Automation issues, SOPs not consistent with stable approach policy, some training deficiencies and ambiguous standards for flight crew training in relation to automation proficiency, found as contributing factors.
Photo(C) Eddie Heisterkamp Jetphotos.net
Unstable approach and hard landing
Air Canada Rouge LP
Airbus A319, C-FZUG Sangster International Airport Montego Bay, Jamaica 10 May 2014
Aviation Investigation Report A14f0065, released January 2017
1. Factual information
History of the flight
At 1034, (All times are Eastern Daylight Time -Coordinated Universal Time minus 4 hours) the Air Canada Rouge LP, Airbus A319 (registration C-FZUG, serial number 697), operating as flight AC1804, departed Toronto Lester B. Pearson International Airport (CYYZ), Toronto, Ontario. The flight was the first crew cycle for the 2 pilots. The captain was seated in the left seat and was the pilot flying (PF). The first officer was seated in the right seat and was the pilot monitoring (PM). The aircraft climbed to flight level (FL) 370 for the cruise portion of the flight.
At 1359, before descent and approximately 30 minutes before touchdown, the PF performed an approach briefing for the instrument landing system (ILS) approach to Runway 07 at Sangster International Airport (MKJS), Montego Bay, Jamaica. The approach briefing did not include the aircraft go-around procedure or the specific published missed-approach procedure, contrary to Air Canada Rouge policy.
At 1403, the aircraft began its initial descent from FL 370.
At 1405, the flight crew held a non-operational conversation, lasting nearly 3 minutes, in contravention of Air Canada Rouge policies regarding operational conversation during critical phases of flight, including flight from the top of descent on arrival.
At 1415, approach air traffic control (ATC) at MKJS asked which specific approach the flight crew preferred, offering the area navigation (RNAV) for Runway 07 or the VOR/DME for Runway 07. At this point, the flight crew became aware of a published Notice to Airmen (NOTAM) specifying that the ILS for Runway 07 was not available. The NOTAM had been included in the company flight release documents before departure but had not been noticed by the flight crew. The crew decided to perform the VOR/DME Runway 07 approach.
At 1417 (12 minutes before landing), the PF re-briefed the PM for the VOR/DME approach to Runway 07. As with the initial approach briefing for the ILS approach to Runway 07, the PF did not brief the aircraft go-around and published missed-approach procedures for the VOR/DME approach to Runway 07. The PF advised that a managed approach would be conducted (In a managed approach, “the aircraft is guided along the FMS [flight management system] lateral and vertical Flight Plan and speed profile. These modes and targets are armed or engaged by pressing the FCU [flight control unit] knobs.” Air Canada Rouge, Aircraft Operating Manual A319 (AOM), Volume 1 (10 May 2013), Standard Operating Procedures, section 1.04.00, p. 4).
During the re-briefing, the PF indicated that the final approach fix (FAF) crossing altitude was 2000 feet above sea level (asl), with a flight path angle (FPA) of 3.2 degrees.
At 1421:20, the flight crew held a non-operational conversation that ended at 1422:04 (approximately 8 minutes before touchdown), while the aircraft was descending through 10 000 feet.
At 1423:56 (6 minutes before landing), ATC queried whether the flight crew was able to proceed directly to LENAR9 at that time. The flight crew advised ATC that they were able to do so, and the aircraft was then cleared to LENAR. At this point, the aircraft was being flown using the autopilot and autothrust systems. (LENAR is the name of the initial fix for the very high frequency (VHF) omnidirectional range with associated distance measuring equipment (VOR/DME) Runway 07 approach, located 10.8 nautical miles from the threshold of Runway 07).
At 1424:46, before turning onto the final approach track, the PF selected a target speed of 190 knots on the flight control unit (FCU); the autothrust decreased the thrust and, as a result, the aircraft began to decelerate from 250 knots. The aircraft was level at 3000 feet.
At 1425:03, the PF requested flaps 1, which is the first configuration change in the approach sequence.
From 1425:28 to 1426:02, the PM was engaged in dialogue with ATC. During this time, the aircraft turned onto its final approach track.
At 1425:44, the final approach track was intercepted from the left (north), at a distance of approximately 9.6 nautical miles (nm) from the threshold (inside of LENAR). The aircraft was at an altitude of 3000 feet, with flaps 1 selected. According to Air Canada Rouge standard operating procedures (SOP), at this point (4 nm before the FAF), the aircraft should be configured with flaps 2. The autopilot was engaged and the autothrust was on. The airspeed was approximately 200 knots, and the aircraft was slightly above the 2.95-degree precision approach path indicator (PAPI), but below the 3.2° FPA. The aircraft began its final approach descent. Shortly afterwards, the flight mode annunciator (FMA) lateral and vertical modes changed to NAV and FINAL DES respectively, indicating that the aircraft was being managed by the flight management and guidance system (FMGS). The selected airspeed was still 190 knots. In these modes, the aircraft will fly the required lateral and vertical flight path, while the autothrust will vary the thrust to maintain the selected speed.
At 1426:00, 9.2 nm from the runway, the airspeed slowed to 195 knots. The PF selected a target speed of 180 knots to slow the aircraft down, and the autothrust system reduced the engine thrust to idle. The aircraft was at an altitude of 2950 feet.
At about 1426:08 (8.7 nm from the runway), the PF requested landing gear down to expedite the descent. This request was outside of the normal aircraft configuration sequence in Air Canada Rouge SOPs. The normal sequence is to select flaps 2 before extending the landing gear. However, the SOPs permit flight crew to lower the landing gear at any time during the approach, to aid in the descent.
At 1426:25, the airspeed was 188 knots. Using the FCU, the flight crew changed the selected target speed from 180 knots to 190 knots, then to 200 knots. Because of this selection, the autothrust momentarily increased the engine thrust, resulting in an increase in airspeed. The descent rate also increased, reaching 2000 feet per minute (fpm).
At 1426:28, the landing gear was down and locked. The aircraft was 7.7 nm from the runway and 1.7 nm from the FAF, with flaps 1 selected. At this point, according to Air Canada Rouge SOPs, the aircraft should have already been configured with flaps 3 selected.
At 1426:37, the aircraft was 1.6 nm from the FAF. The flight crew changed the target speed from their previous selection of 200 knots to a managed target speed11 of 134 knots, equivalent to the final approach speed (VAPP).12 At this point, the aircraft’s airspeed was 198 knots, and its altitude was decreasing through 2440 feet. As a result of the change in target speed, the aircraft began to decelerate.
At 1427:02, the aircraft crossed the FAF at the appropriate height (2000 feet) with an airspeed of 188 knots (VAPP plus 54 knots). At that time, the landing gear was down, with flaps 1 selected. According to Air Canada Rouge SOPs for a non-precision managed approach, at this point, the aircraft should have been stable at VAPP, with landing gear down and flaps 3 selected.
During the FAF crossing, using the vertical speed/flight path angle (VS/FPA) knob on the FCU, the PF selected 3.2° FPA, which is the appropriate FPA from the FAF. The FMA lateral and vertical modes changed to track mode (TRK) and to FPA, respectively. The flight crew did not perform the FAF-passage verbal calls required by the SOPs or their respective actions, which include setting the appropriate missed-approach altitude in the FCU.
At 1427:13, the PF disengaged the autopilot as the aircraft descended through 1780 feet, at a distance of approximately 5.2 nm from the threshold; airspeed was 186 knots. The remainder of the approach was flown manually by the PF, with the autopilot off.
At 1427:16, while the aircraft was descending through 1690 feet, 5 nm from the runway, with an airspeed of 187 knots, the PF requested flaps 3. The PM momentarily selected flaps 3, from flaps 1. The airspeed was 2 knots faster than the maximum flap selection speed for flaps 3, and the PM quickly retracted the flap lever to flaps 2. Contrary to Air Canada Rouge SOPs, the PM did not verbalize that the speed was correct for the selected flap setting, nor did he communicate the changes in flap position to the PF. During these flap selections, there was a radio call from ATC, clearing the aircraft to land.
Although data from the cockpit voice recorder (CVR) indicated that the PF had requested flaps 3, the investigation determined that the PF believed that he had requested flaps 2.
At 1427:22, the flight crew pulled the altitude selector (ALT/SEL) on the FCU. However, the FCU-selected altitude was set at 2000 feet. As a result, since the aircraft was below that altitude, the vertical mode changed from FPA to open climb (OP CLB) mode, and the autothrust changed to climb thrust (THR CLB) mode. The autopilot was off, so the aircraft did not climb, as requested by the automation. However, the autothrust increased the engine thrust from 34% to 87%, which resulted in an increase in airspeed.
At 1427:25, approximately 4.5 nm from the runway, with an airspeed of 185 knots and at an altitude of 1530 feet, the aircraft levelled off momentarily. Shortly afterwards, the aircraft began to deviate above the 3.2° FPA (Appendix A in the full report).
At 1427:26, the PM moved the flap selector lever from flaps 2 to flaps 3 a second time, again without communicating the selection or acknowledging that the speed was correct for the flap setting. Owing to the thrust increase described above, the airspeed increased to greater than the 185 knots maximum speed for flaps 3 selection, reaching 193 knots.
Within 3 seconds of the flaps 3 selection, the flaps extended to the flaps 3 position and the flight data recorder (FDR) recorded a master warning. A continuously repetitive chime, consistent with the flap overspeed warning, sounded for about 3.5 seconds. (
The Air Canada Rouge Aircraft Operating Manual A319 indicates that the maximum airspeed is 200 knots at flaps position 2, and 185 knots at flaps position 3. )
At 1427:29, the flight crew changed the FPA on the FCU from 0° to 3.2°. As a result, the FMA lateral and vertical modes returned to TRK and FPA, respectively; the autothrust changed from THR CLB to SPEED mode.
At 1427:32, the PM again momentarily retracted the flaps to the flaps 2 position. The PF disengaged the autothrust (by pressing the instinctive disconnect pushbutton and moving thrust levers to idle). The PM communicated to the PF that the flaps were at position 2.
At 1427:38, the PM moved the flap lever to the flaps 3 position for the final time, where it remained for the landing. The PM advised the PF of this flap selection. The aircraft was descending through 1420 feet, with an airspeed of 182 knots, thrust levers at idle, and autothrust off. The vertical rate of descent was 300 fpm.
At 1427:42, the PF stated that the aircraft was too high and that he was correcting, then stated that the autothrust was off. The PM did not hear the statement that the autothrust was off. The aircraft continued on the approach, and the rate of descent increased to 1400 fpm. During this time, the aircraft descended and began to converge on the 3.2° FPA followed by the FPA for the 2.95° PAPI. The aircraft was established on the PAPI at approximately 1428:24 (1.9 nm from the runway).
At 1427:52, the PM initiated the callouts associated with the landing flap selection portion of the final approach and landing check. The PM called out “autothrust,” which is the first callout item. The PF did not immediately respond, but shortly afterwards he initiated a dialogue regarding the FAF and the missed-approach altitude, interrupting the checklist. The PF requested that the PM dial in the missed-approach track and altitude. The pre-landing check was not completed. The autothrust remained off, and thrust levers remained at idle.
During the exchange between the PF and PM, the aircraft continued from 3.8 nm to 1.9 nm from the runway, descended from 1430 feet to 670 feet, and decelerated from 177 knots to 160 knots. The aircraft also descended through the Air Canada Rouge 500-foot arrival gate (100 feet above minimum descent altitude) used for the stabilized approach criteria, at which time the stabilized approach check must be completed, according to the Air Canada Rouge SOPs. The check was not done at this time.
At 1428:34, when the aircraft was 1.5 nm from the threshold, at 500 feet, with an airspeed of 155 knots, the flight crew acknowledged that the aircraft was back on profile.
At 1428:44, the flight warning computer (FWC) issued an aural alert of “four hundred.”
At 1428:48, the PF made the 500-foot stable approach call, which included “a hundred above, stable, minimums, runway in sight.” The aircraft was approximately 1 nm from the runway, at 370 feet, with an airspeed of 146 knots (VAPP plus 12 knots). The engines were at idle thrust, with autothrust off. At that time, the aircraft did not meet the Air Canada Rouge stabilized approach criteria, as the airspeed was high, the thrust setting was at idle, and the landing checklist was incomplete. The stabilized approach criteria will be explained in greater detail later in this report.
At 1429:05, the flight crew confirmed with each other that they were cleared to land. The aircraft was approximately 0.5 nm from the threshold; the airspeed was decreasing through 134 knots (VAPP). The aircraft was descending through approximately 200 feet above ground level (agl) with a pitch of 5.6° nose-up, and engine thrust was at idle; the rate of descent was 570 fpm. At 1429:13, the FWC emitted an aural warning of “one hundred.”
At 1429:15, approximately 0.2 nm from the threshold, the PF applied nose-up side-stick input, consistent with the landing flare, as the aircraft descended through 80 feet agl. The airspeed was 123 knots (11 knots below VAPP), the rate of descent was approximately 650 fpm, and the calculated true angle of attack (AOA) was approximately 9.9°. The normal technique is to reach a 30-foot flare height at VAPP in a stabilized condition and to begin a progressive flare while simultaneously closing the thrust levers, in order to be at idle before touchdown. (Air Canada Rouge, Aircraft Operating Manual A319 (10 May 2013), Standard Operating Procedures, Normal Landing, 1.04.13, p. 1.)
At 1429:17, the FWC issued the aural alert “fifty.”
At 1429:18, at 40 feet agl, the airspeed was decreasing through approximately 115 knots (19 knots below VAPP). The pitch angle had stabilized at 9.8° nose-up, the rate of descent was approximately 860 fpm, and the calculated true AOA was approximately 13.8°. At this point, the aircraft was in a low-energy state. The FWC issued an alert of “thirty,” and the thrust levers were momentarily advanced to maximum take-off thrust (take-off/go-around [TOGA]) power. The engine thrust responded but increased by only 4% before the aircraft touched down.
During the flare, with full nose-up side-stick input, the nose-up pitch command increased, the calculated true AOA reached a maximum of approximately 15.3°, and the elevator position oscillated between 1° and 5° nose-up. This sequence is consistent with alpha protection, a mode of the aircraft’s high-AOA protection system that enables the PF to pull the side-stick full aft and achieve the best possible lift, minimizing the risk of aerodynamic stall or control loss.( Air Canada A319 Flight Crew Training Manual (29 July 2011), Normal Operations, Operational Philosophy, Flight Controls, p. 10.) The pitch attitude subsequently began to decrease from the maximum 9.8° nose-up value before touchdown.
At 1429:21, the aircraft touched down hard, with a vertical load factor of 3.12g. The airspeed was 108 knots, and the pitch angle was 7.7° nose-up. At main gear touchdown, the calculated distance past the displaced threshold was approximately 125 feet.
Immediately following the touchdown, the ground spoiler was extended and the autobrake was activated normally, and the flight crew applied reverse thrust. The aircraft taxied off the runway without further incident.
The flight crew reported the hard landing, after which an initial inspection of the aircraft was performed. After a review of the FDR data, Air Canada Rouge maintenance personnel inspected the aircraft.
Injuries to persons
Damage to aircraft
The aircraft did not sustain structural damage or damage that adversely affected its flight characteristics. However, it was determined that the left and right main landing gear had been subjected to a high load exceedance. As a result, a flight permit was obtained from Airbus and Transport Canada (TC) to fly the aircraft to Miami, Florida, with the landing gear down. Both left and right shock absorbers were replaced as a precaution, as recommended by Airbus.
Personnel information/ Flight crew
The flight crew was certified and qualified within existing regulations. The occurrence flight was the first time the crew had flown together.
The PF had approximately 10 000 hours of total flight time, including 4200 hours on the aircraft type, 500 of which were as pilot-in-command. In October 2013, the PF was hired by Air Canada Rouge as a captain on the Airbus A319. Previously, he had been employed by Air Canada mainline since March 2006. He had received initial training as a first officer on the A319/A320 in 2008 and had completed upgrade training to become a captain in December 2013.
The PM had approximately 12 000 hours of total flight time, including 475 hours on the Airbus A319/A320, all of which were as second-in-command. His employment with Air
Canada Rouge began in October 2013. Previously, he had been employed by Air Canada mainline since March 2013. The PM’s biannual recurrent training had been conducted in October 2013.
Organizational and management information
Air Canada Rouge is a wholly owned subsidiary of Air Canada. It became a Canadian Aviation Regulations (CARs) Subpart 705 operator in June 2013 and had its first revenue flight in July of that year. The airline is fully integrated into the Air Canada mainline and Air Canada Express networks. According to the TC Canadian Civil Aircraft Register, the company operates 20 Airbus A319 and 14 Boeing 767 aircraft.
2. Flight crew training
Air Canada uses the advanced qualification program training system that is common among larger airlines. This training system does not involve traditional pilot proficiency checks following training but instead, includes validation sessions to assess the trainee. However, Air Canada Rouge uses the traditional method, in which a pilot proficiency check follows the requisite training.
Although the validation of trainees is accomplished differently at Air Canada Rouge than at Air Canada, the training is similar. The session summaries for each training event are identical at both airlines. The autothrust simulator training is the same for both Air Canada and Air Canada Rouge flight crews.
At the time of the occurrence, simulator training in autothrust-off approaches was part of the training syllabus at both airlines for flight crew members receiving initial type training and recurrent training. As Air Canada Rouge has a 36-month recurrent training cycle, the items in the initial training syllabus are covered again at some point in the 36-month period.
The PF had completed the first of the 6 recurrent training modules in the 36-month matrix, and the PM was not yet required to complete the first module. Both training schedules were in accordance with company policy and current regulations.
When the PF was upgraded to captain, he received the upgrade training that is provided to flight crew who are currently qualified on the aircraft type as first officer and are upgrading to captain. There is no training in autothrust-off approaches in the upgrade course, and none is required by regulation. The PF had completed training in non-autothrust approaches during his initial A319/A320 training in 2008.
Crew resource management (CRM), including threat and error management, forms part of the initial flight-crew training syllabus at Air Canada Rouge, and a refresher course is given during recurrent training.
At the time of the occurrence, Air Canada Rouge did not provide flight crews with simulator training to recognize unstable approaches, nor was such training required by regulation.
3. Air Canada Rouge stable approach policy
At the time of the occurrence, the Air Canada Rouge stable approach policy differed, in part, from that recommended by the Flight Safety Foundation (FSF) (section 1.18.2).
Air Canada rouge Stable Approach Policy is built around an Arrival Gate concept whereby a flight shall not continue the approach unless the required criteria for each Arrival Gate are met. There are two Arrival Gates for every approach; the first is the FAF (or FAF equivalent), the second Arrival Gate is at 500 feet AGL (or 100′ above minimums, whichever is higher). A Go-around is mandatory if the criteria for each Arrival Gate is not met [sic]. (Air Canada Rouge, Flight Operations Manual (17 February 2014), 8.11.6 Stabilized Approach Criteria).
The Air Canada Rouge criteria for a stabilized approach at the FAF arrival gate did not include several of the FSF-recommended criteria, including airspeed and sink rate, configuration, power settings, briefings or checklist completion. Aircraft were required to meet the recommended criteria only at the 500-foot gate, regardless of weather conditions.
4. Air Canada Rouge stabilized approach criteria
According to the Air Canada Rouge stabilized approach criteria, the aircraft was stable at the FAF arrival gate. However, the airspeed was 54 knots faster than VAPP, and the aircraft was not configured with the proper flaps settings as per the Air Canada Rouge SOPs. The aircraft was not stable at the 500-foot arrival gate (actually 710 feet as per the SOPs) because of its excessive airspeed, vertical speed deviations, incomplete landing checklist, and unstabilized thrust.
Photo (C) Galen Burrows Jetphotos.net
The flight crew was certified and qualified in accordance with existing regulations, and nothing was found to indicate that there was any aircraft failure or system malfunction that contributed to the occurrence before or during the flight. The analysis will focus on explaining how the series of operational and non-operational events encountered by the crew drew their attention away from monitoring and from executing a stable, non-precision approach, and resulted in their lack of awareness of the aircraft’s low-energy state just before touchdown. The analysis will also explain the defences that were in place but that were ineffective in preventing an unstable approach from being continued to a landing.
Flight planning and briefing
Before departure, the flight crew did not notice the Notice to Airmen (NOTAM) explaining that the instrument landing system (ILS) for Runway 07 was not available. As a result, they initially performed an approach briefing for the inoperative ILS approach. Following a call from air traffic control (ATC) enquiring about their selected approach, a second approach briefing for the very high-frequency omnidirectional range with associated distance measuring equipment (VOR/DME) Runway 07 approach was conducted. Neither briefing included the aircraft go-around procedure or the specific published missed-approach procedure, which form part of the first approach briefing of the day according to company procedures. In this occurrence, the flight crew was not under any time pressure. It is possible that, given the visual meteorological conditions, a go-around was deemed unlikely, and this may have reduced the perceived importance of the required briefings.
Briefings such as those for approach and for a missed approach are designed to establish a common action plan, to set priorities, and to cue altitudes and other critical information to memory. If flight crews do not conduct thorough briefings, including missed-approach briefings, they may not have a common action plan or set priorities, resulting in reduced crew coordination, which might compromise the safety of flight operations.
Managing non-operational and operational activities during approach
As the flight proceeded toward the final approach track, the flight crew engaged in non-operational conversation. As a countermeasure against crew distraction, non-operational conversation during critical phases of flight is prohibited by company policy. During this time, the crew also received a call from ATC and reprogrammed the flight management and guidance system (FMGS) for a direct flight to the LENAR waypoint.
The Air Canada Rouge standard operating procedures (SOPs) guide flight crews to configure the aircraft at flaps 2 at least 4 nautical miles (nm) prior to reaching the final approach fix (FAF); however, in this occurrence, the aircraft remained configured at flaps 1 until after the aircraft had passed the FAF. Managing the series of operational and non-operational events before the final approach track (i.e., communicating with ATC, reprogramming the FMGS, and carrying out a conversation) may have drawn the flight crew’s attention away from appropriately managing airspeed and configuring the aircraft. Also, the aircraft turned onto the final approach track after the LENAR waypoint, which reduced the amount of time the flight crew had to configure the aircraft and manage airspeed.
If flight crews are distracted by other operational and non-operational activities and do not follow SOPs, critical tasks associated with flying the aircraft may be delayed or missed.
Unstable approach – occurrence flight
1. Managing the aircraft systems with and without automation
When the aircraft was established on the final approach track, it was at the approximate altitude required for the desired 3.2° approach path. However, because the aircraft was still decelerating, its airspeed was greater than the target airspeed that had been selected. At that point, the aircraft vertical and lateral modes were managed, meaning that the autopilot or flight director systems were directed by the FMGS. When this is the case, the aircraft should follow the vertical and lateral approach path generated by the FMGS, and the autothrust (if in managed mode) should adjust the engine thrust as required.
In this occurrence, however, the autothrust was in a non-managed mode, and the selected speed was 180 knots. As a result, the aircraft was attempting to maintain 180 knots. At this point, the aircraft should have been decelerating to meet the FAF final approach speed (VAPP) of 134 knots. If the autothrust had been in a managed mode, the aircraft would have decelerated automatically.
The aircraft did not immediately start to descend, likely because it was moving too fast to descend on the given approach profile from its current location. Subsequently, the crew lowered the landing gear to slow down the aircraft and expedite the descent.
The flight crew then selected a higher target speed on the flight control unit (FCU), increasing it from 180 knots to 190 knots, and finally to 200 knots, likely in an attempt to increase the vertical descent rate. The descent rate increased, reaching 2000 feet per minute (fpm). However, the aircraft also accelerated, reaching 198 knots, when it should have been decelerating. The flight crew’s selection of a higher target speed before the FAF resulted in an increased-thrust and high-airspeed condition. This condition contributed to the crew’s confusion and misunderstanding of what the aircraft was doing and resulted in their mismanagement of the configuration sequence.
Shortly afterwards (12 seconds later), as a result of flight crew input, the target speed switched from a selected airspeed to a managed airspeed of 134 knots (VAPP). As a result, the autothrust reduced the engine thrust, and the airspeed began to decrease.
After deviating above the approach profile, the aircraft crossed the FAF at the appropriate altitude; however, its airspeed (188 knots) was 54 knots faster than VAPP, with flaps 1 still selected. Company SOPs state that the aircraft should cross the FAF stabilized at VAPP, with flaps 3 selected.
At this point, the pilot flying (PF) selected a flight path angle (FPA) of 3.2° on the FCU, which is the appropriate FPA from the FAF to the runway. The vertical flight mode changed to FPA. These modes were appropriate for the aircraft’s position on the approach and were within company and aircraft operating procedures. The autopilot and autothrust were on.
As the aircraft passed the FAF arrival gate, it met all of the stabilized approach criteria in the company policy. The aircraft had regained the approach profile, and its vertical speed was acceptable. The aircraft was tracking appropriately laterally. However, its airspeed was much higher than that specified by the SOPs, and its flaps were set to 1 instead of 3. Therefore, although the stabilized approach criteria were met, the airspeed and flap setting were contrary to the SOPs. If an air operator’s SOPs are not consistent with its stable approach policy, there is a risk that flight crews will continue an approach while deviating from the SOPs, resulting in an unstable approach.
According to company SOPs, the landing gear is normally selected down after flaps 2 is selected and before flaps 3 is selected. However, the SOPs permit flight crew to lower the landing gear at any time owing to operational requirements. During the occurrence approach, the landing gear selection was made outside of the normal procedural sequence, before the flaps 2 selection, to increase the deceleration and descent rate in response to the first high-airspeed condition.
The PF requested flaps 3 from the pilot monitoring (PM), bypassing flaps 2. The PF had intended to request flaps 2, but his error was not detected by the PM. The PM moved the flap selector from flaps 1 to flaps 3, although the speed was higher than the maximum allowable for that flap setting. It could not be determined why there was no corresponding call from the PM to ensure that the speed was correct, nor why there was no communication between the flight crew members clarifying the flap settings. During this time, there was also a call from ATC. The PM made 2 further attempts to select flaps 3. On the third attempt, the flaps reached the flaps 3-position.
Shortly afterwards, the flight crew pulled the altitude selector (ALT/SEL) knob on the FCU; as a result, the flight modes switched to open climb (OP CLB) and climb thrust (THR CLB). Consequently, there was a sudden and substantial increase in thrust from near idle to 87%. The PF had disengaged the autopilot, so the aircraft did not climb, as commanded by the automation. However, given that the autothrust was still engaged, the airspeed increased a second time, and a flap overspeed alarm sounded.
The increased speed and climb commanded by the automation when the flight crew pulled the ALT/SEL knob were not required during this phase of the approach. Furthermore, when the knob was pulled, the preselected altitude was above the current altitude, which did not correspond to any descent strategy. This further destabilized the aircraft. There are several other knobs and pushbuttons on the FCU and on the adjacent panels in the area of the glare shield. The pulling of the ALT/SEL knob was likely the result of an inadvertent FCU selection; that is, the flight crew had meant to select a different input.
The inadvertent FCU selection resulted in a second high-airspeed and increased-thrust condition. The aircraft deviated above the approach profile between the FAF and the 500-foot arrival gate, and a flaps-3 overspeed alarm sounded. In response, the PF disengaged the autothrust, which he called out to the PM.
2. Unstable approach
The PM initiated the flap-selection check after the PF had disengaged the autothrust and the PM had configured the aircraft with flaps 3. At the “Autothrust” item of the checklist, the check was interrupted by a discussion about the missed-approach altitude and was subsequently not completed. These 2 operational events occurred as the aircraft descended past the 500-foot arrival gate (100 feet above minimums), and a call of “Stable” was not made. The timing of the operational discussion as the aircraft descended past the 500-foot arrival gate may have diverted the attention of the PM from his duties, causing an essential task (a “Stable” call) to be missed. As a result, the flight crew missed an opportunity to recognize an unstable approach.
When the aircraft was on final approach, at 400 feet, the flight warning computer (FWC) annunciated “four hundred.” Following the FWC annunciation, the PF made the stable call of “hundred above, stable, minimums.” However, the PF made the “Stable” call when the aircraft was not stabilized, as its airspeed was high, the landing checks were incomplete, and the thrust was at idle. As a result, the flight crew continued an unstable approach. The aircraft had returned to the approach vertical profile, which was likely what the PF recognized as stable.
3. Energy management
As previously explained in the report, an aircraft’s energy condition is a function of its airspeed (and airspeed trend), altitude, drag, and thrust. In this occurrence, just before the first high-airspeed condition, the flight crew extended the landing gear, thereby increasing drag. However, the airspeed did not decrease; rather, it increased, because the crew selected a higher airspeed on the FCU. The flight crew eventually returned the autothrust to a managed mode; as a result, the target airspeed decreased to VAPP, and the aircraft began to decelerate.
The second high-airspeed condition occurred when the PF called for flaps 3 after the aircraft had crossed the FAF. A series of inputs to the FCU by the flight crew then caused the aircraft to increase thrust because of its mode of operation, which resulted in the flight crew misunderstanding what the aircraft was doing. To reduce airspeed and regain control, the PF disengaged all of the automation, including the autothrust.
Management of the aircraft’s energy condition diverted the flight crew’s attention from monitoring and controlling airspeed during the descent. As a result, the aircraft passed the FAF arrival gate at a high airspeed and with a flaps configuration that was not in accordance with the SOPs.
It is normal practice and standard procedure for flight crews to use autothrust for landing and to maintain thrust above idle to maintain the approach profile and facilitate a missed approach. However, the flight crew’s management of the second high-airspeed condition and the interruption of the landing flap check resulted in an autothrust OFF and thrust IDLE condition of which the flight crew was unaware.
The flight crew did not recognize that the airspeed was decaying as the aircraft approached the runway, nor that the autothrust was off. While on short final approach, the airspeed decayed well below VAPP, placing the aircraft in an undesired aircraft state at a very low altitude. The PF applied full nose-up side-stick input, and the angle of attack (AOA) reached maximum levels. As a result, during the flare, the aircraft’s AOA protection system engaged, reducing the pitch angle. The protection system functioned as designed, and as a result no significant nose-up elevator movement occurred, although full nose-up side-stick input had been applied before touchdown.
The crew were unaware of the low-energy state just before touchdown, as they believed that the autothrust was on. At 50 feet before touchdown, the flight crew suddenly realized that airspeed had been decaying and applied full manual thrust (i.e., maximum take-off thrust); however, in the time remaining before touchdown, the thrust increased by only 4%. When the flight crew recognized the undesired aircraft state, the late addition of engine power was insufficient to arrest the descent rate, resulting in a hard landing.
4. Monitoring approach stability
This occurrence involved factors that have been shown to increase the likelihood that an unstable approach is continued to a landing. For example, there were no environmental issues, such as wind shear, runway contamination, or instrument meteorological conditions, that would increase the perceived risk of the situation. As a result, the pilots likely anticipated a routine approach and landing. This may have contributed to the crew’s acceptance of deviations from the stabilized approach criteria. Until it reached the 500-foot stabilized approach gate, the aircraft was slightly high and fast but regained the profile twice as the flight crew worked to manage the conditions of high airspeed and increased thrust. The actions taken by the crew to reduce the airspeed indicated that they were aware of the high and fast energy state of the aircraft. Past the 500-foot arrival gate, with the autothrust disengaged and the thrust at idle, the aircraft’s airspeed continued to decay, resulting in an on-profile and low-energy state by 100 feet above ground level.
A number of situational factors likely contributed to the flight crew not recognizing that the aircraft had shifted from a high-energy state to a low-energy state:
- The flight crew had spent most of the approach working to reduce airspeed while descending and had finally reduced airspeed sufficiently just past the 500-foot arrival gate. They did not anticipate a low-airspeed condition.
- The flight crew was behind schedule in changing flap configurations and in approach-and-landing checks until just past the 500-foot arrival gate. They believed the aircraft to be stabilized at that point.
- Procedures, parameter-deviation calls, and checks were interrupted, delayed, or missed, reducing the flight crew’s awareness of actual flight parameters and aircraft system states.
- Monitoring of the overall approach was not maintained as the flight crew focused on resolving the condition of high airspeed and increased thrust.
Air Canada Rouge SOPs require the PM to call out excessive deviations from normal sink rate or from the approach profile in both visual flight rules and instrument flight rules meteorological conditions. In this occurrence, it could not be determined why the PM did not recognize the flight parameters that indicated that the approach was unstable. It is possible that the transition from the PF flying the aircraft with the automation on to flying the aircraft manually, combined with the thrust increases, contributed to a high workload, and that these deviations were therefore not noted by the PM. In addition, because the flight crew regained the approach profile following each airspeed deviation, there were recent cues that the aircraft, which was perceived as stable, was on profile. As a result, the degree of instability, including the shift from a high-airspeed condition to a low-airspeed condition, was not identified, and a go-around was not initiated.
Air Canada Rouge had stabilized approach criteria and policy, a no-fault go-around policy, and a safety management system hazard- and occurrence-reporting policy. Despite these factors, which encourage flight crews to conduct a go-around when an aircraft is not stabilized for approach, the unstable approach was continued. The flight crew did not adhere to the SOPs, which required the monitoring of all available parameters during approach and landing. With both flight crew members focused on the airspeed conditions and aircraft configuration delays, the instability of the approach was not identified and a go-around was not conducted.
Current defences against continuing unstable approaches have proven less than adequate. Unless further action is taken to reduce the incidence of unstable approaches that continue to a landing, the risk of controlled flight into terrain (CFIT) and of approach-and-landing accidents will likely persist.
At Air Canada Rouge, it is normal procedure to fly approaches in managed mode. The flight crew’s handling of the 2 high-airspeed conditions (i.e., thrust increase before the FAF and the climb thrust increase after the FAF) while attempting to maintain the approach profile demonstrated that the crew misunderstood what the aircraft was doing in its given modes of automation. After a few attempts to reduce airspeed by directing the automated systems, and following the unexpected thrust increase, the PF disengaged all of the automation, including the autothrust, in order to control the aircraft manually. This disengagement is a recommended course of action in such a situation, and the appropriate calls were made.73
Further, the PF’s switching to manual control resulted in the aircraft slowing down and regaining the approach profile near the 500-foot arrival gate. However, the PF did not remember that the autothrust was disengaged and that thrust was at idle as the aircraft continued to landing.
6. Crew resource management and standard operating procedures
As part of the normal discharge of their operational duties, flight crews employ countermeasures to prevent threats, errors, and undesired aircraft states from reducing safety margins during flight operations. Examples of such countermeasures include checklists, checks, briefings, calls, and SOPs, as well as crew resource management (CRM) skills (i.e., decision making, automation management, communication, and maintenance of situational awareness and attention). In this occurrence, throughout the approach to landing, critical elements of communication between the flight crew, including checks, calls, and cross-checks of excessive flight parameter deviations and flight mode annunciator (FMA) mode changes, were delayed or missed altogether.
Humans are inclined to focus attention on responding to problems or abnormal situations, even when the issues involved are benign in nature. CRM skills and SOPs, and regular training in them are designed as a countermeasure against flight crews focussing on threats and errors rather than on flying the aircraft or managing an undesired aircraft state. If flight crews do not adhere to standard procedures and best practices that facilitate the monitoring of stabilized approach criteria and excessive parameter deviations, there is a risk that threats, errors, and undesired aircraft states will be mismanaged.
7. Flight crew training
Air Canada Rouge has a stabilized approach criteria and policy. However, at the time of the occurrence, Air Canada Rouge did not provide flight crews with simulator training in recognizing an unstable approach leading to a missed approach. As a result, the occurrence flight crew did not recognize the multiple deviations in airspeed and thrust or the deficiencies in coordination and communication, and they continued the approach well beyond the stabilization gates. Training scenarios that involve go-arounds following an unstable approach may increase the likelihood that pilots will carry them out during active flight operations.
At the time of the occurrence, Air Canada Rouge did not include autothrust-off approach scenarios in each recurrent simulator training module, nor are they required to do so by regulation. The flight crews routinely fly with the automation on. As a result, the occurrence flight crew was not fully proficient in autothrust-off approaches, including management of the automation.
According to the Commercial Air Service Standards (CASS), air operators are required to provide flight crew members with training in all types of instrument approaches, using all levels of automation. At the time of the occurrence, Air Canada Rouge was providing training for autothrust-off approaches during initial training, but not during recurrent training. However, there is no specification in the CASS regarding the frequency of such training or how it is to be conducted, only that all items for the initial training syllabus must be covered over a defined period of time (through a cycle).
If standards for flight crew training in relation to automation proficiency (CASS 725.124) are not explicit with regard to frequency, there is a risk that air operators will exclude critical elements from recurrent training modules and that flight crews might not be proficient in all levels of automation.
Findings as to causes and contributing factors
- The flight crew’s selection of a higher target speed before the final approach fix resulted in an increased-thrust and high-airspeed condition. This condition contributed to the crew’s confusion and misunderstanding of what the aircraft was doing and resulted in their mismanagement of the configuration sequence.
- The inadvertent flight control unit selection resulted in a second high-airspeed and increased-thrust condition. The aircraft deviated above the approach profile between the final approach fix and the 500-foot arrival gate, and a flaps-3 overspeed alarm sounded. In response, the pilot flying disengaged the autothrust.
- The timing of the operational discussion as the aircraft descended past the 500-foot arrival gate may have diverted the attention of the pilot monitoring from his duties, causing an essential task (a “Stable” call) to be missed. As a result, the flight crew missed an opportunity to recognize an unstable approach.
- The pilot flying made the “Stable” call when the aircraft was not stabilized, as its airspeed was high, the landing checks were incomplete, and the thrust was at idle. As a result, the flight crew continued an unstable approach.
- Management of the aircraft’s energy condition diverted the flight crew’s attention from monitoring and controlling airspeed during the descent. As a result, the aircraft passed the final approach fix arrival gate at a high airspeed and with a flaps configuration that was not in accordance with the standard operating procedures.
- While on short final approach, the airspeed decayed well below final approach speed (VAPP), placing the aircraft in an undesired aircraft state at a very low altitude.
- When the flight crew recognized the undesired aircraft state, the late addition of engine power was insufficient to arrest the descent rate, resulting in a hard landing.
- The flight crew did not adhere to the standard operating procedures, which required the monitoring of all available parameters during approach and landing. With both flight crew members focused on the airspeed conditions and aircraft configuration delays, the instability of the approach was not identified and a go-around was not conducted.
- Air Canada Rouge did not provide flight crews with simulator training in recognizing an unstable approach leading to a missed approach. As a result, the occurrence flight crew did not recognize the multiple deviations in airspeed and thrust or the deficiencies in coordination and communication, and they continued the approach well beyond the stabilization gates.
- Air Canada Rouge did not include autothrust-off approach scenarios in each recurrent simulator training module, and flight crews routinely fly with the automation on. As a result, the occurrence flight crew was not fully proficient in autothrust-off approaches, including management of the automation.
Findings as to risk
- If flight crews do not conduct thorough briefings, including missed-approach briefings, they may not have a common action plan or set priorities, resulting in reduced crew coordination, which might compromise the safety of flight operations.
- If flight crews are distracted by other operational and non-operational activities and do not follow standard operating procedures, critical tasks associated with flying the aircraft may be delayed or missed.
- If flight crews do not adhere to standard procedures and best practices that facilitate the monitoring of stabilized approach criteria and excessive parameter deviations, there is a risk that threats, errors, and undesired aircraft states will be mismanaged.
- If an air operator’s standard operating procedures (SOP) are not consistent with its stable approach policy, there is a risk that flight crews will continue an approach while deviating from the SOPs, resulting in an unstable approach.
- If standards for flight crew training in relation to automation proficiency (Commercial Air Service Standards 725.124) are not explicit with regard to frequency, there is a risk that air operators will exclude critical elements from recurrent training modules and that flight crews might not be proficient in all levels of automation.
Safety action taken
Air Canada Rouge conducted an internal safety management system (SMS) investigation into this occurrence and an assessment of its flight operations. In the course of the investigation, the company identified and took steps to mitigate the risks associated with portions of its flight operations, specifically unstable approaches. Air Canada Rouge has taken the following corrective actions:
- It has incorporated simulator training for unstable approaches leading to a go-around into the syllabus for the recurrent training of flight crew. The intent is to incorporate the same training into the initial type training, but this action has not been completed yet.
- It has modified the recurrent training syllabus to include more manual flying, including controlled flight into terrain (CFIT) recovery, steep turns, approach to stall, upset recovery, autothrust disconnection and reconnection, and operations with autothrust off.
- It has implemented standard operating procedure (SOP) changes, which refined the company’s stable approach policy. The changes were developed based on consultation with Air Canada, the findings of the company’s internal investigation on this occurrence, and the latest proposals from the Flight Safety Foundation.
- It has improved the annual recurrent training program, including new and/or improved modules on dealing with distractions on the flight deck; leadership and professional standards, focusing on open communication; and dealing with non-compliance with standard operating procedures by the other flight crew member.
Excerpted from Transportation Safety Board of Canada Aviation Investigation Report A14F0065 Unstable approach and hard landing, Air Canada Rouge LP Airbus A319, C-FZUG, Sangster International Airport, Montego Bay, Jamaica, 10 May 2014
By Laura Duque-Arrubla, a medical doctor with postgraduate studies in Aviation Medicine, Human Factors and Aviation Safety. In the aviation field since 1988, Human Factors instructor since 1994. Follow me on facebook Living Safely with Human Error and twitter@dralaurita. Human Factors information almost every day