Don’t Touch the Throttles!

Don’t Touch the Throttles!

by Richard S. Hefner, Col, USAF (retired) C-141, B-52, C-5 Pilot

Running out of gas in a car can be an embarrassment and the consequences are not too serious. Running out of gas in an airplane is a totally different matter with potentially serious and deadly consequences. Therefore, I almost hate to write this article because, to my embarrassment and with almost deadly consequences, I once nearly ran my tanks dry when flying a C-5 from Elmendorf AFB, Alaska to Kadena AB, Japan.

As I’ve mentioned in previous articles, flying across the Pacific involves fairly long legs, usually 8 or 9 hours. I’ve described the southern routing to Hawaii and Guam and the Philippines, but have not discussed much about the northern route, which runs from Elmendorf AFB to Yokota AB or Kadena AB, both in Japan. Kadena AB is on the island of Okinawa and is about 2 hours flying time south of Yokota AB, which is on Honshu, the main island of Japan. Typically, cargo was flown into Yokota AB then distributed throughout the system as needed. Seldom did cargo go directly to Kadena AB from Alaska.

One winter day we loaded our Galaxy at Travis AFB CA with cargo to be flown to Kadena AB via the northern route. Elmendorf AFB was only about 5 hours northwest of Travis, so that leg of the mission was short and easy. The next leg was looking to be more difficult. In the winter, the jet stream is stronger and more northern than in the summer. Our routing from Elmendorf to Kadena took us right into the teeth of that wind, which often exceeded 200 knots.

With the load we had on the C-5 and no air refueling scheduled, we were right on the cusp of having enough fuel to fly directly to Kadena. We ran the fuel numbers a 2nd time and reassured ourselves that we could make it all the way to Kadena if all the performance charts matched up with the airplane’s actual performance. Additionally, we had a safety valve…we could always land at Yokota, which was about a 9-hour flight instead of the 11-hour flight to Kadena. No sweat.

Takeoff and climbout from Elmendorf was normal. The computer flight plan had adjusted the North Pact One routing to minimize the impact of the jet stream. As we pushed through the skies, we found the winds were pretty much as forecasted and identical to our computerized flight plan. As we reached the halfway point, our actual fuel consumption was exactly as the enroute fuel charts and flight plan had predicted…therefore, no problem.

We had planned to make the decision on whether to divert to Yokota for fuel or continue to Kadena about an hour out from Yokota, which was still 3 hours from Kadena. As we reached the decision point, the engineer rechecked our fuel. Again, according to the charts, we were right on the minimum fuel required line for making it to Kadena; however, we were not going to have any extra gas as a safety cushion. Stopping at Yokota was not needed, so we pressed on.

Shortly after over-flying Yokota, the engineer called and said, “Sir, we don’t have as much fuel as I earlier figured. Kadena might be tough to make!”

“What?? Why??” I asked in dismay.

  • “Well, when we ran the fuel figures earlier, we used the totalizer fuel gauge. I rechecked by totaling the individual tanks and came up with a 10,000 pound difference.”
    That’s when I learned the totalizer gauge, which automatically adds up the fuel readings from the different wing and body tanks, was not the most accurate instrument for measuring the actual fuel carried in the plane. However, using the totalizer gauge was normal procedure when the destination was still 3 hours away. Luckily, I was flying with an engineer who took that extra precaution to individually check the fuel in each tank, then total the numbers.
    “Great,” I deadpanned … then pondered my decision. Let’s see, I can either turn around and drop into Yokota for fuel…after telling the command post that we were a “go” for Kadena and thereby looking like a total idiot…or I can press on to Kadena and land with a little less than legal fuel and nobody will know the difference. Hmmm….
    Looking back at the engineer, I asked, “What do you think? Can we still make Kadena safely?”
     
    Giving me a head nod, the engineer replied, “Yes Sir, we may land with less than the minimum fuel required, but we should have plenty to get there.”
    “Sounds good … let’s press,” I decided.
    (…30 minutes later and still an hour out from Kadena …)
     
    “Pilot, this is the engineer. We have encountered headwinds about 30 knots greater than the forecast winds and we are going to use more fuel than expected to get there.”
    Now I was getting concerned. We were equidistance between Yokota and Kadena and fuel was getting short. By the time we could get clearance to turn around and head back to Yokota, we would be that much closer to Kadena. There wasn’t a clear choice. Either decision, Yokota or Kadena, had the same potential consequence. So, I elected to continued to Kadena.
     
    “Engineer, can we make it to a higher altitude?” I queried.
    “Yes Sir, but only another 2,000 feet,” he responded.
     
    “Co-pilot, get us a higher altitude from Center,” I directed. The higher the C-5 flew, the more fuel efficient it was. Every pound of fuel just might be important. Nothing was above us, so Center cleared us to 37,000 feet, which was 2,000 feet above our cruising altitude of 35,000 feet.
     
    As we approached Kadena, I drove the C-5 past the point I normally began a descent. Having altitude was like having stored energy. We were coming in from the north, but based on the surface winds, the approach would be from the south. Approach Control would vector us south of the field then turn us back towards the runway. Maneuvering the C-5 at a low altitude consumes a lot of gas. If I could maneuver for the approach while in a descent, I could save a lot of fuel. I chopped the throttles to idle and gently nosed the Galaxy into a free fall. If at all possible, I did not want to advance those throttles.

by Richard S. Hefner, Col, USAF (retired) C-141, B-52, C-5 Pilot

Aviation Writer, http://20thCenturyAviationMagazine.com

 

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