Flap Foul

Two statements of dissent from among the five members of the National Transportation Safety Board (NTSB) accompany the report I detail below. A third concurring statement was included, detailing some of the discussion of the Board. Icing and fatigue were the primary topics of all three letters because of the amount of emphasis put on these subjects in the report.  The Probable Cause

and Contributing Factors do not include icing at all and fatigue comes last on the list with “likely” as a qualifier. I focus here on the procedural and crew resource management (CRM) factors, which I see as most important. 

Flap Foul

We join our accident crew on the ILS 17R just after they are cleared for landing. There is a 500 foot ceiling and 2 miles visibility. Some ice accumulated on the aircraft during the descent. The First Officer (FO) calls for flaps, landing gear, and the landing checklist. The captain sets 15 degrees of flaps. Airspeed ticks up and the FO pulls power to about 3% to slow down. She verbalizes a question about what is going on because ATRs do not normally speed up in landing configuration. 

The big power reduction by the FO is quite baffling to me. While the vast majority of my time is rotary, I started with about 100 hours in fixed wing. Extending gear and flaps increases rate of descent. Bringing power back so much while on an approach is going to drop you below glide slope, no matter what you fly. I digress . . .

The captain recognizes there is an flap issue, but misdiagnoses it as no flaps at all. He says, “You know what? We have no flaps.” In fact, the left flap extended about 8 degrees and the right did not extend at all. Autopilot works to keep the plane upright by trimming ailerons 20 degrees left. In the captain’s defense, the flap position indicator in this aircraft shows the average position of the two flaps on a single needle and 4 degrees is easy to mistake for 0, based on the photo in the report. On the other hand, flap position fairings are mounted on the underside of each wing and thoughtfully marked at the four flap setting positions. Neither pilot looks out their side window to take advantage of this nicety. 

Neither pilot mentions or takes any action associated with the ATR FLAPS JAM/UNCOUPLED/ASYM or REDUCED FLAPS LANDING procedure. The captain cycles the flap handle and uses a flashlight to check for popped circuit breakers behind the FO’s head. Finding none, he positions the flap handle at 0 degrees. Again, not part of the appropriate procedure. During this time, airspeed deceases from 160 knots to 125. Maybe because the autopilot is sacrificing airspeed to maintain glideslope? Oops, I’m digressing again. 

Low airspeed triggers an aural warning and the stick shaker activates. The captain says, “Yeah, don’t do that. Just keep flying the airplane. Okay.” If this is an attempt at crew coordination (You fly while I troubleshoot.), it was pretty weak. Because the autopilot disconnected when the stick shaker kicked in, the FO starts flying the aircraft manually and increases power to about 70%. She does not mention the loss of autopilot to the captain. Instead, she asks if she should go around. This was her hint to the captain the stick shaker activation met the unstabilized approach criteria and they should execute the missed approach. Another weak attempt at crew coordination. He tells her to continue. He decides to continue because of the runway and flight conditions and flap problem. He later states he felt “…things started piling up, and it was better to land…” 

Just after this exchange the FO says, “we’re getting close here.”; in a strained voice.  Not sure what she meant by this. It could have been close to decision height or close to acceptable Instrument Landing System (ILS) limits since she is high and right. They strain in her voice was probably due to the force she was using on the pedals to keep the plane on course. Surprised she is flying manually, the captain offers to finish the approach and she accepts. He takes over at 700 feet Above Ground Level (AGL), pulls power back to about 10%, and soon encounters stick shaker. If you are making such big changes this far into the approach, perhaps going around is a good idea. Maybe that’s why there are rules about this in the company flight training manual. Over the next 37 seconds, airspeed increases, stick shaker activates, airspeed decreases, the terrain warning sounds, power comes back up, bank angles reach up to 50 degrees, and the captain uses forces up to 112 pounds attempting to control the aircraft. 

The ATR first impacted the ground about 300 short of Runway 17 and came to rest on fire about 2500 feet later.

Empire Airlines Flight 8284, operating as a supplemental cargo flight for FedEx, crashed on January 27, 2009, at 4:27 AM local at Lubbuck Preston Smith International Airport. The ATR 42 was substantially damaged and the two pilots were injured, but survived.

While the captain was the one taking action regarding the flap situation, both pilots failed to even get out a checklist to address the problem. Crew coordination during this high workload portion of the flight was also subpar. Both pilots could have done better, but the First Officer should have done more than hint at the need to go around.  Stick shaker and an unstabilized approach are just two of the reasons they should have executed the missed approach. Other factors are discussed in the report, but these stand out to me as the most critical. 

Whether you fly single or multi piloted, how would you handle a flap problem so close to landing?  Would weather influence your decision?

Information from NTSB/AAR-11/02

Video discovered via AIRBOYD

What say you?