Takeoff (climb)

On 2 July 2014, about 01.14 UTC, 5Y-CET, a Fokker F50, an international cargo flight, operated by Skyward International, crashed shortly after takeoff from Jomo Kenyatta International Airport (JKIA), Nairobi, Kenya (JKIA). Instrument Meteorological Conditions prevailed at the time and the airplane was on an instrument flight plan. The four crewmembers were fatally injured. The airplane was destroyed and consumed by post-crash fire. The destination of the flight was Aden Adee International Airport, Mogadishu, Somalia. The airplane was repositioned from its home base at Wilson Airport in Nairobi, the day before. The accident captain (CAPT) and another first officer conducted the repositioning flight. (see Aircraft Information). At JKIA, the airplane was loaded with cargo in preparation for the accident flight. The accident crew consisted of the Capt and FO in addition to a maintenance engineer and loadmaster. According to air traffic control (ATC), the flight plan was filed for duration of 2.5 hours at an altitude of 19,000 feet along with 5 hours of fuel aboard. Based on flight recorder data, the Capt was the pilot-flying and the FO was the pilot-monitoring. The accident flight was reconstructed using data from air traffic control and flight recorder information. According to FDR data, engine start occurred at at 01.50.20. At about 01.10.59 the flight made initial contact with JKIA air traffic control tower and after routine communication, including the confirmation of the number of person and fuel endurance, the flight was cleared for takeoff at 0112.30. At 01.11.58, both engines accelerated to a high power setting with engine no. 1 stabilizing at 78% torque, 100% propeller speed and engine 2 stabilizing at 80% torque, 99% propeller speed. About six seconds later, the Capt indicates “power is set”. About 2 seconds afterwards the Capt indicated “the auto-feather is off, left” and then 5 seconds later, the FO calls out “seven eighty” (?). About 16 seconds after initial engine acceleration was applied, the first of a series of three chimes audio alerts occurred, and continued at 1 second interval throughout the CVR recording. Immediately after the initial chimes, the Capt said “you see” and “how much is that?”. The FO responded “okay niner”. The Capt then asked “it has gotten to?” The FO replied “thirty four thirty ninety two” and shortly afterward “the left one is thirty”. About 24 seconds after initial engine acceleration, engine 1 torque climbs over a period of 2 seconds to a recorded value of 119.9%, the maximum value the recorder is capable of recording. Simultaneously Engine 1 propeller speed falls from 100% to 57%. Other engine shaft speeds remain at approximately their original high power values. Airspeed at the point this change occurs was less than 30 knots. During this period, the FO called out “one twenty two now [pause] torque”. The Capt responded “it is rising eh? The FO then noted “torque one twenty six now”. About 31 seconds after initial engine acceleration, the FO called out “okay speed alive sixty”. About a second later the Capt asked “do we reduce or”? The FO responded “we can just cut”. The Capt inquired “do we abort or continue?” The FO responded, “okay one one twelve and nine four point three” and then “okay one sixteen [pause] ninety four.” The Capt acknowledged “yeah okay” About 47 seconds after initial engine acceleration, the Capt said twice “did I reduce it?”and the FO responded sequentially “yeah” and “okay”] About 52 seconds after initial engine acceleration, the Capt asked “how is it now?” and the FO replied “yeah one oh two [pause] ninety four”. About 7 seconds later the FO called out “okay, one sixteen ninety four”. About 1 minute after initial engine acceleration, the Capt inquired “Is it really going?” The FO replied “one oh one, ninety five”. The Capt acknowledged and shortly afterward he queried “is it going really, is the aircraft really moving”. The FO responded “okay, one oh one, ninety five”. About 4 seconds later, the Capt indicated “it is not giving power” About 1 minute 9 seconds after the initial engine acceleration the FO called out “okay speed has now reached about hundred”. The Capt responded “oh yeah” and immediately afterward the FO called out “okay one eleven, ninety five”. About 1 minute 18 seconds after the initial engine acceleration, the FO indicated “hundred now”. The Capt acknowledged. About 1 minute 26 seconds after the initial engine acceleration, the FO called out “V one V R rotate” About 1 minute 33 seconds after the initial engine acceleration a transition of the airplane from ground to air mode is recorded and the pressure altitude begins to climb along with the Capt immediately afterward expressing two exclamations. Following the transition to air mode there were 51 seconds of flight recorder data before the recording ended. During this time and over a period of about 3 seconds, the FO calls out “positive rate of climb” and the Capt responded “gear up”. About 3 second later, the Capt expressed “it doesn’t have power [pause] it’s on one side.” About 6 seconds afterward, the FO said “we can also turn back”. About 3 seconds later the first of seven “don’t sink” (GPWS aural warning alerts) begins over a period of 23 seconds. After the second GPWS alert the Capt queried “ok, we’re ok?” After the third GPWS alert, the FO said “we can turn back” and the Capt immediately responded “let’s just go”. The FO replied “okay”. After the fifth GPWS alert, the Capt indicated “and this one is showing one fourteen” and then queried? “we can turn back?”. About 2 seconds later, the FO called out “okay speed is one hundred” and the Capt responded “but this one has nothing” About 1 second later and about the time of the sixth GPW alert, JKIA control tower radioed “five yankee charlie echo tango contact radar one two three decimal three. Good morning.” After the seventh GPWS alert the recording ended about 13 seconds later. During this time, the controller called the aircraft again. The Capt expressed “tell him [pause] tell him we have no power”. The last CVR data indicates the FO radioed, “ah tower charlie echo” and the transmission abruptly ended along with simultaneous sounds of distress. According to FDR data, about 15 seconds after the airplane transitioned from ground to air mode the recorded altitude peaked about 5060 feet and accompanied by a maximum airspeed of 100 knots. Along with a variation of airspeed between 90 knots and 100 knots for the remainder of the recording, during the following 20 seconds the altitude decreased to about 5000 feet and then increased to 5050 feet over the next 10 seconds where it remained until the recording ended at 1.14.27. Witness Accounts (Air Traffic Controller Civilians). The aircraft crashed during the hours of darkness at geographical coordinates of 01° 17’16”S, 36° 57’5”E.

A pilot proficiency examiner (PPE) was using the airplane to conduct a pilot-in-command (PIC) proficiency check for two company pilots. Before the accident flight, one of the two company pilots on board received a PIC proficiency check, which terminated with a full-stop landing and reverse thrust application; no discrepancies with either thrust reverser were discussed by either flight crewmember. The pilot being examined then left the cockpit, and the accident pilot positioned himself in the left front seat while the PPE remained in the right front seat. The flight crew then taxied to the approach end of the runway to begin another flight. Data from the enhanced ground proximity system (EGPWS) revealed that, the flight began the takeoff roll with the flaps retracted, the thrust reversers armed, and both engines stabilized at 96 percent N2. About 2 seconds later, the cockpit voice recorder (CVR) recorded the "V1" call while on the airplane was on the runway; acoustic analysis indicated that the N2 speed of one engine, likely the right, decreased; the N2 speed of the other engine remained constant. This decrease in N2 speed was consistent with the PPE retarding right engine thrust to flight idle with the intent of simulating an engine failure. The takeoff continued, and, while the airplane was in a wings-level climb at an airspeed of 148 knots about 18 ft radar altitude, the CVR recorded the pilot command that the landing gear be retracted. The landing gear remained extended, and, about 1 second after the command to retract the landing gear, or about 3 seconds after becoming airborne, while about 33 ft above the runway and at the highest recorded airspeed of 149 knots, the CVR recorded the beginning of a rattling sound, which was consistent with the deployment of the right thrust reverser, and it continued to the end of the recording. About 1.5 seconds after the rattling sound began, the CVR recorded the PPE asking, "…what happened," which indicates that the deployment was likely not annunciated in the cockpit. The right engine N2 speed continued to gradually decrease, and the airplane rolled slightly left, back to a wings-level position. The airplane continued climbing with the landing gear extended as pitch changes continued to occur. During this time, the flight crew exchanged comments about their lack of understanding about what was occurring. While flying 10 knots above V2 speed with the left engine N2 speed remaining steady and the right engine N2 speed decreasing at a slightly greater rate than previously, the airplane began a right roll with a corresponding steady decrease in airspeed from about 144 knots. About 9 seconds after the original call to retract the landing gear, the CVR recorded the PPE requesting that the landing gear be retracted, which occurred 1 second later. The airplane then continued in the right turn with the airspeed steadily decreasing, and about 11 seconds after the PPE asked "…what happened", the EGPWS sounded a bank angle alert. At that time, the airplane was in a right roll of about 30 degrees, and the airspeed was about 132 knots. The right roll continued to a maximum value of about 39 degrees, which was the last valid bank angle value recorded. The airplane impacted the ground off the right side of the runway in a nose- and right-winglow attitude. The landing gear and flaps were retracted, and there was no evidence of preimpact failure or malfunction of the flight controls for roll, pitch, and yaw; nor was there any evidence of a mechanical failure or malfunction of either engine. A definitive reason for the deployment of the right thrust reverser could not be determined. No previous instances of inadvertent in-flight thrust reverser deployment were documented by the operator of the accident airplane or by the airframe manufacturer for the accident airplane make and model. Certification flight testing of an airplane with the same thrust reverser system determined that the airplane remained controllable with the right thrust reverser deployed and throttle retarder system functioning. The flight testing also included application of a momentary, peak burst of right engine thrust, again with no controllability issues noted. It was also noted that with the installed throttle retarder system, in the event of inadvertent thrust reverser deployment, that the engine's thrust should have been reduced to idle within 4 to 8 seconds. Acoustic analysis of the accident flight indicated that the lowest recorded N2 rpm value was about 84 percent and that the reduction in rpm occurred over a period of about 8.5 seconds, after the right thrust reverser deployed. No determination could be made as to why the throttle retarder system did not reduce the right engine thrust to flight idle as designed. Additionally, no determination could be made as to why the flight crew was not able to maintain directional control of the airplane following deployment of the right thrust reverser. Although the PPE had severe coronary artery disease, which placed him at risk for an acute coronary event that would cause symptoms like chest pain, shortness of breath, or sudden unconsciousness, the CVR recorded no evidence of impairment. Neither the heart disease nor the medications he was taking to treat it would have impaired his judgement or physical functioning. Therefore, it is unlikely any medical condition or substance contributed to the PPE's actions. Additionally, there was no evidence that any medical condition would have impaired judgement or physical functioning of the pilot being examined.

The pilot arrived at the fixed-base operator on the morning of the accident and requested that his airplane be brought outside and prepared for an immediate departure; this occurred 1 hour 15 minutes before his scheduled departure time. Radar data showed that the airplane departed 23 minutes later. According to air traffic control data, shortly thereafter, the ground and departure controllers contacted the tower controller and asked if the airplane had departed yet; the tower controller responded, "I have no idea. We have zero visibility." Weather conditions about the time of the accident included a 200-ft overcast ceiling with about 1/4-mile visibility. Only five radar targets identified as the accident airplane were captured, and all of the targets were located over airport property. The first three radar targets began about midpoint of the 6,500-ft-long runway, and each of these targets was at an altitude of about 60 ft above ground level (agl). The final two targets showed the airplane in a shallow right turn, consistent with the published departure procedure track, at altitudes of 161 and 261 ft agl, respectively. The final radar target was about 1/2 mile from the accident site. Witnesses reported observing the airplane impact trees in a wings-level, slightly right-wing-down attitude at high speed. Examination of the wreckage revealed no preimpact mechanical malfunctions or anomalies of the airplane. The pilot's personal assistant reported that the pilot had an important meeting that required his attendance on the day of the accident flight. His early arrival to the airport and his request to have the airplane prepared for an immediate departure were actions consistent with self-induced pressure to complete the flight. Due to the poor weather conditions, which were expected to continue or worsen, he likely felt pressure to expedite his departure to ensure he was able to make it to his destination and to attend the meeting. This pressure may have further affected his ability to discern the risk associated with departing in low-visibility and low-ceiling conditions. As noted, the weather conditions were so poor that the local air traffic controller stated that he could not tell whether the airplane had departed. Such weather conditions are highly conducive to the development of spatial disorientation. Further, the altitude profile depicted by the radar data and the airplane's near wings-level attitude and high speed at impact were consistent with the pilot experiencing a form of spatial disorientation known as "somatogravic illusion," in which the pilot errantly perceives the airplane's acceleration as increasing pitch attitude, and efforts to hold the nose down or arrest the perception of increasing pitch attitude can exacerbate the situation. Such an illusion can be especially difficult to overcome because it typically occurs at low altitudes after takeoff, which provides little time for recognition and subsequent corrective inputs, particularly in very low-visibility conditions.

Shortly after takeoff from Starosel'ye Airfield, while in initial climb, the aircraft impacted trees, stalled and crashed in a wooded area, bursting into flames. The aircraft was totally destroyed by a post crash fire and both occupants were killed. It was reported that the aircraft was not on the Russian Aviation Register and that the registration RF-02883 was unknown to the authority. Also, the pilot decided to takeoff from an airstrip that was closed to traffic and failed to announce his flight to ATC.

Shortly after takeoff from Bahía Solano-José Celestino Mutis Airport, while in initial climb, the crew encountered engine problems. The captain attempted an emergency landing in a prairie. The aircraft landed gear up and slid for few dozen metres before coming to rest. While all three occupants escaped with minor injuries, the aircraft was damaged beyond repair.

The aircraft crashed after it overran the end of runway 11 during a rejected takeoff at Laurence G. Hanscom Field (BED), Bedford, Massachusetts. The airplane rolled through the paved overrun area and across a grassy area, collided with approach lights and a localizer antenna, passed through the airport’s perimeter fence, and came to a stop in a ravine. The two pilots, a flight attendant, and four passengers died. The airplane was destroyed by impact forces and a postcrash fire. The corporate flight, which was destined for Atlantic City International Airport, Atlantic City, New Jersey, was conducted under the provisions of 14 Code of Federal Regulations (CFR) Part 91. An instrument flight rules flight plan was filed. Night visual meteorological conditions prevailed at the time of the accident. During the engine start process, the flight crew neglected to disengage the airplane’s gust lock system, which locks the elevator, ailerons, and rudder while the airplane is parked to protect them against wind gust loads. Further, before initiating takeoff, the pilots neglected to perform a flight control check that would have alerted them of the locked flight controls. A review of data from the airplane’s quick access recorder revealed that the pilots had neglected to perform complete flight control checks before 98% of their previous 175 takeoffs in the airplane, indicating that this oversight was habitual and not an anomaly. A mechanical interlock between the gust lock handle and the throttle levers restricts the movement of the throttle levers when the gust lock handle is in the ON position. According to Gulfstream, the interlock mechanism was intended to limit throttle lever movement to a throttle lever angle (TLA) of no greater than 6° during operation with the gust lock on. However, postaccident testing on nine in-service G-IV airplanes found that, with the gust lock handle in the ON position, the forward throttle lever movement that could be achieved on the G-IV was 3 to 4 times greater than the intended TLA of 6°. During takeoff, the pilot-in-command (PIC) manually advanced the throttle levers, but the engine pressure ratio (EPR) did not reach the expected level due to the throttles contacting the gust lock/throttle lever interlock. The PIC did not immediately reject the takeoff; instead, he engaged the autothrottle, and the throttle levers moved slightly forward, which allowed the engines to attain an EPR value that approached (but never reached) the target setting. As the takeoff roll continued, the second-in-command made the standard takeoff speed callouts as the airplane successively reached 80 knots, the takeoff safety speed, and the rotation speed. When the PIC attempted to rotate the airplane, he discovered that he could not move the control yoke and began calling out “(steer) lock is on.” At this point, the PIC clearly understood that the controls were locked but still did not immediately initiate a rejected takeoff. If the flight crew had initiated a rejected takeoff at the time of the PIC’s first “lock is on” comment or at any time up until about 11 seconds after this comment, the airplane could have been stopped on the paved surface. However, the flight crew delayed applying brakes for about 10 seconds and further delayed reducing power by 4 seconds; therefore, the rejected takeoff was not initiated until the accident was unavoidable. Among the victims was Lewis Katz, co-owner of the 'Philadelphia Inquirer'.

During the takeoff roll from Coari-Urucu Airport by night, the aircraft collided with a tapir that struck the right main gear. The crew continued the takeoff procedure and the flight to Manaus. After two hours and burning fuel, the aircraft landed at Manaus-Eduardo Gomes Airport. Upon touchdown, the right main gear collapsed and the aircraft veered to the right and came to rest. All 49 occupants evacuated safely while the aircraft was damaged beyond repair.

The commercial pilot reported that the purpose of the flight was to perform a check/orientation flight with the airline transport pilot (ATP), who was new to the area; the ATP was the pilot flying. The airplane was started, and an engine run-up completed. The commercial pilot reported that, during the takeoff roll, all of the gauges were in the “green.” After reaching an airspeed of 80 knots, the airplane lifted off the ground. About 350 ft above ground level (agl), the pilots felt the airplane “jolt.” The commercial pilot stated that it felt like a loss of power had occurred and that the airplane was not responding. He immediately shut off the boost pumps, and the ATP initiated a slow left turn in an attempt to return to the airport to land. The airplane descended rapidly in a nose-low, right-wing-low attitude and impacted the ground. A witness reported that he watched the airplane take off and that it sounded normal until it reached the departure end of the runway, at which point he heard a distinct “pop pop,” followed by silence. The airplane then entered an approximate 45-degree left turn with no engine sound and descended at a high rate with the wings rolling level before the airplane went out of sight. Another witness made a similar statement. Based on the witnesses’ statements and photographs of the twisted airplane at the accident site, it is likely that a total loss of engine power occurred and that, during the subsequent turn back to the airport, the ATP did not maintain sufficient airspeed and exceeded the airplane’s critical angle-of-attack, which resulted in an aerodynamic stall and impact with terrain. Although a postaccident examination of the airframe and engines did reveal an inconsistency between the cockpit control positions and the positions of the fuel shutoff valves on the sump tank, this would not have precluded normal operation. No other anomalies were found that would have precluded normal operation.

Shortly after takeoff from El Wak Airfield, bound for Garissa, the twin engine aircraft stalled and crashed. The copilot was killed while 11 other occupants were injured. The aircraft was destroyed.

The aircraft was returning to its base in Gryazi after taking part to a demonstration in Terbuny. After takeoff, while in initial climb, the engine lost power. The aircraft encountered difficulties to gain height, impacted power cables and crashed in an open field. All nine occupants evacuated safely and the aircraft was damaged beyond repair.