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Cases › DCA05MA099 · Major investigation

Airbus A321-231SPIRIT AIRLINES INC

Fort Lauderdale, FL, USA · 2005-09-18·N583NK

0
fatal
0
serious
No injury
highest injury
Substantial
damage
Read the cockpit voice recorder7 lines18:07:23 – 18:12:25AnalyseThe analystOne timeline · precedents · ask the docket · what the record saysGenerateInvestigation briefFacts, cause, recorder extremes, sequence, sourcesSourceNTSB docket11 documents on data.ntsb.gov

What happened

NTSB summary, verbatim

Upon landing, an Airbus A321, experienced a tail strike upon landing. The First Officer (FO) stated that over the threshold at an altitude of about 50 feet, "it just literally felt like we lost inertia." The Captain believed that the flare was initiated too late and was incomplete. The FO stated that before touchdown, he lowered the nose a little bit and the aircraft touched down firmly. The aircraft bounced and the FO believed he again lowered the nose to prevent a tail strike. The Captain remembered that as the nose of the aircraft was lowering prior to the second touchdown, he may have pulled back on his side stick controller slightly to prevent the nose gear from striking the runway at too great a speed. After the aircraft touched down a second time the tailstrike occurred. Information extracted from the aircraft's flight data recorder revealed that both side stick controllers were activated simultaneously during the tailstrike. According to the manufacturer, when both side stick controllers are activated simultaneously (at least 2 degrees deflection off the neutral position) in the same or opposite directions and neither pilot takes priority via the takeover push button, the system adds the signals of both pilots algebraically. Airbus had issued Flight Crew Operating bulletins concerning bounced landings and tailstrikes but the pilots stated that no classroom or simulator training was received to reinforce the meaning and contents of the bulletins.

Probable cause

the Board's determination
Following a bounced landing, the pilot in command activated his sidestick controller while the first officer was in control of the airplane, which subsequently resulted in the overcontrol of pitch and a tailstrike. Contributing to the circumstances of this accident were the pilot-in-command's failure to properly activate his sidestick takeover push button prior to his remedial action, and the operator's insufficient emphasis on bounced landing recovery techniques and tailstrike avoidance procedures.

Sequence of events

6 timed eventsfrom the FDR factual report · claude-fable-5-1 (in-session)
  1. 06:11:06 localapproachp.2
    Autopilot disengaged at about 920 ft radio altitude; sidestick pitch and roll active on the first officer's side
  2. 06:12:20 localflarep.2
    At 25 ft radio altitude pitch attitude began to increase and the captain's sidestick pitch and roll parameters began to register activity (dual input)
  3. 06:12:22 localtouchdownp.2
    Left and right main gear WOW indicated ground; vertical acceleration maximum 2.7 g followed by 0.531 g as pitch increased through 7 degrees; spoilers began to deploy
  4. 06:12:23-06:12:24 localbouncep.3
    All gear WOW indicated air for 2 seconds (bounce); pitch reached a maximum of 10.5 degrees (tail strike)
  5. 06:12:25 localsecond touchdownp.3
    Left and right gear again indicated ground; vertical acceleration 2 g followed shortly by 0.5 g
  6. 06:12:29 locallanding rollp.3
    Nose gear indicated ground; a flaps fault indication at this time; thrust reversers did not indicate deployment after landing

NTSB analysis

from the final report

Upon landing, an Airbus A321, experienced a tail strike upon landing. The First Officer (FO) stated that over the threshold at an altitude of about 50 feet, "it just literally felt like we lost inertia." The Captain believed that the flare was initiated too late and was incomplete. The FO stated that before touchdown, he lowered the nose a little bit and the aircraft touched down firmly. The aircraft bounced and the FO believed he again lowered the nose to prevent a tail strike. The Captain remembered that as the nose of the aircraft was lowering prior to the second touchdown, he may have pulled back on his side stick controller slightly to prevent the nose gear from striking the runway at too great a speed. After the aircraft touched down a second time the tailstrike occurred. Information extracted from the aircraft's flight data recorder revealed that both side stick controllers were activated simultaneously during the tailstrike. According to the manufacturer, when both side stick controllers are activated simultaneously (at least 2 degrees deflection off the neutral position) in the same or opposite directions and neither pilot takes priority via the takeover push button, the system adds the signals of both pilots algebraically. Airbus had issued Flight Crew Operating bulletins concerning bounced landings and tailstrikes but the pilots stated that no classroom or simulator training was received to reinforce the meaning and contents of the bulletins.