phil65 wrote:
Side question, what's the big benefit of running so close to empty ?
In G.A. it's the weight, but that can't be a factor here. I hope it's not the piece of the fuel.
Phil
In a generic sense, the benefit of running close to empty for big, multi-engine aircraft, could be numerous factors:
1) Performance - yes, the B-25 does have performance issues at high density altitudes, particularly in single engine situations.
2) Sponsorship/free gas - if someone else is paying the gas bill to fill up your tanks, it makes sense to take on as much "free gas", as one can. FYI, it is a very popular "technique" for warbirds to show up at airshows/flying events with very low fuel tanks - as little as the pilots are comfortable arriving with. Many airshows/events will "fill your tanks" and allow you to take on as much gas as you can hold. With this being the case, I know of several warbird pilots, particularly privately owned who pay their own bills, who will plan on showing up close to minimum/emergency fuel, just to take advantage of the "free gas".
2) Cost of gas - keep in mind that the B-25 carries close to 1000 gallons of gas. The big effect of a small difference in gas price is the following exercise. I looked up the cost of 100LL at both Nut Tree and Stockton, which were the last legs of "Old Glory". Here is what it costs today (Oct 8th):
KSCK: $5.57/gallon
KVCB: $3.55/gallon
According to online sources, the B-25 carries 974 gallons of internal fuel, not including bomb bay tanks, etc.
So, if we do the math, we find a difference of $2.02/gallon between the above fuel stops.
Then we find the difference in cost between filling full tanks at both locations:
2.02 x 974 =
$1967.48So, the difference saved is nearly
$2000. That is not insignificant, and I am in no way suggesting that was in play with this accident - in fact, it couldn't be - as the cost at Nut Tree was cheaper than Stockton.
Whether any of the above was at at play is way, way too early to speculate about in regards to "Old Glory", and I am NOT suggesting it was. I only bring this up as an academic exercise to show that there are many situations where it makes sense to show up with a minimal amount of fuel on an aircraft to answer the original question.