Remarks:
The aircraft lifted off at a point of 1173ft-1486ft down the runway and was then seen to begin a steep climb at an angle of 20-45deg. to 300ft-400ft height. The plane then turned left and descended nose-down at a flightpath angle of about 45deg. until it struck the ground 1669ft past the runway end and caught fire.
PROBABLE CAUSE: "The failure and inability of the flightcrew to prevent rapid pitchup and stall by exerting sufficient push force on the control wheel. The pitchup was induced by the combination of a mistrimmed horizontal stabilizer and a center of gravity near the aircraft's aft limit. The mistrimmed condition resulted from discrepancies in the aircraft's trim system and the flightcrew's probable preoccupation with making a timely departure. Additionally a, malfunctioning stabilizer trim actuator detracted from the flightcrew's efforts to prevent the stall. Contributing to the accident were inadequate flightcrew training, inadequate trim warning system check procedures, inadequate maintenance procedures, and ineffective FAA surveillance."

Maintenance - Substandard practices (general)

 

Source: (also check out sources used for every accident)
NTSB-AAR-78-15
Accident Investigation Report NTSB-AAR-78-15 [PDF 1,1 MB]

Remarks:
The aircraft was on a flight from Chengdu to Wenzhou and was approaching Wenzhou when, at 1000m, the flaps were extended. At that moment, the aircraft suddenly pitched down and dove into the ground out of control. The Tupolev crashed into a farm field and exploded, causing a 200x100ft hole in the ground. Several farmers were injured by the flying debris. PROBABLE CAUSE: A self-locking nut, other than castle nut with cotter pin as specified, had been installed at the bolt for connection between pull rod and bellcranck in the elevator control system. The nut screwed off, resulting in bolt loss, which led to the loss of pitch control.
 

Related information/accidents:
Maintenance - Wrong installation of parts
Airplane - Flight surfaces - Elevator

Result - Crash out of control

Remarks:
Embraer 120 N33701 was pulled into the Continental Express hangar at Houston around 21.30h for scheduled maintenance which included removal and replacement of both left and right hand horizontal stabilizer deice boots. The second shift mechanics started working on the right hand deice boot. Although planned for the third shift, the 47 screws from the top of the left leading edge assembly for the horizontal stabilizer were already removed by the second shift. The third shift mechanics finished the replacement of the right hand deice boot but did not have time to replace the left hand boot as well. The first flight was a 07.00h scheduled flight from Houston to Laredo. Flight 2574 departed Laredo for the return leg to Houston at 09.09h. The cruise portion of the flight was uneventful and at 10.03h the aircraft was descending through 11800ft to 9000ft when the air loads caused the left horizontal stabilizer leading edge to bend downward and separate. A sudden severe nose down pitchover occurred and the wings stalled negatively. A negative g of 3.5 was recorded by the FDR. Eyewitnesses reported a bright flash and saw the aircraft breaking up while descending in a flat left spin until impact.
PROBABLE CAUSE: "The failure of Continental Express maintenance and inspection personnel to adhere to proper maintenance and quality assurance procedures for the airplane's horizontal stabilizer deice boots that led to the sudden in-flight loss of the partially secured left horizontal stabilizer leading edge and the immediate severe nose-down pitchover and breakup of the airplane. Contributing to the cause of the accident was the failure of the Continental Express management to ensure compliance with the approved maintenance procedures, and the failure of FAA surveillance to detect and verify compliance with approved procedures."
NTSB board member John K. Lauber filed a dissenting statement on the investigation report, believing the probable cause should read as follows: "1) The failure of Continental Express management to establish a corporate culture which encouraged and enforced adherence to approved maintenance and quality assurance procedures, and 2) the consequent string of failures by Continental Express maintenance and inspection personnel to follow approved procedures for the replacement of the horizontal stabilizer deice boots. Contributing to the accident was the inadequate surveillance by the FAA of the Continental Express maintenance and quality assurance programs."

Follow-up / safety actions::
The NTSB made 2 recommendations during the investigation (on February 28, 1992). Recommendation A-92-6 asked the FAA to enhance flight standard surveillance of Continental Express. Recommendation A-92-7 called for actions to enhance flight standard Program Guidelines, including the National Aviation Safety Inspection Program (NASIP). Following the investigation 2 other recommendations were issued.
 

Maintenance - Substandard practices (general)

Maintenance - Substandard practices (general)
 

Remarks:
Flight 191 left the gate at Chicago-O'Hare at 14.59h and taxied to runway 32R. At 15.02h the flight was cleared for takeoff. The takeoff roll was normal until just before rotation at which time sections of the No. 1 engine pylon structure came off the aircraft. During rotation the entire No.1 engine and pylon separated from the aircraft, went over the top of the wing, and fell to the runway. Flight 191 lifted off about 6,000 ft down the runway, climbed out in a wings level attitude, and reached an altitude of about 300ft agl with its wings still level. Shortly thereafter, the aircraft began to turn and roll to the left, the nose pitched down, and the aircraft began to descend. As it descended, it continued to roll left until the wings were past the vertical position. The DC-10 crashed in an open field and trailer park about 4,680 ft northwest of the departure end of runway 32R. The aircraft was demolished during the impact, explosion, and ground fire. Two persons on the ground were killed.
PROBABLE CAUSE: "The asymmetrical stall and the ensuing roll of the aircraft because of the uncommanded retraction of the left wing outboard leading edge slats and the loss of stall warning and slat disagreement indication systems resulting from maintenance-induced damage leading to the separation of the no.1 engine and pylon assembly procedures which led to failure of the pylon structure. Contributing to the cause of the accident were the vulnerability of the design of the pylon attach points to maintenance damage; the vulnerability of the design of the leading edge slat system to the damage which produced asymmetry; deficiencies in FAA surveillance and reporting systems which failed to detect and prevent the use of improper maintenance procedures; deficiencies in the practices and communications among the operators, the manufacturer, and the FAA which failed to determine and disseminate the particulars regarding previous maintenance damage incidents; and the intolerance of prescribed operational procedures to this unique emergency."

Related information/accidents:
Maintenance
Airplane - Engines - Separation
Result - Crash out of control

Source: (also check out sources used for every accident)
NTSB Safety Recommendations A-79-98/105 + NTSB-AAR-79-17
Accident Investigation Report NTSB-AAR-79-17 [PDF 5,5

Remarks:
The HAL-manufactured Dornier 228 was operating on a flight from Agathi to Thiruvananthapuram via Kochi (Cochin). On takeoff from Kochi an engine reportedly caught fire. The plane then nose-dived into an aircraft components repair shed on the Southern Naval Command yard, killing two persons on the ground. The captain had a flying experience of 5366 hours (2271 of which as a pilot-in-command on the Dornier). PROBABLE CAUSE: "The Committee has concluded that poor aircraft maintenance practices at Short Haul Operations Department contributed to the accident. After take off, the aircraft pitched up uncontrollably, stalled, fell to its right and crashed. The uncontrollable pitch up was caused by sudden uncommanded downward movement of the Trimmable Horizontal Stabilizer leading edge. This was due to partial detachment of its actuator forward bearing support fitting due non-installation of required hi-lok fasteners. "
 

Remarks:
Boeing 737 PP-SMV departed Sao Paulo-Guarulhos for a flight to Buenos Aires. Following flap retraction the nr. 3 flap 'in transit' light remained on and the crew noticed some other problems: they were not able to reduce nr.2 engine thrust below 1.15 EPR and the A hydraulic system suffered a pressure loss. An emergency return was made and the aircraft touched down on runway 09L at 185kts, flaps at 15deg. The 737 overran the runway by 200m and came to rest following a collapse of the nosegear and right hand main gear. It appeared that the nr. 3 leading edge flap actuator attachment fitting on the wing front spar had fractured due to corrosion. The actuator came away and caused the failure of some hydraulic lines and damage to the thrust control cables. Some 1981 Boeing Service Bulletins had not been complied with. One of these included the replacement of the aluminium leading edge flap actuator attachment fitting with a steel one; this had not been done. Hull hulk now used as fire trainer.
 

Remarks:
The Airbus took off from Taipei for a flight to Nagoya where it arrived over the Outer Marker at 20.12:26h. The 1st officer started the runway 34 ILS-approach with auto throttles engaged. At an altitude of 1070ft (at 145kts and 5 degrees pitch) he inadvertently selected TOGA (Take Off Go Around) mode. Unknowingly of the TOGA selection, the crewmembers tried to override the flight director's throttle and pitch control movements. In order to remain on the glide slope, the 1st officer disengaged the auto throttle and reduced thrust manually. At 1030ft the crew hoped that the autopilots would get them on the glide slope, and engaged them. The autopilot immediately entered the go-around mode (because TOGA had been selected 12 seconds earlier) with a 18 degrees pitch up. To get back on the glide slope, the crew applied down elevator. This caused the flight director guidance system to select pitch-up stabilizer. Forty-two seconds after TOGA selection, the autopilots were disengaged again, but the aircraft kept climbing. Eight seconds afterwards, the alpha floor was activated due to an excessive angle-of-attack. Alpha floor triggered maximum thrust, which increased the nose-up attitude to 52.6 degrees. The captain disengaged alpha-floor by retarding engine thrust. The speed had dropped to 78kts by then, causing the Airbus to enter a stall at 1800ft. The aircraft hit the ground tail-first 300ft right of the runway and burst into flames. The Airbus had 8550 flying hours and 3910 cycles. The weather was fine: wind 290 degrees/6kts (varying between 230deg and 320deg) >10 km visibility; scattered clouds at 3000ft.
CAUSES: "While the aircraft was making an ILS approach to runway 34 of Nagoya Airport, under manual control by the F/O, the F/O inadvertently activated the GO lever, which changed the FD (Flight Director) to GO AROUND mode and caused a thrust increase. This made the aircraft deviate above its normal glide path.
The APs were subsequently engaged, with GO AROUND mode still engaged. Under these conditions the F/O continued pushing the control wheel in accordance with the CAP's instructions. As a result of this, the THS (Horizontal Stabilizer) moved to its full nose-up position and caused an abnormal out-of-trim situation.
The crew continued approach, unaware of the abnormal situation. The AOA increased the Alpha Floor function was activated and the pitch angle increased. It is considered that, at this time, the CAP (who had now taken the controls), judged that landing would be difficult and opted for go-around. The aircraft began to climb steeply with a high pitch angle attitude. The CAP and the F/O did not carry out an effective recovery operation, and the aircraft stalled and crashed.
The AAIC determined that the following factors, as a chain or a combination thereof, caused the accident:
 

1. The F/O inadvertently triggered the Go lever It is considered that the design of the GO lever contributed to it: normal operation of the thrust lever allows the possibility of an inadvertent triggering of the GO lever.
2. The crew engaged the APs while GO AROUND mode was still engaged, and continued approach.
3. The F/O continued pushing the control wheel in accordance with the CAP's instructions, despite its strong resistive force, in order to continue the approach.
4. The movement of the THS conflicted with that of the elevators, causing an abnormal out-of-trim situation.
5. There was no warning and recognition function to alert the crew directly and actively to the onset of the abnormal out-of-trim condition.
6. The CAP and F/O did not sufficiently understand the FD mode change and the AP override function. It is considered that unclear descriptions of the AFS (Automatic Flight System) in the FCOM (Flight Crew Operating Manual) prepared by the aircraft manufacturer contributed to this.
7. The CAP's judgment of the flight situation while continuing approach was inadequate, control take-over was delayed, and appropriate actions were not taken.
8. The Alpha-Floor function was activated; this was incompatible with the abnormal out-of-trim situation, and generated a large pitch-up moment. This narrowed the range of selection for recovery operations and reduced the time allowance for such operations.
9. The CAP's and F/O's awareness of the flight conditions, after the PlC took over the controls and during their recovery operation, was inadequate respectively.
10. Crew coordination between the CAP and the F/O was inadequate.
11. The modification prescribed in Service Bulletin SB A300-22-602 1 had not been incorporated into the aircraft.
12. The aircraft manufacturer did not categorise the SB A300-22-6021 as "Mandatory", which would have given it the highest priority. The airworthiness authority of the nation of design and manufacture did not issue promptly an airworthiness directive pertaining to implementation of the above SB.

Remarks:

PROBABLE CAUSE: "The accident was the result of the ejection in flight of the aft cargo door on the left-hand side: the sudden depressurization which followed led to the disruption of the floor structure, causing six passengers and parts of the aircraft to be ejected, rendering No.2 engine inoperative and impairing the flight controls (tail surfaces) so that it was impossible for the crew to regain control of the aircraft. The underlying factor in the sequence of events leading to the accident was the incorrect engagement of the door latching mechanism before take-off. The characteristics of the design of the mechanism made it impossible for the vent door to be apparently closed and the cargo door apparently locked when in fact the latches were not fully closed and the lock pins were not in place. It should be noted, however that a view port was provided so that there could be a visual check of the engagement of the lock pins. This defective closing of the door resulted from a combination of various factors: - incomplete application of Service Bulletin 52-37; - incorrect modifications and adjustments which led, in particular, to insufficient protrusion of the lock pins and to the switching off of the flight deck visual warning light before the door was locked; - the circumstances of the closure of the door during the stop at Orly, and, in particular, the absence of any visual inspection, through the viewport to verify that the lock pins were effectively engaged, although at the time of the accident inspection was rendered difficult by the inadequate diameter of the view port. Finally, although there was apparent redundancy of the flight control systems, the fact that the pressure relief vents between the cargo compartment and the passenger cabin were inadequate and that all the flight control cables were routed beneath the floor placed the aircraft in grave danger in the case of any sudden depressurization causing substantial damage to that part of the structure. All these risks had already become evident, nineteen months earlier, at the time of the Windsor accident, but no efficacious corrective action had followed." (Aircraft Accident Report 8/76)

Related information/accidents:
Maintenance - Failure to follow AD and SB's
Airplane - Airframe - Cargo door
Result - Crash out of control

Source: (also check out sources used for every accident)
ICAO Circular 132-AN/93 (116-125)