Recent content by Gordon_R

  1. Gordon_R

    The ‘wild’ physics of the ( non supersonic) passenger plane that just hit 800 mph

    The ultimate propeller driven aircraft was the Boeing B-29 Superfortress, developed towards the end of WW2, and used by the US to drop bombs on Japan, from distant island bases. This had a service ceiling of 31,850 feet (9,710 m) which was well into the jet stream levels, and accurate wind...
  2. Gordon_R

    The ‘wild’ physics of the ( non supersonic) passenger plane that just hit 800 mph

    There are aviation charts for almost everything, and pilots crossing a jet stream would try fly at a lower altitude to avoid the worst of the turbulence (not always possible due to air traffic restrictions). This morning's jet stream chart for Africa shows the same winds as the other chart, but...
  3. Gordon_R

    The ‘wild’ physics of the ( non supersonic) passenger plane that just hit 800 mph

    In case anyone was wondering, we rarely get strong jet stream winds over South Africa, particularly in summer. During winter, strong cold fronts can be accompanied by a jet stream, often visible in the form of fast-moving cirrus clouds. In this morning's chart, all is quiet over SA, but there...
  4. Gordon_R

    The ‘wild’ physics of the ( non supersonic) passenger plane that just hit 800 mph

    Contrary to what the article states, jet stream winds were not properly evaluated until WW2. Lindbergh did fly west to east, but at modest altitude due to lack of cabin pressurisation. High performance US bombers flying at extreme altitude towards Japan, noticed much stronger winds than...
  5. Gordon_R

    The ‘wild’ physics of the ( non supersonic) passenger plane that just hit 800 mph

    Pedantic quibble: Aircraft don't calculate where the jet stream is, meteorologists do. What aircraft (and ships) do is periodically measure wind speeds aloft, and feed the data back into the weather models. Aviation charts are produced 18-24 hours in advance, and careful flight planning will...
  6. Gordon_R

    The ‘wild’ physics of the ( non supersonic) passenger plane that just hit 800 mph

    This morning's jet stream chart for the North Atlantic (apologies for large file size). Wind speeds range up to 180-190 knots (330-350 km/h). Add that to the aircraft speed, and you have a high ground speed. Going in the opposite direction, gives a much lower ground speed.
  7. Gordon_R

    The ‘wild’ physics of the ( non supersonic) passenger plane that just hit 800 mph

    Ho-hum, much hype!? Jet-stream winds are not new, must be a slow news day... Most passenger aircraft fly around Mach 0.85, anything faster becomes less fuel efficient, subject to uncomfortable buffeting, and eventually air-frame damage. Mach 1 is a reference, not a target.
  8. Gordon_R

    The SABC will run out of money in 3 months

    No bailouts from the taxman: https://www.dailymaverick.co.za/opinionista/2019-02-21-following-mbowenis-budget-sabcs-five-little-words/ Edit: There are consequences:
  9. Gordon_R

    Ramaphosa brings back Mbeki securocrats to probe State Security Agency

    Some interesting perspective from Ronnie Kasrils: https://www.dailymaverick.co.za/article/2019-02-21-cleaning-out-the-augean-stables-of-state-security/
  10. Gordon_R

    How much of your tax money South Africa's pathetic state-run enterprises are getting

    Reforming SOEs will not be easy, in the face of vested political interests: https://www.dailymaverick.co.za/article/2019-02-21-mortal-combat-fixing-the-soes-take-238/
  11. Gordon_R

    State capture inquiry begins

    Lots of various Eskom reports and evidence, as well as some subpoenas, to be placed before the Zondo Inquiry: https://www.dailymaverick.co.za/article/2019-02-21-gupta-incs-eskom-woes-reloaded-before-justice-zondo/
  12. Gordon_R

    VBS Mutual Bank being victimised - EFF

    https://www.fin24.com/Companies/Financial-Services/accounting-body-strips-former-vbs-board-chairperson-of-membership-20190220 Small step forward...
  13. Gordon_R

    Ford Figo Brake Lights

    The neutral wire on car rear lights is a frequent problem on some cars. Check the tail lights first as suggested. Otherwise you need a multi-meter, and/or a known good bulb and some wire. A two person job, unless you put a brick on the brake pedal.
  14. Gordon_R

    Eskom needs at least R200bn from government – Busa

    I think you may have missing a decimal point or two!? A typical nuclear reactor produces between 600-1000MW of electricity, which is roughly that used by 1 million homes. The numbers you have quoted are completely wrong...
  15. Gordon_R

    How much of your tax money South Africa's pathetic state-run enterprises are getting

    https://www.fin24.com/Budget/mboweni-does-sa-really-need-state-owned-enterprises-20190220
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