NavList:

Dear Richard,

If not confidential ...

When ? Aircraft Type ? Where ? As an Airline, Pilot (A343/345) , I find a few things "strange" if not inconsistent in the reported story ...

Thanks in advance,

Kermit

There are a plenty of clues in the story:

"droning of multiple jet engines in the background"

-2 or more engine aircraft with the implication of more than 2, so 4, 6 or 8 engines.

"special mission aircraft"

-Probably a recon aircraft, but possibly a B-52.  Later references to the large crew in the cabin eliminate the B-52.

"this particular aircraft enroute to what must remain an undisclosed location down under"

-This implies Australia and strongly implies southern hemisphere.

"a multi-hundred-million-dollar modern reconnaissance aircraft"

Tada, reconn bird, like I said.  E-3, RC-135, EC-135, . . . 

 "the senior navigator had not used one (sextant) since navigator school at Mather Air Force Base in California ..."

-Navigation training at Mather was from 1946-93 so not very helpful.

-Title of Senior navigator implies he'd been doing it a while, let's say 7yr minimum.  He hadn't used a sextant since training so his training occured at the point or after Loran-C and interial systems had beecome ubiquitous enough that Celestial was not commonly used.  Let's say that that Loran-C became common about 1970, and it was 5yr or so before celestial nav requirements were relaxed.  So the story occured about 1982 or later. 

"racks for a GPS receiver that had yet to be installed"

-This implies the GPS constellation was in process of being launched or had just been finished launching and aircraft were still in the process of being upgraded with the equipment.  The first round of for real satellites started going up in 1989. (Earlier satellites were prototypes and experimental)  Let's say this was about 1990 or so.

"and were shortly thereafter intercepted by a Canberra aircraft that was conveniently in the area"  

-In the pacific region the Canberra and its American built version the B-57 were operated by Australia, Taiwain and a number of western South American countries.  Previous references to Down Under implied Australia where the Canberra was in service until 1982 so probably not Australia after all.  Taiwan only had the Canberra in the late 50's and again in the early '60's, so definitely not Taiwan.  Equador, Peru and Chile had Canberras that served until 1981, 2008, 1998 respectively so Peru or Chile are the most likely destinations.    (http://warships1discussionboards.yuku.com/topic/10250#.VfEAsxFViko)

 "politically the number of foreign airports where we could land our type of reconnaissance aircraft were few and far between"

-If the aircraft was being flown US to Australia, they could have diverted to American Samoa which had a 9,000 runway in 1990.  If flying Japan or Shemya to Australia there would have been Guam as well.  Flying from Japan or Shemya to Chile or Peru they would have a very long stretch with no diversions except to Peru or Chile both of which experienced a bit of upheaval around 1990 so going to one would have been a sensitive mission and diverting to the other would have been unwise.  The exact time of the mission would have affected which country was in favor at the time and which was out.

"after the fifth and last over-water air refueling things were progressing nominally — until they weren’t"

"The copilot calculated the aircraft could fly for another 10+ hours "

Having refueled in the recent past, lets say 1hr or so plus the 10+hr left that implies a flight duration of 12ish hours on a single tank.  At 460 kt (C-135 cruising speed) that's about 5520 nm.

Technically most of the following aircraft don't have that range, but the listed ranges are probably under-reported to begin with plus the plane didn't need to expend fuel getting to altitude so any of them might be the aircraft from the story.

https://en.wikipedia.org/wiki/Boeing_E-6_Mercury

https://en.wikipedia.org/wiki/Boeing_EC-135

https://en.wikipedia.org/wiki/Boeing_RC-135

https://en.wikipedia.org/wiki/Boeing_WC-135_Constant_Phoenix

So the story occured about 1990 or so, the aircraft was some reconn version of the C-135 (Boeing 707) and it was flying NW Pacific to SW South America and was about half way from Hawai'i to it's final destination when the lights went out.