Refuel Policy

[bear]

Hi,

I wonder what refueling was of DC6b's on long distance flights in 1956?
Example:
KLM Night flight KL301, August 1956: from Amsterdam to Cairo with 3 stopovers at Dusseldorf - Vienna - Istanbul. All routes Payload = 2/3.
The flight is too long for 1 refueling.
What was the refuel policy?
1. Always refuel a minimum amount at depature and the 3 stopovers (refuel 4 times),
2. Refuel as much as possible until the furthest stopover (2x refueling) <MTOW,
3. Refuel the least amount until the nearest stopover (refuel twice),
4. Refuel the largest amount at the cheapest airport (2x refueling),
5. Refuel "halfway" (refuel twice).

Regards, Guus.
​

[Tom/CalClassic]

Check a timetable. Generally speaking the refueling stops will last 45 minutes to one hour. The non-refueling stops will be shorter.

[Defender]

Apart from the initial MTOW the MLW at subsequent stops might be the limitation.

Bill

[bear]

Ok Tom, what is the general speed of the transfer from the tanker to the plane ? (Gal./min.).
In the time table I indeed see a delay time of 50 and 55 minutes, and in Istanbul a delay time of 75 minutes ! The open time at the stopovers can therefore indicate whether refueling is taking place or not ?! So I can adjust my fuel planning accordingly (Amsterdam - Istanbul and Istanbul - Cairo).

Guus.

[Tom/CalClassic]

Correct. There is little reason for airliners to make a stop of over 30 minutes unless they are refueling. I don’t know what the typical fueling rate is (it’s not in the flight manuals) because a lot of the time was spent on top of the wings moving the hose from one tank to another. Each set of tanks had its own fueling point - no single point fueling in piston propliners.

And Bill’s point about MLW certainly applies - you cannot take off at MTOW for a short leg because you would be over MLW at the destination. Thus fueling would normally be before long legs, or they might just fill the tanks partially full if there was no fuel available at the next airport.

And fueling practices for shorter domestic flights would change because airlines would refuel at whatever airport was cheapest!