Honolulu

The airplane departed Santa Rosa-Sonoma County Airport on a ferry flight to Honolulu, carrying two pilots. It crashed in unknown circumstances into the Pacific Ocean some 54 km west of Half Moon Bay. No trace of the aircraft or the crew was found.

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 pilot stated that the flight was conducted at night and he used his GPS track to align with the runway. When the pilot activated the runway lights, the airplane was about 1/4 mile to the left of the runway and 1/2 mile from the approach end. The pilot made an aggressive right turn then hard left turn to make the runway for landing. While maneuvering on short final, at 50 feet above ground level (agl), the airplane's right wing impacted the tops of a number of trees that lined the southeast side of the runway. The airplane descended rapidly and landed hard, collapsing the landing gear and spinning the airplane around 180 degrees laterally, where it came to rest against some trees. The right wing's impact with trees and the hard landing resulted in substantial damage. The pilot reported no preimpact mechanical failures or malfunctions with the airplane that would have precluded normal operation.

The airline transport pilot was conducting an air taxi commuter flight between two Hawaiian islands with eight passengers on board. Several passengers stated that the pilot did not provide a safety briefing before the flight. One passenger stated that the pilot asked how many of the passengers had flown over that morning and then said, “you know the procedures.” The pilot reported that, shortly after takeoff and passing through about 500 ft over the water, he heard a loud “bang,” followed by a total loss of engine power. The pilot attempted to return to the airport; however, he realized that the airplane would not be able to reach land, and he subsequently ditched the airplane in the ocean. All of the passengers and the pilot exited the airplane uneventfully. One passenger swam to shore, and rescue personnel recovered the pilot and the other seven passengers from the water about 80 minutes after the ditching. However, one of these passengers died before the rescue personnel arrived. Postaccident examination of the recovered engine revealed that multiple compressor turbine (CT) blades were fractured and exhibited thermal damage. In addition, the CT shroud exhibited evidence of high-energy impact marks consistent with the liberation of one or more of the CT blades. The thermal damage to the CT blades likely occurred secondary to the initial blade fractures and resulted from a rapid increase in fuel flow by the engine fuel control in response to the sudden loss of compressor speed due to the blade fractures. The extent of the secondary thermal damage to the CT blades precluded a determination of the cause of the initial fractures. Review of airframe and engine logbooks revealed that, about 1 1/2 years before the accident, the engine had reached its manufacturer-recommended time between overhaul (TBO) of 3,600 hours; however, the operator obtained a factory-authorized, 200-hour TBO increase. Subsequently, at an engine total time since new of 3,752.3 hours, the engine was placed under the Maintenance on Reliable Engines (MORE) Supplemental Type Certificate (STC) inspection program, which allowed an immediate increase in the manufacturer recommended TBO from 3,600 to 8,000 hours. The MORE STC inspection program documents stated that the MORE STC was meant to supplement, not replace, the engine manufacturer’s Instructions for Continued Airworthiness and its maintenance program. Although the MORE STC inspection program required more frequent borescope inspections of the hot section, periodic inspections of the compressor and exhaust duct areas, and periodic power plant adjustment/tests, it did not require a compressor blade metallurgical evaluation of two compressor turbine blades; however, this evaluation was contained in the engine maintenance manual and an engine manufacturer service bulletin (SB). The review of the airframe and engine maintenance logbooks revealed no evidence that a compressor turbine metallurgical evaluation of two blades had been conducted. The operator reported that the combined guidance documentation was confusing, and, as a result, the operator did not think that the compressor turbine blade evaluation was necessary. It is likely that, if the SB had been complied with or specifically required as part of the MORE STC inspection program, possible metal creep or abnormalities in the turbine compressor blades might have been discovered and the accident prevented. The passenger who died before the first responders arrived was found wearing a partially inflated infant life vest. The autopsy of the passenger did not reveal any significant traumatic injuries, and the autopsy report noted that her cause of death was “acute cardiac arrhythmia due to hyperventilation.” Another passenger reported that he also inadvertently used an infant life vest, which he said seemed “small or tight” but “worked fine.” If the pilot had provided a safety briefing, as required by Federal Aviation Administration regulations, to the passengers that included the ditching procedures and location and usage of floatation equipment, the passengers might have been able to find and use the correct size floatation device.

The pilot was flying a night, single-pilot, cargo flight over water between two islands. He had routine contact with air traffic control, and was advised by the controller to maintain 6,000 feet at 0501 hours when the airplane was 11 miles from the destination airport. Two minutes later the flight was cleared for a visual approach to follow a preceding Boeing 737 and advised to switch to the common traffic advisory frequency at the airport. The destination airport was equipped with an air traffic control tower but it was closed overnight. The accident flight's radar-derived flight path showed that the pilot altered his flight course to the west, most likely for spacing from the airplane ahead, and descended into the water as he began a turn back toward the airport. The majority of the wreckage sank in 4,800 feet of water and was not recovered, so examinations and testing could not be performed. As a result, the functionality of the altitude and attitude instruments in the cockpit could not be determined. A performance study showed, however, that the airspeed, pitch, rates of descent, and bank angles of the airplane during the approach were within expected normal ranges, and the pilot did not make any transmissions during the approach that indicated he was having any problems. In fact, another cargo flight crew that landed just prior to the accident airplane and an airport employee reported that the pilot transmitted that he was landing on the active runway, and was 7 miles from landing. Radar data showed that when the airplane was 6.5 miles from the airport, at the location of the last recorded radar return, the radar target's mode C altitude report showed an altitude of minus 100 feet mean sea level. The pilot most likely descended into the ocean because he became spatially disoriented. Although visual meteorological conditions prevailed, no natural horizon and few external visual references were available during the visual approach. This increased the importance of monitoring flight instruments to maintain awareness of the airplane attitude and altitude. The pilot's tasks during the approach, however, included maintaining visual separation from the airplane ahead and lining up with the destination runway. These tasks required visual attention outside the cockpit. These competing tasks probably created shifting visual frames of reference, left the pilot vulnerable to common visual and vestibular illusions, and reduced his awareness of the airplane's attitude, altitude and trajectory.

The airplane descended into terrain during the takeoff initial climb from a private airstrip in dark night conditions. The four passengers had been flown to the departure airport earlier in the day. After several hours at the destination, the pilot and passengers boarded the airplane and waited for two other airplanes to depart. During the initial climb, the pilot banked the airplane to the right, due to the upsloping terrain in the opposite direction (left) and noise abatement concerns; this maneuver was a standard departure procedure. The airplane collided with the gradually upsloping terrain, coming to rest upright. The pilot did not believe that he had experienced a loss of power. The accident occurred in dark night conditions, about 1 hour after sunset. In his written report, the pilot said he only had 10 hours of total night flying experience.

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 trees and mountainous terrain at the 3,600-foot-level of Mauna Kea Volcano during an en route cruise descent toward the destination airport that was 21 miles east of the accident site. The flight departed Honolulu VFR at 0032 to pickup a patient in Hilo, on the Island of Hawaii. The inter island cruising altitude was 9,500 feet and the flight was obtaining VFR flight advisories. At 0113, just before the flight crossed the northwestern coast of Hawaii, the controller provided the pilot with the current Hilo weather, which was reporting a visibility of 1 3/4 miles in heavy rain and mist with ceiling 1,700 feet broken, 2,300 overcast. Recorded radar data showed that the flight crossed the coast of Hawaii at 0122, descending through 7,400 feet tracking southeast bound toward the northern slopes of Mauna Kea and Hilo beyond. The last recorded position of the aircraft was about 26 miles northwest of the accident site at a mode C reported altitude of 6,400 feet. At 0130, the controller informed the pilot that radar contact was lost and also said that at the airplane's altitude, radar coverage would not be available inbound to Hilo. The controller terminated radar services. A witness who lived in the immediate area of the accident site reported that around 0130 he heard a low flying airplane coming from the north. He alked outside his residence and observed an airplane fly over about 500 feet above ground level (agl) traveling in the direction of the accident site about 3 miles east. The witness said that light rain was falling and he could see a half moon, which he thought provided fair illumination. The area forecast in effect at the time of the flight's departure called for broken to overcast layers from 1,000 to 2,000 feet, with merging layers to 30,000 feet and isolated cumulonimbus clouds with tops to 40,000 feet. It also indicated that the visibility could temporarily go below 3 statute miles. The debris path extended about 500 feet along a magnetic bearing of 100 degrees with debris scattered both on the ground and in tree branches. Investigators found no anomalies with the airplane or engines that would have precluded normal operation. Pilots for the operator typically departed under VFR, even in night conditions or with expectations of encountering adverse weather, to preclude ground holding delays. The pilots would then pick up their instrument flight rules (IFR) clearance en route. The forecast and actual weather conditions at Hilo were below the minimums specified in the company Operations Manual for VFR operations.

The pilot reported that about 150 miles southwest of Monterey, the right engine made unusual noises, began to run rough, and exhibited high cylinder head temperature at the limits of the gauge. He advised Oakland Center of his position and situation, but did not declare an emergency. The pilot attempted to open the right engine cowl flap; however, it malfunctioned. He then increased fuel flow to the right engine in order to cool it and eventually had to reduce power on that side to keep it running. To compensate for the power loss in the right engine, he had to add power to the left engine. The combination of remedial actions increased the fuel consumption beyond his planned fuel burn rate. The flight attitude required by the asymmetric power also induced a periodic unporting condition in the outboard fuel tank pickups. The pilot said he was forced to switch to the inboard tanks until that supply was exhausted and then attempted to feed from the outboard tanks. The pilot said he was unsuccessful in maintaining consistent engine power output and was forced to ditch 20 miles short of the coastline. The pilot's VFR flight plan indicated that the total time en route would be 13 hours 10 minutes and total fuel onboard was 14 hours. The lapsed time from departure until the aircraft ditching was approximately 13 hours 12 minutes.