By Simon Hradecky, created Wednesday, Mar 8th 2017 21:38Z, last updated Thursday, Mar 7th 2019 19:20Z An Ameristar McDonnell Douglas MD-83, registration N786TW performing charter flight 7Z-9363 from Detroit Willow Run,MI to Washington Dulles,DC (USA) with 109 passengers and 7 crew, was accelerating for takeoff from Willow Run's 23L at about 15:40L (20:40Z) when the crew rejected takeoff at high speed but overran the end of the runway, broke through the instrument landing system and approach lighting runway 05R, the airport perimeter fence, went over a road and came to a stop about 340 meters/1120 feet past the runway end with collapsed nose gear and main gear in a ditch. One passenger received a minor injury in the evacuation, the aircraft sustained substantial damage.



The aircraft was carrying Michigan's Men Basketball Team.



The Basketball team reported the aircraft attempted takeoff in high winds, the takeoff was rejected, following strong braking the aircraft went beyond the runway. There were no injuries, everyone on board is safe and sound. The team is now arranging alternative travel.



The FAA reported the aircraft on departure roll went off the runway into a fence, the persons on board evacuated via slides, no injuries, the aircraft sustained substantial damage. The occurrence was rated an accident.



The NTSB dispatched investigators on site.



On Mar 11th 2017 The Aviation Herald received information, that in addition to the collapsed nose gear both main gear struts received fractures to their upper bodies and were folded back when the aircraft went over a rise before the service road inside the airport perimeter.



On Mar 12th 2017 the aircraft became briefly "flying" again with the assistance of two cranes, which moved the aircraft into a better location (see video below).



On Mar 21st 2017 the NTSB reported the aircraft ran off the end of runway 23L after rejecting takeoff (reason for the rejected takeoff not mentioned). The aircraft was evacuated via emergency slides, one passenger received a minor injury. Although no post accident fire ensued the aircraft sustained substantial damage. Visual meteorological conditions prevailed at the time of the accident.



On Mar 22nd 2017 the NTSB reported that the flight controls moved normally and were free to move, the elevator control tabs moved as commanded, however, the right hand elevator was jammed in a trailing edge down/aircraft nose down position and did not move, while the left hand elevator commenced a large nose up movement as the aircraft accelerated through 152 KIAS and continued in this position for 5 seconds, aircraft accelerating through 166 KIAS with no change in aircraft attitude however. The crew rejected takeoff, the aircraft reached a maximum speed of 173 KIAS. The aircraft went beyond the end of the runway and came to a stop about 1000 feet past the end of the runway. One passenger received a minor injury in the evacuation. The NTSB reported a post flight inspection found the right elevator geared tab inboard pushrod linkage damaged which restricted movement of the right elevator surface but allowed movement of the control tab. After the damaged components were removed, the elevator could be moved by hand.



The NTSB reported the pilot in command was Ameristar's chief pilot occupying the right hand seat providing captain differences training to the captain occupying the left hand seat and being pilot flying. The chief pilot had accumulated 9,960 hours total with 2,462 hours on type, the captain had accumulated 15,518 hours total and 8,495 hours on DC-9 type aircraft.



On Apr 11th 2018 the NTSB opened their investigation docket. The systems group reported for the right hand elevator: "A visual examination of the tab hinges and control linkages found that the inboard right geared tab links and actuating crank were damaged and in an over-centered position." The NTSB reported subsequently: "The damaged links and associated attachment hardware were removed. After the links were removed, the right elevator was free to move, by hand, within the confines of the elevator stops."



On Mar 7th 2019 the NTSB released their final report, praising the crew in the comments associated with the release of the report and concluding the probable cause of the accident was:



The NTSB determines that the probable cause of this accident was the jammed condition of the airplanes right elevator, which resulted from exposure to localized, dynamic wind while the airplane was parked and rendered the airplane unable to rotate during takeoff.



Contributing to the accident were



(1) the effect of a large structure on the gusting surface wind at the airplanes parked location, which led to turbulent gust loads on the right elevator sufficient to jam it, even though the horizontal surface wind speed was below the certification design limit and maintenance inspection criteria for the airplane, and



(2) the lack of a means to enable the flight crew to detect a jammed elevator during preflight checks for the Boeing MD-83 airplane.



Contributing to the survivability of the accident was the captains timely and appropriate decision to reject the takeoff, the check airmans disciplined adherence to standard operating procedures after the captain called for the rejected takeoff, and the dimensionally compliant runway safety area where the overrun occurred.



The NTSB analysed:



The captain, who was the PF, executed the rejected takeoff after V1 when he perceived that the airplane did not respond normally when he pulled back on the control column to command rotation. All 116 persons on board evacuated the airplane via the emergency escape slides with only one reported minor injury; however, one slide failed to inflate.



FDR data showed that the airplanes right elevator was full TED (trailing edge down) when the flight crew first powered up the airplane on the day of the accident and remained there throughout the accident sequence. An airplane performance study (based, in part, on FDR data) confirmed that airplane did not respond in pitch when the captain pulled on the control column. Before the accident flight, the airplane had been parked on the ramp at YIP for 2 days near a large hangar, and the elevators (which, by design, did not have gust locks) were exposed to high, gusting surface wind conditions. Postaccident examination showed that the right elevators geared tabs inboard actuating crank and links had moved beyond their normal range of travel and became locked overcenter, effectively jamming the right elevator in a full-TED position. Thus, the NTSB concludes that the right elevators jammed condition rendered the airplane unable to rotate during takeoff.



...



Ameristars AMM for the Boeing MD-83 included a warning that the airplane must be parked headed into the wind if gusts were expected to exceed 60 kts and a caution that a visual and physical inspection of all flight control surfaces was required if the airplane was subjected to wind exceeding 65 kts. However, none of the recorded or forecasted wind at YIP exceeded these limits during the time that the airplane was parked on the ramp (the highest reported wind gust was 55 kts and the highest forecasted gust was 48 kts). Thus, the NTSB concludes that, based on the available wind data for YIP, the flight crew was not required to perform high-wind parking procedures or request flight control inspections from maintenance personnel.



The amplified normal checklist in the AOM and Ameristar training specified that a pilot must visually check the general condition of the elevators and tabs before each flight segment. The captain performed the preflight inspection and noted no visible damage. Flight crews are not required to physically move the elevator surfaces (which are about 30 ft above the ground), and the geared tab linkage is not visible from the ground. Although it is possible to see when an elevator is positioned full TED (as evident in figure 2, which shows that the accident airplanes jammed elevator was in a full-TED position), a full-TED elevator position is not necessarily indicative of an anomaly because the elevators can freely move to that position under nominal ground wind.

The amplified procedures in AOM for the taxi checklist specified that a pilot must move the control column through the full range of travel to determine if the controls are free and normal. The check airman performed this check and noticed nothing unusual, and postaccident examination found that moving the control columns forward and aft resulted in the correct corresponding movement of the elevator control tabs. (Investigators noted some difficulty moving the cockpit control columns; however, this was likely due to impact-damaged airplane structure that was in contact with the control cables.) The control tabs are the only parts of the elevator system that are connected to the control column, and the control tabs were not damaged. Thus, the NTSB concludes that the flight crews preflight inspection and control check during taxi, which were performed in accordance with the procedures specified in the AOM, could not have detected the overcenter position of the right elevator geared tabs linkage or the resultant jammed elevator condition.



...



V1 is the maximum airspeed at which a rejected takeoff can be initiated and the airplane stopped on a runway that is limited by field length. Company guidance specified that initiating a rejected takeoff even 4 to 6 kts (about 1 second) after V1 may result in a runway overrun at high speed. Although the flight crews use of the increased rotation speed to mitigate a possible windshear encounter during takeoff was appropriate, it resulted in the check airman not calling rotate until 5 seconds after the airplane achieved V1. By the time the captain recognized that the airplane would not rotate and called to abort the takeoff, 12 seconds had elapsed since V1, essentially guaranteeing that the airplane would overrun the runway.



Ameristar guidance and training specifically stated that the captain was solely responsible for the decision to continue or reject a takeoff and that the no-go decision must be madeand the appropriate procedures initiatedbefore the airplane reached V1. The guidance stated that, in many cases, rejected takeoffs at high speed have resulted in far more negative or catastrophic outcomes than would have been likely if the takeoffs had been continued. For decades, pilot training has extensively emphasized that the no-go decision must be made before V1.



However, company guidance also stated that a high-speed rejected takeoff should be made only for safety of flight items, such as a condition where there is serious doubt that the airplane can safely fly. Boeing guidance also stated that rejecting the takeoff after V1 is not recommended unless the captain judges the airplane to be incapable of flight.



In the case of this attempted takeoff, it was not until after the airplane had exceeded V1 that the captain discovered that the airplane would not rotate in response to his control inputs. When the check airman called rotate, the captain pulled back on the control column, observed that the airplane did not respond in pitch, then added more back pressure until the control column came further back than for a normal rotation, but the airplane still did not respond. The captain called for the rejected takeoff, and the flight crewmembers applied maximum braking, but the airplane went off the end of the runway. The airplane performance study showed that, assuming the same deceleration profile as that of the accident flight, the captain would have had to start braking 4 seconds sooner for the airplane to have come to a stop on the paved surface. However, at that point in the accident flights takeoff, the captains control column input had been applied for only 3 seconds. A review of FDR data showed that, during the airplanes previous successful takeoff, at 3 seconds after control column input, the airplane had only begun to respond in pitch. Thus, the NTSB concludes that the airplanes lack of rotational response to the control column input during the accident takeoff did not become apparent to the captain in time for him to have stopped the airplane on the runway.



Rarely could all of the safeguards in place to ensure an airplane is airworthy before departure (such as proper aircraft maintenance, preflight inspections, and control checks) fail to detect that an airplane was incapable of flight, as occurred with the jammed elevator on the accident airplane. Perhaps even more remarkable was that a flight crew would be placed in a situation in which the airplanes inability to fly would not be discoverable until after it had accelerated past V1 during a takeoff roll. The captain had extensive flight experience with many takeoffs, but none of them presented a scenario like the one he faced during the accident takeoff. Although the captain was relatively new to flying the Boeing MD-83, because of his prior experience in the Boeing DC-9 (a variant with an identical elevator system and controls), he correctly assessed the state of the accident airplane and quickly called for and initiated the rejected takeoff. Thus, the NTSB concludes that, once the airplanes inability to rotate became apparent, the captains decision to reject the takeoff was both quick and appropriate.



Crew coordination during takeoff is essential to managing one of the most critical phases of a flight. Effective crew coordination and performance depend on the flight crewmembers having a shared mental model of each task; such a mental model, in turn, is founded on effective standard operating procedures (SOPs) (FAA 2017b). Flight crew adherence to SOPs during a takeoff, including maintaining the defined roles of PF and PM, is of paramount importance to flight safety (FAA 2017b).



Although Ameristars procedures for a rejected takeoff clearly establish that the responsibility for the go/no-go decision is exclusively that of the captain, in this flight, the PM was also a check airman providing airplane differences instruction to the captain trainee; thus, the check airman was the PIC of the flight. This increased the potential for confusion as to who was truly responsible for the go/no-go decision during an anomalous situation. Instructors typically have more experience in the airplane than the pilot receiving instruction (as was the case with this crew) and are primed to assume control should the trainees actions pose a risk to the flight. Although the check airman instinctively reached toward the control column after the captains abort call out (and stated to the captain that they should not reject a takeoff after V1), the check airman did not take control of the airplane but rather observed that the captain had initiated the rejected takeoff procedures and then took action to assist the captain in executing those procedures.



The flight crews coordinated performance around the moment that the captain rejected the takeoff showed that both pilots had a shared mental model of their responsibilities. By adhering to SOPsrather than reacting and taking control of the airplane from the captain traineethe check airman demonstrated disciplined restraint in a challenging situation. Had the check airman simply reacted and assumed control of the airplane after the captain decided to reject, the results could have been catastrophic if such action were to further delay the deceleration (at best) or to try to continue the takeoff in an airplane that was incapable of flight. Thus, the NTSB concludes that the check airmans disciplined adherence to company SOPs after the captain called for the rejected takeoff likely prevented further damage to the airplane and reduced the possibility of serious or fatal injuries to the crew and passengers.



Related NOTAMs:

03/041 - NAV ILS RWY 23L LOC U/S. 08 MAR 20:53 2017 UNTIL 09 MAR 23:59 2017. CREATED: 08 MAR 20:53 2017



03/040 - RWY 05R ALS U/S. 08 MAR 20:15 2017 UNTIL 15 MAR 18:00 2017 ESTIMATED. CREATED: 08 MAR 20:15 2017



03/039 - AD AP CLSD. 08 MAR 20:02 2017 UNTIL 09 MAR 05:00 2017. CREATED: 08 MAR 20:02 2017



Metars:

KYIP 082053Z A2983 RMK AO2 SLPNO 53013 $

KYIP 081953Z A2980 RMK AO2 SLPNO $

KYIP 081853Z A2977 RMK AO2 SLPNO $

KYIP 081753Z A2979 RMK AO2 PK WND 24046/1656 SLPNO 58012 $

KYIP 081653Z 26035G50KT 10SM CLR 11/M11 A2981 RMK AO2 PK WND 26055/1639 SLP095 T01061106

KYIP 081553Z AUTO 26033G48KT 10SM CLR 10/M09 A2982 RMK AO2 PK WND 26051/1537 SLP098 T01001089

KYIP 081453Z 24029G45KT 10SM CLR 09/M06 A2983 RMK AO2 PK WND 23045/1449 SLP103 T00891056 58020

KYIP 081353Z 22020G29KT 10SM CLR 07/M03 A2986 RMK AO2 PK WND 21030/1306 SLP112 T00671033

KYIP 081253Z 22020G30KT 10SM CLR 05/M03 A2987 RMK AO2 PK WND 21030/1245 SLP117 T00501028



Recovery of the aircraft (Video: MLive):

https://www.youtube.com/watch?v=ymnLpHXdAn0



The elevators seen by the NTSB (Photo: NTSB):





N786TW past the runway end (Photos: Jon Sanderson):









N786TW past the runway end (Photos: Matt Shepard):









Map (Graphics: AVH/Google Earth):









