LOT E195 at Warsaw on Oct 11th 2019, speed dropped to 95 knots during balked landing

Last Update: June 6, 2023 / 18:13:25 GMT/Zulu time

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Photo of LOT Polish Airlines SP-LNO, Embraer ERJ-195 — LOT Polish Airlines SP-LNO, Embraer ERJ-195 (Photo credit: FlugZüge / Flickr / License: CC by-sa)

Incident Facts

Date of incident
Oct 11, 2019

Classification
Report

Airline
LOT Polish Airlines

Flight number
LO-236

Departure
Brussels, Belgium

Destination
Warsaw, Poland

Aircraft Registration
SP-LNO

Aircraft Type
Embraer ERJ-195

ICAO Type Designator
E195

A LOT Polish Airlines Embraer ERJ-195, registration SP-LNO performing flight LO-236 from Brussels (Belgium) to Warsaw (Poland) with 99 passengers and 6 crew, landed on Warsaw's runway 33 (flaps at position 5) in gusting winds, the first officer (38, CPL, 726 hours total, 519 hours on type) was pilot flying. The aircraft touched down hard at +1.96G and bounced off the runway, the pilot flying initiated a go around, the autothrust disengaged and the first officer advanced the thrust levers to 72 degrees (TLA) without pushing the TOGA button. The aircraft reached a maximum climb rate of 4,384 feet per minute, tower noticed the vertical speed and queried the climb rate, the thrust was further increased to 75 degrees TLA, the pitch reached 32.2 degrees nose up. At 1470 feet MSL the aircraft speed had reduced to 95 knots, the system warning of critical angle of attack and the stick shaker activated. The crew initiated an upset recovery procedure pushing the yoke forward reducing the pitch, losing some height and increasing speed. At 1382 feet MSL (1077 feet AGL) the aircraft was recovered, the stick shaker ceased. The TOGA button was pushed which engaged the flight guidance control system. The aircraft stabilized, positioned for another approach and landed safely on runway 33.

The Polish PKBWL released their final report concluding the probable causes of the serious incident were:

1)- Incorrect execution of the “Bounced Landing Recovery” and “Go-Around” procedures.

- Delayed reaction of the Pilot Monitoring to the errors made by the Pilot Flying during landing and Go-Around.

Contributing factors

- Weather conditions (gusty crosswind).

- Aircraft control error during landing.

- Low experience of the FO.

- Failure to follow standard procedures during the “Bounced Landing Recovery” and “Go-Around”.

- Lack of proper cooperation in the crew.

- Incorrect application of the “Stall Recovery” procedure.

- Incorrect execution of the “Upset Recover Manoeuvre”.

The PKBWL analysed:

The crew performed a standard, routine flight from EBBU to EPWA, which is a base aerodrome very well known to both pilots. The landing approach, completely stabilised at the altitudes of 1,000 ft. and 500 ft., gave the pilots a sense of comfort.

After receiving the landing clearance, the PF disengaged the auto-pilot and performed the further part of the approach manually. The low experience of the PF (519 FH on type) caused that the landing conditions were too difficult for him. When “countering” the crosswind and correcting the aircraft attitude, the pilot made an incorrect assessment of the sink rate, which resulted in a hard landing. That error during landing and the PIC failure to properly monitor the PF response led to the aircraft bounce. The PM did not recognise a hazard and did not react timely to prevent the hard landing.

The plot based on the data recorded (Fig. 6) shows the moment of touchdown which took place with g-load of 1.96 g.

Following the aircraft bounce, the PF immediately made the Go-Around decision, but did not use the standard phraseology, thereby surprising the PIC, who needed some time to analyse the current situation.

The procedure for the so-called “Bounced Landing” contained in the Operations Manual states that in such case it is necessary to push the TO/GA button, to increase engine thrust by moving the levers to the TO/GA position and set the trim accordingly.

An analysis of the recorded data shows that the crew used the pitch trim only after initiating the Go-Around at the altitude of 3,000 ft. This is illustrated in the figure (Fig. 8). In the diagram bottom right corner, the green entry in red framing indicates the pitch trim activation.

Failure to change the pitch trim’ setting in combination with the change in the aircraft configuration and increased engine thrust created conditions favourable for the increase in the aircraft positive pitch angle.

The PF initiated execution the procedure contrary to the standards developed by the manufacturer and the airline. Failure to push the TO/GA button (excerpt from procedure below: item one: Go Around Button…PRESS) prevented the “Flight Guidance Control” system from generating standard “Flight Director” indications which would display the correct climb profile to the pilot. Additionally, the autothrottle disengaged automatically upon touchdown, in accordance with its logic.

Furthermore, the procedure applicable to the Go-Around manoeuvre without the “Flight Guidance Control” system indications was not executed. If the FGCS is inoperable, it is necessary to lift the aircraft nose to achieve the positive pitch angle of 8°. This information is specified in the Go-Around procedure - Fig. 9.

The PF did not use standard callouts that are associated with the Go-Around procedure. In addition, the PM did not verify the correct position of the thrust lever. In Fig. 10 below, except from the operator documentation, specifying the division of duties as well as obligatory actions and callouts for the PF and PM.

Increased thrust resulted in increased positive pitch, which is characteristic to jet aircraft with engines positioned below the wings. In combination with the setting of the pitch trim (which remained at values set for landing) it caused the aircraft to commence a high rate of climb.

The crew’s lack of reaction to the increasing positive pitch angle caused the aircraft to lose speed rapidly. The correct positive pitch angle during the initial Go-Around phase should be 8°. The quickly changing flight conditions made the PF, who had low experience, incapable of controlling the aircraft, which led to reaching the positive pitch angle of 32.2° and the vertical speed of 4,384 ft/min.

At that time, the Captain (PM) was changing the aircraft configuration (retracting the flaps and landing gear according to the Go-Around procedure) and responding to the air traffic controller who noticed the non-standard, rapid climb. By concentrating on his tasks as the PM, he did not notice timely the errors of the PF, which led to the substantial speed loss. The Captain reacted to the speed loss by increasing thrust. That action, in combination with the lack of reaction to the additional moment turning up the nose of the aircraft, led to an even greater positive pitch angle of the aircraft, which in turn caused an increase in the angle of attack, which resulted in a decrease in speed to 95 kt, - 42 kt lower than V Ref. At 1218 ft AGL, the "Low Speed Awareness" and "Stick shaker" were activated.

Within a short time, the crew found themselves in a more difficult situation, which directly endangered the flight safety. The Captain became directly involved in the aircraft control and in the “Upset Recovery” procedure. The manoeuvre was completed at the altitude of 1,044 ft. AGL (approx. 300 m). This procedure was not performed in accordance with typical standards specified in the carrier Operations manual.

If the flight is performed with a positive pitch angle of more than 25°, it is necessary to immediately apply the “Upset Recovery” procedure and use the pitch trim or thrust reduction to decrease the aircraft positive pitch angle. The crew reduced the thrust; however, the pitch angle was changing too slowly and too late to prevent speed loss and the “Stick shaker” activation.

The crew could have reacted more firmly to prevent the “Stick shaker’s” activation. There is a “Stall recovery” procedure, which specifies that if the aforementioned conditions occur, it is necessary to decrease the pitch angle, maintain the wings in horizontal position (no bank), but most importantly use the engines full thrust (excerpt from the procedure in Fig. 13).

The analysis of the objective flight data monitoring showed that during the “Stall Recovery” procedure, the crew used the engine thrust necessary to carry out the “GoAround” procedure. The crew set 75° TLA for engine #1 and 77° TLA for engine #2 accordingly, which correspond to N1: 87.1% for engine #1 and N1: 90.4% for engine #2 (diagram below in Fig. 10, which shows the thrust lever position in degrees, highlighted in yellow, and the cockpit screenshot: N1 in %). According to the aforementioned procedure, the pilots should use both engines’ full thrust (MAX) during this manoeuvre.

The crew was acting under time pressure and in dynamically changing conditions. The aircraft Captain, acting as the PM, took control over the aircraft, thereby preventing the standard division of tasks between the PF and PM.

An additional factor, which could potentially affect the pilot’s performance, was the presence of a third crew member (stewardess) in the cockpit (during take-off and landing) according to the aircraft weight and balance document. Three other cabin crew members were present in the aircraft cabin, which is compliant with “ORO.CC.100, Number and composition of cabin crew.

During the occurrence analysis, the operator provided information that the additional crew member was present in the cockpit due to the aircraft balancing aspects. At the Commission request, the LS AS company performed a balance simulation with data identical to the original version, i. e. 2 pilots in the cockpit and 4 cabin crew members in the cabin. One cabin crew member was assigned a seat in the last row. The simulation demonstrated that the balance parameters did not exceed the limit and it was possible to perform the flight in the 2/4 configuration.

When continuing the climb, pilots pushed the V/S mode (“vertical speed”) on the autopilot panel several times. Due to the high climb rate, the V/S mode was automatically switching to the ASEL (“Altitude Select”) operating mode. This mode is activated automatically, when the aircraft reaches the altitude pre-set on the autopilot panel. Information about this mode activation is displayed in green in the “FMA – Flight Mode Annunciator”. The fact that the crew pushed the same mode several times indicates that their acquisition of information was impaired, which is typical for stressful situations. The second landing approach was uneventful.