Head-2-Head Feature V: Fortress Sprint

By Ron Blehm
November 25, 2011

Seriously folks, you'd be insane to put a World War II piston-engine plane up against a modern jet but I was curious. It seems to me that just taxiing the jet would burn more gas. Might the propeller plane be more efficient on a very short flight? So where is the line when using a heavy jet becomes more efficient? Sure, when you have a 100,000 pound bomb load! I know.

Have you ever seen those challenges where it's man versus horse in a foot race? The track star might lead out for 15-20 meters but the horse catches up; it's more a question of how long can the weaker entity hang on really. (I saw a Ferrari take on an F-18 in a standing start mile once. That was fun!) That's what we are doing today. We took two bombers with the name "Fortress" and put them each to a 25 and 95 mile flight to see which was the most efficient. Again, the math is time plus two seconds for each gallon of fuel used. We removed all weight from these aircraft, no cargo, no load, no crew, nothing but 10% fuel.

Flight One: B-17H from Everett Washington to Renton

Time = 10.5 minutes
Fuel = 298 pounds
Total Score = 20.4

Flight Two: B-52 from Everett Washington to Renton

Original model by Mike Stone, corrected by Doug Trapp
Time = 9.4 minutes
Fuel = 1632.5 pounds
Total Score = 63.8

B-17 wins by 32%

Flight Three: B-17 from Renton Washington to Vancouver

Time = 39.6 minutes
Fuel = 1,012 pounds (this was, in fact, ALL of my fuel! I had to dead-stick the landing after gliding the last 4-plus miles!)
Total Score = 73.3

Flight Four: B-52 from Renton Washington to Vancouver

Time = 30.1 minutes
Fuel = 4,744 pounds
Total Score = 188.2

The B-17 wins by nearly 39% (helped no doubt by the gliding!) Anyone else surprised by that? I certainly was.

So, from Pearson Airpark we put 90% fuel and 20,000 pounds on board both aircraft and headed for Edwards AFB in California. This is actually a bit overloaded for the B-17 and I had to "cheat" by boosting the horsepower for all four engines by 750hp for take-off. I did then, immediately, put it back to normal for climb and cruise. Frankly, I was so busy flying and trying not to stall that I don't have screen shots from the B-17's departure; trust me, it was REALLY TIGHT (image below, left)!

The B-17's flight time was 3.5 hours for a total efficiency score of 490 minutes. (That's around eight hours.) (Images above, center and right.)

The B-52 crashed, unable to get airborne from Pearson. B-17 wins again (below, left)!

From Portland, we put 50% fuel and 20,000 pounds on board the B-52 and headed for Edwards AFB in California (above, center and right).

The B-52's flight time was 1.8 hours (much faster) but with the fuel calculations the final score is 700.5. (That's 11.68 hours!) (Image below, left.)

The truth is that the B-52 (above, center) can haul a payload equal to about three fully-loaded B-17s while flying higher and faster and much, much further. However, the old-timer wins this "efficiency challenge" by almost 30% (above, right).

Next time we'll compare some small, GA aircraft.

Ron Blehm
pretendpilot@yahoo.com