Why must the distance between the fuel bladders and the BEAR Power Unit not exceed 100 feet?

Why must the distance between the fuel bladders and the BEAR Power Unit not exceed 100 feet?

• A. To prevent vapor lock in intake
• B. The on board fuel transfer pump does not generate enough negative pressure
• C. To minimize fuel evaporation
• D. To improve cooling efficiency

Answer: (B)

The distance is limited because the fuel transfer pump that feeds the BEAR Power Unit must create enough suction to pull fuel from the bladders through the line. The longer the line, the more friction losses and the greater the vertical head the pump has to lift, which reduces the negative pressure available at the pump inlet. If the distance exceeds what the pump can overcome, fuel flow can drop or stop, leading to an unstable or starving power unit operation. Keeping the bladder within about 100 feet ensures the pump can maintain reliable delivery. The other choices aren’t the primary issue here: vapor lock and evaporation aren’t the controlling factor for this distance, and cooling efficiency isn’t directly affected by how far the fuel is from the unit.

The distance is limited because the fuel transfer pump that feeds the BEAR Power Unit must create enough suction to pull fuel from the bladders through the line. The longer the line, the more friction losses and the greater the vertical head the pump has to lift, which reduces the negative pressure available at the pump inlet. If the distance exceeds what the pump can overcome, fuel flow can drop or stop, leading to an unstable or starving power unit operation. Keeping the bladder within about 100 feet ensures the pump can maintain reliable delivery. The other choices aren’t the primary issue here: vapor lock and evaporation aren’t the controlling factor for this distance, and cooling efficiency isn’t directly affected by how far the fuel is from the unit.