Safe Landings - October 2013

Automation Issues

As autoflight system managers, Flight Crews are responsible for entering correct information into the flight management system, selecting the appropriate flight mode and monitoring the aircraft’s compliance with the desired flight path. As pilots, Flight Crews must maintain situational awareness, stay ahead of the aircraft, use good judgment, make sound decisions based upon training and experience, and do whatever is necessary (within the constraints of good airmanship) to put the airplane where it is supposed to be. These responsibilities apply not only to air carrier and corporate crews, but with the growing use of automation, to general aviation pilots as well.

This CALLBACK presents a few recent reports in which Air Carrier Flight Crews and a General Aviation Pilot share some lessons learned regarding automation issues

A Case of Complacency

Proper use of the autoflight system requires that pilots stay “in the loop” and maintain a proactive stance in regard to “flying” the aircraft. When the automation is consistently working as advertised, monitoring becomes more of a challenge. It becomes easier for pilots to enter a reactive state of mind and unconsciously disengage from anticipating the desired flightpath. In this case of autoflight complacency, the autoflight system went off track, but the A319 Flight Crew assumed everything was okay.

■ Approach cleared us for the visual approach to Runway 22L via direct to the Final Approach Fix. We inserted “Direct” to the fix in the box and verified NAV mode. Autopilot #1 and “APPR” modes were selected to intercept the localizer and glideslope at the Final Approach Fix. We were at 7,000 feet, the glideslope intercept altitude, three to four miles outside of the fix and east of the centerline for 22L. As we proceeded, still in NAV mode, the airplane remained left of a direct path to the Final Approach Fix. Both pilots were watching outside the aircraft. We were still tracking towards 22L, but not tracking to the fix anymore. Tower asked us to verify that we were landing on 22L. We acknowledged that we were. It was at this point that we saw we were going to intercept the 22L centerline inside of the final approach fix rather than at the fix. We landed without incident on 22L. 

We intercepted the LOC inside of the final approach fix instead of at the fix as we were cleared. We as a crew assumed the automation was doing what it was supposed to be doing. Being that we were cleared direct and the aircraft was confirmed to do this, we did not think the track was drifting off course (15 miles away). I have never seen this happen, but I will be more aware even in visual conditions.

Distracted and Dependent

Historically, distraction has been an element in many aviation incidents and accidents. Now, with the prevalence of automation, pilots are less actively engaged in flying the aircraft and it may well be that they are even more susceptible to distractions. 

An Air Carrier First Officer reported how a cockpit conversation, when combined with autoflight dependency, was enough to adversely affect their flight.

■ ATC cleared us to cross [a fix] on the arrival…at the expected, planned, and standard FL230. Our altitude was FL270. The Captain and I were talking. The fix started flashing indicating station passage. I recorded the fuel on the dispatch release and then realized that I had not begun descending. I told the Captain I had forgotten to descend and reduced power to idle, full spoilers, and adjusted vertical speed to 3,500 feet per minute. As I began descending, ATC told us to change to Center. We were 4,000 feet above our crossing altitude and leveled at FL230 five to six miles after the fix. 

It was a quiet morning with conversation on the flight deck to keep our minds active. My error as the flying pilot was not initiating the descent when assigned by ATC, not perceiving the [glideslope] guidance in my scan, and the Captain not catching my error in his monitoring cross check. I should, as I usually do, begin descending immediately when assigned crossing fixes. I should, if planning a three-degree descent, ask the Captain to remind me if he sees me not acting at the descent point. I should be aware that conversation, though good in keeping the mind active, also leads to distraction from flying responsibilities especially during low levels of activity and when the automation is “flying.”

“I Was Depending on My Autopilot…”

A BE35 Pilot interrupted monitoring the autopilot to deal with a radio problem. Fortunately, an Approach Controller wasn’t distracted from the responsibility to monitor the aircraft’s flight path.

■ Approach Control descended me to 3,000 feet. My heading was 160 degrees. I was told to maintain 3,000 feet and turn left to 060. I was depending on my autopilot to maintain my altitude and make the turn. The radio transmission from Approach was weak and barely audible. As I tried to ascertain the problem with the radio by turning the volume up and down and tapping on the radio, Approach Control said, “What are you doing? Where are you going? What altitude are you supposed to be at?” I then noticed that my altitude was approximately 2,000 feet. I stopped the descent and asked Approach, “What do you want me to do?” Approach gave me a left turn to 040 degrees, a right turn to base leg, and then a turn to final…. 

In a telephone conversation with ATC after landing, I was told that I had busted the assigned altitude and had come within 100 feet of another aircraft.