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Monday
Jun162014

Safe Landings - June 2014

Message from the Editor: Though these incidents are all airline related, the systems involved are now also used in GA and could cause accidents.

Autoflight control modes generally involve interrelated functions of the Flight Management System (FMS), the flight director, the autopilot and autothrottles. The mode logic controlling the combined input of these systems can be very complex. Despite focus on design improvements and training emphasis on flight management modes, ASRS continues to receive a significant number of incident reports on mode related errors. While they usually result in minor “altitude busts” or crossing restrictions not met, mode errors can also lead to more serious outcomes including Controlled Flight Toward Terrain (CFTT).

Some of the more common mode errors seen in ASRS reports include:

  • Selection of the wrong mode
  • Inadequate knowledge of mode functions
  • Undetected automatic mode sequencing
  • Failure to monitor for activation of selected mode

    The following reports all deal with one or more of these mode errors, but may reference terms and procedures that are unfamiliar. There are system variances among manufacturers and procedural differences among companies. Some aircraft were designed around autoflight systems and others have been retrofitted with various levels of automation. What is common to all of these scenarios, however, is that by using a procedure such as suggested by the acronym CAMI (Confirm, Activate, Monitor, Intervene) and by maintaining situational awareness, mode errors can be recognized before they adversely affect flight safety.

Wipe Out

By “cleaning up” the FMS after localizer capture, an MD-11 Captain inadvertently wiped out the NAV/LOC mode.

• While being vectored to final, ATC gave us a heading with clearance to intercept the localizer course… The Pilot Flying instructed me to arm the localizer. I responded that we needed to be in NAV before arming the localizer because of the strong overshooting winds (42 knots at 4,000 feet MSL).

The Pilot Flying selected NAV and then I armed the localizer for him as he requested a cleanup of the FMS. I saw that NAV/LOC had both armed and went heads down to clean up the FMS. I looked up to see the airplane starting a left-hand turn away from the runway and immediately instructed the Pilot Flying to turn back towards the runway. I also glanced at the PFD and noticed we were now in Heading mode (no NAV or LOC armed/selected). The result was an overshoot of the final approach course. I instructed the Pilot Flying to be aggressive in getting back over to final as we received a follow-on intercept heading from ATC.
Selecting NAV and then LOC was needed, but the FMS should have been cleaned up prior to selecting these modes. By selecting them first and then cleaning up the FMS, I may have inadvertently put us in Heading mode. Also, the First Officer needed to monitor our lateral mode and be ready for any reversions or changes to that mode. When the plane attempts to do something we don’t want it to do, the Pilot Flying needs to turn the autopilot off immediately and put the airplane in the correct position.
FMS clean up should take place well before the intercept to final and as Pilot Monitoring, I should have been more aggressive in making that happen earlier.


Mismanaged Mode

After an inquiry from ATC, an A320 Captain realized that the Airbus FMC’s Managed Descent mode requires proper management in order to start a descent.

• Center gave us a clearance to descend to FL330 and fly direct to a fix. I pushed the ALT (Altitude) button to descend in Managed Descent mode then typed in the clearance to fly directly to the fix. I then checked the crossing altitude in the FMC for the arrival. Four minutes later ATC called and asked if we were descending.
While on a heading, the A320 will not descend in Managed mode, so the aircraft stayed at FL350. If I would have programmed the FMC first, then pushed the ALT button, the aircraft would have descended in the Managed Descent mode. I also could have pulled the ALT button and descended in Open Descent mode or in the Vertical Speed mode. Our procedure is to check the FMA’s once you have made an input to the auto flight system. I did not do this.

“This One Scared Me”


Mode selection is not limited to the Flight Management Computer. In the following report, an air carrier Flight Crew demonstrated why selection of the proper Nav Display mode was a critical item in their localizer approach procedure.

• Cleared to descend to 2,000 feet, we were turned towards final by Approach Control. [We were] then given another turn to intercept and cleared for LOC 31 approach, maintain 2,000 until QUENE. The final intercept vector was going to bring us well inside QUENE, so I extended off FABRY (FAF), armed the LOC, and switched to ARC mode on my NAV Display to monitor DME in order to identify abeam QUENE, and to monitor LOC capture.

After passing abeam QUENE at 10.3 DME, with LOC capturing and FABRY (FAF) next, I called for the First Officer to set and arm 600 feet, which was our MDA, and I initiated descent out of 2,000 feet. It was a busy time now completing final configuration for landing, slowing down, and completing the Landing checklist. I had left ARC mode on my NAV Display. I was not aware that the First Officer was also in ARC mode, thus neither of us were watching the “football” on the NAV Display which was now our only protection for crossing FABRY at 1,700 feet, the published altitude at the FAF.
On the LOC and descending, we were told to contact Tower. Before Tower contact was made, the First Officer figured it out and said, “Hey, we’re really low. We need to climb.” The altitude was approximately 1,100 feet, or 600-feet low, a couple of miles outside FABRY. I realized what I had done and climbed back to 1,700 feet just as we reached FABRY. Tower…issued a low altitude alert. After FABRY a normal descent to landing was made. We were IMC until about 1,100 feet… We did not get a GPWS warning. ?
This one scared me. I fully grasp that being that far (600 feet) below a hard altitude on an approach will get you killed in many places. I honestly don’t think complacency was our issue. I was not cavalier about this approach and neither was the First Officer. The approach was thoroughly briefed. One thing I did not specify though was who would have what (ARC or MAP) displayed on the NAV Display. We needed both for at least a short while, in order to see DME.
As pilot flying, it was my responsibility to see that I had displayed what I needed to shoot this approach in accordance with our procedures. I made a mistake when I did not go back to MAP mode after passing abeam QUENE. If MAP mode had not been available, then I would have had to set 1,700 feet for FABRY, followed by 600 feet for the MDA after passing FABRY. If MDA is set outside the FAF, then I MUST be in MAP prior to the FAF.

I am fortunate to have had a good First Officer who regained situational awareness before I did.

Early Descent


Luckily this MD11 Flight Crew was in visual conditions when “the airplane” tried to descend early.

• After being cleared for the ILS…under visual conditions, at some point the aircraft came out of Profile Descent mode or it was deselected. The aircraft descended below the Profile Descent path.
At about 12 miles from the field, we elected to level off at approximately 1,500 feet AGL. We had the field visually and…the rest of the approach was flown without issue.

The altitude that was set in the Altitude Select window was the Decision Height. The airplane was trying to descend early to the Decision Height because Profile Descent was not engaged. A better check of the Profile mode would have stopped this from happening. We also should have left the last assigned altitude in the Altitude Select window. This also would have stopped the plane from descending early.

Wednesday
Apr092014

Safe Landings - April 2014

Checklist Checkup

Checklists are used by pilots to assure that the aircraft is properly configured for each phase of flight. Checklists are also used to provide appropriate response to abnormal or emergency situations. While checklists do provide a means of guiding a pilot or flight crew through complex procedures, they are not impervious to human error. Reports submitted to ASRS indicate that errors related to checklist usage generally fall into one of these five categories:

  1. Checklist interrupted
  2. Checklist item overlooked
  3. Use of the wrong checklist
  4. Failure to use a checklist
  5. Checklist confusion

Examples of these errors are found in the following ASRS reports.

1. Checklist Interrupted

Distractions and interruptions are the factors most often cited in ASRS reports involving checklist errors. This B737-300 Captain’s report shows that the distractions inherent in last minute preparations prior to pushback can easily lead to checklist omissions.

• During the accomplishment of the Before Pushback checklist, the Flight Attendant brought in the passenger count documentation at exactly the moment the First Officer read the “Takeoff Trim” item. I responded to the Flight Attendant interruption and subsequent verbal exchange and then the First Officer and I proceeded to the next item, “Cockpit Door,” without actually having reset the takeoff trim to the correct setting. During the takeoff, we received a Takeoff Warning horn as I advanced the throttles for takeoff. At approximately 10 knots, I rejected the takeoff and accomplished the immediate action items while the First Officer notified the Tower of the rejected takeoff. After clearing the runway and finishing the checklist items, I discovered the takeoff trim was not set in the proper position and was out of the green band area.

This event reminded me to be extra vigilant of the impact of distractions during checklist accomplishment. In fact, it took several errors in procedure to arrive at the runway without the trim set properly.

2. Checklist Item Overlooked

An MD11 Captain allowed a habit pattern to affect the proper completion of the Shutdown checklist. Fortunately, the First Officer returned to the cockpit and noticed that one more item needed to be “shut off.”

• Pulled into the gate, set the parking brake, and shut down the Number 3 engine. We waited a short time for external power and when we got it, I connected to it then shut down the Number 1 engine. I did the Shutdown checklist, debriefed, discussed the strange taxi routing, and left the aircraft. There was no crew bus so the First Officer went up to the cockpit to call for one and saw that the Number 2 fuel lever was still up. He shut off Number 2 and came back down to the ramp and informed me that the engine was still running when he went up to the cockpit.

I rarely taxi in on three engines and in this case did just that. I went through my normal shutdown habit pattern which is just shutting down one and three. I missed it on the shutdown checklist because I didn’t actually look at the levers because, in my mind, I was convinced I had shut them down.

Visually check everything on the checklist because it will help when your habit pattern is broken.

3. Use of the Wrong Checklist

By using the appropriate checklist, a crew can mitigate or eliminate the adverse effects of a system malfunction. But, as this B757 Crew learned, the wrong checklist can make the situation worse.

• On departure at approximately 300 feet AGL the First Officer’s Primary Flight Display (PFD) and Nav Display (ND) went blank. I assumed control of the aircraft and after reaching a safe altitude called for the First Officer to open his QRH and find the appropriate abnormal checklist for our situation (loss of right PFD and ND). The First Officer said he was ready to proceed and he read the first item on the checklist. I do not recall whether the First Officer read the title of the checklist aloud before he read the first item on the checklist.

The checklist called for us to check two circuit breakers supplying power to the Symbol Generator. Both circuit breakers were in. Next item on the list called for the Symbol Generator-1 Power circuit breaker to be pulled and then reset. The circuit breaker was pulled and this resulted in the loss of the Captain’s PFD and ND. At this point it was determined that the First Officer was reading the checklist for loss of left PFD and ND and we immediately attempted to reset the Symbol Generator-1 power circuit breaker with no success. We then completed the QRH procedure for loss of right PFD and ND, but we did not regain the First Officer’s PFD or ND.

After consulting with Dispatch, Maintenance Control, and the First Officer, and considering the potential for developing weather along the route of flight to our scheduled destination we elected to divert and make an overweight landing. We declared an emergency, requested that Airport Rescue and Fire Fighting vehicles be standing by to check for potentially hot brakes on roll-out and proceeded to land uneventfully.

Upon reaching the gate, Maintenance met the aircraft and upon opening the E&E Compartment they discovered a great deal of water had accumulated in that compartment from an unknown source. It would appear that the accumulated moisture/water caused the loss of the First Officer’s PFD and ND and prevented the successful reset of the Symbol Generator-1 Power circuit breaker. We obviously made our situation worse by starting the wrong checklist; however, absent the water in the E&E bay the Symbol Generator-1 circuit breaker should have reset. Additionally, from a systems point of view I should have questioned the First Officer as to why we were pulling the Symbol Generator-1 power circuit breaker for a loss of the right PFD and ND.

In the future I will always confirm that the appropriate checklist for the situation at hand is being utilized by referring to my QRH or the First Officer’s prior to accomplishment of any individual steps in that checklist. I will also attempt to ascertain that from a systems point of view the steps of the checklist make sense for the abnormal situation encountered.

4. Failure to Use a Checklist

We have already seen how interruptions can lead to missing items on a checklist. This BE36 Pilot learned what can happen when an interruption results in missing the whole checklist.

• Upon reducing power over the numbers, I heard the gear warning horn. I began to apply power for a go-around, but saw the propeller stop. At this point, I continued the flare, focused on flying the airplane, landed the aircraft gear-up, and quickly exited the aircraft with two passengers. We proceeded a safe distance to the west into the runway grass and notified Emergency Personnel.

This was the third of three takeoffs and landings for night currency. The other two landings were uneventful. Upon turning base, I noted another aircraft nearing the vicinity. I made another radio call announcing turning base to be certain it was not a faster aircraft on final approach for our destination. This transmission interrupted my habit pattern and I failed to do the BCGUMP (Boost pump, Carb heat, Gas, Undercarriage [landing gear], Mixture and Prop) landing checklist. I believed that the gear was down and that I had three green lights until the prop stopped.

5. Checklist Confusion

Checklists, especially those dealing with emergency or abnormal procedures have to present a clear, unambiguous sequence of actions that will provide the safest and most efficient method of handling a given problem. However, the logic branches in complex procedures can sometimes be problematic. This CRJ900 Flight Crew misread one of the checklist items and the checklist itself may have also contributed to their confusion.

• While descending for arrival, the “R FADEC” caution illuminated. We followed the Quick Reference Handbook (QRH) procedures which included shutting down the Number 2 engine, but only after reviewing the procedure and agreeing that it did indeed require shutting the engine down….

The QRH procedure for a L/R FADEC caution message is somewhat confusing. We had to read the procedure several times just to make sure that we were required to shut the engine down. The procedure calls for shutting down the engine “prior to landing” if all other indications are “normal,” but that is poorly defined. Doing the shutdown right away obviously isn’t required, but should you wait until short final or do it further out? In the end we elected to shut the engine down as we made our descent and were probably still 20 miles or more from the field. This gave us time to review the procedure for single engine landing, make our PA announcement, talk to the flight attendants, coordinate with Approach, etc. Also, while the “NO” side of the checklist leads you to the Single Engine Approach and Landing Abnormal checklist, the “YES” side does not. And yet the “YES” side still requires that the engine be shut down. It would seem only logical that the Single Engine checklist be performed in that case as well.

Upon further review of the QRH, it has come to my attention that the procedure for a FADEC caution, when all other engine indications are normal, was not completed correctly. I misread one of the steps in the procedure that called for the Thrust Reverser to be turned off and instead read it as though the Thrust Lever should be shut off. In the end, having the engine shut off instead of at idle as the QRH called for, made little difference in the outcome.

Thursday
Mar062014

Safe Landings - March 2014

What Would You Have Done?

Once again CALLBACK offers the reader a chance to “interact” with the information given in a selection of ASRS reports. In “The First Half of the Story” you will find report excerpts describing the event up to the decision point. You may then use your own judgment to determine the possible courses of action and make a decision regarding the best way to resolve the situation. 

The selected ASRS reports may not give all the information you want and you may not be experienced in the type of aircraft involved, but each incident should give you a chance to exercise your aviation decision-making skills. In “The Rest of the Story…” you will find the actions actually taken by reporters in response to each situation. Bear in mind that their decisions may not necessarily represent the best course of action. Our intent is to stimulate thought, discussion, and training related to the type of incidents that were reported.

The First Half of the Story 

Situation # 1 Cessna 210 Pilot’s Report

■ I was on an IFR flight plan…in cruise at 8,000 feet. The autopilot stopped operating. While I was troubleshooting the problem, I noticed that the battery charge was low and falling rapidly. I attempted to notify Approach of the problem and believe that they understood that I…was about to lose communications…. I started turning off some electrical systems in an attempt to save battery power while troubleshooting the alternator. It did not come back online and I turned off the battery to conserve what power remained. I attempted to make radio contact with a hand-held radio, but either its transmissions were too weak or its battery was too low…. I had a hand-held GPS, an iPad and an ADS-B receiver to use for navigation and weather avoidance…. 

To continue along my flight-planned route would be hazardous due to thunderstorm avoidance, a possible frozen pitot tube and potential conflict with other aircraft without transponders. During a break in the IFR conditions, I observed clear air to the southeast and turned toward it…. I decided to continue in the clear air and…descend to a VFR altitude below the cloud bases. Once I got to the east of the line of storms, I turned south paralleling the line of storms…. The more time passed, the more [battery] charge returned…. If I continued on to [destination] there was a reasonable chance that the battery would have sufficient power to lower the gear…[without] an emergency extension procedure…. 

I…was able to make radio contact briefly. I stated my situation, cancelled IFR and explained that while I was likely to lose contact again, I was going to continue on to my destination. The Controller was very helpful and asked if I required assistance and mentioned that [an alternate field] was to the east if I wanted to land there.

What Would You Have Done?

Situation #2  C45 (Beechcraft Model 18) 
Pilot’s Report

■ The aircraft I was flying…did not have a current altimeter and static system inspection which prevented me from filing an IFR flight plan. Weather analysis indicated a thin overcast layer with bases between 500 and 900 feet AGL and a second overcast layer at around 7,000 feet. It was VMC 30 miles to the northeast, the direction of my flight. The forecast indicated the low cloud layer would dissipate before reforming with IMC persisting for the remainder of the day. 

My plan was to be ready to go when the low cloud layer opened up…. I was comfortable with the fact that I could end up between layers because there was plenty of cloud clearance and visibility for VFR flight…to the clear weather along my course…. 

When the lower layer opened up…I was granted a Special VFR clearance. Moments prior to takeoff, the lower layer closed back up and the tower advised the ceiling was 700 broken. I thought that I could takeoff, fly to the open area safely, and climb above the lower layer, all while complying with the FARs. I was wrong. 

After takeoff…I was…trying to fly toward the area where the lower cloud layer was open. As I pressed on, I realized that the open area I intended to climb through was gone. However, I felt okay as I was still 600 to 700 feet above the ground and clear of clouds. 

That didn’t last long. The ceiling began to lower and my comfort level rapidly decreased. I was unable to maintain a minimum safe altitude and remain clear of the clouds. I had lost track of where to turn toward better weather. While I was high enough that I was not concerned about flying into terrain, I became very concerned about radio towers…. I realized that I could become a VFR into IMC statistic.

What Would You Have Done?

Situation #3  EMB-145 First Officer’s Report

■ Takeoff was normal. At around 400 feet, Tower…[advised] that our left engine was producing smoke. No specifics were given on the amount or color. Tower then asked for our intentions…. Both the Captain and I checked engine and all system instruments. There were no abnormal readings. We could not detect any smell of smoke or any abnormal flight characteristics…. We said we would continue and Tower handed us off to Departure. Departure told us they had received the smoke notification from the Tower. We checked all our instruments and systems again and could still not find any faults. 

The Captain then called…Maintenance Control. They said that it was most likely the cold engines that had just warmed up combined with the cold temperature of -2C.

What Would You Have Done?

The Rest of the Story

Situation #1  Cessna 210 Pilot’s Report

The Reporter’s Action:

■ Given…the fact that I could navigate VFR around the weather and any airspace, and possibly avoid an emergency gear extension, I declined to land [at the alternate airfield]. I lost contact as the battery charge dropped again. I continued VFR to the southeast around the line of storms. A few minutes out, I slowed the aircraft, turned on the battery and had enough charge to extend the gear. With all other electrical off, other than the rotating beacon, one NAV Comm and the transponder squawking VFR, I made radio calls for the pattern and performed a no flap landing. 

In reviewing my decision making in this situation, I believe that the decision to get into VFR flight conditions was a good one as well as to use these conditions to navigate around the storms. I might second guess my decision not to land at [an enroute alternate].

Situation #2  C45 (Beechcraft Model 18) 
Pilot’s Report

The Reporter’s Action:

■ My only remaining option was to initiate a climb through the lower layer up to VMC above. As I entered the clouds, I began to think about calling Center to confess my predicament and declare an emergency if necessary. The good news is that after climbing 500 feet I broke out between layers in VMC. Since I was still below any usable IFR altitudes and no longer needed any assistance, I did not call center. 

I determined my position by referencing the VOR and GPS and proceeded on course. In reviewing the airspace [in the area], I realized that I probably went through the edges of the Class D and Class E as I searched for the opening in the lower layer. I am not sure my Special VFR clearance covered this possibility. 

I have flown many years and I am very comfortable flying VFR and IFR, even VFR when the ceiling is low as long as the visibility is as good as it was this day. However, I let my comfort level lull me into departing without a viable Plan A and no Plan B.

Situation #3  EMB-145 First Officer’s Report

The Reporter’s Action:

■ We continued the flight and no problems were encountered…. While in cruise, the Captain and I reviewed the situation and both agreed that we should have returned after Tower notified us of the smoke. We both agreed that it would have been better to have erred on the safe side and returned, as opposed to continuing based on our instrument indications and flight characteristics.

 

Monday
Jan132014

Safe Landings - January 2014

Autoflight Associated Loss of Situational Awareness

The following reports are all airline related, but very applicable to GA high technology airplanes.  Of the 16 hours of training required in a Flight Instructor Refresher Clinic, nearly six hours is spent on this one subject. 

ASRS continues to receive reports in which Flight Crews appear to focus on the autoflight system to the extent that situational awareness is reduced, sometimes during critical phases of flight. In the following reports, awareness of the aircraft’s actual flight path seems to have been compromised by:

• Attention to programming the autoflight system

• Assumption that the autoflight system is accomplishing the desired task despite input or mode errors

• Failure to reference other visual cues or raw data

In many of these reports, workload, confusion, unexpected situations, distractions and fatigue are seen as factors that may exacerbate autoflight related issues. Autoflight human factor issues are a particular concern when both pilots lose situational awareness. This may occur with greater frequency as flight crews are trained primarily or exclusively in the more passive task of autoflight system management. ASRS reports suggest that the ability to maintain real world awareness can be eroded by over-reliance on the highly dependable programmed control of the aircraft. With that in mind, perhaps the following incidents should be viewed as the result of human nature rather than human error.

Telling It Like It Is — One Captain’s Opinion

A confusing departure chart and what the Captain characterized as over-reliance on automation resulted in a track deviation and traffic conflict for this air carrier Flight Crew. The Captain elaborates on his assessment of automation dependency and cluttered charts.

Two major points here: 1) I’m tired of flying around with people who are predisposed to let LNAV and automation lead them around by the nose and, 2) charts have gotten ridiculous….

It was the First Officer’s leg. We were late, but I really try to provide a laid back, don’t rush CRM posture. We did all the things we were supposed to do, but I guess we didn’t spend 15 minutes reading every word on the NEWARK ONE 22L/R departure page. This chart is a triple folded, 10-inch wide encyclopedia. The important piece of information is what to do on takeoff, yet it’s practically hidden in a box towards the bottom of the page…. When you consider the congested airspace in that area, it’s critical that you don’t turn the wrong way after takeoff, but that’s exactly what we did. Why we did that, I don’t know. We’re human I guess. At 400 feet the First Officer said, “LNAV.” I furrowed my brow…and thought, “Okay, maybe I missed something.” But I went ahead and punched LNAV and looked down at the LEGS page on my side and saw LANNA at the top. I said something like, “That doesn’t sound right.” Meanwhile our VSI was pegged because we were climbing like a fighter since we only had twenty-some people onboard.

While we were in the right turn, obviously towards the wrong place…I’m feeling like this is not going well while the First Officer is climbing and turning right toward an aircraft crossing our nose from left to right. He’s still a bit away, but…this looks like it’s going to be unusually close. I say…“Watch that guy,” pointing at the traffic, when I hear Departure say, “Did Tower give you a heading?” All my senses now tell me my first gut feeling was correct and I answer, “Ah, we’re checking,” while Departure rapidly rattles off, “Stop at 4,000 feet; turn left to 270; traffic 12 o’clock.” I told him we had the traffic in sight and he says, “You guys need to be careful.”

So, back to point number one. When I first was blessed to be a part of this fine group of pilots, the Captains I flew with all told me, “Never trust that box.” And we didn’t. We used our brains to fly the airplane. Now however, we bow to that thing! This is the second time this has happened to me and yes, of course it’s “my fault,” but both times it’s because [pilots] just let LNAV lead them around. These are not RNAV departures, they are ‘heading’ departures, but we’ve brainwashed everyone to think, “Just hit LNAV and it will be all right.” It’s not. Please don’t tell me, a “proper briefing” would’ve solved all this because we’ve reached briefing overload. [Pilots] are more worried about doing all the briefings than paying attention to actually flying the airplane….

The First Officer didn’t see the traffic because he was face down in the instrument panel following the FD LNAV guidance. When all this happened, his first reaction was to put on the autopilot and start reading the departure chart to see where we screwed up. I had to ask him to let it go until we got higher.

Managing the Automation — More or Less?

An A320 First Officer’s focus on managing the automation led to an approach deviation that prompted a warning from the Captain and triggered ATC low altitude alerts. Proper programming and proper use of the automation might have eliminated the problems in this incident, but errors can be made and systems can malfunction. Situational awareness will save the day (or the dark and stormy night).

In the transition to the visual (backed up by the ILS), I thought I needed to cross [the Outer Marker] at 1,600 feet, placing the aircraft high on profile. I selected 1,800 feet/minute [descent] Vertical Speed to intercept the glide slope from above. As the Captain crosschecked he realized the aircraft was low on profile. At that time (approximately 1,600 feet), I disconnected the autopilot, arrested the descent, and maintained level flight until re-intercepting the glide slope (at approximately 1,400 feet)…. Approach Control and Tower informed us they had received a low altitude alert. Spend more time flying the aircraft and less time managing the automation. Had I tracked the LDA course and flown a visual approach it would have eliminated a high workload in a time-compressed situation.

“We Were Supposed To Be Descending”

It is interesting to note that situational awareness, in this case knowing that the aircraft was climbing when it should have been descending, was not mentioned by the reporter as an element in preventing future deviations. The B737-700 Captain focused instead on automation as the sole remedy.

We were given clearance to descend to FL240…. As we began the descent, the VNAV would not engage. I tried entering a lower altitude so the VNAV would engage…. I thought we were all set and that the descent was occurring. I later noticed we had climbed from about 27,600 feet to 30,000 feet. We were supposed to be descending to FL240. After I noticed the aircraft level off, I used Vertical Speed to continue the descent…. We should have monitored our FMC entries better. This would prevent what had occurred.

 

Friday
Dec062013

Safe Landings: December 2013

Expectation Bias

An expectation of what we think will happen has a tendency to alter what we subsequently observe or hear. This expectation bias is often exacerbated by confirmation bias, i.e., being focused on information that confirms one’s interpretation of a situation while giving less weight to that which contradicts it. The following ASRS reports show how mistakes can be made when Pilots and Controllers are carried along by familiar cues, slip into habit patterns, and become less aware of changes to what is “expected.”

“I Absolutely… Heard Our Callsign”


Circumstances confirmed this CRJ900 crew’s expectations to the point where the First Officer “absolutely” believed that their callsign was given with a takeoff clearance. The Captain, also hearing what he expected to hear, started to taxi across the hold short line before a voice from the Tower raised a red flag.

• As we approached the end of the runway, an air carrier flight in front of us was cleared for takeoff. We pulled up to the hold short line and stopped. We were the only aircraft in the Number One position at the end of the runway. There was nobody across the runway waiting to depart from the east side. It was just us and a few aircraft behind us…. I heard Tower clear us to, “Line up and wait” and I read back the clearance on the Tower’s frequency. The Captain called for the line-up checklist and started to advance the thrust levers. As the nose of the aircraft crossed the hold short line, somebody transmitted on the Tower frequency, “Who’s taking the runway?” This immediately raised a red flag and before I could say anything, the Captain brought the aircraft to an abrupt stop. We were barely across the hold short line and the Tower said something to the effect of, “Who is Number One at Runway 32?” I replied with our flight number and stated, “You cleared us to line up and wait on 32.” The Tower Controller replied, “Actually, I cleared another flight (it was behind us) to line up and wait on 32, but if you’re Number One for the runway, line up and wait, Runway 32.”

We…departed uneventfully. In retrospect, I can see that expectation bias was clearly in play. I absolutely believed that I heard our call sign being cleared to line up and wait and did not consider the possibility that the Tower had inadvertently cleared the aircraft behind us to line up and wait. Interestingly, both of us were positive that the clearance was for us, so checking with the other pilot would not have yielded a different result. In the words of the Captain, this was a wake-up call for both of us to ensure we are more alert to all clearances and transmissions. Bottom line, I made a mistake and erroneously responded to another aircraft’s clearance.

Familiarity Breeds Expectations

Even after briefing a departure with a specific reminder about maintaining runway heading to an assigned altitude, this Air Carrier Crew was “predisposed” to turn earlier, just as they had on previous departures.

• Non-towered airport procedures were reviewed and thoroughly briefed to include the Obstacle Departure Procedure (ODP). The ATC clearance received at the end of the runway stated, “You are released; fly runway heading; maintain 5,000; direct your first NAVAID; as filed; expect FL340 ten minutes after departure; departure frequency…” The First Officer was flying and briefed, “Runway heading to 5,000 feet.” The takeoff was uneventful with a strong crosswind out of the south and significant weather to the east and north. As Pilot Not Flying, I made the final call on CTAF (Common Traffic Advisory Frequency) that we were departing the airport airspace and would be turning west. I contacted Center as the First Officer entered a right bank at 2,100 feet MSL to proceed on course. Center immediately answered my check-in and asked if we were maintaining runway heading. We had turned approximately 30 degrees right and I directed the First Officer to turn immediately back to 090 degrees. I told Center we were executing the ODP and turning back to runway heading. He replied, “OK” and said we could maintain current heading which by then was back to runway heading. About 30 seconds later Center said “Radar Contact” and gave us a right turn direct, as filed… For me, I was predisposed for the right turn on course after the ODP since that was the standard clearance we received from Departure Control on my two previous departures. So even though we had just briefed “Runway heading to 5,000 feet” per our clearance, once airborne at the minimum turn altitude for the ODP, I expected a right turn. When the Pilot Flying turned right, it didn’t flag as an error like it should have. The clearance was copied, appropriately briefed and two folks let “the standard” occur when “non-standard” was the clearance. Don’t allow familiarity with a situation to set “expectation bias.”

 “I Heard What I Was Expecting to Hear”


It would seem improbable for someone to hear “right” when he or she is told, “left,” but the Pilot of a corporate jet heard what was expected, not what was said, and made a wrong turn. The incident is a clear lesson in the power of expectation bias to influence what we hear.

• I departed on Runway 7 and climbed on runway heading on Tower frequency…. During the climb, I was given instructions to, “Turn (left) heading 360” along with a frequency change. I was expecting a right turn when I heard the clearance… I commenced a right turn. This was a great example of how expectations can affect us. I heard what I had been expecting to hear and not what was said. With the close proximity of [another] airfield, which was departing to the west, I was anticipating a right turn back over the airport on departure. I am convinced this played a role in my believing that I had heard the command for a right turn. I made the frequency change and the new Controller issued an immediate left turn to course 360. The flight was continued without further incident.

Perhaps the best advice for avoiding the errors cited in this CALLBACK was given many centuries ago by the Chinese philosopher Loa Tzu, “Act without expectation

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