gigneil
Posts: 14133
Joined: Fri Nov 08, 2002 10:25 am

Classic Jet Airliner Navigation

Thu Mar 06, 2003 1:45 pm

Take the DC-10, or the 742, or the L-1011, for example.

When I look at these cockpits I see very little in the way of computerized electronics.

Do these planes have autopilot? If so, how did they function, and, if not, what all goes into navigating these planes? Do you just pay attention and make the appropriate turns by hand at the right times? Is it based on timers like old sub navigation?


Thanks for answering a silly question...

N
 
jhooper
Posts: 5560
Joined: Thu Dec 13, 2001 8:27 pm

RE: Classic Jet Airliner Navigation

Thu Mar 06, 2003 1:55 pm

Yes, these planes still have autopilot. While some of them still have the old analog systems, some have been upgraded to digital autopilots. This would be a perfect question for B747Skipper.
Last year 1,944 New Yorkers saw something and said something.
 
POSITIVE RATE
Posts: 2121
Joined: Sun Sep 16, 2001 11:31 am

RE: Classic Jet Airliner Navigation

Thu Mar 06, 2003 3:03 pm

Even the old "classic" jets like the DC-10 and the 747-100/200/300 had an INS fitted. These are extremely accurate for Navigation and can deliver the aircraft literally anywhere in the world. One exception i think was the 727 which didn't come out with an INS because it was designed for short haul routes- had to be flown purely from navaid to navaid- i.e VOR to VOR. But i see what Gigneil is saying. In todays EFIS aircraft like the 747-400 a display comes up on the EHSI and shows you exactly where you are in relation to your flightplanned route. I have a question for any "classic" deivers out there, how do you know exactly where you are in relation to your flight planned track and waypoints etc without an EHSI??? Do you have to constantly read maps???
 
XFSUgimpLB41X
Posts: 3960
Joined: Fri Aug 25, 2000 1:18 am

RE: Classic Jet Airliner Navigation

Thu Mar 06, 2003 3:22 pm

Oh no!!!! God forbid I ever pull a map out en route!


hehe.... even with the moving map and such I always have the appropriate en route chart and map out. It's easy purely by reference to VOR or any type of distance measuring for that matter to figure out right where you are on a map. edited in: You don't even need DME, either.

Even with the Garmin 4/530's or the EHSI we have in the King Air, I always am cross referencing to the en route chart.

Seriously.. it's really easy to stay oriented and always know exactly where you are if you practice it.

[Edited 2003-03-06 07:23:47]
Chicks dig winglets.
 
AAR90
Posts: 3140
Joined: Fri Jan 21, 2000 11:51 am

RE: Classic Jet Airliner Navigation

Thu Mar 06, 2003 5:30 pm

AA's domestic DC10s never had INS installed. Those DC10s used VOR/ILS and ADF for navigation. The autopilots could track a VOR course pretty well and multiple autopilot ILS autolands were fairly common on the redeye transcons I flew in 1987.
*NO CARRIER* -- A Naval Aviator's worst nightmare!
 
saintsman
Posts: 2037
Joined: Fri Mar 15, 2002 12:34 am

RE: Classic Jet Airliner Navigation

Thu Mar 06, 2003 9:35 pm

I remember not that long ago that aircraft used to be fitted with a periscope sextant for navigation purposes http://www.geocities.com/petanoz/aviation/celestnav.htm.

But in those days you needed a navigator.....
 
dc10hound
Posts: 460
Joined: Fri Dec 15, 2000 4:18 pm

RE: Classic Jet Airliner Navigation

Thu Mar 06, 2003 11:02 pm

AA's domestic DC10s never had INS installed.

The international DC-10-30s did. It was replaced by Omega, and Omega was replaced by GFMS (Global Flight Management System).
"Eagles soar. But weasels never get sucked into jet intakes.."
 
747Teach
Posts: 176
Joined: Wed Nov 29, 2000 3:05 am

RE: Classic Jet Airliner Navigation

Fri Mar 07, 2003 3:01 am

Gigneil: Autopilot and navigation are two separate, but interrelated functions. Autopilot is used to provide automatic airplane stabilization in pitch, roll, and yaw axis, and control the airplane with selective guidance from navigation systems (747 AMM, Chapter 22-00-00, Description and Operation, Page 1). Navigation systems are used to determine and display attitude, altitude, and position with respect to the earth (747 AMM, Chapter 34-00-00, Description and Operation, Page 1). The 747's I've been associated with carried the Sperry SPZ-1 autopilot system, and the Litton LTN-92 INS system (and years ago, the Delco system). With this combination, the INS system knows where it is, and it knows the route the aircrew has asked it to maintain. It sends this information to the AP/FD, and the autopilot, if it is engaged and the mode select switch set to INS, will command the flight control surfaces to move to position the aircraft to acquire and maintain the selected track. Of course, there are numerous other systems that come into play, but that is the operation in a nutshell. Regards,
 
411A
Posts: 1788
Joined: Mon Nov 12, 2001 10:34 am

RE: Classic Jet Airliner Navigation

Fri Mar 07, 2003 6:29 am

If we dial the clock back...way back to the preINS days, airliners (B707 for example) used...
navigator (yes the living breathing kind)
Doppler (Bendix was best IMO, Marconi so-so)
astro nav
Loran A (NOT the 'C' used today).

Even further back (piston engine days), navigators and high range radio altimeters for astro nav/pressure pattern navigation....not suitable for the organized track system used today.
 
timz
Posts: 6081
Joined: Fri Sep 17, 1999 7:43 am

RE: Classic Jet Airliner Navigation

Sat Mar 08, 2003 6:58 am

How many intercontinental 707s/DC-8s carried navigators in, say, the late 1960s? A small fraction?

And presumably no airlines used astro navigation without a navigator?

(Just wondering how common astro was just before INS came in.)
 
411A
Posts: 1788
Joined: Mon Nov 12, 2001 10:34 am

RE: Classic Jet Airliner Navigation

Sat Mar 08, 2003 11:22 am

Dunno about the late sixtys, but in the 70's, when no INS , and long overwater routes necessary, always personally had a navigator present...and using astro.

However, do know that PanAmerican operated over the N>Atlantic without INS, using Loran A and Doppler nav, not sure if they had a navigator or not.
Loran A was very accurate, so long as lane skip was not involved.
 
vc10
Posts: 1339
Joined: Thu Nov 15, 2001 4:13 am

RE: Classic Jet Airliner Navigation

Sat Mar 08, 2003 10:52 pm

The 707 and VC-10 of BOAC always carried a 4 man crew during the 1960's and early 1970's and one of these was always qualified as a navigator. They would use what ever nav aid they could which would include Astro. By the 1960 's BOAC had no straight Navigators ,but used pilots who had also been trained to be a Navigator
timz Astro was very common form of navigation aid, prior to the installation of INS, which saw the end of navigators. Within BOAC INS sets were being installed as a retro fit to VC-10s in the early 1970s and once all the crews were checked out on their use the aircraft was reduced to a 3 man crew
regards little vc10

 
POSITIVE RATE
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Joined: Sun Sep 16, 2001 11:31 am

RE: Classic Jet Airliner Navigation

Sun Mar 09, 2003 2:08 pm

A question for you US guys. Since the USA is literally covered with VOR's do airliners still today use VOR-VOR tracking for short-haul domestic flights??? And what about the 737-200/DC-9 still in use today, do they have INS/IRS fitted???
 
411A
Posts: 1788
Joined: Mon Nov 12, 2001 10:34 am

RE: Classic Jet Airliner Navigation

Mon Mar 10, 2003 12:46 am

Those aircraft that are fitted with approved area navigation equipment can use same, depending on route(s) and controller approval...those that don't have the aforementioned area nav equipment use vor point-point navigation, or controller provided radar vectors, traffic permitting.
 
timz
Posts: 6081
Joined: Fri Sep 17, 1999 7:43 am

RE: Classic Jet Airliner Navigation

Mon Mar 10, 2003 8:09 am

As for VORs in the US: no idea how many airliners navigate by the actual VOR radio signals, instead of by treating the VOR as just another lat-lon. But I'd say 98+% of US airline flights are tracking (one way or another) toward a VOR at some point in their flight.
 
saab2000
Posts: 1216
Joined: Thu Jun 21, 2001 6:19 pm

RE: Classic Jet Airliner Navigation

Tue Mar 11, 2003 8:53 pm

I do not know how it is in the US, but here in Europe conventional navigation is practically gone for airliners. Generally, we are cleared to waypoints which are not related to VORs or NDBs. Here in Switzerland, some form of approved RNAV is required above FL100 for all aircraft. I believe that there are some exceptions for VFR flights in the mountains, but not many.

The Saab2000 that I fly is equipped with 2 IRS systems, GPS, VOR receivers and ADF receivers. These are interconnected with the FMS which knows where it is and will fly the programmed flight path. We can check to see what we are using for nav at any time. Above FL100 we generally, set the radios to "Auto-tune" and the VOR/DME signals will be automatically compared with the known position based on GPS and IRS signals. If there is a conflict we get warning.

In order to change route in flight, for example, "Fly direct to RLP", we just insert the VOR RLP into the FMS and execute the command. We could also fly conventionally to RLP.

My answer does not answer the original question, but maybe sheds some light on modern navigation for someone who may have been curious.

Frankly, it is too easy and boring. But it is extremely accurate.

smrtrthnu
 
Guest

RE: Classic Jet Airliner Navigation

Wed Mar 19, 2003 10:46 am

To the rescue here... about "old classic planes"...
In the late 1960s, the 707s navigation for oceanic flights, was with 2 Dopplers and 1 Loran-A receiver... then the planes got 2 INS as newer equipment...
xxx
Some planes got later equipped with 2 Omega/VLF systems, as they were cheaper systems to buy and maintain, compared to the INS...
xxx
The 747 classics I presently fly, are equipped as follows:
3 INS systems, positions updated by 2 GPS systems...
3 Autopilots, permitting CAT IIIa ILS approach and landings...
2 VOR receivers, 2 ADF receivers, 3 VHF comm radios, 2 HF comm radios...
1 Satellite phone, with phone/fax - can even connect your laptop...
 Smile
(s) Skipper
 
LZ-TLT
Posts: 427
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RE: Classic Jet Airliner Navigation

Wed Mar 19, 2003 4:56 pm

I wonder nobody noticed the range radio beacons...

Altough the role they played was fairly a minor in the 60's, they were still there and used on occasions. AFAIK, the last one in the US has been decomissioned by the beginning of the 70's

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