Austrian E195 at Salzburg on Oct 27th 2017, go around without thrust

Last Update: February 5, 2022 / 18:09:57 GMT/Zulu time

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Incident Facts

Date of incident
Oct 27, 2017

Classification
Incident

Airline
Austrian Airlines

Flight number
OS-266

Departure
Frankfurt/Main, Germany

Destination
Salzburg, Austria

Aircraft Registration
OE-LWJ

Aircraft Type
Embraer ERJ-195

ICAO Type Designator
E195

An Austrian Airlines Embraer ERJ-195, registration OE-LWJ performing flight OS-266 from Frankfurt/Main (Germany) to Salzburg (Austria) with 97 passengers and 5 crew, was on a final ILS approach to Salzburg's runway 15 about 2.3nm before touchdown at about 17:35L (15:35Z) when the aircraft encountered windshear prompting the captain (44, ATPL), pilot flying, to initiate a go around. The captain moved the thrust levers forward and pitched up to about 13 degrees nose up. However, autothrust was active, and as the TOGA buttons had not been pressed autothrust reduced the thrust again to maintain the selected airspeed (113 KIAS). The stick shaker activated for about 1-3 seconds as result when the aircraft was about 740 feet AGL. The crew subsequently applied TOGA, climbed out to safety and further up to FL100, positioned for another approach to runway 15 and landed safely at 18:01L (16:01Z) about 26 minutes after the go around.

On Apr 15th 2019 Austria's SUB released their interim report in German stating the captain initiated a go around due to windshear, moved both thrust levers forward but did not engage to the TOGA switches. As result autothrust returned the thrust levers to maintain the selected airspeed while the aircraft rotated to 13 degrees nose up. Due to the lag of the autothrust attempting to reduce the airspeed while the aircraft was already climbing the stick shaker activated for about 1-3 seconds as result of the IAS reducing to 113 KIAS (Vapp - 20 knots). Only 73 seconds after the first stick shaker activation the aircraft settled on a normal climb rate again. The captain was assisted by a first officer (24, ATPL).

The SUB further report the aircraft subsequently landed on runway 34 (??) at 16:01Z (clearly contradicted by ADS-B data, runway 34 had long been renamed to runway 33, also see runway 15).

On Aug 2nd 2021 the SUB released their final report in German only (Editorial note: to serve the purpose of global prevention of the repeat of causes leading to an occurrence an additional timely release of all occurrence reports in the only world spanning aviation language English would be necessary, a German only release does not achieve this purpose as set by ICAO annex 13 and just forces many aviators to waste much more time and effort each in trying to understand the circumstances leading to the occurrence. Aviators operating internationally are required to read/speak English besides their local language, investigators need to be able to read/write/speak English to communicate with their counterparts all around the globe).

The report concludes the probable causes of the serious incident were:

- deviations from standard operating procedures by the crew as result of "surprise and startle" effects

- delayed reaction and activation of TOGA

Contributing probable factors:

Crew:

- interference by "surprise and startle"

- delayed activation of TOGA button

- deviations from standard operating procedures

Weather:

- windshear

- varying tail wind components

- thunderstorm activity in the vicinity of the aerodrome

The SUB reported they received two messages from the operator. On Oct 30th 2017 the operator informed the SUB: "Windshear at 1300 ft. Performed escape maneuver and missed approach. Entered holding overhead SBG VOR. Waited for weather improvement. Second approach was successful." On Jan 17th 2018 the operator sent another report stating: "Stick shaker activation for 1-3 seconds during windshear escape procedure." The SUB indicated that after comparison with the message of Oct 30th 2017 it turned out that both reports concerned the same flight, however time and content differed.

The SUB summarized the sequence of events stating that the aircraft was on final ILS approach to Salzburg's runway 15 about 2.3nm before the threshold of the runway, when a windshear warning triggered. The pilot flying decided to go around and perform a windshear escape maneouver, however, did not activate any of the TOGA buttons. Therefore the autothrust system reduced the thrust of the engines again. Due to a high pitch angle and the reducing airspeed a stall warning activated. The autothrottle system remained in speed mode despite the stall warning, therefore only a very shallow climb was achieved during the first 73 seconds of the go around maneouver. Only 73 seconds after the windshear warning the TOGA buttons were pressed permitting to achieve a normal climb out. The aircraft subsequently entered the holding pattern doing two race tracks and subsequently landed safely on runway 15.

In the factual report the SUB stated that upon initiating the go-around the pilot flying pushed the thrust levers forward to about 75 degrees TLA (Thrust Lever Angle), but then removed his right hand from the thrust levers while pulling the yoke with both hands. Both pilots assumed that the thrust levers had been advanced far enough and TOGA had been activated. However, neither of the conditions was met, hence autothrust did not activate the automatic takeff thrust control system but remained in speed mode to maintain 133 KIAS. With the pitch angle increased to 14 degrees the airspeed reduced to 113 KIAS in the following resulting in a stall warning activating for 2 seconds.

Minimum height was 650 feet AGL about 4 seconds after the windshear warning, the speed minimum of 113 KIAS was reached 11 seconds after the windshear warning.

The report does not specify expressis verbis who was pilot flying and who was pilot monitoring, however, the context suggests the captain (44, ATPL, 15,000 hours total hours, 595 hours on type) was pilot flying, the first officer (24, CPL, 450 hours total, 359 hours on type) was pilot monitoring. A student was occupying the observer seat in the cockpit.

The SUB analysed that the automatic takeoff thrust control system would have taken over if the thrust levers had been advanced to 78 degrees or more, which however was not achieved. The system remained in standby.

The activation of the TOGA button would have accelerated the engines to 87.4% N1, in addition with the windshear warning active the activation of the TOGA would also have activated the windshear escape mode, in addition to the GA-RSV mode achieved by pushing the thrust levers forward to the mechanical stop or the TOGA button. As result not only did the engines not achieve TOGA thrust, the flight director indications did not change as needed for the go around.

It was likely that the pilot flying did not activate TOGA as result of the surprise and startle effects both at the windshear warning nor at the activation of the stall warning. The pilot monitoring also did not check whether TOGA had been activated, the engines had achieved required thrust and the autothrottle system had been switched off.

The restriction due to the startle effect caused the omission of problem solving measures and brought the aircraft into a stall, which was the by far greater risk to the aircraft.

The reaction time by both crew until the correct measures (TOGA) were taken, is within expected time range. Tests had identified the startle effect can impair the reaction of humans to solve arithmetic problems in about 30-60 seconds.

A similiar scenario, a go around without activating TOGA, had caused an accident, see Accident: Emirates B773 at Dubai on Aug 3rd 2016, long landing, go around without thrust results in runway impact, aircraft on fire, TOGA switches inhibited.

On Feb 5th 2022 the SUB also released the English Version of their final report.

METARs:
LOWS 271750Z 27004KT 240V310 9999 FEW018 SCT050 BKN070 08/05 Q1027 NOSIG=
LOWS 271720Z 27004KT 230V330 9999 FEW032 BKN060 08/05 Q1027 NOSIG=
LOWS 271650Z 29006KT 250V320 9999 -SHRA FEW012 SCT036 BKN044 07/05 Q1026 RERA NOSIG=
LOWS 271620Z 28011KT 250V310 8000 SHRA FEW010 SCT024 BKN032 06/05 Q1026 BECMG NSW=
LOWS 271550Z 31016G28KT 260V340 9999 SHRA FEW003 SCT026 FEW030CB BKN036 07/05 Q1025 RETS BECMG NSW=
LOWS 271520Z 25004KT 210V280 9999 FEW028 FEW030CB SCT050 BKN060 09/05 Q1024 TEMPO 4000 TSRA=
LOWS 271450Z 22007KT 9999 FEW013 FEW030CB SCT038 BKN050 09/05 Q1024 TEMPO SHRA=
LOWS 271420Z 22011KT 9999 VCSH FEW015 SCT040 BKN070 08/04 Q1024 TEMPO SHRA=
LOWS 271350Z 22010KT 180V240 9999 VCSH FEW015 SCT040 BKN070 08/05 Q1024 TEMPO SHRA=
LOWS 271320Z 22010KT 9999 FEW009 SCT040 BKN060 08/04 Q1024 NOSIG=
LOWS 271250Z 22008KT 190V250 9999 FEW006 SCT025 BKN035 07/04 Q1024 NOSIG=