Tales From the Swan: Last Flight of a Sow

[steuben]

KSP Incident Investigation Committee

Summary Report on the crash of Fueler-159

Document Number: K-IIC-0025798-S

The following is a summary of the investigation into the crash for Fueler-159. The full report can be found under document number K-IIC-0025798-F.

Time Line

The timeline begins at 1847.142 9:34 KST, which shall be termed time zero. All events in the timeline are indexed from this point.

T 0:00:00

Fueler-159 disengages from surface fuel transport.

T 0:00:17

F-159 lifts off from the surface of Minmus.

T 0:03:25

Anomalies in the fuel flow in the starboard engines are noted by on board systems

T 0:03:28

All starboard engines shut-down. Reactors in the starboard engines soft scram. F-159 begins clockwise roll.

T 0:03:29

Port engines are reduced to zero thrust. RCS is engaged to SAS.

T 0:03:30

F-159 contacts Minmus flight control declaring emergency situation.

T 0:03:31

Roll is arrested and F-159 is returned to nominal horizon. Attempt to restart engine S-1 started.

T 0:03:32

Emergency dump of cargo failed.

T 0:03:35

Engine S-1 fails to restart. Attempt to restart engine S-2 started.

T 0:03:39

Engine S-2 fails to restart. Attempt to restart engine S-3 started. Port engines are throttled up to 32%.

T 0:03:43

Engine S-3 fails to restart. Engine S-3 hard scrams. No further attempts were made to restart this engine. Attempt to restart engine S-4 started.

T 0:03:45

F-159 declares inability to reach orbit and will attempt a hard landing on the surface.

T 0:03:37

Attempt to restart engine S-4 fails.

From this point until impact the flight records indicate that multiple attempts were made to restart engines S-1, S-2, and S-4. These attempts are documented in the full report.

The first craft to the impact site reported no survivors.

Causes

Due to the energies involved in the crash the investigation of the incident was difficult. However, enough information as gathered to determine the cause and its effects.

Approximately two minutes after lift-off, three minutes in the time line, a meteorite impacted the aft starboard side of the spine of F-159. The impact damaged the fuel pumps for engines S-3 and S-4. The damage then caused a pressure spike with damaged the fuel pumps for Engines S-1 and S-2.

Sufficient fuel had been used at this point to create a gas cushion in the main fuel tanks. This gas cushion absorbed the pressure spike. This prevented the propagation to the port fuel systems.

The starboard engines continues operating on the remaining fuel in the lines until a lack of fuel flow caused the engines to soft scram. Debris from the damaged fuel pump entered Engine S-3. This caused the engine to hard scram during the restart attempt.

Spallation debris from the impact damaged the cable connection for the fuel transfer ports. This damage prevented the emergency dump of the cargo.

Recommendations

Crew training and procedures:

The crew of F-159 preformed in the best traditions of the KSP. No additional training is recommended at this time.

The variations on restart procedures attempted by the crew should be investigated for efficiency and effectivity. As multiple safety protocols were ignored during the attempts they are not recommended procedures at this time.

Equipment maintenance and supply:

Equipment maintenance was not a cause or a contributing factor in this incident. No recommendations are made at this time.

Equipment supply was not a cause or a contributing factor in this incident. No recommendations are made at this time.

Equipment construction and design:

Equipment construction was not a cause or contributing factor in this incident. No recommendations are made at this time.

While equipment design did not cause the incident, it was a contributing factor. The following recommendations are made:

1. The Minmus TWR be increased to two.

2. Sufficient control force be added such that in the event of a loss of half the engines the craft will be able to remain in nominal level flight.

3. Additional control lines for emergency cargo dump be added. These control lines are to be run through channels at least three metres apart.

4. A separation system be implemented that will allow the safe separation of the cargo tanks from the craft.

5. Expansion chambers be placed on the fuel lines between the fuel pumps and the engines, and the fuel pumps and main fuel tank.

Review of the implementation of all recommendations will occur in six months.

Edited May 18, 2016 by steuben
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[KSK]

A strange little piece but very well written with exellent attention to detail.

[Generalstarwars333]

I like it.