FTW04FA235

A single-engine airplane, operating in dark night instrument meteorological conditions as a Part 135 mail cargo flight, impacted terrain after an in-flight break up. Several minutes before the impact, the pilot reported to air traffic control that he had lost his vacuum pump. An on-site examination of the wreckage revealed that the vacuum pump the drive was separated from the engine and the flex coupling displayed a torsion-type separation with coupling wear consistent with engine operation after the separation. Disassembly of the model 211CC vacuum pump revealed the following. A number was assigned to each of the rotor segments and the corresponding vanes were marked and removed from their respective slots. Five of the six vanes were intact, and vane #4 was broken. Four pieces were reassembled to recreate approximately 80 percent of vane #4. Three of the four pieces were found in the mounting flange, and one piece was found in the back flange. The rotor segments were marked such that vane slot #4 is between segment 4 and segment 5. Upon examination of the walls of vane slot 4, a groove approximately .450 inches by .120 inches by .020 inches deep was found on both sides of the vane slot. These grooves corresponded in dimension and position to the portion of the vane that was missing. Three carbon pieces were found, which exhibited extensive wear, which, in two cases, were smooth and round like a "BB." The rear fracture surface of vane #4 exhibited a smooth, polished, spherical wear mark corresponding with the carbon pieces found. The pump housing had severe wear such that there were washboard marks around its entire circumference. At the bottom of the bore, a burr was found on the edge of one of the back flange discharge ports. Corresponding rotational marks were found on the pump's rotor. According to Parker Hannifin, the rule of thumb for vane wear versus service life is: .025-inches of wear for every 100 hours of operation. Using Parker's original new vane length of .845 inches, the estimated time of operation of the vanes of the accident pump was approximately 1,380 hours. According to Parker the vacuum pump had been overhauled. Parker's service letters require replacement of model 211CC vacuum pumps after 500 hours of operation or 6 years from the date of manufacture, which ever occurs first. Examination of the directional gyro revealed that the housing was intact and the gyro was free to move. No rotational marks were found on the gyro or inside the housing. The turn coordinator gyro was examined and no rotational scoring was found when removed from the housing. A small portion of the housing was fractured and missing. The attitude indicator gyro was free to move within its housing and the housing was intact. No rotational scoring was noted when the gyro was removed from the housing. The filament of the vacuum enunciator bulb # PL33[0] exhibited stretching.

History of flight:

On September 9, 2004, approximately 0614 central daylight time, a Piper PA-32R-300, N6209J, owned by a private individual and operated by San Antonio Piper, Inc., of San Antonio, Texas, was destroyed when it impacted the ground following an in-flight break up near Rachel, Texas. The commercial pilot was fatally injured. Dark night instrument meteorological conditions prevailed and an instrument flight rules (IFR) flight plan was filed for the cargo flight being conducted under the provisions of Title 14 Code of Federal Regulations Part 135. The flight originated from Stinson Municipal Airport (SSF), near San Antonio, Texas, at 0510 and was destined for Mc Allen Miller International Airport (MFE) near McAllen, Texas.

According to radar data that was provided by Houston Air Route Traffic Control Center (ARTCC), the airplane initially climbed to an en route cruising altitude of 9,000 feet mean sea level (msl) after departing from San Antonio. According to air traffic control (ATC) information provided by the FAA, the pilot requested to descend to 7,000 feet msl, at 0537. At 0556, the pilot reported that he "lost the vacuum pump," and at 0559, he requested to descend to 5,000 feet. Radar data depicted the airplane passing through 6,600 feet at 0606.

At 0613, the pilot requested to divert to Brooks County Airport (prior to the request, radar depicted the airplane in a right turn from a heading of 180 degrees toward 130 degrees). The diversion to Brooks County was cleared by air traffic control and a controller asked the pilot if he needed a telephone number to cancel his flight plan once he landed. At 0613:45, the pilot radioed that he did not need a telephone number to cancel his flight plan. At 0613:59, radar depicted the airplane passing through 4,600 feet. The next radar sweep (12 seconds later) depicted the airplane passing through 4,100 feet. The last position of the airplane prior to the loss of contact was approximately 10 miles southwest of Brooks County on a heading of 014 degrees.

Personnel information:

The pilot held a valid Federal Aviation Administration (FAA) commercial pilot certificate with ratings for single-engine land, multi-engine land, and instrument airplane. He also held a flight instructor certificate with airplane single-engine land rating and an advanced ground instructor certificate. His most recent first- class medical certificate was issued on February 4, 2004. A review of the pilot's logbook revealed he had accumulated 2,290 hours of flight time as of April 20, 2004. The flight time logs showed 182.7 hours of actual instrument flight time and 65 hours of simulated instrument time. The operator reported that the pilot had flown approximately 30 hours in the accident model airplane (PA32R-300) and 200 hours in PA-32 series aircraft (Cherokee and Lance) in the last 90 days.

Aircraft information:

The 1976-model Piper PA-32R-300, serial number 32R-7680332, was powered by a 250-horsepower Lycoming I0540-K1G5D engine, serial number L-24893-48-A, which was overhauled at Lycoming on November 5, 2001, at 1,822.0 hours of tachometer time. The engine was then installed on the above aircraft on February 7, 2002, at a tachometer time of 6,380.45. The tachometer was reset to "0" at 7,560.28 on August 11, 2003.

Entries in the aircraft's maintenance records showed that the last annual inspection was completed on October 1, 2003, tachometer time of 73.3 (total time of 8,411.4). The last 100-hour inspection was completed on August 2, 2004, at a tachometer time of 761.7 hours, and the last 50-hour inspection was completed on August 25, 2004, at a tachometer time of 817.5. Static system and transponder tests were performed on January 27, February 11, and February 27 of 2004.

Aircraft and engine maintenance logbooks revealed that the following items were removed and replaced between October 1, 2003, and the date of the accident:

Date item tach time

October 16, 2003 Power Pack 111.0

Turn Coordinator

Directional Gyro

December 7, 2003 Aircraft Battery 223.4

January 8, 2004 Turn Coordinator 282.6

January 27, 2004 Airspeed Indicator 324.9

February 11, 2004 Airspeed Indicator 361.8

April 12, 2004 Aircraft Battery 499.8

May 7, 2004 Vacuum Pump 563.9

May 27, 2004 Propeller Governor 611.9

June 18, 2004 Propeller Governor 664.0

Flight log entries showed that the tachometer time at the time of departure from SSF was 850.0 hours, and the Hobbs time was 8461.0 hours. Hobbs time at the time of the accident was 8,462.1. The tachometer time computed from the Hobbs time at the time of the accident was 851.1 hours.

Meteorological information:

At 0605, the automated weather observing system at Brooks County Airport (BKS), near Falfurrias, Texas, located approximately 10 miles northeast from the site of the accident, reported wind from 320 degrees at 5 knots, 10 statute miles visibility, broken clouds at 4,400 feet, overcast clouds at 5,000 feet, temperature 71 degrees Fahrenheit, dew point 64 degrees Fahrenheit, and a barometric pressure setting of 29.94 inches of Mercury.

A satellite image taken at 0615 indicated a low-level layer of overcast to broken cloud layer extending from the coast inland to approximately 20 miles west of Falfurrias and extended northward to McMullen, Texas. The radiative cloud top temperature over Falfurrias was approximately 6.2 degrees Celsius, which according to the Corpus Christi, Texas sounding, indicated cloud tops near 8,600 feet msl.

The beginning of civil twilight on the morning of the accident was at 0652, and sunrise was at 0715. The phase of the moon on the morning of the accident was a waning crescent with 22% of the moon's visible disk illuminated. Moonset was at 1612 on the preceding day, and moonrise was at 0229 on the morning of the accident.

Wreckage and impact information:

The main wreckage of the aircraft, which consisted of the engine, propeller assembly, main fuselage, and right wing, was found on ranchland in close proximity to a natural gas processing center, GPS coordinates, latitude 26 degrees 57.56 minutes North, longitude 98 degrees 15.03 minutes West. Remaining components of the aircraft were scattered within a 1/4 mile distance from the main wreckage over brush and desert-like terrain in a general southeast direction.

Engine and propeller assemblies were found embedded into the ground approximately 12-18 inches. The engine remained attached to the firewall and airframe and the propeller and spinner was attached to the crankshaft flange. One propeller blade was buried, and when exposed, exhibited severe twisting and bending. The other blade remained relatively straight, and both both blades exhibited leading edge polishing and chord-wise scoring. The vacuum pump was found partially detached from the engine and was recovered for further examination. (See Tests and Research for more details.)

Found laying on its left side, the fuselage was found crushed along its length and was split down the left portion of the cabin ceiling. The fuel selector was destroyed and the fuel valve was positioned in the "OFF" position. The instrument indications that were visible in the cockpit are as follows: Gyro suction indicated +4, magnetos were in the "BOTH" position, the altimeter indicated 300 feet, and the directional gyro indicated 302 degrees. The fuel selector valve was in the "OFF" position. The mode C transponder displayed "4522" in the "ALT" position. Navigation radio number one was set to 109.0, and navigation radio number two was set to 111.4. A large amount of mail cargo was found compacted in the tail cone section of the main wreckage.

The right wing was detached from its respective mounts and was bent rearward and parallel to the fuselage. The aileron was secure at all hinges points and the flap remained attached by the inboard hinge. The f