Modern Air and Spantax were the last bigger operators of the Coronados. Modern Air set 1968 a world record with the Coronado, the only one airliner which cricled the globe over both poles and the first comercial airliner who has landed on McMurdo´s 3000 m ice-runway.
For that flight it was equipped with a polar compass. Could have looked like that:
Nice screen shots of the Convair 990 Coronado Walter, and also the Polar Compass and other navigational instrumentation imported from one of the Russian airliners. I'll have to read up on the principle of operation of the polar compass.
Post by aerofoto - HJG Admin on Jun 6, 2016 21:16:24 GMT
Modern Air set 1968 a world record with the Coronado, the only one airliner which cricled the globe over both poles
I understand the above-mentioned flight tech-stopped in Christchurch, New Zealand, after it's departure fromj McMurdo Station in Antarctica.
MODERN AIR .... are also credited for undertaking one of, if not the, longest point-to-point flights ever undertaken by a CV990 too .... operating from Philadelphia to Vienna "direct" and with a full PAX load (remember range and airspeed, due to drag, were among the CV990's early problems .... which were resolved, but, only for the undesirable imposition of much greater fuel burn during high altitude cruise, and with an aircraft that couldn't carry anything like a B707/720 or DC-8 payload dure to its narrower fuselage cross-section). The above-hinted story goes something like this ....
An AA pilot apparently came aboard a MODERN AIR CV990 (to admire it .... an aircraft he'd apparently once flown earlier in his career with AA) at Philadelphia prior to its departure. Upon asking the crew where they were headed .... he was promptly informed "VIENNA".
"OH" .... replied the AA pilot .... "Where are you stopping for fuel en route" ? .... he further enquired .... only to be informed by the MODERN AIR crew .... "we're not" (stopping). The AA pilot apparently, and somewhat perplexedly, responded .... "I couldn't even get one of these across the country (USA) let alone the Atlantic".
What MODERN AIR .... and SPANTAX too .... were doing by this time (around the early/mid 1970's) was reducing high altitude MACH cruise velocity (as a cost saving/fuel reduction excercize when effects of the first oil price shock of the 1970's began to bite) .... all the way down to M0.78, and which dramatically reduced fuel consumption to, of course, promote greater range.
SPANTAX later introduced GE designed smokeless engine combustion chambers on its aircraft .... and which unexpectedly reduced fuel burn by some further 2%.
Both MODERN AIR and SPANTAX also later introduced a customised seat design especially for the CV990 and which finally promoted a 6-abreast seating configuration (the original 5-abreast seating having previously earlier dogged both the CV880 and CV990 limiting the appeal of these aircraft to quite a number of operators) .... increasing PAX compacity to 149X .... comparable to that of B707/720 and DC-8 PAX configurations of the same 1970's period.
An "Interesting" aircraft .... the CV990 .... but one which only MODERN AIR, SPANTAX, and SWISSAIR seem to have been able to operate "successfully/contendely". The former 2 carriers were charter operators .... of course .... leaving SWISSAIR as being really the only successful major/scheduled operator among the few whom flew the CV990.
"Polar Compass" is a device which is able to hold its setting for a long time and has an internal device for corretion due to changes of geographical latitude. With that device one is independent from magnetic declination and its changes and can fly great circle tracks much easier. In Western aviation that device is set to the meridian halfway on your flight, in sowjet aviation it was set to the magnetic or true bearing of the departing airport. Before landing its setting was corrected by the difference of departing and landing airports. Necessary was a flightplan based on that form of navigation. I have published exampleflights e.g. for the Tu-154M:
In the original airplane manual of the PT Tu-154M one can find also the basic principles as well as in the documentation of SAMDIMS AN-24 and SAMDIMS TU-124.
P.S.: On the picture of "my navigators station" one can see the polar compass, the NAS doppler radar based navigation system (both borrowed from the AN-24), the GROZA weather radar representing the cathode tube for analyzing LORAN signals (only optical not functional) and the KLN 90B GPS representing the KLN 77 LORAN. The KLN 77 came out some years later after MODERN AIR´s round the globe flight.