Huntsville

The pilot was conducting an instrument landing system (ILS) approach in instrument meteorological conditions at the conclusion of a cross-country flight. The airplane had been cleared to land, but the tower controller canceled the landing clearance because the airplane appeared not to be established on the localizer as it approached the locator outer marker. The approach controller asked the pilot if he was having an issue with the airplane’s navigation indicator, and the pilot replied, “yup.” Rather than accept the controller’s suggestion to use approach surveillance radar (ASR) approach instead of the ILS approach, the pilot chose to fly the ILS approach again. The pilot was vectored again for the ILS approach, and the controller issued an approach clearance after he confirmed that the pilot was receiving localizer indications on the airplane’s navigation equipment. The airplane joined the localizer and proceeded toward the runway while descending. The pilot was instructed to contact the tower controller; shortly afterward, the airplane entered a left descending turn away from the localizer centerline. At that time, the airplane was about 3 nautical miles from the locator outer marker. The pilot then told the tower controller, “we’ve got a prob.” The tower controller told the pilot to climb and maintain 3,000 ft msl and to turn left to a heading of 180°. The pilot did not respond. During the final 5 seconds of recorded track data, the airplane’s descent rate increased rapidly from 1,500 to about 5,450 ft per minute. The airplane impacted terrain about 1 nm left of the localizer centerline in a left-wing-down and slightly nose down attitude at a groundspeed of about 90 knots. A postimpact fire ensued. Although the pilot was instrument rated, his recent instrument flight experience could not be determined with the available evidence for this investigation. Most of the fuselage, cockpit, and instrument panel was destroyed during the postimpact fire, but examination of the remaining wreckage revealed no anomalies. Acoustic analysis of audio sampled from doorbell security videos was consistent with the airplane's propellers rotating at a speed of 2,500 rpm before a sudden reduction in propeller speed to about 1,200 rpm about 2 seconds before impact. The airplane’s flightpath was consistent with the airplane’s avionics receiving a valid localizer signal during both instrument approaches. However, about 5 months before the accident, the pilot told the airplane’s current maintainer that the horizontal situation indicator (HSI) displayed erroneous heading indications. The maintainer reported that a replacement HSI was purchased and shipped directly to the pilot to be installed in the airplane; however, the available evidence for the investigation did not show whether the malfunctioning HSI was replaced before the flight. The HSI installed in the airplane at the time of the accident sustained significant thermal and fire damage, which prevented testing. During both ILS approaches, the pilot was cleared to maintain 3,000 ft mean sea level (msl) until the airplane was established on the localizer. During the second ILS approach, the airplane descended immediately, even though the airplane was below the lower limit of the glideslope. Although a descent to the glideslope intercept altitude (2,100 ft msl) would have been acceptable after joining the localizer, such a descent was not consistent with how the pilot flew the previous ILS approach, during which he maintained the assigned altitude of 3,000 ft msl until the airplane intercepted the glideslope. If the HSI provided erroneous heading information during the flight, it could have increased the pilot’s workload during the instrument approach and contributed to a breakdown in his instrument scan and his ability to recognize the airplane’s deviation left of course and descent below the glideslope; however, it is unknown if the pilot had replaced the HSI.

Shortly after takeoff in day visual meteorological conditions, when the airplane was climbing through 3,000 ft mean sea level, a complete electrical failure occurred that affected electrical instrumentation and additional airplane equipment, including the landing gear. The pilot reported that he performed the electrical failure checklists and could not restore power. After additional troubleshooting with no success, he chose to divert to and land at another airport. While in the traffic pattern at his diversion airport, he attempted to lower the landing gear using the emergency landing gear extension procedures but could not confirm the landing gear were down and locked. Without any capability to communicate or confirmation that the landing gear were down, he decided to leave the airport traffic pattern and land on a nearby field to avoid airport traffic; the airplane sustained substantial damage to the fuselage, landing gear doors, engines, and propellers during the off-airport landing. The reason for the loss of electrical power could not be determined. Examination of the cockpit revealed that the landing gear's emergency engage handle, also known as the "J" handle, was not pulled up and turned, which was one of the steps listed in the airplane flight manual for the manual landing gear extension procedure. The "J" handle engages the clutch and allows for the handle to operate the landing gear chain. Without engaging the "J" handle, the landing gear handle pumping action would not have worked, which resulted in the gear-up landing.

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 stated that after landing, the nose landing gear collapsed. Examination of the airplane nose strut down-lock installation revealed that the strut on the right side of the nose landing gear trunnion was installed incorrectly; the strut installed on the right was a left-sided strut. Incorrect installation of the strut could result in the bearing pulling loose from the pin on the right side of the trunnion, which could allow the nose landing gear to collapse. A review of maintenance records revealed recent maintenance activity on the nose gear involving the strut. The design of the strut is common for the left and right. Both struts have the same base part number, and a distinguishing numerical suffix is added for left side and right side strut determination. If correctly installed, the numbers should be oriented facing outboard. The original MU-2 Maintenance Manual did not address the installation or correct orientation of the strut. The manufacturer issued MU-2 Service Bulletin (SB) No. 200B, dated June 24, 1994, to address the orientation and adjustment. Service Bulletin 200B states on page 8 of 10 that the “Part Number may be visible in this (the) area from the out board sides (Inked P/N may be faded out).”

The multiengine airplane was at an altitude of 6,000 feet when it experienced a catastrophic right engine failure, approximately 15 minutes after takeoff. The pilot elected to return to his departure airport, which was 30 miles away, instead of diverting to a suitable airport that was located about 10 miles away. The pilot reported that he was not able to maintain altitude and the airplane descended until it struck trees and impacted the ground, approximately 3 miles from the departure airport. The majority of the wreckage was consumed by fire. A 5 1/2 by 6-inch hole was observed in the top right portion of the crankcase. Examination of the right engine revealed that the No. 2 cylinder separated from the crankcase in flight. Two No. 2 cylinder studs were found to have fatigue fractures consistent with insufficient preload on their respective bolts. In addition, a fatigue fracture was observed on a portion of the right side of the crankcase, mostly perpendicular to the threaded bore of the cylinder stud. The rear top 3/8-inch and the front top 1/2-inch cylinder hold-down studs for the No. 2 cylinder exceeded the manufacturer's specified length from the case deck by .085 and .111 inches, respectively. The airplane had been operated for about 50 hours since its most recent annual inspection, which was performed about 8 months prior the accident. The right engine had been operated for about 1,425 hours since it was overhauled, and about 455 hours since the No. 2 cylinder was removed for the replacement of six cylinder studs. It was not clear why the pilot was unable to maintain altitude after the right engine failure; however, the airplane was easily capable of reaching an alternate airport had the pilot elected not to return to his departure airport.

The airline transport pilot reported that shortly after takeoff from runway 36, he heard a loud noise from the left engine area, and observed smoke trailing the left engine nacelle. He confirmed that the left engine was losing power, and he feathered the left propeller. He was unable to maintain altitude, and the aircraft was force landed on wooded terrain. The aircraft caught fire on the ground after colliding with trees and was destroyed. An inspection of the left engine turbocharger revealed that the rotor shaft was seized, with evidence of metal transfer to the bearing journals.

Before takeoff, an IFR flight plan was filed for a 15 minutes flight from Rome, GA, to Huntsville, AL. Takeoff was commenced at 0937 est with the copilot flying the aircraft. After a VFR takeoff, the captain contacted Atlanta Center to obtain an IFR clearance. The controller advised that other traffic was in the area and instructed the flight to remain VFR (while an IFR clearance was being arranged). At that time, the flight reported at 1,300 feet in VFR conditions. While waiting for an IFR clearance, the crew became concerned about higher terrain and low ceilings. At about 0940, the captain directed the copilot to fly 'back to the right.' Approximately one minute later, the CVR stopped recording and radio contact was lost with the aircraft. Later, the aircraft was found where it had collided with the top of Mt Lavender. Elevation of the crash site was approximately 1,580 feet msl. The aircraft was not equipped with a ground proximity warning system. All nine occupants were killed, among them Angelo J. Bruno, the chairman of Bruno's Inc. company; his brother, Lee J. Bruno, vice chairman; Sam A. Vacarella, senior vice president for merchandising; Edward C. Hyde, vice president for store operations, and R. Randolph Page Jr., vice president for personnel.

Two minutes after takeoff the pilot reported a loss of the left engine. He was immediately cleared for a landing at Eglin AFB. While maneuvering for a landing the left engine and wing separated from the aircraft. The engine was separated from the wing and showed evidence of in flight fire. The most intense heat was in the engine accessory section in the area between the bendix fuel servo and the inboard turbocharger. There was extensive fire damage to the oil and fuel lines on the right side of the accessory section, the oil dipstick showed no oil and there was no evidence to show that the oil had spilled in the impact crater. About 25 min prior to takeoff the pilot telephoned the maintenance facility who had accomplished recent major repairs on the aircraft and related he was experiencing difficulty with the left throttle. The pilot was advised to have a mechanic check it out. All three occupants were killed.

Southern Airways Flight 242, a DC-9-31, operated as a scheduled passenger flight from Muscle Shoals, Alabama, to Atlanta, Georgia, with an intermediate stop at Huntsville, Alabama. Flight 242 departed Muscle Shoals at 15:21 and landed at Huntsville about 15:44. About 15:54, Flight 242 departed Huntsville on an instrument flight rules (IFR) flight plan for the Hartsfield-Atlanta International Airport; there were 81 passengers and 4 crew members aboard. The flight's route was direct to the Rome VOR and then a Rome runway 26 profile descent to Atlanta. Its estimated time en route was 25 min and its requested en route altitude was 17,000 ft. At 15:56, the controller told Flight 242 that his radarscope was showing heavy precipitation and that the echos were about 5 nmi ahead of the flight. At 15:57:36, the controller said, "...you're in what appears to be about the heaviest part of it now, what are your flight conditions." Flight 242 replied, "...we're getting a little light turbulence and...I'd say moderate rain." At 15:57:47, the controller acknowledged Flight 242's report and told the flight to contact Memphis Center. The Memphis Center controller advised the flight that a SIGMET was current for the area. He then told Flight 242 to contact Atlanta Center. At 16:03:20, Flight 242 switched to another sector of Atlanta Center, established communications on the new frequency and reported being level at FL170. As the aircraft entered an area of rain, the flight crew began discussing the weather depicted on their radar. Based on information from the airborne radar, the captain initially decided that the storms just west of the Rome VOR were too severe to penetrate. Shortly after his initial assessment of the storm system, the captain decided to penetrate the storm area near the Rome VOR. At 16:06:41 Atlanta Center cleared Flight 242 to descend to and maintain 14,000 ft. Shortly afterwards the aircraft entered an area of heavy hail or rain, which continued for at least one minute. The ingestion of intense rain and hail into the engines caused the rotational speed of both engines to decrease below the engine-driven electrical generator operating speeds, and resulted in normal electrical power interruption for 36 seconds. The flight crew likely advanced one or both thrust levers, restoring its generator to operation and provide normal electrical power. After establishing contact with Atlanta Center again, the flight was told to maintain 15,000 ft. At 16:09:15, Flight 242 reported to Atlanta Center, "Okay...we just got our windshield busted and... we'll try to get it back up to 15, we're 14." After reported that the left engine had flamed out, the flight was cleared to descend to 13,000 ft. Meanwhile both engines' high-pressure compressors began to stall severely due to ingestion of massive quantities of water. The severe compressor stalls produced an overpressure surge which deflected the compressor blades forward in the sixth stage of the low-pressure compressors; these blades clashed against the fifth-stage stator vanes and broke pieces from the blades and vanes. Pieces of blades and stator vanes were then ingested into the high-pressure compressors and damaged them severely. Continued high thrust settings following the severe damage to the high-pressure compressors probably caused severe overheating in the turbine sections of both engines, and the engines ceased to function. Shortly before normal electrical power was again, the flight crew radioed that both engines had failed. Atlanta Center told the crew to contact approach control for vectors to Dobbins Air Force Base. Power was then lost for 2 min 4 sec until the APU-driven generator restored electrical power. After establishing contact with Atlanta Approach Control the flight was told they were 20 miles from Dobbins. As the flight was descending, the captain began to doubt their ability to reach Dobbins. Cartersville was closer at 15 miles, so the controller gave vectors for Cartersville. Unable to make it to Cartersville, the crew began looking for a clear field or highway for an emergency landing. At 16:18:02, Flight 242's last transmission to Approach Control was recorded: "... we're putting it on the highway, we're down to nothing." The aircraft's outboard left wing section first contacted two trees near State Spur Highway 92 south-southwest of the community of New Hope. About 0.8 miles farther north-northeast, the left wing again contacted a tree alongside the highway within the community of New Hope. The left and right wings continued to strike trees and utility poles on both sides of the highway, and 570 ft after striking the first tree in New Hope, the aircraft's left main gear contacted the highway to the left of the centerline. Almost simultaneously, the outer structure of the left wing struck an embankment, and the aircraft veered to the left and off the highway. The aircraft traveled another 1,260 ft before it came to rest. As it traveled, the aircraft struck road signs, utility poles, fences, trees, shrubs, gasoline pumps at a gas station-store, five automobiles, and a truck. Of the 85 persons aboard Flight 242, 62 were killed, 21 were seriously injured, and 1 was slightly injured. Additionally, eight persons on the ground were killed. Within a month of the accident, one of the surviving passengers and one person on the ground both died of their injuries.

Weather conditions in Huntsville were poor so the crew decided to divert to Houston-William P. Hobby Intercontinental Airport. The approach was initiated in low visibility due to foggy conditions. On final approach, the airplane struck a 75 feet high electronic tower located two miles short of runway and crashed in a field. Both pilots and three passengers were killed. At the time of the accident, the visibility was a 1/4 mile or less in fog. The charter flight was completed on behalf of Mohawk Airlines.