reducing "Crew-caused"
approach and landing
accidents 

Pilot-in-charge Monitored Approach

2014 ATR72 CFIT Magong Taiwan

Brief account : 

During a thunderstorm at around sunset, the crew of the ATR72 conducted a "dive and drive" VOR approach with crosswind from the right. The Captain descended to and attempted to hold level at approximately 150 feet below the MDA. 

After the pilots acquired some visual cues, the aircraft turned left through the centre-line and descended further. It was destroyed when it struck a group of houses just as a missed approach was being initiated.

Crew-related factors : 

In what was a fairly typical accident of its type, the official report notes that "There was probably a steep trans-cockpit authority gradient, resulting from large differences between the crew in terms of age, experience, and position in the airline. Reports had indicated concerns about the captain’s unsafe operational behavior; and that the first officer and the airline’s junior first officers generallywere not naturally assertive. 

A steep trans-cockpit authority gradient without appropriate crew resource management (CRM) skills reduced the likelihood that the first officer would voice any concerns that he may have had about the captain’s decisions and actions. It would have also increased the probability that the captain made decisions without consulting the first officer".

It also noted that the Captain, having not briefed the F/O for the approach, also deliberately descended below the 330ft MDA, intending to hold level at 200ft. Actual altitude was typically between 160 and 180 ft.  Then, "instead of commencing a missed approach at or prior to the MAPt both pilots spent about 13 seconds attempting to locate the runway. During their search for the runway, the heavy thunderstorm rain activity intensified .... that further reduced the visibility to 500 meters".

If PicMA had been the SOP, then the probability is that 

1) There would have been a discussion of the approach.

2) During the approach the Captain would have been better able to keep track of the changing weather conditions which were not being adequately reported. The flight had already been holding and conditions were varying significantly.  

3) Aside from the known inadequacies of "dive-and-drive" approaches compared to continuous descent non-precision approaches, the F/O would probably held the correct MDA, and been anticipating flying a go-around from that altitude. An instruction from the Captain to hold BELOW MDA would have stood at least some chance of being questioned.

4) The Captain would not have been inhibited from correcting any errors in the F/Os flying. 

5) When some visual cues were sighted, the aircraft was slightly to the right and upwind of the centre-line, with a right crosswind. The cues were to the left of the aircraft and the Captain turned to the left. As a consequence and assisted by the cross-wind, the aircraft rapidly crossed the centre-line while recommencing its descent. This was a direct consequence of the Captain's inadequate assessment of the aircraft's position and rate of change of position, the specific decision required at MDA/DH.  

At the actual point of transition to visual cues, both the position and rate of change of position were actually not too bad. With control of the aircraft in his hands, the Captain's immediate and instinctive reaction to the fact that the runway was visible to the left (due to the drift angle, not displacement) was to make a left turn.  

In a PicMA approach the Pilot would have had more time to evaluate the fact that the visual picture was due to the drift angle, not to a lateral displacement that needed correcting, and his judgment may have had time to overcome his instincts.

At the same time the copilot would still have been watching the instruments and been better placed to detect the developing divergences.  

Type: 
ATR72
Where: 
Magong Taiwan
Expected weather: 
Instrument
Pilot in charge: 
Capt
Early transition: 
No
Go-around : 
Below DH/A
Damage: 
Serious
PicMA potential: 
Major
Year: 
2014
Time: 
Dusk
Deterioration: 
Yes
Vert Guidance: 
None
Both Head Up: 
Yes
LoC: 
No
Operator: 
TransAsia
Fully prepared: 
No
Actual Weather: 
Thunderstorm
Autopilot : 
Y
CCAG: 
High