NHTSA Engineering Analysis EA89029

SUMMARY:SCHOOL DISTRICT REPORTS EXTENDED SEAT BACKS ARE BREAKING AWAYFROM THE SEATS SOLID FRAME.SEAT BACK SEPARATION COULD HAVE A DETRIMENTALEFFECT ON THE VEHICLES COMPARTMENTALIZATION PRINCIPLE IN THE EVENT OF ASERIOUS ACCIDENT.COMPARTMENTALIZATION, AS OUTLINED IN THE STANDARD, REQUIRES STRENGTH INTHE ENTIRE SEATING SYSTEM WHICH INCLUDES THE FLOOR, THE SEAT FRAME AND THEFASTENING OF THE FRAMES TO THE FLOOR WHILE AT THE SAME TIME PROVIDING SEATSYSTEM PADDING AND FLEXIBILITY TO ABSORB ENERGY IN A CRASH.CROWN CLAIMS THE FAILURES RESULT FROM ABUSE AND ARE ISOLATED.A RECENTTELEPHONE CONVERSATION WITH THE FLEET INVOLVED INDICATED THAT 43 ADDITIONALSEATS WERE RECENTLY REMOVED (BY CROWN) FOR WELDING REPAIRS.===