A26 Special K wrote:
We always used a calibrated stick in the B-25 we operated for over ten years to determine fuel on board. However, there are some airplanes that a stick cannot be inserted into the tank. For example, the A-26 has a nearly 90 degree bend that leads to the tank. Kay has a fairly accurate fuel flow meter on each engine that takes some of the guesswork out of it, but we have also put a lot of effort into having accurate fuel gauges. We still run the timer and start paying a lot closer attention when approaching time to switch tanks. The fuel pressure will start fluctuating slightly as a first clue. That’s when you better catch it by switching and turning the appropriate boost pump on until established on the new tank. We did learn one other trick to get more fuel out of the B-25 tanks when getting low and that was to lower 10 degrees of flaps to lower the nose attitude and move some fuel forward to the pickup from the back of the tank.
Thanks for that info, A26 Special K, I was not aware of that limitation on the B-26. A few questions for you:
1) Is the fuel quantity indicating system on Special K different from the one they used on factory A-26's in W.W.II? In other words, was that fuel indicating system an "upgrade" put into place on the On Mark conversions to B-26K standard? Is your fuel flow meter part of that standard, or is it the same one from W.W.II?
2) For tanks where dips can't be taken, there has to be another way to mitigate fuel errors. If you can't use a dipstick, does the B-26 have a fuel dripstick? I'm not familiar with the B-26 fuel tank system - does the B-26 have that functionality? It sounds like your fuel flow indicator is one way to mitigate errors/inaccuracies. I'm assuming that in order to have "known" fuel quantities prior to takeoff, you probably fill up one or more tanks to full levels. Is this a strategy you employ?
3) I've heard in anecdotal stories from Vets that one of the things they did in the MTO was to use partial flaps in those B-25's to extend the range. So, what you say is validated by Veterans' recollections.