General comments on the United Airlines Air Transport Command (UAL ATC) Pacific routes.

1. The flights generally are over water, but high mountains may be experienced near the airports. The minimum safe altitude is provided in the flight .pln file, which may also be used as a general area map, when it is called up by the Microsoft flight planner. (Select flights, flight planner, edit to see the plan and print out the map). Since the plan shows the location of the aircraft, you should do this only when the aircraft is at a known location.

2. There are two maps included in this package, of the Pacific Theater in 1941 and in Location of Forces,Pacific Theater in 1942. The ATC flights stayed well south of the fighting, and these maps indicate the areas of generally safe operation. Please consult them before planning your flight.

3. Daylight Sextant Navigation depends almost exclusively on the sun. Careful pre-planning can improve your payload safely, by selecting times of arrival at destination where the sun provides appropriate speed or course lines of position. The Latitude and Longitude of the origin and destination of each flight are provided, to aid in the pre-flight planning.

4. Winds aloft predictions in the 1940's, especially over enemy territory, were not reliable, and prudent navigation would include several en-route "fixes" to determine drift and wind correction headings.

5. For each flight, the average magnetic heading (initial heading plus final heading divided by 2) is provided, for a magnetic Rhumb line. All flights may be flown in reverse direction, and just add 180 degrees to the average magnetic heading to get the reverse heading. The magnetic deviation is also given, to provide True bearings for combining with the wind data. (Add the Easterly deviation to the Magnetic heading to get the True Heading.)

6. All airports have the closest NDB radio listed (Except Canton, which doesn't have one), to simulate the short range radio direction finding capability of the period. This DF may actually have been on an early NDB, or voice tower transmitter, or other transmitter. Use of VOR, ILS, or GPS is discouraged for proper period simulation.

7. The UAL rules call for daylight flying only. This includes a 2 hour fuel reserve, and specification of an alternate airport, or 3 hours reserve fuel. The calculations shown below show the DC-3 maximum range profile. In most cases, however, you may fly the standard 90 gph, 2050/30 power settings. For the DC3Airways DC-4, the standard flight planning values are 240 gph, and 195 KTAS for long range flights.

MAXIMUM RANGE CALCULATIONS:

To plan a very long UAL passenger flight in the DC-3, the fuel required is 1/2 gal per nautical mile, plus 10 gallons taxi and Take Off, Plus 10 Gal initial climb. Add 198 gallons reserve for 3 hours at the long range cruise power setting. The maximum range is therefore 1172 NM.

The DC-3 will cruise at 66 gph and 132 KTAS average, if the Take Off GW is 26,200 lbs, and the first 500 NM is flown at 5,000 ft, and the remainder is flown at 10,000 ft. The properly leaned P&W engines will provide 115 KIAS for the first 500 NM, and, after the second climb, about 118 KIAS.

The reference for this data is the part III operating data from the first MAAM CD "ww2manuals\uk_dak\pg34.jpg" and the sheet titled "C-47 - DC3A - C-53 SUGGESTED POWER CONTROL FOR P&W R-1830-92 ENGINES, PD12H4-1 CARBURETOR".

Of course this is the "no wind" range, seldom seen in real weather. It does, however, explain the limit set for the Pacific routes in the DC-3.

All flights should be planned with careful attention to weather and distance, and the goal is to fly the maximum payload on each flight, so the fuel load should be tailored for each flight. In the DC-3 you should touch down with 198 gallons fuel remaining if you have no en-route surprises. The Beaumont/Bitzer modified Stock DC-3 will perform "to the numbers" on these routes. For the DC3Airways DC-4, the fuel capacity is more than sufficient to handle all of these routes, even on 3 engines, and in severe headwinds. Use the power settings provided in the DC-4 checklist or reference, and you should land with your calculated reserve fuel on board.