Sextants
 

Hey folks,

when did the us military stop using sextants on their aircraft? Ive seen the ports, but never understood how and when they were used.

Thanks,

-DILLA

As for how, it was all PFM to me. As to when, we were still using them on the -135 in 1994 when I quit flying them. The navs would use them for celestial navigation on training flights, or as a nav system backup on overwater missions. We would often use the port to stick a vacuum hose in to clean the flightdeck in flight. Worked great!:D

A number of years ago I was tasked to be a TAM, or Tactical Air Monitor, whose job it was to fly on the tanker and provide technical support to a group of fighters, in this case, 6 A-10's who were being dragged across the Atlantic from Bradley ANG Base to Nordholtz AB, in (at the time) West Germany, by said KC-135.

This particular 135 had two pilots and dual INS's on their pedestal panel and a Navigator, who started taking his star shots the moment we began our initial taxi for takeoff. During the flight he never stopped working, and it got to a point where I was feeling sorry for him. For a good portion of the flight I was sitting in the jumpseat, between the two pilots, so that we could bs, and because the back of the tanker was much colder than I had cared for.

Anyway, we were scheduled for a mid-ocean rendezvous with another tanker, who had come out of England, and who had enough gas, such that the A-10's could join up on him, and he'd then take them the rest of the way, while the original tanker, with me on board, would proceed to and land at Mildenhall AB, in England.

Anyway, the Navigator was busily fixing our position the whole way across, with the real test of his skills being the mid-ocean rendezvous. The pilots of course were navigating with their INS's, and when we got within a few hundred miles of our rendezvous point, all eyes and ears were on the Navigator, who had been working non-stop. When he finally called out that our point was a few minutes ahead, both 135 pilots looked at each other and then at me. The point the Nav had identified was well over 200 miles away, not 20 miles away as he had thought. It was a good thing that they had the INS's, because otherwise, we'd probably still be out there, looking for that other tanker.

JJ

The U-2 used them until the 1970's.

I think they stopped teaching Cel Nav at Nav school around 1998 or so. The Sextant ports main purpose now is In flight vaccum or Garbage disposal.

I taught at the Marine Aerial Navigation School from 1997-1999. We stopped teaching cel to the nav students during my tour there. The sextants were left on the aircraft in the fleet for a few more years so the older navs could still use cel to maintain thier qualification, but with dual INS and GPS recievers in most aircraft by now, about the only time it was used was to retain currency. The last time I shot a cel line was probably around 2003 or so, just to show the crew how it was done "back in the day".

As one of the last C-141C Navigators to go through Nav training at Randolph AFB I believe Celestial Navigation was still taught as late as 2000. Ski-equipped LC-130's and C-141's that flew the resupply missions to Mcmurdo Station (before the C-17's took over) in the South Pole had Navs who did grid navigation and some celestial navigation since there were some significant challenges to conventional navigation the closer you flew to the poles (even with INS's).

I do believe that Air Force One has a sextant port and they do fly with a Navigator because if the ish ever hit the fan and WWIII kicked off with nukes and that 747 became an airborne command post for the president, conventional ground and space-based navigational aids would be rendered useless due to the nuclear cloud...

I was a C-141B Loadmaster from the late 80's-early 90's. I remember the sextant itself being on the flight deck but the port was no longer on the aircraft-it was covered by the refueling tube when the aircraft was stretched in the early 80's. Several guys told me they also used the sextant port (on the aft ceiling of the flight deck) as a vacuum. The story was that practice was stopped when maintenance found dents in the T-Tail. Im curious how they did the navigation on the C models myself

Stupid question. Was the port was something you had to open during flight to shoot the sextant or could open to jury rig a hose for the vacuum option? Also, what was its operation like as far as getting it open during flight (i.e. while pressurized)?

I sarted celestial with an A-14 sextant in the astrodome of a T-29 (aviation cadet navigator training) and shot celestial in B-52s for four years with a D-2 sextant. After Pilot training I flew C-141s. In 1965 the crew included a Navigator. (Before dual INS or GPS) The engineers would often use the sextant port in flight for vaccuum cleaner "suction." A hose was attached and the port opened (lever) in flight. Kept the cockpit clean but the pencils, paper clips, coins, etc hitting the tail raised hell with the sheet metal. :eek: