Kahului

The medical transport flight was en route to pick up a patient on a neighboring island on an instrument flight rules (IFR) flight plan in dark night conditions over the ocean. About 13 minutes after departure, at 13,000 ft mean sea level (msl), the airplane’s vertical gyro failed, which subsequently failed the pilot’s Electric Attitude Director Indicator (EADI), which also caused the autopilot to disconnect. The failure of the EADI and autopilot disconnect required the pilot to manually fly the airplane using the copilot’s attitude gyro for his horizon information (bank angle and pitch attitude) for the duration of the flight. The pilot did not declare an emergency, nor did he inform air traffic control (ATC) that his electric attitude indicator had failed and that his autopilot had disengaged. After the instrumentation failure and autopilot disconnect, the airplane entered a series of right banks before being brought back to level, followed by a left turn, and then subsequent right banks. ATC asked the pilot to change course and the pilot agreed. The copilot attitude indicator indicated that the airplane entered a descending, steep right bank turn. Over the next 5 minutes, ATC issued varying instructions to the pilot. During this time, the airplane entered several right- and left-hand banks and rolls and descended 1,000 ft per minute (fpm), which increased to -3,500 fpm as the airplane’s airspeed increased. About 7 minutes after the instrumentation failure, the airplane was in a 65° bank angle when ATC asked the pilot to verify his heading. As the pilot responded, the airplane bank angle increased to 90° and the airspeed exceeded 260 knots. The bank angle and airspeed continued to increase; a loud metallic bang was recorded that was consistent with an in-flight separation of the empennage from the fuselage before impacting with the water. After an extensive underwater search, the main wreckage was located on the seabed at a depth of about 6,420 ft. The wreckage was recovered and transported to a facility for examination.

Transair flight 810, a Title 14 Code of Federal Regulations Part 121 cargo flight, experienced a partial loss of power involving the right engine shortly after takeoff and a water ditching in the
Pacific Ocean about 11.5 minutes later. This analysis summarizes the accident and evaluates (1) the right engine partial loss of power, (2) the captain's communications with air traffic control (ATC) and the first officer's left and right engine thrust reductions, (3) the first officer's misidentification of the affected engine and the captain's failure to verify the information, (4) checklist performance, and (5) survival factors. Maintenance was not a factor in this accident. The flight data recorder (FDR) showed that, when the initial thrust was set for takeoff, the engine pressure ratios (EPR) for the left and right engines were 2.00 and 1.97, respectively. Shortly after rotation, the cockpit voice recorder (CVR) recorded a “thud” and the sound of a low-frequency vibration. The captain (the pilot monitoring at the time) and the first officer (the pilot flying) reported that they heard a “whoosh” and a “pop,” respectively, at that time. As the airplane climbed through an altitude of about 390 ft while at an airspeed of 155 knots, the right EPR decreased to 1.43 during a 2-second period. The airplane then yawed to the right; the first officer countered the yaw with appropriate left rudder pedal inputs. The CVR showed that the captain and the first officer correctly determined that the No. 2 (right) engine had lost thrust within 5 seconds of hearing the thud sound. After moving the flaps to the UP position, the captain reduced thrust to maximum continuous thrust, causing the left EPR to decrease from 1.96 to 1.91 while the airplane was in a climb. (The right EPR remained at 1.43). The captain reported that he did not move the thrust levers again until after he became the pilot flying. The first officer stated that, after the airplane leveled off at an altitude of about 2,000 ft, he reduced thrust on both engines. FDR data showed that thrust was incrementally reduced to near flight idle (1.05 EPR on the left engine and then 1.09 EPR on the right engine) and that airspeed decreased from about 250 to 210 knots. (A decrease in airspeed to 210 knots was consistent with the operator’s simulator guide procedures for a single-engine failure after the takeoff decision speed [V1]. The simulator guide, which supplemented information in the company’s flight crew training manual, contained the most recent operator guidance for single-engine failure training at the time of the accident.) The captain was unaware of the first officer’s thrust changes because he was busy contacting the controller about the emergency. The captain told the controller, “we’ve lost an engine,” but he had declared the emergency to the controller twice before this point, as discussed later in this analysis. The captain instructed the first officer to maintain a target speed of 220 knots (which the captain thought would be “easy on the running engine”), a target altitude of 2,000 ft, and a target heading of 240°. (About 52 seconds earlier, the controller had issued the 240° heading instruction to another airplane on the same radio frequency.) About 3 minutes 14 seconds after the right engine loss of thrust occurred, the captain assumed control of the airplane; at that time, the airplane’s airspeed was 224 knots and heading was 242°, but the airplane’s altitude had decreased from about 2,100 ft (the maximum altitude that the airplane reached during the flight) to 1,690 ft. The captain increased the airplane’s pitch to 9°; the airplane’s altitude then increased to 1,878 ft, but the airspeed decreased to 196 knots. The captain subsequently stated, “let’s see what is the problem...which one...what's going on with the gauges,” and “who has the E-G-T [exhaust gas temperature]?” The first officer stated that the left engine was “gone” and “so we have number two” (the right engine), thus misidentifying the affected engine. The captain accepted the first officer’s assessment and did not take action to verify the information. Afterward, the EPR level on the right engine began to increase in response to the captain advancing the right thrust lever so that the airplane could maintain airspeed and altitude. Right EPR increased and decreased several times during the rest of the flight (coinciding with crew comments regarding the EGT on the right engine and low airspeed) while the left EPR remained near flight idle. The first officer asked the captain if they “should head back toward the airport” before the airplane traveled “too far away,” and the captain responded that the airplane would stay within 15 miles of the airport. During a postaccident interview, the captain stated that, because there was no fire and an engine “was running,” he intended to have the airplane climb to 2,000 ft and stay within 15 miles of the airport to avoid traffic and have time to address the engine issue. The captain also stated that he had been criticized by the company chief pilot for returning to the airport without completing the required abnormal checklist for a previous in-flight emergency. Although the captain’s decision resulted in the accident airplane flying farther away from the airport and farther over the ocean at night, the captain’s decision was reasonable for a single-engine failure event. The captain directed the first officer to begin the Engine Failure or Shutdown checklist and stated that he would continue handling the radios. The first officer began to read aloud the conditions for executing the Engine Failure or Shutdown checklist but then stopped to tell the captain that the right EGT was at the “red line” and that thrust should be reduced on the right engine. The captain then decided that the airplane should return to the airport and contacted the controller to request vectors. The flight crew continued to express concern about the right engine. The first officer stated, “just have to watch this though…the number two.” The captain asked the first officer to check the EGT for the right engine, and the first officer responded that it was “beyond max.” Afterward, the captain told the first officer to continue with the Engine Failure or Shutdown checklist and finish as much as possible. The first officer resumed reading aloud the conditions for performing the checklist but then stopped to state, “we have to fly the airplane though,” because the airplane was continuing to lose altitude and airspeed. The captain replied “okay.” As a result, the flight crew did not perform key steps of the checklist, including identifying, confirming, and shutting down the affected (right) engine. The first officer told the captain that the airplane was losing altitude; at that time, the airplane’s altitude was 592 ft, and its airspeed was 160 knots. The captain agreed to select flaps 1 (which the first officer had previously suggested likely because the airplane was slowing). The CVR then recorded the first enhanced ground proximity warning system (EGPWS) annunciation (500 ft above ground level); various EGPWS callouts and alerts continued to be annunciated through the remainder of the flight. The captain then told the controller that “we’ve lost number one [left] engine…there’s a chance we’re gonna lose the other engine too it’s running very hot….we’re pretty low on the speed it doesn't look good out here.” Also, the captain mentioned that the controller should notify the US Coast Guard (USCG) because he was anticipating a water ditching in the Pacific Ocean. Because of the high temperature readings on the right engine, the flight crew thought, at this point in the flight, that a dual-engine failure was imminent. During a postaccident interview, the captain stated that his priority at that time was figuring out how the airplane could stay in the air and return safely to the airport. The captain also stated that he attempted to resolve the airplane’s deteriorating energy state by advancing the right engine thrust lever. However, with the left engine remaining near flight idle, the right engine was not producing sufficient thrust to enable the airplane to maintain altitude or climb. The captain’s communication with the controller continued, and the first officer stated, “fly the airplane please.” The controller asked if the airport was in sight, and the captain then asked the first officer whether he could see the airport. The first officer responded “pull up we’re low” to the captain and “negative” to the controller; the captain was likely unable to respond to the controller because he was trying to control the airplane. The captain asked the first officer about the EGT for the right engine; the first officer replied “hot…way over.” The captain then asked about, and the controller responded by providing, the location of the closest airport. Afterward, the CVR recorded a sound similar to the stick shaker, which continued intermittently through the rest of the flight. The CVR then recorded sounds consistent with water impact. The airplane came down into the Pacific Ocean about two miles offshore and sank. Both crew members were rescued, one was slightly injured and a second was seriously injured. The wreckage was later recovered for investigation purposes.

The airplane departed during dark (moonless) night conditions over remote terrain with few ground-based light sources to provide visual cues. Weather reports indicated strong gusting wind from the northeast. According to a surviving passenger, shortly after takeoff, the pilot started a right turn; the bank angle continued to increase, and the airplane impacted terrain in a steep right bank. The accident site was about 1 mile from the airport at a location consistent with the airplane departing to the northeast and turning right about 180 degrees before ground impact. The operator's chief pilot reported that the pilot likely turned right after takeoff to fly direct to the navigational aid located southwest of the airport in order to escape the terrain induced turbulence (downdrafts) near the mountain range northeast of the airport. Examination of the airplane wreckage revealed damage and ground scars consistent with a high-energy, low-angle impact during a right turn. No evidence was found of preimpact mechanical malfunctions or failures that would have precluded normal operation. It is likely that the pilot became spatially disoriented during the right turn. Although visual meteorological conditions prevailed, no natural horizon and few external visual references were available during the departure. This increased the importance for the pilot to monitor the airplane's flight instruments to maintain awareness of its attitude and altitude. During the turn, the pilot was likely performing the additional task of engaging the autopilot, which was located on the center console below the throttle quadrant. The combination of conducting a turn with few visual references in gusting wind conditions while engaging the autopilot left the pilot vulnerable to visual and vestibular illusions and reduced his awareness of the airplane's attitude, altitude, and trajectory. Based on toxicology findings, the pilot most likely had symptoms of an upper respiratory infection but the investigation was unable to determine what effects these symptoms may have had on his performance. A therapeutic level of doxylamine, a sedating antihistamine, was detected, and impairment by doxylamine most likely contributed to the development of spatial disorientation.

The twin-engine medical transport airplane was on a positioning flight when the pilot reported a loss of power affecting one engine before impacting terrain 0.6 miles west of the approach end of the runway. The airplane was at 2,600 feet and in a shallow descent approximately 8 miles northwest of the airport when the pilot checked in with the tower and requested landing. Three and a half minutes later, the pilot reported that he had lost an engine and was in a righthand turn. Radar data indicated that the airplane was 2 miles southwest of the airport at 1,200 feet msl. The radar track continued to depict the airplane in a descent and in a right-hand turn, approximately 1.9 miles west of the approach end of the runway. The altitude fluctuated between 400 and 600 feet, the track turned right again, and stabilized on an approximate 100- degree magnetic heading, which put the airplane on a left base for the runway. The track entered a third right-hand turn at 500 feet. The pilot's last transmission indicated that one engine was not producing power. The last radar return was 6 seconds later at 200 feet, in the direct vicinity of where the wreckage was located. Using the radar track data, the average ground speed calculations showed a steady decrease from 134 knots at the time of the pilot's initial report of a problem, to 76 knots immediately before the airplane impacted terrain. The documented minimum controllable airspeed (VMC) for this airplane is 68 knots. The zero bank angle stall speed varied from 78 knots at a cruise configuration to 70 knots with the gear and flaps down. A sound spectrum study using recorded air traffic control communications concluded that one engine was operating at 2,630 rpm, and one engine was operating at 1,320 rpm. Propeller damage was consistent with the right engine operating at much higher power than the left engine at the time of impact, and both propellers were at or near the low pitch stops (not feathered). Examination and teardown of both engines did not reveal any evidence of mechanical malfunction. Investigators found that the landing gear was down and the flaps were fully deployed at impact. In this configuration, performance calculations showed that level flight was not possible with one engine inoperative, and that once the airspeed had decreased below minimum controllable airspeed (VMC), the airplane could stall, roll in the direction of the inoperative engine, and enter an uncontrolled descent. The pilot had been trained and had demonstrated a satisfactory ability to operate the airplane in slow flight and single engine landings. However, flight at minimum controllable airspeed with one engine inoperative was not practiced during training. The operator's training manual stated that during single engine training an objective was to ensure the pilot reduced drag; however, there was no procedure to accomplish this objective, and the ground training syllabus did not specifically address engine out airplane configuration performance as a dedicated topic of instruction. The operator's emergency procedures checklist and manufacturer's information manual clearly addressed the performance penalties of configuring the airplane with an inoperative engine, propeller unfeathered, the landing gear down, and/or the flaps deployed. The engine failure during flight procedure checklist and the engine inoperative go-around checklist, if followed, configure the airplane for level single engine flight by feathering the propeller, raising the flaps, and retracting the landing gear.

The airplane collided with terrain 200 yards short of the runway during an emergency landing following a loss of engine power. The pilot was on an intermediate leg of a ferry trip. Approximately 300 miles from land, the fuel flow and boost pump lights illuminated. Then, the right engine failed. The pilot flew back to the nearest airport; however, approximately 200 yards from the runway, the airplane stalled and the right wing dropped and collided with the ground. The fuel system had been modified a few months prior to the accident to allow for a ferry fuel tank installation. Post accident examination of the airplane could not find a reason for the power loss.

The airplane collided with mountainous terrain after the flight crew terminated the instrument approach and proceeded visually at night. The flight crew failed to brief or review the instrument approach procedure prior to takeoff and exhibited various cognitive task deficiencies during the approach. These cognitive task deficiencies included selection of the wrong frequency for pilot controlled lighting, concluding that the airport was obscured by clouds despite weather information to the contrary, stating inaccurate information regarding instrument approach headings and descent altitudes, and descending below appropriate altitudes during the approach. This resulted in the crew's lack of awareness regarding terrain in the approach path. Pilots approaching a runway over a dark featureless terrain may experience an illusion that the airplane is at a higher altitude that it actually is. In response to this illusion, referred to as the featureless terrain illusion or black hole phenomenon, a pilot may fly a lower than normal approach potentially compromising terrain clearance requirements. The dark visual scene on the approach path and the absence of a visual glideslope indicator were conducive to producing a false perception that the airplane was at a higher altitude. A ground proximity warning device may have alerted the crew prior to impact. However, the amount of advanced warning that may have been provided by such a device was not determined. Although the flight crew's performance was consistent with fatigue-related impairment, based on available information, the Safety Board staff was unable to determine to what extent the cognitive task deficiencies exhibited by the flight crew were attributable to fatigue and decreased alertness.

During cruise flight the accident aircraft lost oil pressure in the n°2 engine. Flight could not be sustained using the remaining engine. According to the pilot, the remaining engine would overheat when power was applied. The crew descended to just above the water and tried to fly the aircraft in ground effect, but to no avail. They elected to ditch the aircraft. During the landing, the aircraft received substantial damage and was almost immediately flooded, causing the aircraft to sink. The crew escaped, but did not have time to retrieve emergency gear. They were rescued after about 20 hours in the water. Evidence revealed that the pilot did not have a pilot's certificate. No evidence could be found to indicate that the pilot had any experience in the accident aircraft or with any sea plane. Since the aircraft sank, a cause for the engine problems could not be determined.

De Havilland DHC-6, N707PV (Aloha Islandair flight 1712), collided with mountainous/hilly terrain near Halawa Bay, HI, while en route on a scheduled passenger flight at night from Maui to Molokai, HI. Impact occurred at an elevation of about 500 feet, shortly after the aircraft had descended over water, then crossed the shoreline. There was evidence that the captain had made a navigational error and mistakenly believed that he was circumnavigating the northern portion of Molokai Island. The aircraft crashed while on a heading that was parallel with the island's northern shoreline. Low clouds obscured the mountain tops in the area of the accident. There was also evidence of inadequate supervision of personnel, training and operations by Aloha Islandair management and insufficient oversight of Aloha Islandair by the FAA during a period of Aloha Islandair's rapid operational expansion. All 20 occupants were killed.

Scenic Air Tours flight 21 (Beech H18, N34AP) was on an air taxi, sightseeing flight from Hilo to Kahului, HI. The pilot took off at approximately 1300 hst. After takeoff, flight 21 proceeded northwest along the coastline at an altitude of about 2,000 feet. The aircraft subsequently crashed in a scenic canyon area near a waterfall in Waipio Valley, approximately 50 miles northeast of Hilo. Impact occurred at an elevation of about 2,800 feet, approximately 600 to 900 feet below the rim. No preimpact mechanical problem of the aircraft or engines was found. A passenger, who was on a previous sightseeing flight, reported the pilot had maneuvered below the rim of a canyon. Company officials reported that flying below rims of canyons was against company policy; however, the operations manual did not contain any guidance or cautions about such operations. All 11 occupants were killed.

On April 28, 1988, an Aloha Airline Boeing 737, N73711, was scheduled for a series of interisland flights in Hawaii. The crew flew three uneventful roundtrip flights, one each from Honolulu to Hilo (ITO), Kahului Airport, HI (OGG) on the island of Maui, and Kauai Island Airport (LIH). At 11:00, a scheduled first officer change took place for the remainder of the day. The crew flew from Honolulu to Maui and then from Maui to Hilo. At 13:25, flight 243 departed Hilo Airport en route to Honolulu. The first officer conducted the takeoff and en route climb to FL240 in VMC. As the airplane leveled at 24,000 feet, both pilots heard a loud "clap" or "whooshing" sound followed by a wind noise behind them. The first officer's head was jerked backward, and she stated that debris, including pieces of gray insulation, was floating in the cockpit. The captain observed that the cockpit entry door was missing and that "there was blue sky where the first-class ceiling had been." The captain immediately took over the controls of the airplane. He described the airplane attitude as rolling slightly left and right and that the flight controls felt "loose." Because of the decompression, both pilots and the air traffic controller in the observer seat donned their oxygen masks. The captain began an emergency descent. He stated that he extended the speed brakes and descended at an indicated airspeed (IAS) of 280 to 290 knots. Because of ambient noise, the pilots initially used hand signals to communicate. The first officer stated that she observed a rate of descent of 4,100 feet per minute at some point during the emergency descent. The captain also stated that he actuated the passenger oxygen switch. The passenger oxygen manual tee handle was not actuated. When the decompression occurred, all the passengers were seated and the seat belt sign was illuminated. The No. 1 flight attendant reportedly was standing at seat row 5. According to passenger observations, the flight attendant was immediately swept out of the cabin through a hole in the left side of the fuselage. The No. 2 flight attendant, standing by row 15/16, was thrown to the floor and sustained minor bruises. She was subsequently able to crawl up and down the aisle to render assistance and calm the passengers. The No. 3 flight attendant, standing at row 2, was struck in the head by debris and thrown to the floor. She suffered serious injuries. The first officer tuned the transponder to emergency code 7700 and attempted to notify Honolulu Air Route Traffic Control Center (ARTCC) that the flight was diverting to Maui. Because of the cockpit noise level, she could not hear any radio transmissions, and she was not sure if the Honolulu ARTCC heard the communication. Although Honolulu ARTCC did not receive the first officer's initial communication, the controller working flight 243 observed an emergency code 7700 transponder return about 23 nautical miles south-southeast of the Kahalui Airport, Maui. Starting at 13:48:15, the controller attempted to communicate with the flight several times without success. When the airplane descended through 14,000 feet, the first officer switched the radio to the Maui Tower frequency. At 13:48:35, she informed the tower of the rapid decompression, declared an emergency, and stated the need for emergency equipment. The local controller instructed flight 243 to change to the Maui Sector transponder code to identify the flight and indicate to surrounding air traffic control (ATC) facilities that the flight was being handled by the Maui ATC facility. The first officer changed the transponder as requested. At 13:50:58, the local controller requested the flight to switch frequencies to approach control because the flight was outside radar coverage for the local controller. Although the request was acknowledged, Flight 243 continued to transmit on the local controller frequency. At 13:53:44, the first officer informed the local controller, "We're going to need assistance. We cannot communicate with the flight attendants. We'll need assistance for the passengers when we land." An ambulance request was not initiated as a result of this radio call. The captain stated that he began slowing the airplane as the flight approached 10,000 feet msl. He retracted the speed brakes, removed his oxygen mask, and began a gradual turn toward Maui's runway 02. At 210 knots IAS, the flightcrew could communicate verbally. Initially flaps 1 were selected, then flaps 5. When attempting to extend beyond flaps 5, the airplane became less controllable, and the captain decided to return to flaps 5 for the landing. Because the captain found the airplane becoming less controllable below 170 knots IAS, he elected to use 170 knots IAS for the approach and landing. Using the public address (PA) system and on-board interphone, the first officer attempted to communicate with the flight attendants; however, there was no response. At the command of the captain, the first officer lowered the landing gear at the normal point in the approach pattern. The main gear indicated down and locked; however, the nose gear position indicator light did not illuminate. Manual nose gear extension was selected and still the green indicator light did not illuminate; however, the red landing gear unsafe indicator light was not illuminated. After another manual attempt, the handle was placed down to complete the manual gear extension procedure. The captain said no attempt was made to use the nose gear downlock viewer because the center jumpseat was occupied and the captain believed it was urgent to land the airplane immediately. At 13:55:05, the first officer advised the tower, "We won't have a nose gear," and at 13:56:14, the crew advised the tower, "We'll need all the equipment you've got." While advancing the power levers to maneuver for the approach, the captain sensed a yawing motion and determined that the No.1 (left) engine had failed. At 170 to 200 knots IAS, he placed the No. 1 engine start switch to the "flight" position in an attempt to start the engine; there was no response. A normal descent profile was established 4 miles out on the final approach. The captain said that the airplane was "shaking a little, rocking slightly and felt springy." Flight 243 landed on runway 02 at Maui's Kahului Airport at 13:58:45. The captain said that he was able to make a normal touchdown and landing rollout. He used the No. 2 engine thrust reverser and brakes to stop the airplane. During the latter part of the rollout, the flaps were extended to 40° as required for an evacuation. An emergency evacuation was then accomplished on the runway.