TUI B738 at Arrecife on Mar 25th 2019, EGPWS PULL UP, aircraft continued final approach

Last Update: February 13, 2021 / 12:44:01 GMT/Zulu time

Bookmark this article

Photo of TUI Airways G-TAWA, Boeing 737-800 — TUI Airways G-TAWA, Boeing 737-800 (Photo credit: Hawkeye UK / Flickr / License: CC by-sa)

Incident Facts

Date of incident
Mar 25, 2019

Classification
Incident

Airline
TUI Airways

Flight number
BY-4140

Departure
London Gatwick, United Kingdom

Destination
Arrecife, Spain

Aircraft Registration
G-TAWA

Aircraft Type
Boeing 737-800

ICAO Type Designator
B738

Airport
Lanzarote Airport, Lanzarote Island

Airport ICAO Code
GCRR

A TUI Airways Boeing 737-800, registration G-TAWA performing flight BY-4140 from London Gatwick,EN (UK) to Arrecife,CI (Spain), was on a VOR approach to Arrecife's runway 21 about 4.25nm before touchdown at about 14:47L (13:47Z), when the aircraft descended through 1120 feet AGL and the EGPWS issued a "PULL UP!" warning. The aircraft temporarily levelled off at about that height and continued for a safe landing on runway 21.

On Apr 8th 2019 Spain's CIAIAC reported, providing the date and time erroneously as Mar 26th 2019 19:00Z (at that time the aircraft was on a flight from Hurghada Egypt to London Gatwick, a TUIFly A20N was on a normal approach to Arrecife landing on runway 21 at about 18:21Z on a normal vertical profile), that the aircraft was on a VOR approach to runway 21 about 4.25nm from the runway threshold at 1120 feet AGL when the EGPWS sounded "PULL UP!", the crew continued the approach in manual flight and landed without further incident. The CIAIAC opened an investigtion into the occurrence.

ADS-B data show the aircraft at about 1150 feet MSL on Mar 25th 2019 at about 13:47Z about 4nm before the runway 21 threshold, maintaining that height for a minute subsequently before continuing the descent towards the runway.

On Feb 13th 2021 Spain's CIAIAC released their technical report with the remark: "Please note that this report is not presented in its final layout and therefore it could include minor errors or need type corrections, but not related to its content. The final layout with its NIPO included (Identification Number for Official Publications) will substitute the present report when available."

The report concludes the probable cause of the incident was:

The investigation has concluded that the incident was caused by an incorrectly executed approach to Lanzarote Airport.

The CIAIAC analysed the approach:

The flight crew was cleared by ATC to make the "direct VOR A approach to runway 21" and acknowledged the authorisation.

They configured the plane for landing at an early stage and carried out the pre-landing checklist so as to be able to focus on the final leg of the approach.

With the autopilot and autothrottle engaged, the flight crew used LNAV mode for horizontal navigation and V/S mode to fly the vertical profile of the approach. When using the V/S mode, the pilot calculates the vertical speed required to fly the vertical profile of the approach path and makes the necessary adjustments to stay on it by modifying the vertical speed value. When the aircraft reaches the altitude selected by the flight crew in the MCP altitude window, the autopilot maintains that altitude.

According to the captain’s statement, at mile 10 DME LTE, they had the terrain, obstacles and the airport environment in sight. They passed the TUXAM point and continued the descent to 2,800 feet according to the VOR A instrument procedure, which was selected in the altitude window of the MCP.

In his testimony, the captain said that once he had made visual contact, he selected 2,200 feet on the MCP10. The QAR recorded that when the aircraft was at mile 9.5 DME LTE and descending through 3,136 feet, an MDA rounded to the higher hundred of 2,100 feet was selected in the MCP altitude window. This altitude is lower than the previously selected, 2,800 feet, which they should have maintained until the FAF. Thus, at mile 8.75 DME LTE, in other words, 1.35 miles before the FAF, the aircraft descended below the minimum altitude of 2,800 feet. They continued the descent, and when the aircraft reached 2,100 feet, the flight crew selected 1,400 feet in the MCP altitude window. The aircraft continued to descend, passing mile 7.4 DME LTE a few moments later at 2,080 feet (720 feet below minimum altitude). The descent continued with the subsequently selected altitudes of 1,000 feet in the MCP altitude window and, lastly, the missed approach altitude (6,000 feet) until the ground proximity warnings were received.

Based on the preceding information, we can conclude that the flight crew deviated from the flight profile for the manoeuvre, and on making visual contact, descended prematurely below the minimum altitude published for between the IF and FAF (2,800 feet). They then proceeded to fly over the FAF at approximately 720 feet below the minimum altitude and continued to descend below the vertical profile, which generated the EGPWS warnings.

In his statement, the captain also said that he was possibly expecting to follow a 3-degree visual path, instead of the required 3.7 degrees.
The co-pilot, who was undergoing line training under supervision (LIFUS), performed the functions of PM (pilot monitoring). According to the captain, his workload was high, and he performed his job in accordance with his level of experience. We believe that this aspect of the flight could have influenced the effectiveness of the flight crew’s approach monitoring.

On receiving the two ground-proximity warnings, the captain declared that he had the obstacles in sight and, given that he was unsurprised by the warnings, decided to continue the approach instead of performing the terrain escape manoeuvre. He disconnected the autopilot and autothrottle, levelled the plane, and subsequently continued the descent following the correct profile.

As a result of the incident, the operator drew up an individualised training plan for the captain, which covered the flight procedures for non-precision approaches and the response to EGPWS warnings, among other things. Following a favourable report from the training department, he resumed his regular flight activity. The co-pilot, who was carrying out line flying under supervision (LIFUS), continued with his training which was expanded to include aspects related to the incident.

Metars:
GCRR 251430Z 22011KT 200V260 9999 FEW030 SCT041 22/13 Q1007=
GCRR 251400Z 21012KT 190V260 9999 FEW026 SCT035 21/15 Q1007=
GCRR 251330Z 21012G25KT 170V270 9999 FEW026 SCT035 22/15 Q1008=
GCRR 251300Z 21012KT 9999 FEW026 SCT035 21/15 Q1008=
GCRR 251230Z 20011KT 9999 FEW030 22/16 Q1008=
GCRR 251200Z 20010KT 170V230 9999 FEW025 23/15 Q1009=
GCRR 251130Z 20010KT 170V230 9999 FEW025 21/15 Q1009=
GCRR 251100Z 23010KT 190V260 9999 FEW025 22/13 Q1009=
GCRR 251030Z 22011KT 9999 FEW020 22/15 Q1009=
GCRR 251000Z VRB04KT 9999 FEW018 22/14 Q1009=