NTSB Factual Report

HISTORY OF FLIGHT

On November 5, 2005, at 0958 central standard time (CST), a twin-engine Cessna 500 airplane, N505K, was destroyed upon impact with terrain following a loss of control during takeoff from the William P. Hobby Airport (HOU), near Houston, Texas. The instrument rated commercial pilot and one passenger were fatally injured. The airplane was owned and operated by the pilot. Visual meteorological conditions prevailed, and an instrument flight plan was filed for the 14 Code of Federal Regulations Part 91 personal flight. The local maintenance test flight was originating at the time of the accident, with Corpus Christi, Texas, as the intended destination.

Airport personnel reported that the owner of the airplane rented an office and hangar from a fixed base operator (FBO) on the east side of runway (RW) 22. Records indicate that 377 gallons of jet fuel was purchased on November 5, 2005, from the FBO's fueling vehicle about 0800; the fueling technician stated that the airplane was "topped off." Witnesses reported that the airplane had not been flown in over nine months, and was on its first flight since heavy maintenance was accomplished. Maintenance records confirmed that the airplane had not flown since January 31, 2006.

Several eyewitnesses observed the mishap. The three statements below recount their observations:

"A Citation C-500 was taking off on runway 22. The aircraft lifted off and climbed to approximately 200 to 300 feet. The aircraft appeared to have stalled during the ascent, banked to the right, crashing onto runway 12L/30R. It then tumbled for approximately 500 feet, coming to rest on taxiway Hotel and Mike."

"As the aircraft came more into my field of vision, it was 100 to 150 feet off the runway. I observed it roll hard to the right, become inverted, and crash into the ground. A large fireball followed the impact."

"I remember seeing the belly of the airplane, it was lime green color, then it winged-over to its right and went down."

PERSONNEL INFORMATION

The 55-year old pilot held a commercial pilot certificate with a rating for multiengine land and instrument airplane. In addition, he was also typed-rated in the Cessna 500 and 650 models. On February 20, 2005, the pilot satisfactorily completed the annual single-pilot training program and the single-pilot proficiency check in the CE-S550 airplane, as required by FAA exemption 405 and amended on June 27, 1984. The training included authorization for circling approaches.

The pilot was issued a second-class medical certificate on February 4, 2005, with the limitation that "airman must wear corrective lenses." Pilot flight records were not found; however, at the time of the medical application, the pilot reported having accumulated a total of 4,100-flight hours, with 110 hours in the last 6 months. The pilot also owned and operated a 1991-model Cessna 650 twin-engine business jet that was certified for two-pilot operation. Witnesses stated that the pilot had never flown this airplane as pilot-in-command, only as a co-pilot. From January 2005 until the accident, the pilot had flown the Cessna 650 as a co-pilot for approximately 60 hours, and had accumulated 25 hours in the last 90 days, with October 15, 2005, being his last logged flight.

It was reported to the FAA that the passenger was employed by the pilot as a maintenance technician, and had been performing maintenance on the airplane. Records reveal that the 37-year passenger was issued an airframe/powerplant mechanic certification on June 8, 1999. Previously, he had been issued a student pilots certificate (FF242243) on May 31, 2002, that expired on May 31, 2004. A first-class medical certificate was issued on May 3, 2002, with the restriction of "must wear corrective lenses." No additional records were located.

AIRCRAFT INFORMATION

The 1972-model airplane, serial number 004, was a twin-engine business turbojet, configured for a maximum of eight occupants, with a retractable landing gear. The airplane was certified for two-pilot operation, but this particular model could have been flown with only one pilot if an exempted FAA endorsement was approved. This exemption requires an FAA approved single-pilot training program, which is not controlled or approved by Cessna Aircraft Company. The airplane was powered by two 1971 Pratt & Whitney JT-15D1A engines, S/N 76177 and S/N 76633. According to Cessna owner/operator records, the initial delivery date was April 14, 1972. FAA records indicated that the airplane had been operated by 11 different owners since the airplane came off the assembly plant in 1972.

After the accident, incomplete airplane and engine records were located at different locations, and it was not determined if other records were aboard the airplane before being consumed by fire. However, the available information is as follows:

The last recorded inspections accomplished on the airplane were: phase 1 and phase 2 on August 15, 2002; phase 3 and phase 4 on June 5, 2002; and phase 5 on March 30, 2003. Phase 1-4 inspections have 2-year or 400-hour requirements. Phase 5 is a 3-year or 1,200-hour requirement.

The aircraft flight log records indicate January 31, 2005, as its last previous flight. Total aircraft time indicated 6,229.9 hours and 6,195 landings. At that time, engine 1 indicated 2,506.1 hours and 2,246 cycles, and engine 2 indicated 2,473.2 hours and 2,353 cycles.

Records that were found indicated that the accident flight was the first flight since the latest phase 1-5 inspections had been initiated; however, no completed documentation was found indicating that the inspections had been accomplished, or that the airplane maintenance was approved for the return-to-service flight.

Airframe inspection phases 1 through 5 from the maintenance manual were initialed by various mechanics, but no complete signoffs, completion dates, or component times were noted. Inspection phases 41 and 50 was signed on February 25, 2005, with total time of 6,229.9 hours and 6,195 landings.

53 pages of discrepancy worksheets (4 discrepancies to the page) were listed for the airframe, and some of the worksheets indicated corrective actions were taken, including replacing parts/components. The dates from the worksheets start on February 25, 2005, and extend to October 27, 2005. Some of the written discrepancies include: "corrosion on left and right gear axles, removed all flight controls per phase 5 inspection, right hand aft wing fairing cracked with loose rivets, repair wing fuel leaks as required, removed landing gear for repairs, replaced left and right speedbrake hydraulic lines, left and right upper outboard trailing edge of horizontal stabilizer suspected of corrosion between skin and hinge, and main entry door linkage work (reference item 155, which states that the crew door locking linkage has play)."

11 pages of discrepancy worksheets (4 discrepancies to the page) were listed for the phase 4 and 8 engine inspections. Some of the worksheets indicated corrective actions were taken, including replacing parts/components. The dates from the worksheets start on January 19, 2005, and extend to May 30, 2005. Some of the written discrepancies include: "remove left and right hand engine inlets for repair, removed right and left thrust reverser for inspection, left engine start sequence inoperative, replace all engine cowl fasteners, right pylon aft lower section has rivets pulled through, engine sync system inoperative, right and left engine fire loops improperly routed, left pylon aft trailing edge needs repair, left engine has wrong class exhaust nozzle."

On February 18, 2004, an emergency locator transmitter and antenna were installed on N505K, which changed the weight and balance status. The revision change showed the new empty weight to be 7,264.39 pounds, with the new center of gravity being 261.61 and the new moment as 1,900,429.7.

METEORLOGICAL INFORMATION

At 0953, the automated surface observing system at HOU reported wind from 170 degrees at 10 knots, visibility 10 statute miles, scattered clouds at 2,500 feet, broken clouds at 3,000 feet, broken clouds at 25,000 feet, temperature 27 degrees Celsius, dew point 21 degrees Celsius, and a barometric pressure at 29.93 inches of Mercury. The Investigator-in-Charge calculated the density altitude at 1,472 feet.

COMMUNICATIONS

According to Air Traffic Control (ATC), Southwest Airlines (SWA) flight 422 departed HOU a few minutes earlier and was returning to the airport. The Southwest flight, a Boeing 737, declared an emergency with HOU tower while on a 10-mile final for runway 22. The flight crew of SWA flight 422 performed a precautionary engine shutdown of the right engine due to an excessive oil temperature indication, thus the reason for the emergency.

While approaching the approach end of runway 22, the pilot of N505K called the tower and reported he was ready for departure. The controller instructed the pilot to hold short. A second airplane, SWA flight 1274, also called ready for takeoff. The tower controller then instructed N505K "cleared for takeoff, fly heading 210 degrees, no delay on the roll." Citation N505K replied "roger" as he initiated its takeoff roll. SWA 1274 was then instructed to taxi into position and hold "aircraft on 8-mile final, be ready." Neither the flight crew for SWA 1274 or SWA 422 reported witnessing the accident.

The tower controller stated that she turned to look at the airplane on final, and when she turned back, she observed N505K impacting the runway in the inverted position while in a pronounced nose low attitude. The point of impact was about 4,000 feet from the takeoff end of the runway. Subsequently, SWA 1274 taxied from the takeoff position, and HOU tower closed the runway.

AERODROME INFORMATION

Runway 22/4 at the William P. Hobby Airport (HOU) is 7,602-feet long and 150-feet wide with a concrete surface. Elevation at the approach end of runway 22 is 39 feet. Runway 12L/30R (5,148-feet long and 100-feet wide, with a concrete surface) is the first runway crossing runway 22, about 3,750 feet from the takeoff end. According to ATC services at the time of the accident, runway 22 was in use, and all others were closed for construction/maintenance reasons.

FLIGHT RECORDERS

The airplane was not equipped with a flight data recorder (FDR) or cockpit voice recorder (CVR), and neither was required by the FAA.

WRECKAGE AND IMPACT INFORMATION

The airplane initially impacted the runway near its centerline, about 354 feet northwest from the centerline of runway 22. The Global Positioning System (GPS) coordinates for the initial impact point using a hand-held unit were latitude 29 degrees 38.843 minutes North and longitude 95 degrees 16.664 minutes West. The distance from the takeoff end of runway 22 to the initial point of contact on runway 12L was approximately 3,900 feet. Witnesses stated "the airplane exploded in flames as it cart-wheeled" and slid westerly across a grassy area (200 feet wide) to its final resting location at the intersection of taxiway Mike and taxiway Hotel, approximately 520 feet from the first point of impact on runway 12L. The 520-foot debris path field was approximately 64 feet wide.

The nose of the airplane and forward cabin area of the fuselage were observed folded under the right wing. All of the flight control surfaces and major airframe components were accounted for at the accident site. The aft cabin fuselage area and aft fuselage empennage section were observed separated on the aft side of the aft pressure bulkhead. The empennage flight control cables, with the electrical cables and bleed air plumbing, connected the two sections together. The flaps and flap selector handle were both observed in the takeoff and approach position. A mechanical detent is installed at the takeoff (T.O.) and approach (APPR) 15 degree position of the flap lever. The control lock, which engages the ailerons, elevators, and rudder in the neutral position, was observed in the "unlocked position." Several control cables were observed separated in tension overload. Control cable continuity could not be established on-site; however, all of the flight control cables in the aft fuselage remained in place. They were marked and cut to facilitate recovery from the runway.

The main cabin door handle was observed in the stowed position; however, none of the cabin door locking pins were observed engaged in their fully locked position. The lower aft pin was observed extended 3/8 inches; the forward pin was extended 1/8 inches. The forward door pins were extended 3/8 inches and the aft door pins were extended 1/2 inches.

Note: The cabin door locking system operates to the open position by moving the inside cabin door handle counter-clockwise from the stowed position to retract the door locking pins and then moving it back to the center stowed position. The cabin door may then be opened by pushing outward on the door. The door is closed and the door handle is moved clockwise from the center stowed position to extend the door locking pins to lock the door. The handle is then returned to the center stowed position. Full extension of the locking pins is 1 inch. When the door handle is operated to the locked position, the handle drives the bellcrank to an over-center position and prevents the mechanism from inadvertently opening.

The entire cabin area was torn open. Most of the cockpit instrumentation was damaged and burned. All of the engine indication instruments are of the vertical tape indicating style. The pilot's seat base remained attached to the seat tracks, but the copilot's seat base was observed separated from the seat track.

The airframe fuel system was compromised, but fuel was observed on the ground and on various airplane components during the recovery process.

Both engines remained attached to the airplane and exhibited power signatures. The right engine fan blades were observed separated from the hub, but the hub remained attached to the engine. The left engine fan blades remained attached to the hub.

On November 7, 2005, the wreckage was recovered to Air Salvage of Dallas (ASOD), near Lancaster, Texas, for further examination.

MEDICAL AND PATHOLOGICAL

An autopsy was performed on the pilot on November 6, 2005, in the Joseph A. Jachimczyk Forensic Center of Harris County, Houston, Texas, by a medical examiner from the center, with the cause of death as multiple blunt force injuries.

Toxicological testing on the pilot was performed by the FAA's Civil Aeromedical Institute (CAMI) Forensic Center, Oklahoma City, Oklahoma, for carbon monoxide, cyanide, volatiles, and tested drugs. Test results were reported as negative.

FIRE

Southwest Airlines flight 422 had just taken off from HOU before reporting the shutdown of the right engine by the flightcrew. The flight then declared an emergency and was returning on downwind to RW 22. The Houston Fire Department (HFD) vehicles at Hobby Airport were standing-by on alert-2 status alongside the runway awaiting the Southwest flight when the Citation accident occurred; they were thus able to respond immediately.

TESTS AND RESEARCH

On February 28, 2006, at the facilities of ASOD, representatives from the Cessna Aircraft Company and Pratt & Whitney Canada Engines Services examined the engines and airframe under the supervision of the NTSB investigator-in-charge (IIC). The results are as follows:

All of the control cables, which had been previously marked, were verified to have been connected to their appropriate input and output devices. The upper and lower left wing aileron control cables were attached to both the aileron bellcrank and the center fuselage aileron bellcrank. The left aileron remained attached to the wing structure, and had movement when actuated. The upper and lower outboard right aileron control cables were observed separated in a tension overload separation near the outboard bellcrank. The right aileron was attached to the rear wing spar, which was separated from the inboard section of the wing. The rudder control cables were connec

NTSB Probable Cause

The pilot's failure to maintain directional control of the airplane resulting in an inadvertent stall/mush. Contributing factors were the unsecured passenger door and the pilot's diverted attention.