Date: 201504
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: B737 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class C ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Oxygen System/Pax
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Not Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness
Second reporter function: Pilot Flying; First Officer
Anomaly: ATC Issue All Types; Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Fuel Issue
Detector: Person Air Traffic Control; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Executed Go Around / Missed Approach
Contributing factors: Aircraft; Procedure; Human Factors
Primary problem: Ambiguous

Narrative: Oxygen masks drop on takeoff. Had to stay FL250 for the entire flight.   Got to destination with approximately 5.5 on the fuel. On a 2 mile final tower clear a Dash 8 for takeoff.  He wasn't that close to end of the runway when tower cleared him for takeoff.  By the time he got on the runway we were on a 1 mile final.  I made a comment to tower at about 200 feet this isn't good. Shortly after that he sent us around.  First off; tower made a gross error; and the Dash 8 pilot compounded towers mistake by not looking out the window.  On the go-around I told my first officer to angle to the south side off the runway to keep eyes on the Dash 8.  Tower instructed us to turn to 330; the First Officer looked down and said that's not a good idea; I looked out that side and the Dash 8 was almost at our altitude.   If we would have turned we would have had a midair collision.   I immediately told tower we were turning southwest. He said climb to 3;000 feet.  I looked down after clean up and saw 4;200 lbs of fuel.  I knew that was a little low due to our climb angle.   I declared [minimum] Fuel; I instructed approach to tell tower we cannot afford a go-around again.  Approach said he would shut the runway down for us.  We made a short approach to limit our fuel burn.  We were configured and on speed a 1;000 feet; and in the slot and on speed at 500 feet.  It was not unsafe however; it was expeditious. As we taxied the low level fuel light came on in the right wing tank.


Second narrative: As a secondary factor to this event; note that we flew the segment at FL250 due to a row of O2 masks that had deployed in flight. Having received a revised clearance; we reached destination with approximately 5;500 lbs. of fuel. During a stable approach; while we were on short final; a previously 'cleared for takeoff' aircraft took the runway and proceeded to takeoff. We executed a go-around and proceeded to return with minimum fuel. We executed a short approach and landed uneventfully. We arrived at the gate with approximately 4;000 lbs. of fuel. We arrived at the gate with a Low Fuel message on the Right fuel quantity indicator.The takeoff clearance seemed to be granted well in advance of the departing aircrew's readiness to execute the takeoff. Thus; when the flight crew taxied onto the runway; it was evident that separation was an issue to the Captain and I and I prepared to go around. I am curious if the departing flight crew ever checked the final as it seemed highly unlikely that their aircraft could depart before our landing would commence. Taking the runway seemed imprudent from my perspective. Upon contacting the tower to debrief the scenario; it was relayed to me by Captain that the tower supervisor stated that training was in progress during this event. A review of the training protocol for takeoff and landing separation criteria may have value where perhaps additional separation maybe indicated when training is in progress (I suspect this may already be in place).


Synopsis: A B737 flight crew reports arriving at their destination with low fuel and then having the Tower clear an aircraft for takeoff in front of them with tight spacing which results in a go-around. A tight visual pattern is flown and the aircraft arrives at the gate with 4;000 pounds of fuel.