Skip Ribbon Commands
Skip to main content
Safety Recommendation Details

Safety Recommendation A-97-016
Details
Synopsis: ON MARCH 3, 1991, AT 0944 MOUNTAIN STANDARD TIME, UNITED AIRLINES FLIGHT 585, A BOEING 737-291 AIRPLANE, CRASHED DURING AN APPROACH TO THE COLORADO SPRINGS, COLORADO, AIRPORT. THE CREW OF 5 AND THE 20 PASSENGERS WERE KILLED. THE AIRPLANE WAS DESTROYED BY THE IMPACT AND A POSTCRASH FIRE. THE WEATHER WAS CLEAR WITH UNLIMITED VISIBILITY. THERE WERE WINDSHEAR REPORTS DURING THE DAY. AT THE TIME OF THE ACCIDENT THE SURFACE WINDS WERE REPORTED TO BE OUT OF THE NORTHWEST AT 20 KNOTS GUSTING TO 28. THE SAFETY BOARD HAS NOT DETERMINED THE CAUSE(S) OF THE ACCIDENT, AND AN INVESTIGATION OF AIRFRAME, OPERATIONAL, AND WEATHER FACTORS IS CONTINUING.
Recommendation: THE NTSB RECOMMENDS THAT THE FAA: REQUIRE THE EXPEDITIOUS INSTALLATION OF A REDESIGNED MAIN RUDDER POWER CONTROL UNIT ON BOEING 737 SERIES AIRPLANES TO PRECLUDE REVERS OPERATION OF THE RUDDER & TO ENSURE THAT THE AIRPLANES COMPLY WITH THE INTENT OF THE CERTIFICATION REQUIREMENTS.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Aviation
Location: COLORADO SPGS, CO, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA91MA023
Accident Reports: Uncontrolled Descent and Collision with Terrain, United Airlines Flight 585, Boeing 737-200, N999UA, 4 Miles South of Colorado Springs Municipal Airport
Report #: AAR-92-06
Accident Date: 3/3/1991
Issue Date: 2/20/1997
Date Closed: 2/2/1999
Addressee(s) and Addressee Status: FAA (Closed - Acceptable Action)
Keyword(s):

Safety Recommendation History
From: NTSB
To: FAA
Date: 2/2/1999
Response: A-97-16 ASKED THE FAA TO REQUIRE THE EXPEDITIOUS INSTALLATION OF A REDESIGNED MAIN RUDDER PCU (SERVO VALVE) ON 737 SERIES AIRPLANES TO PRECLUDE REVERSE OPERATION OF THE RUDDER AND ENSURE THAT THE AIRPLANES COMPLY WITH THE INTENT OF THE CERTIFICATION REQUIREMENTS. ON 6/23/97, THE FAA ISSUED AD 97-14-04 TO REQUIRE, WITHIN 2 YEARS, ON ALL 737 SERIES AIRPLANES, THE INSTALLATION OF A NEWLY DESIGNED MAIN RUDDER PCU, WHICH BOEING INDICATES WILL PRECLUDE THE RUDDER REVERSAL SCENARIOS PREVIOUSLY IDENTIFIED OR HYPOTHESIZED. BECAUSE THE FAA'S ACTION COMPLIES WITH THE INTENT OF A-97-16, IT IS CLASSIFIED "CLOSED--ACCEPTABLE ACTION."

From: FAA
To: NTSB
Date: 5/13/1998
Response: ON 6/23/97, THE FAA ISSUED AN AD TO REQUIRE THE INSTALLATION OF A NEWLY DESIGNED MAIN RUDDER PCU ON ALL B-737 SERIES AIRPLANES WITHIN 2 YEARS.

From: NTSB
To: FAA
Date: 7/15/1997
Response: A-97-16 ASKED THE FAA TO REQUIRE THE EXPEDITIOUS INSTALLATION OF A REDESIGNED MAIN RUDDER PCU ON B-737 SERIES AIRPLANES TO PRECLUDE REVERSE OPERATION OF THE RUDDER & TO ENSURE THAT THE AIRPLANES COMPLY WITH THE INTENT OF THE CERTIFICATION REQUIREMENTS. PENDING THE BOARD'S REVIEW OF THE FINAL AD, A-97-16 IS CLASSIFIED "OPEN--ACCEPTABLE RESPONSE."

From: FAA
To: NTSB
Date: 4/18/1997
Response: THE FAA AGREES WITH THE INTENT OF THE RECOMMENDATION & ON 3/7/97, ISSUED A NOTICE OF PROPOSED RULEMAKING (NPRM) PROPOSING TO ADOPT AN AIRWORTHINESS DIRECTIVE (AD) TO REQUIRE THE INSTALLATION OF A NEWLY DESIGNED MAIN RUDDER POWER CONTROL UNIT ON ALL BOEING 737 SERIES AIRPLANES WITHIN 2 YEARS. THE FAA BELIEVES THAT THIS TIMEFRAME MEETS THE INTENT OF THIS RECOMMENDATION.