DC-9 Navigation

[RobMinter]

A thought crossed my mind recently having no experience with DC-9's at all...

How do they navigate? Northwest has loads of DC-9 10's, 30's, 40's etc... in use domestically. I know they are equipped with VOR/DME tracking equipment and an Autopilot able to track radials, but is this all they use? What about intersection fixes on the airways, do they take distances and bearings to determine when they are over the fix? It seems far too crude for this day and age.

Alternatively, do they have INS equipment aboard and a coupled autopilot? I havent seen any evidence of it in pictures i have seen of DC-9 flight decks.

If they did at some stage have a navigation system upgrade, when was such a system offered?

Early nineties saw even more airlines using DC-9's in modern airway structures, for instance Valujet.

Any comments/answers greatly appreciated. Thanks all.
Best Regards, Rob Minter

[bafanguy]

Rob,

Can't speak to NWA's DC9 fleet but would be surprised if it were any different from anyone else. The DC9 ( not MD80 or B717 ) is an old airplane with perhaps a limited life given the state of the US airline industry, but at least they're paid for !!

The DC9's I flew had 2 VOR's, 2 DME's, and one ADF. DME was most often used to ID intersections as that info is usually published. Absent that, VOR cross radials were used.

It may seem a bit antiquated compard to GPS, FMS, EFIS, INS, etc., but the system still works well.

Pehaps out there somewhere is a DC9 with a more advanced nav system but I've not heard of such a thing...so far.

[Boss Raptor]

There is no reason an FMS/RNAV (as for example fitted laterly in the Finnair DC9-51's in Europe under BRNAV requirement) cannot be fitted to a DC9 (or any other older acft 727/732 etc. for that matter) and coupled accordingly to the existing A/P and FD units (via an interface) - as to the NWA fit I am not aware of what they have

[Larry in TN]

There is no reason an FMS/RNAV cannot be fitted to a DC9

$$$$$

[5150]

It costs next to nothing to install a basic Garmin type GPS as a "secondary" form of nav equipment.

My guess is a lot of older aircraft are fitted with this kind of set-up.

[learr]

The old serie like dc-9 30, 40, 50 only use vor, adf and gps and it works very well!!

Learr

[GearDown&Locked]

bafanguy said
Absent that, VOR cross radials were used

Now thats serious navigation :ok:

[Dockjock]

In the same vein, anyone know why the old King "RNAV" system isn't in use any more? We used to be able to input into the VOR box a radial/dme combination to create a phantom VOR and then track directly to it. Never seen it since, but it was a great system. Did any DC-9's have this?

[filejw]

5150
Here in the US every thing cost and the carriers will not spend if they don't have a need.DC 9's can get from KDTW to anyware in the system with out GPS so its still VOR ADF.

[Ignition Override]

RobMinter: At Northwest (over 100 flying, and for many more years) there are the two VORs and at least one ADF. Everyone trains each year for a Cat 2 approaches:one to a missed and the other for the landing. The autopilot does a lousy job of smoothly tracking VOR radials, and so we rarely use it-this increases the workload, never mind flying partly solo as the non-flying pilot listens to ATIS at smaller airports and reponds to (5) wheelchair requests etc along with various other duties-they now call it multi-tasking. This existed in the 1930s.

They are reportedly the most reliable fleet (others are A-319/320, 757, DC-10, 330 and 744) on the property! They don't mistakenly display error messages, as there is no FMC :D . If you want to be constantly busy, maybe very busy on the shorter legs (35 min. or less enroute time), that is the plane to fly-sometimes 5-7 legs in one long duty period. Guessing which crossing restrictions to plan on and when to descend with a 70-knot tailwind and over 100 people into LGA, ORF, PHL etc are just some variables (the leaky airfoil anti-ice system also creates much more work-the cabin might climb at over 1,000'/min., with idle power). ATC is a guessing game. The DC-9 FO is so much busier than a 747 FE (some did both jobs), yet the pay has no correlation :rolleyes: , none at all.

It is ironic that few of the original Northwest pilots bid to fly it. Some of them looked down their noses at it during our wonderful merger, yet few had the "marbles" (to put it diplomatically) to tackle it, or most simply wanted the higher pay on the 727 etc. The DC-9 pilots work much harder than the 757 pilots (I flew it) and probably the A-320 and any widebody pilots... the record of who has ever bid for whatever kind of flying, in a general way, speaks for itself.

[frazer]

As I'm only familiar with the Scandinavian Airlines (SAS) DC9ers, so I can just tell you what they used when operating the DC9ers.

They had the KNS 660 Area Nav System installed in all DC9ers.
Here's some more info on this system:
http://www.casa.gov.au/avreg/aircraft/AAC/PART-6/6-045.HTM