Boeing 737-291 N999UA

Summary

On 3 March 1991 at about 16:44 local time, a Boeing 737-291 registered N999UA, operated by United Airlines, was involved in an accident near Colorado Spgs, Colorado, United States. 25 people were on board and 25 died. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

3 March 1991 at 16:44

Classification

Accident

Location

Colorado Spgs, Colorado, United States

Coordinates

Not recorded

Aircraft

Boeing 737-291

Registration

N999UA

Category

Airplane

Engines

2

Operator

United Airlines

Operating rule

Part 121: Air Carrier

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Denver → Unknown

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

DCA91MA023

25 people died.

A loss of control of the airplane resulting from the movement of the rudder surface to its blowdown limit. The rudder surface most likely deflected in a direction opposite to that commanded by the pilots as a result of a jam of the main rudder power control unit servo valve secondary slide to the servo valve housing offset from its neutral position and overtravel of the primary slide.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

Executive Summary On March 3, 1991, a United Airlines (UAL) Boeing 737, registration number N999UA, operating as flight 585, was on a scheduled passenger flight from Denver, Colorado, to Colorado Springs, Colorado. Visual meteorological conditions (VMC) prevailed at the time, and the flight was on an instrument flight rules (IFR) flight plan. Numerous witnesses reported that shortly after completing its turn onto the final approach course to runway 35 at Colorado Springs Municipal Airport (COS), about 0944 Mountain Standard Time, the airplane rolled steadily to the right and pitched nose down until it reached a nearly vertical attitude before hitting the ground in an area known as Widefield Park. The airplane was destroyed, and the 2 flight crewmembers, 3 flight attendants, and 20 passengers aboard were fatally injured.

Quoted verbatim from the NTSB record.