Page 25 - Volumer 13 Number 7

numbers before BB-1098, the standby pumps were “hot- wired,” receiving power from two 5-amp, parallel-wired fuses off the Hot Battery Bus in addition to the left or right pump’s circuit breaker (CB) that received power from the #3 or #4 Dual Fed Bus. Solution? Remove those two 5-amp CBs before we commenced operation. Afterall, we were going to have an approved ferry permit anyway, authorizing our procedures, right? Plus, Beech removed the hot-wiring in the later airplanes anyway.
As the tank plan was being discussed with the ferry tank company that would install it, a discussion arose about the venting of the tanks. As they had done hundreds of times before in unpressurized singles and twins, they planned to simply install a vent line from the ferry tank combination through a fitting in the belly’s skin to the ambient, outside air.
I said, “Wait a minute! That won’t work! Remember that our cabin is pressurized. If the inside of those tanks is subjected to ambient air pressure while the outside is subjected to cabin pressure – 6 psi greater – they will collapse!”
The tanking people assured me that I was mistaken; that their tanks were strong enough to handle the pressure differential. I was quite skeptical of their belief but the project went forward to the installation and testing phases.
I accepted the new airplane at the Wichita factory and after a thorough test flight there flew it to Beechcraft West at the Hayward airport for temporary storage. Knowing that the crossfeed line would be cut open to
JULY 2019
install the T-fitting, I wanted to have the fuel quantity on board as low as possible, so there would be less to defuel before opening the line.
On the day I was to make the short hop from Hayward to Oakland to begin the tanking process, I discovered that the “helpful” fuelers had topped off both side’s main tanks. Darn! I was told that the tanking company was not equipped to accept that much Jet-A for temporary storage so I should burn it off before arriving at KOAK. “It’s a tough job but someone has to do it!” I chuckled, as I envisioned flying up and down the lovely northern California coast for a few hours at low altitude and high power, burning up the unwanted fuel.
About the time I passed the Golden Gate bridge heading north, this thought came to me: All I really need to do is burn off the fuel on the right side. Since the crossfeed valve is in the left side, the left fuel cannot find its way into the crossfeed line section in the cabin unless the valve is open. When that insight registered – and with only myself on board – I moved the crossfeed switch from the center position to the left. This action opened the crossfeed valve and turned on the right standby pump. As expected, the right main fuel was now feeding both engines while the left fuel was no longer being consumed.
Wow! Look at the fuel quantity gauge go down! At my cruise altitude of 1,500 feet I was burning about 400 pounds per-hour, per-engine so in an hour I had about 1,200 pounds remaining on the left side and 400 on the right. The imbalance limit on the 200-series
Sabah
KING AIR MAGAZINE • 23