Northwest Airlines

Boeing 747-200

During the initial approach, the red GEAR annunciator light above the gear lever illuminated, and the landing gear warning horn sounded after the gear handle was selected down and the flaps were selected to 25 degrees. During the go-around, the captain asked the second officer (SO), "what do you have for the gear lights?" The SO responded, "four here." When all gear are down and locked on the Boeing 747-200, the landing gear indication module located on the SO’s instrument panel has five green lights: one nose gear light above four main landing gear lights. The crew then read through the "Red Gear Light Remains On (After Gear Extension)" emergency/abnormal procedure from the cockpit operations manual to troubleshoot the problem. Although the checklist twice presented in boldface type that five lights must be present for the gear to be considered down and locked, the crew did not verbalize the phrase either time. The captain did not directly request a count, and the SO did not verbally confirm, the number of gear down annunciator lights that were illuminated; instead, the flight crew made only general comments regarding the gear, such as "all gear," "all green," or "got 'em all." Because the crew believed that all of the gear annunciator lights were illuminated, they considered all gear down and locked and decided not to recycle the landing gear or attempt to extend any of the gear via the alternate systems before attempting a second approach. During all communications with air traffic control, the flight crew did not specify the nature of the problem that they were troubleshooting. Although the checklist did not authorize a low flyby, if the flight crewmembers had verbalized that they had a gear warning, the controller most likely would have been able to notify the crew of the nose gear position before the point at which a go-around was no longer safe. Multiple gear cycles were conducted after the accident, and the nose gear extended each time with all nose gear door and downlock indications correctly displayed on the landing gear indication module. Post accident examination of the nose gear door actuator found that one of the two lock keys was installed 180 degrees backward. Although this improper configuration could prevent proper extension of the nose gear, the actuator had been installed on the accident airplane since 2001 after the actuator was overhauled by the operator. No anomalies were found with the landing gear indication module, the nose gear-operated door sequence valve, and the nose/body landing gear selector valve.

Douglas DC-9

The DC-9 was taxiing to the gate area when it collided with a company A319 that was being pushed back from the gate. Prior to arriving at the destination airport, the DC-9 experienced a loss of hydraulic fluid from a fractured rudder shutoff valve located in the DC-9's right side hydraulic system. The left side hydraulic system had normal hydraulic pressure and quantity throughout the flight. The flightcrew elected to continue to the scheduled destination and declared an emergency while on approach to the destination airport. After landing, the emergency was negated by the flight crew and the airplane taxied to the gate. Flight data recorder information indicates the left engine, which provides power for the left hydraulic system, was shut down during taxi. The captain stated he did not remember shutting the left engine down, and that if he had, it would have been after clearing all runways. The first officer stated that he was unaware that the left engine was shut down. Upon arrival at the gate with the left engine shut down and no hydraulic pressure from the left system and a failure of the right hydraulic system, the airplane experienced a loss of steering and a loss of brakes. The flightcrew requested company maintenance to chock the airplane since they were unable to use brakes to stop the airplane. The crew said they were going to keep the "...engines running in case we have to use reversers..." The airplane began to roll forward and the captain applied reverse thrust but the reversers did not deploy. The airplane impacted the A319 with a speed of approximately 15.65 miles per hour to 16.34 miles per hour. Evacuation of the DC-9 was completed approximately 5:22 minutes after the collision and evacuation of the A319 occurred approximately 13:08 minutes after the collision. Examination of the left hydraulic system revealed no anomalies and examination of the right hydraulic system revealed a fractured rudder shutoff valve that displayed features consistent with fatigue. Following the accident, the airplane manufacturer issued a service letter pertaining to the replacement of the rudder shutoff valve based upon reliability information that was reported to them. The number of reports was greater than that of the Federal Aviation Administration's Service Difficulty Reports database, and less than the operators records.

Airbus A319

Two maintenance technicians where on board Northwest Airlines' Airbus A319 N313NB which was taxied from a maintenance area to Gate 10. When they arrived in the vicinity of gate 10, the mechanic who was steering the plane, activated the parking brake and waited for ground personnel and a jetway operator to arrive. After the ground personnel arrived he released the parking brake. The airplane did not move and he advanced the throttles out of their idle detents "a couple of inches, about halfway." The airplane began to move at a "fairly decent speed," and he realized the throttles were still out of the idle detent position. He pulled the throttle back and applied brakes; however, the airplane did not slow and continued until it struck the concrete support column of the jetway, and the left wing contacted the right side of a Boeing 757-251 (N550NW, parked at gate 9). The nose gear sheared off the Airbus, and the right side of the Boeing sustained a 6-foot long, 2-foot wide gash, just aft of the R1 door. The mechanic estimated that the airplane was about halfway down the parking line when he pulled back the throttles. Initial review of the flight data recorder for the time period surrounding the accident revealed that about 10 seconds after the parking brake was released, the thrust lever angles for both engines were increased to about 17 degrees for about 8 seconds, before they were returned to the idle position. During that time, the engines N1 and N2 speeds increased to about 71, and 85 percent, respectively.

Douglas DC-9

On December 3, 1990, at 1345 est, Northwest flight 1482, a DC-9 (N3313L), and Northwest flight 299, a Boeing 727 (N278US), collided near the intersection of runway 09/27 and 03C/21C in dense fog at Detriot-Metropolitan-Wayne County Airport, MI. At the time of the collision, the B-727 was on its takeoff roll, and the DC-9 had just taxied onto the active runway. The B-727 was substantially damaged, and the DC-9 was destroyed. Seven of the 40 passengers and 1 crew member aboard the DC-9 received fatal injuries. None of the 146 passengers and 8 crewmembers aboard the B-727 were injured.

McDonnell Douglas MD-82

A McDonnell Douglas DC-9-82 operating Northwest Airlines flight 255 was destroyed when it crashed onto a road during takeoff from Detroit-Metropolitan Wayne County Airport, Michigan, USA. Just one of the 155 occupants survived the accident. Additionally, Two persons on the ground were killed. Flight NW255 was a regularly scheduled passenger flight between Saginaw, Michigan and Santa Ana, California, with en route stops at Detroit and Phoenix, Arizona. About 18:53, flight 255 departed Saginaw and about 19:42 arrived at its gate at Detroit. About 20:32, flight 255 departed the gate with 149 passengers and 6 crewmembers on board. During the pushback, the flightcrew accomplished the BEFORE (engine) START portion of the airplane checklist, and, at 20:33, they began starting the engines. The flight was then cleared to "taxi via the ramp, hold short of (taxiway) delta and expect runway three center [3C] (for takeoff)..." The ground controller amended the clearance, stating that the flight had to exit the ramp at taxiway Charlie. The crew was requested to change radio frequencies. The first officer repeated the taxi clearance, but he did not repeat the new radio frequency nor did he tune the radio to the new frequency. At 20:37, the captain asked the first officer if they could use runway 3C for takeoff as they had initially expected 21L or 21R. After consulting the Runway Takeoff Weight Chart Manual, the first officer told the captain runway 3C could be used for takeoff. During the taxi out, the captain missed the turnoff at taxiway C. When the first officer contacted ground control, the ground controller redirected them to taxi to runway 3C and again requested that they change radio frequencies. The first officer repeated the new frequency, changed over, and contacted the east ground controller. The east ground controller gave the flight a new taxi route to runway 3C, told them that windshear alerts were in effect, and that the altimeter setting was 29.85 inHg. The flightcrew acknowledged receipt of the information. At 20:42, the local controller cleared flight 255 to taxi into position on runway 3C and to hold. He told the flight there would be a 3-minute delay in order to get the required "in-trail separation behind traffic just departing." At 20:44:04, flight 255 was cleared for takeoff. Engine power began increasing at 20:44:21. The flightcrew could not engage the autothrottle system at first, but, at 20:44:38, they did engage the system, and the first officer called 100 knots at 20:44:45. At 20:44:57, the first officer called "Rotate." Eight seconds later, the stall warning stick shaker activated, accompanied by voice warnings of the supplemental stall recognition system (SSRS). The takeoff warning system indicating that the airplane was not configured properly for takeoff, did not sound at any time prior or during takeoff. After flight 255 became airborne it began rolling to the left and right before the left wing hit a light pole in a rental car lot. After impacting the light pole, flight 255 continued to roll to the left, continued across the car lot, struck a light pole in a second rental car lot, and struck the side wall of the roof of the auto rental facility in the second rental car lot. The airplane continued rolling to the left when it impacted the ground on a road outside the airport boundary. The airplane continued to slide along the road, struck a railroad embankment, and disintegrated as it slid along the ground. Fires erupted in airplane components scattered along the wreckage path. Three occupied vehicles on the road and numerous vacant vehicles in the auto rental parking lot along the airplane's path were destroyed by impact forces and or fire. One passenger, a 4-year-old child was injured seriously.

Boeing 727-200

Flight NW6231 departed New York-JFK at 19:14 for a ferry flight to Buffalo and was cleared by departure control to climb to FL140. At 19:21 the flight was cleared to climb to FL310. The aircraft began to climb 2,500 fpm at an airspeed of 305 knots. As the aircraft climbed through FL160, both the airspeed and the rate of climb began to increase. Reaching FL230, the airspeed had reached 405 knots and the rate of climb had exceeded 6,500 fpm. The overspeed warning horn sounded a little later, followed 10 seconds later by a stick shaker stall warning. The aircraft then leveled at 24800 feet with a speed of 420 knots until it turned rapidly to the right, 13 seconds later. The airplane started to descend out of control, reaching a vertical acceleration of +5g until it struck the ground in a slightly nose down and right wing-down attitude. The aircraft had descended from 24000 feet to 1090 feet in 83 seconds.

Douglas DC-7

A Northwest Airlines, Inc., Douglas DC-7C, N290 MATS charter Flight 293, crashed in the north Pacific Ocean approximately 116 nautical miles west-southwest of Annette Island, Alaska, at approximately 1816 G.m.t., June 3, 1963. The flight departed McChord AFB, Washington, for Elmendorf AFB, Alaska, carrying 95 passengers and a crew of 6. The passenger list included military personnel, dependents, Department of Defense employees and a Red Cross employee. All occupants of the aircraft were lost at sea and the aircraft was destroyed. The aircraft had been airborne approximately 2 hours and 35 minutes when radio contact was lost. No difficulties were reported by the crew prior to this time. The wreckage was sighted by a Royal Canadian Air Force aircraft at 0322 C.m.t., June 4, 1963, at 54 degrees 21' N - 134 degrees 39' W but no survivors were observed. Approximately 1,500 pounds of floating aircraft wreckage was recovered.

Boeing 720

The aircraft arrived in Miami at 1240, following a routine flight from Chicago, Illinois The captain of the inbound flight reported that the only mechanical discrepancy was, "the outflow valves being a little sticky merely made it a little difficult to maintain the pressurization in a smooth manner. "These valves were cleaned, and a leaking rivet at the No. 4 reserve fuel tank was plugged when it was noticed by the mechanic. This was the only maintenance performed during the "turnaround". Flight 705 is regularly scheduled from Miami. to Portland, Oregon, with intermediate stops at Chicago, Illinois and Spokane and Seattle, Washington. The computed takeoff gross weight of 175,784 pounds, and center of gravity (e.g.) of 25 percent mean aerodynamic chord (MAC) were both well within the allowable limits. Prior to departing the ramp at 1325, the crew asked the ground controller about the departure routes being utilized, and he replied that most flights were departing ". . either through a southwest climb or a southeast climb and then back over the top of it. . . "The flight departed Miami with an Instrument Flight Rules (IFR) clearance at 1335 In accordance with the pilot's request for a". . . southeast vector "a left turn was rude after takeoff from runway 27L and circuitous routing was utilized in conjunction with radar vectors from Miami Departure Control, to avoid *** of anticipated turbulence associated with thunderstorm activity (See Attachment A). A similar departure pattern had been previously flown by another flight Subsequently, while maintaining 5,000 feet and a heading of 300 degrees, Flight 705 requested clearance to climb to a higher altitude. Following a discussion between the flight and the Federal Aviation Agency (FAA) radar departure controller about the storm activity, and while clearance to climb was being coordinated with the Miami Air Route Traffic Control Center (ARTCC), the flight advised "Ah-h we're in the clear now. We can see it out ahead . . . looks pretty bad." At 1343, Flight 705 was cleared to climb to flight level 2/ 250 (FL250). They responded, "OK ahhh, we'll make a left turn about thirty degrees here and climb. . "The controller asked of 270 degree was their selected climbout heading, and they replied that this would take them". . . out in the open again". . Accordingly, clearance was granted. Following some discussion about the severity of the turbulence, which was described as moderate to heavy, the flight advised, "OK, you better run the rest of them off the other way then." At 1345 radar service was terminated and control of Flight 705 was transferred to Miami ARTCC. When the flight did not establish radio communication with ARTCC on the initial frequency, Departure Control provided a secondary frequency, and instructed the flight to turn to a heading of 360 degrees which was acknowledged. When Miami ARTCC requested position and altitude, the flight replied, "We're just out of seventeen five (17,500 feet) and standby on the DME one." This transmission ended at 1348, and was the last known communication with Flight 705 The voice transmissions emanating from the flight were made by the first officer. Witnesses in the area reported that a loud explosion had occurred in the air, and several felt a subsequent ground tremor. They also reported that heavy rain had been failing in the area. One witness, in company with five other persons, was seven miles south of the main wreckage site She heard the sound of an explosion which had no echo. When she looked in that direction she saw an orange ball of flame in the edge of a cloud. As she directed the attention of her companions toward this flame, it dropped straight down, becoming a streak, and disappeared behind trees. Shortly after the disappearance a second sound was heard. Statements were received from the crews of four other flights operating in the Miami area at the approximate time of the accident. The first, in a large jet which approached Miami from the west at 7,000 feet, reported the weather as ". . . in and out of broken clouds and light rain showers with light turbulence. Darker heavy shower activity was observed to the (south) of course. We observed no small cells on our radar scope. . only a broad rain area. . . "Another crew, in a four-engine aircraft, departed Miami at 1318, via a departure pattern similar to that which Flight 705 later followed. They described the worst turbulence as". medium to moderate . . . "from west of the airport to north of the Miami VORTAC .3/ They were maintaining 5,000 feet at the time. A third crew in a 720B was folding southeast of Miami at 13,000 feet. They observed numerous rain cells on radar in the Miami area and encountered light ice at this altitude. The fourth crew, also flying a large jet, taxied out shortly after Flight 705 but delayed takeoff for nearly an hour because of the weather. The weather in the Miami area at the time of the accident was characterized by a pre-frontal squall line approximately 250 miles in length, oriented on a northeast-southwest line immediately northwest of Miami (See Attachment A). The U. S. Weather Bureau (USWB) radar observation at Miami at 1344 indicated a broken area of thunderstorms associated with this line, with cells two to twenty miles in diameter, and tops of detectable moisture at 30,000 feet. The line was moving southeast at eight knots, and moderate rain showers were occurring at the station. The 0600 and 1800 Miami radiosonde ascents showed the freezing level to have been at 11,100 and 12,400 feet m.s.1., respectively. SIGMET 4/ No. 3 prepared by the USWB at Miami, valid from 0900-1300, forecast moderate to severe turbulence 5/ in thunderstorms, with a chance of extreme turbulence in heavier thunderstorms. This advisory was called to the attention of the crew of Flight 705 by the operations agent at Miami, and was attached to their dispatch papers. SIGMET No. 4, valid from 1300-1700, was not received until approximately 1315, after the crew of Flight 705 had left the operations office. It forecast moderate to severe turbulence, but deleted the reference to extreme turbulence indicated in SIGMET No 3. Since the dispatcher for this flight is stationed in Minneapolis, the physical Limitations involved made it difficult to apprise the crew of this latest advisory prior to their taxi time of 1325. The aircraft was completely destroyed by impact forces and all 43 occupants have been killed.

Douglas DC-7

A Northwest Airlines DC-7CF, N285, was ditched near Biorka Island, Sitka Sound, Alaska, on October 22, 1962, about 2052 G.m.t. All 95 passengers and 7 crew members successfully evacuated and were quickly rescued. No serious injuries were reported. The flight was operating as Military Air Transport Charter Flight No. 293 en route from McChord Air Force Base, Tacoma, Washington, to Elmendorf AFB, Anchorage, Alaska. While cruising at an altitude of 20,000 feet No. 2 engine lost power. Remedial measures failed, the propeller oversped and the engine seized. Attempts at feathering failed and the flight radioed a declaration of emergency and started descent toward Sitka Sound, Alaska. Other futile attempts were made to feather as the No. 2 engine became dangerously hot and shed parts. The captain elected to ditch. Passengers were moved aft and away from the plane of rotation of No. 2 propeller, crew members issued ditching instructions, and occupants and flotation gear were readied. The aircraft was put down skillfully under favorable conditions of weather and sea during daylight, and all occupants were quickly in liferafts. Previously alerted marine craft were nearby and took all hands aboard. Amphibious rescue aircraft were also close by. The aircraft sank in water 250 feet deep in about 24 minutes.

Lockheed L-188 Electra

At approximately 0855 1, the flight was cleared for takeoff on runway 14R. At this time the aircraft was taxing on a westerly heading in the runup area adjacent to runway 14R. Flight 706 acknowledged the clearance, while continuing toward the runway, and made a running takeoff No witnesses were found who observed the actual lift-off. N137US was observed after lift-off, 3,000 to 4,000 feet down the runway at an estimated altitude of 50 to 75 feet and in a normal climb attitude. At the 8,000-foot marker the altitude of the aircraft was estimated to have been approximately 100 feet, which is a slightly lower altitude than Electra aircraft normally attain at this point during takeoff. Five witnesses noted a change in engine sound during this portion of the flight. Between the 8,000 and the 9,000 foot runway marker the aircraft was observed to commence an apparently coordinated right turn with a slowly increasing rate of bank. When the bank angle was 30 to 45 degrees, the crew made a short, garbled transmission. Immediately thereafter, at a bank angle of 50 to 60 degrees, the aircraft began to lose altitude. The minimum altitude attained in the entire turn was 200 to 300 feet. The right wing near the No. 4 engine struck powerlines adjacent to the Chicago Northwestern Railroad tracks, severing the lines at an angle of about 70 degrees from the horizontal, and causing a bright bluish flash. The aircraft then continued in a direction of about 271 degrees magnetic and, when in a bank of about 85 degrees and a nose-down attitude of about 10 degrees, the right wing of the aircraft struck the railroad embankment. Continuing to roll about its longitudinal axis, the aircraft cartwheeled, the nose crashing into the ground 380 feet beyond the point of first Impact, and landed right side up It then slid tall first another 820 feet. The aircraft disintegrated throughout its path, and wreckage was strewn over an area 200 feet wide and 1,200 feet long. Evidence of ground fire was found at various points along this path. Impact occurred on airport property about 3,800 feet abeam and to the right of the end of runway 14R, about 500 feet north of Irving Park Road. After passing beyond the railroad embankment the aircraft was lost to view by most of the eye witnesses because of trees and other obstructions; immediately thereafter a large mushroom of orange-red flame accompanied by heavy black smoke was seen. Time of impact was established as 0857. The aircraft was demolished by impact and fire. All occupants were fatally injured.