6. #6
    Quote Originally Posted by 2ndsegment View Post

    Yesterday, I was at a grass field in Central America looking again at the difference in sea level between the Atlantic and Pacific sides of the isthmus. I landed at 1000 feet below sea level. This was the Pacific side. The nearest airfield on the Atlantic side is far North in mountains and clouds where earlier lightning ran me off.
    I think after the update of MS-FS 2021 of February 11th that this is no longer true. I tested 3R9, my local Lakeway Regional to KHYI San Marcos and it did not land early as too low now. Because of the instructions to avoid power loads locally, I have not retested the Central American Pacific Coast data. I'll go look now. It had flown the missions out of the grass field but showed their initial altitude as -1000 feet. Today (3-4-2021) flying out of St. Just Land's End my Pipistrell reported -200 feet at 109 kts after lifting off. Later setting up an approach to EGQQ at 7 miles out past the Pattern Entry it reported -200 2 miles out of the field it reported -400 feet.
    Last edited by 2ndsegment; 03-04-2021 at 01:49 PM. Reason: ???

  7. #7
    The altitudes are OK here in the Central America region now. I need to check on ISA vs. ICAO and others for flight planning and performance testing, as well as reading charts.

  8. #8
    I saw in the paper today that the little helicopter on the Perseverance rover on Mars will be dropped at an appropriate place from the main rover in about two months. At that point the dude ranch should need the atmosphere model.

  9. #9
    The Ingenuity first flight projection date is on this link.
    My telescope is from Bendix DASH that flew off destroyers and a personal version using a different build that Barry Briggs and Chuck Heathco developed to sell as Lift Systems Incorporated. There was also the man powered helicopter that attempted to hover in Building 41 at Douglas Aircraft C1 location. The last contact I have with a helicopter drone with counterrotating blades was a toy that my son's friend bought and flew a few years ago. I will start looking again on the 23rd of April for the Mars version. I looked again today and saw that the delay is now to the 14th. The link is in the first post in this series.
    Last edited by 2ndsegment; 04-12-2021 at 04:04 AM. Reason: keep up with NASA and radios

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