N318WA

HISTORY OF FLIGHT

On December 3, 2008, about 1205 Atlantic standard time, a Rockwell International 690B, N318WA, operated by Websta's Aviation Services Inc., was destroyed when it impacted terrain while maneuvering about 4 nautical miles southeast of Rio Grande, Puerto Rico. The certificated airline transport pilot and two passengers were killed. Day instrument meteorological conditions prevailed in the area of the accident. No flight plan had been filed for the flight, which departed Beef Island International Airport (TUPJ), Tortola, British Virgin Islands destined for Luis Munoz Marin International Airport (TJSJ), San Juan, Puerto Rico. The commercial flight was conducted under 14 Code of Federal Regulations (CFR) Part 135.

According to voice and radar data provided by the Federal Aviation Administration (FAA), the accident airplane was inbound to TJSJ from the east, descending at 250 knots ground speed from 8,800 feet above mean sea level (msl), on a 270 degree assigned heading and was instructed to enter the right downwind for runway 10 at TJSJ. The airplane's altitude readout was observed by the approach controller to change to "XXX."

The pilot was queried by the approach controller regarding his altitude and the pilot advised that he was descending to 3,200 feet msl. The pilot was then asked to confirm that he was in visual flight rules (VFR) conditions and was advised by the approach controller that the minimum vectoring altitude (MVA) for the area was 5,500 feet msl. The pilot responded that “We just ahh,” at which time the approach controller advised the pilot that she had missed his transmission and could he repeat it again. The pilot then stated “Ahh roger, could we stay right just a little, we are in and out of some clouds right now.” The approach controller then advised the pilot to “Maintain VFR” and once again advised him of the MVA. The approach controller then made multiple attempts to make contact with the pilot of the accident airplane without result. Moments later another pilot requested an instrument flight rules clearance “to get in to San Juan” as he was observing precipitation.

According to witness statements, just prior to the accident, an airplane was heard flying at low altitude over El Yunque National Forest on an approximate heading of 260 degrees near state road 191. Moments later an explosion was heard.

After a search by multiple local, state, and federal agencies, the wreckage was discovered inside the national forest on the southeast side of a mountain.

PERSONNEL INFORMATION

According to FAA records, the pilot held an airline transport pilot certificate with multiple ratings including airplane multi-engine land and an airframe and powerplant certificate. His most recent FAA first-class medical certificate was issued on April 8, 2008. He reported 9,600 total hours of flight experience on that date.

The pilot was also the owner of Websta's Aviation Services Inc. however; an airport security badge that was discovered in the wreckage identified him as a "Pilot/Mechanic" for Rainbow International Airlines Inc.

AIRCRAFT INFORMATION

The accident aircraft was a high wing, pressurized, twin-engine airplane of conventional construction. It was configured to carry 8 passengers. It was powered by two Garrett TPE331-5-252K single-shaft turbopropeller engines. Each engine produced 776 shaft horsepower. The airplanes maximum cruise speed was 284 knots. Maximum range was 1,467 nautical miles. It was certificated for flight in instrument meteorological conditions.

The airplane was also equipped with an L-3 Communications Landmark TAWS 8100, Terrain Avoidance Warning System (TAWS). According to maintenance records the TAWS unit was installed on March 29, 2005. Post accident examination of the unit revealed that it had received heavy crush and fire damage. No information could be extracted from the unit and it could not be determined if the unit was functional prior to the accident.

According to FAA and airplane flight log records, the airplane was manufactured in 1977. The aircraft had carried several registration numbers, including D-IFAC, N1KC, and N690TG, prior to be registered as N318WA in October of 2003. Maintenance logbook entries after this date were noted as being performed by Websta’s Aviation Services Inc. The logbook entries and description of maintenance actions performed were vague with minimal information provided. It was not possible to determine if all required maintenance actions were completed, which included service bulletins and airworthiness directives. It was also noted that some of the aircraft phase inspections were conducted in accordance with "Rainbow International Airlines procedures."

A total of 20 daily flight log sheet forms found at the accident site also indicated that the operator of the airplane was Rainbow International Airlines. The sheets indicated that in the 2 1/2 years prior to the accident the airplane had only accrued approximately 50 hours of operation, and that as of March 27, 2008, the airplane had accrued 5,286 total hours of operation.

Engine time and cycles recorded referred to the time and cycles since a 1997 engine overhaul and did not include time and cycles since new. In addition to the daily flight logs, the log sheet forms contained information on engine trend monitoring. A total of 16 of the 20 flight log sheet forms had data for engine trending, however all 16 entries had the exact same parameters. There were no entries for non-engine parameters such as airspeed, altitude, and outside air temperature for any of the 16 entries.

METEOROLOGICAL INFORMATION

The reported weather at TJSJ, approximately 14 miles northwest of the accident site, at 1156, included: wind, 070 at 11 knots, visibility 10 miles, few clouds at 3,000 feet, scattered clouds at 7,000 feet, temperature 28 degrees Celsius, dew point 18 degrees Celsius, altimeter setting of 30.00 inches of mercury, and showers to the distant southeast.

According to witness statements however, at the time of the accident, fog and rain were present in the area surrounding the accident site and the mountains were obscured from view.

According to the US Forest Service, low clouds and fog were the norm in the national park. Humidity would remain high all year-round and El Yunque's 28,000 acres would receive up to 240 inches of precipitation a year.

WRECKAGE AND IMPACT INFORMATION

Examination of the accident site revealed that the main wreckage had come to rest perpendicular to a cliff face at an elevation of 2,310 feet. There was no wreckage path. The main wreckage displayed heavy crush and fragmentation damage and a post crash fire had occurred. Examination of the cliff face revealed sooting in a vertical direction. Fragments of the wing structure, nose section, cockpit, flight controls, fuselage, and engine gear boxes were found against the cliff. Fragmented structure, fragmented system components, propeller components and the power sections of both engines were also discovered approximately 200 feet below the cliff perpendicular to the face of the mountain, which sloped downward at approximately 50-degrees. A palm tree located near the base of the cliff, exhibited damage consistent with a propeller strike, and broken limbs and branches existed throughout the accident site. Further examination of some of the limbs and branches revealed multiple breaks and cuts consistent with propeller strikes.

Examination of the wreckage revealed that the landing gear was in the up position. Control continuity could not be established; however no evidence of any preimpact flight control or structural failure was discovered.

Examination of the engines power sections revealed that both were missing their accessory gearboxes.

The left engine’s power section was located on the up slope side of the base of a tree. The front of the engine including the gearbox forward of the first stage compressor impeller was missing. The first stage impeller was exposed and showed bending of the blades in the direction opposite rotation.

The right engine’s power section was also located in the lower debris field with the aft end buried in the ground. The aft end of the power section exhibited heavy compression damage. The third stage turbine rotor was exposed and exhibited heavy damage. Approximately half of the blades of the third stage turbine rotor were missing with the remaining blades bent in the direction opposite rotation. The second stage impeller was also exposed with the blades showing bending opposite the direction of rotation. The forward curvics were also heavily smeared.

One of the two 3-bladed propeller hubs was located down slope from the left engine’s power section. The hub was located with only one blade attached. The second propeller hub was also located, with a single blade attached. Another propeller blade and spring assembly was also found in the surrounding vegetation. All of the propeller blades that were discovered exhibited varying degrees of damage including leading edge gouging, polishing, chordwise scratching, twisting, curling, and S-bending.

AIR TRAFFIC SERVICES

N318WA was receiving VFR radar traffic advisory services from San Juan Center Approach Control Facility (CERAP) when the accident occurred.

Review of the voice and radar data provided by the CERAP revealed that The pilot first contacted San Juan at 1548:23, reporting over Beef Island en route to San Juan International Airport. The controller instructed the pilot to set his transponder to code 4701, issued the St. Thomas altimeter setting, and radar identified the aircraft 11 miles northeast of St. Thomas.

At 1554:06, the controller attempted to obtain the pilot's intended cruising altitude, but the pilot replied that he would be, "...continuing to climb" and was currently at "eight point eight" [8,800 feet.] N318WA was transferred to another controller, and at 1600:18 contacted the new c...