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Safety Recommendation Details

Safety Recommendation H-16-021
Synopsis: On Thursday, September 24, 2015, about 11:11 a.m. Pacific daylight time, the 2005 DUCK 6 amphibious passenger vehicle (APV) was traveling north on the Washington State Route 99 Aurora Bridge in Seattle, Washington. At the same time, a 2009 Motor Coach Industries motorcoach was traveling south in the center lane. The DUCK 6 driver heard a loud noise at the left front of the APV; the vehicle drifted to the right and then veered left suddenly; the driver lost control of the vehicle. The APV crossed the center line into the southbound lanes of oncoming traffic and struck the motorcoach. Three other vehicles were damaged during the crash event: a southbound 2011 Ram Trucks pickup truck and two northbound vehicles—a 2006 Toyota Highlander sport utility vehicle and a 2007 Toyota Tundra pickup truck. As a result of this crash, five motorcoach passengers died. Seventy-one motorcoach and APV occupants reported injuries ranging from minor to serious.
Recommendation: TO RIDE THE DUCKS INTERNATIONAL: Communicate the repair or replacement information concerning the front axle housings of your stretch amphibious passenger vehicles, developed in response to Safety Recommendation H-16-20, to your franchisees and licensees.
Original recommendation transmittal letter: PDF
Overall Status: Open - Acceptable Response
Mode: Highway
Location: Seattle, WA, United States
Is Reiterated: No
Is Hazmat: No
Accident #: HWY15MH011
Accident Reports: Preliminary Report - Highway - HWY15MH011Amphibious Passenger Vehicle DUCK 6 Lane Crossover Collision With Motorcoach on State Route 99, Aurora Bridge
Report #: HAR-16-02
Accident Date: 9/24/2015
Issue Date: 1/3/2017
Date Closed:
Addressee(s) and Addressee Status: Ride the Ducks International, LLC (Open - Acceptable Response)

Safety Recommendation History
From: NTSB
To: Ride the Ducks International, LLC
Date: 4/10/2018
Response: We note that you disagree with our conclusion of “improper manufacturing” in our Seattle report’s probable cause; however, we would like to clarify that our conclusion was specific to the improper manufacturing of the left front axle housing of the stretch APV, not the entire vehicle. We further note that, despite your concern, through analysis with the National Traffic Highway Safety Administration and your independent engineering consultant, you developed the recommended axle repair by including a permanently welded coupler and determined a testing procedure to verify its efficacy. Pending the completion of your efforts to repair the axles of all your stretch APVs and to notify your franchisees and licensees to make the same repairs, Safety Recommendations H-16-20 and -21 are classified OPEN--ACCEPTABLE RESPONSE.

From: Ride the Ducks International, LLC
Date: 1/8/2018
Response: -From Chris Herschend, President, Ride the Ducks International, LLC: Ride the Ducks International, LLC (RTDI) is in receipt of your correspondence dated December 11, 2017, requesting information on the status of the Board’s Safety Recommendation H-16-22. RTDI provides the following response. RTDI respectfully disagrees with the Board’s recommendation in H-16-22 that all franchisees and licensees should halt operations until the axle housings on the APVs were repaired or replaced. Consistent with our understanding of the facts, implementing this recommendation was and still is unnecessary. Following the September 24, 2015 incident, RTDI conducted independent inspections of the axles on all operating “Stretch” APVs to ensure that the collar weld procedures outlined in service bulletin SB-00-14-13 were implemented and were sufficient. Due to the seasonal nature of the RTDI operations, at the time the Board published its report in November 2016, RTDI had sufficient time to conduct this analysis. RTDI is not aware of any issues or concerns that suggest that the procedures set out in SB-00-14-13 were not effective at strengthening the axles housing if the repair was implemented. Additionally, RTDI and its independent engineering consultant worked closely with the National Highway Traffic Safety Administration (NHTSA) to further confirm the quality and strength of the 2013 repair. In addition to independently confirming its sufficiency as-designed, the analysis suggested a magna particle testing procedure and the inclusion of a permanently welded coupler. NHTSA was engaged during RTDI’s implementation of these changes in 2017. At this time, many of the APVs, including those in the Seattle fleet, have already received the updated axle remedy and those that have not yet been remedied will receive the axle replacement before the start of the 2018 operating season. Finally, RTDI would like to take this opportunity to reiterate that it does not agree with the Board’s conclusion that the probable cause of the September 24, 2015 incident was a mechanical failure due to “improper manufacturing" of the APVs. As you are aware, RTDI’s independent consultant previously identified a significant error in the data that NTSB investigators relied on when predicting the stresses applied to the axles. The stresses predicted by the Board’s finite element analysis were significantly above the approximate fatigue endurance limit for the axles. If the NTSB’s assumptions were the case, the APVs would likely have experienced multiple axle failures since their original manufacture in the 1950s – they would never have survived the Korean War, much less millions of over-the-road miles since. This is not consistent with the APVs field experience and demonstrates a significant and fundamental math error in the Board’s underlying analysis. RTDI verbally advised Pete Kotowski, Investigator-In-Charge, and Dr. Robert Molloy, Director, Office of Highway Safety, of this inaccuracy in January 2017 - before the final version of the NTSB’s report was published. At that time, RTDI requested the Board consider this information in preparing its final report. In RTDI’s view, the Board’s Highway Accident Report does not accurately reflect this critical information and RTDI requests that the Board amend its report to provide a full and complete record.

From: NTSB
To: Ride the Ducks International, LLC
Date: 1/3/2017
Response: On November 15, 2016, the NTSB adopted its report concerning the September 24, 2015, crash in which an amphibious passenger vehicle collided with a motorcoach in Seattle, Washington.1 Additional information about this crash and the resulting recommendations may be found in the report of the investigation, which can be accessed at our website,, under report number NTSB/HAR-16/02. As a result of this investigation, we issued 10 new recommendations, including 3 to the National Highway Traffic Safety Administration, 2 to the United States Coast Guard, 1 to Ride the Ducks of Seattle, 1 to the Passenger Vessel Association, and the following 3 recommendations to Ride the Ducks International.