EWRvirgin
Topic Author
Posts: 348
Joined: Tue May 15, 2001 11:38 am

Trans-Oceanic Navigation Prior To GPS

Fri Jun 01, 2001 11:41 am

With the lack of navaids over water, how were trans-Atlantic and trans-Pacific flights navigated prior to the installation GPS equipment in A/C?
 
scxmechanic
Posts: 479
Joined: Sat Dec 25, 1999 10:20 am

RE: Trans-Oceanic Navigation Prior To GPS

Fri Jun 01, 2001 11:55 am

One word...

OMEGA

It used several ground stations based around the world and transmitted a low freq signal that was used for Long Range Nav. But wasn't very accurate and could easily have been distorted by solar flares. Its since been decomissioned by the Navy (I think thats who ran the system as it was used by surface ships too)
 
JT-8D
Posts: 423
Joined: Sun Dec 31, 2000 11:34 pm

RE: Trans-Oceanic Navigation Prior To GPS

Fri Jun 01, 2001 7:14 pm

Dont forget loran. We had a few 727s with a little periscope looking thing in the cockpit ceiling to use a sextant with..JT
 
modesto2
Posts: 2669
Joined: Sun Jul 16, 2000 3:44 am

RE: Trans-Oceanic Navigation Prior To GPS

Sat Jun 02, 2001 1:33 am

I got another word (or acronym)...

INS

Intertial navigation system. Punch in coordinates at gate and with a system of accelerometers, it tracks the aircraft's movement. Even now, aircraft use an IRS (inertial reference unit) that is similar to the INS to back up the GPS.
 
JT-8D
Posts: 423
Joined: Sun Dec 31, 2000 11:34 pm

RE: Trans-Oceanic Navigation Prior To GPS

Sat Jun 02, 2001 1:44 am

Well, your right to a point. The irs does more than provide position data. On our planes, the fmc position is the "accepted" position. It gets data from the gps, and irus. It will update its position from gps, but not from iru. Irus main job is provide output to instruments (hsi, adi, vsi,)..JT
 
TimT
Posts: 168
Joined: Sun Jun 03, 2001 1:38 pm

RE: Trans-Oceanic Navigation Prior To GPS

Sun Jun 03, 2001 2:24 pm

The airline I work for uses Inertial Navigation on some of the planes. The INU has 2 accelerometers and a clock. It all runs off of an internal computer/database and then updates within 150 miles of a DME site. The DME's usually read in pairs and like a 90degree angle. It calculates the position and updates. The accelerometers are sensitive enough to read the earth's rotation. We havin' fun yet??
 
L-188
Posts: 29881
Joined: Wed Jul 07, 1999 11:27 am

RE: Trans-Oceanic Navigation Prior To GPS

Sun Jun 03, 2001 4:12 pm

Most airliners still had a navigator on them untill the early 1970's when the first INS units became available. I belive Flying Tigers laid there navigators off about 74.

All you need is a star chart and a Sextant.

The Air Navigators license is still on the FAA books. I have know idea where you would go and get one though.

It would be a neat license to have though. Anybody know where they still teach a course in it?
OBAMA-WORST PRESIDENT EVER....Even SKOORB would be better.
 
kellmark
Posts: 542
Joined: Thu Dec 21, 2000 12:05 pm

RE: Trans-Oceanic Navigation Prior To GPS

Mon Jun 04, 2001 1:49 am

The military.

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