The following article was originally published on Medium at this link: https://medium.com/@mikechillit_79679/mh370-what-is-wrong-with-the-graphic-below-ad47eaf47c6e
A) it incorrectly identifies the length and location of the “7th BTO arc”;
B) in reality, the “7th BTO arc” extends from 25.8N, 101.1E in Yunnan Province, China to -22.2S, 102.4E in the South Indian Ocean, a distance of 5,312 kilometers across 47.7 degrees of earth’s surface;
C) the southern terminus of the “7th BTO arc” is 1,200 kilometers west of Exmouth, Western Australia, a few kilometers north of Lost Dutchmen Ridge;
D). the graphic purports to be complete “through July 2015”, but fails to mention MH370’s Flaperon, found on Reunion Island, July 30, 2015;
E) at no time was there a need to search south of the tropic of Capricorn.
The laws of physics that both enable and constrain us are generally not onerous if we accept that they exist and respect their inherent opportunities and limitations. Those who attempted to assist in the search for MH370, and who were in tune with the laws of physics, quickly discovered that an easy way to locate the plane was to flip a mirror image of the final ping ring onto itself. When correctly positioned in accordance with the rules for constructing geometric reflections, there were two and only two possible crash locations. Those two locations were where the final ping ring and its mirror image intersect. The northern location was quickly ruled out. These concepts are taught in engineering institutions worldwide. Figure 2 illustrates.
There were / are other ways to locate the plane’s endpoint. Some are geometric and require knowledge of Euclidian or Spherical geometry. But locating MH370 was never Rocket Science: simple tools were more than sufficient, including old standbys like knowing that 1) the shortest distance between two points is a straight line, 2) the shortest distance between a point and a line is a perpendicular line, and 3) use arcs to construct perpendicular bisectors.
An equally quick and easy way to “rough out” the plane’s terminal location did not get much play, but the basics are useful to know. The idea is that when a “baseline” is drawn between the satellite’s GPS location on the final ping and the airport departure GPS, two early assumptions emerge: 1) it likely flew north or south, not east or west, because the direction of flight is expected to be at right angles to the baseline; and 2) the plane should have ended up as far north or as far south as the final ping ring permits, AND the endpoint should be roughly perpendicular to the departure point on the baseline.
To illustrate, the plane departed the Kuala Lumpur Airport runway at about 101.7E longitude according to Flight Radar 24, ADS-B record. With a nearly perfect East / West baseline we initially assume the plane crashed on about the same longitude it was on at takeoff, north or south. In fact, MH370 made contact with the ocean at 102.4°E, only 0.7° from its 101.7°E takeoff. The 0.7° difference is due entirely to the fact that the satellite and the takeoff point are not on the exact same latitude (2.3° apart). That requires a small orthogonal correction before we dispatch scanning vessels to the site, but in the interim, this method is a great tool for “roughing out” an expected endpoint.
In the aftermath of the disappearance and crash, US technitions at NOAA quickly repositioned satellites to check for aircraft debris at the only two locations the plane could have crashed. They did not need fuel estimates or heading information. NOAA’s early work was based entirely on the radius of the final ping, and the plane’s departure point (Kuala Lumpur International Airport). Techs then quickly found that the only two possible endpoints were as noted above.