Transatlantic flights - navigation

[DanKH]

Hi, I'm taking on a small historical project of my own.

To do this I will be flying DC-3, DC-4, DC-6, DC-7, DC-8, maybe DC-9 and DC-10.

For the DC-4, -6 and -7's I would need to know something about how to navigate over the Atlantic Ocean ....

I know that (Honeywell?) made some navigation instruments for Scandinavian Airlines, before they augmented the Copenhagen-New York route.... along with establishing several radio stations where possible en route .... but over open waters .....?

I would think that INS of some kind was invented, but maybe someone here can clear things up for me?

The DC-3 didn't had the range obviously, and I'm pretty familiar with the jets .... shows my knowledge of the prop-liners eh? ;-)

[Tom/CalClassic]

Hi Dan,

Well, we all have to learn sometimes.

First, for communications they had HF radio, which was much the same in the jet era. By the late 1950's they also had SELCAL receivers connected to the VHF and HF radios.

I have an SAS DC-7C manual, and it describes the equipment they used for navigation.

1. VOR and ADF receivers as usual.
2. LORAN receiver
3. Low Range and High Range Radar Altimeters
4. Airborne Radar
5. Polar Path Compass (a crude form of INS)
6. Periscopic Sextant

As I understand it, typically most transatlantic flights were started and ended with regular navigation from high power VOR's and NDB's. Once out of range, the flight was flown using LORAN, Celestial/Solar Navigation, Dead Reckoning, and in the polar regions the Polar Path Compass. Note that there were also Ocean Station ships posted in certain locations that could give aircraft positions (my FS versions have an NDB).

For the early DC-4 flights you can delete the LORAN and Polar Path Compass. The DC-6's often had LORAN, but usually not Polar Path Compasses. LORAN was established in the mid 1950's or so. The Polar Path Compass didn't arrive until 1958 or so, I think.

There is a Sextant gauge available for FS, but not LORAN. To simulate that, pop up the GPS every 20 minutes or so, calculate a corrected course, and fly that for the next 20 minutes without GPS assistance. The Propliner Tutorial on my Tutorials page has more details.

Hope this helps,

[mikeespo]

Celestial Navigation. www.dc3airways.com/useful/downloads/downloads.htm

Only way to fly in the 40s. I always thought it was cheating to use GPS and Radio methods in the 40s. 50s and later, yes.

After reading the tutorial and following the checkflights, I was able to navigate my RR41 DC3 from Ford Island HI to Johnston Atoll just using dead reckoning and the Bubble sextant. Really cool!!! ;D

You do have to have acsess to celestial and solar data which is also available online.

[qar02]

There was a discussion a while back on Polar Navigation. This thread probably isn't the one to post on but, at AVSIM and Flightsim there is now an Astrocompass loaded.

I have not tried this yet but, this was one of the methods used to overcome the magnetic aberations near the Polar regions.

qar02

[DanKH]

Thanks a lot Tom, gives me something to read during my vacation :-)

[mrcapitalism]

propspistonsandoldairliners.blogspot.com/2010/02/navigating-pan-am-dc-6-new-york-shannon.html

Great blog in general.

[Tom/CalClassic]

Other relevant stories from that site:

propspistonsandoldairliners.blogspot.com/2010/10/flying-northern-route-in-dc-6b-empress.html

propspistonsandoldairliners.blogspot.com/2011/02/air-france-1649a-starliner-f-bhbt-over.html

propspistonsandoldairliners.blogspot.com/2009/01/remember-airline-navigator.html

[Lockheed]

Hey Dan.....just head West 'till you find land and then figure out where you are. Head East going back home 'till you find land and repeat. Good luck !! ;D ;D

[DanKH]

Thanks guys, I came across that blog as well, but I think I'll give it some more interest now that you actually recommend it....

Lockheed: Yes I kind of figured out the overall general direction

[emfrat]

;D
Dan, take plenty of fuel if you're going to follow a rhumb line !

Cheers
MikeW

[bob-bgan005]

I just did a flight in FS2004 with a C-47A with skis and a DCA NH panel. I flew from Gander (BGTL) to Alert (CYLT). This gives about 70 Degrees variation between True and Magnetic readings. I used the Astro Compass and it gave me the good true and magnetic readings. It looks like it would be a good gauge for polar navigation. Will test more later.

The NH panel had a digital gauge which does the same thing without longitude inputs. We have two choices. Both work well for keeping a true course.

Bob

[Tom/CalClassic]

I think Gander is CYQX? BGTL is Thule.

[bob-bgan005]

You are right, I took off from Thule. Or one of those cold and snowy places! ;D

Thanks

Bob

[Tom Test]

I do a lot of these flights, but I do it from from the pilot's perspective, so I follow the instructions from my navigator.

From the first regularly scheduled transatlantic (and transpacific) flights in the 1930's until well into the 1970's the navigator (and earlier, radio operator) were important members of the flight crew. The tools changed over the years, moving from dead reckoning and celestial navigation to radio and radar navigation as tools developed and the infrastructure was put into place. Some radio tools functioned like beacons, some functioned as a GPS cruder than what we have today, and some involved interaction between the navigator and location services on the ground. But even with a ground-based GPS like DECCA or LORAN, navigation was the navigator's responsibility, not the pilot's responsibility. Different skill sets are used in the different roles.

I use the default MS GPS (or the Map View) as a navigator, making appropriately imprecise course corrections at intervals, and using period appropriate radio instruments as they come into range.

Long ocean flights in the simulator progress slowly enough in the prop era that you could also play the navigator role, at least for dead reckoning; it is a matter of having the charts, doing the timing and plotting. There is at least one sim celestial navigation tool (I found it in the AE Lockheed 10E package) that you might try learning to use for correction of your D-R plots. For the '50s and '60s, I think you can find ocean weather stations in scenery data sets. These carried NDBs, but even so, pilots did not home on them with ADF, they were another part of the navigator's tool kit for correcting D-R plots.

Keep in mind that a few trans-ocean flights simply disappeared, in the '30s and '40s; navigation errors may have been a factor. The Bermuda Triangle is at least partly about getting lost.

[Tom/CalClassic]

A very good point, Tom. We often get into the habit of doing the work of the entire crew, when we really should be concentrating on being the pilot.