MIA96FA100

After takeoff, according to radar data, the airplane climbed to 200 feet, then descended to 100 feet. The pilot was advised to turn right to pass behind the approach corridor for a departing airplane. Witnesses observed the airplane flying towards buildings, and stated that the airplane, which was about 50-100 feet above the water, started banking to the right which increased to near a 90-degree angle of bank. The airplane then pitched nose down and impacted the water nose and right wing low, rolled inverted and sank in about 6 feet of water about 20 yards from a seawall. Examination and testing of the right magneto revealed that the point gap was 0.018 inch, which is greater than specified by the manufacturer, and the magneto fired intermittently throughout the entire rpm range. After adjusting the point gap to within limits, the right magneto operated normally. The engine was then run with replacement magnetos installed with their point gaps set as found on the accident magnetos. During the right magneto check, the rpm drop was 156 rpm greater than the left magneto check. Damage was also noted to the #1 cylinder top ignition lead. Examination of the aft bottom section of the right float revealed numerous damaged rivets which join the keel to the bottom skin panel near the aft bulkhead.

History of flight

On March 17, 1996, about 1237 eastern standard time, a float equipped Cessna U206G, N9983Z, registered to and operated by Key West Seaplane Service, Inc., crashed shortly after takeoff from the Gulf of Mexico Seaplane Base, Key West, Florida. Visual meteorological conditions prevailed at the time and a DVFR flight plan was filed and activated for the 14 CFR Part 135 on-demand, non-scheduled, domestic, passenger flight. The airplane was destroyed and the commercial-rated pilot and four passengers were fatally injured. One passenger was seriously injured. The flight originated from the Seaplane Base about 3 minutes earlier.

According to company personnel, the pilot fueled the airplane before departure and the passengers were questioned about their weights before boarding the airplane. The seating information is provided by the Director of Maintenance (D.O.M.) for the company who witnessed the loading of and departure of the airplane. The right front seat was occupied by a passenger who was later determined to be a single-engine land rated pilot. The pilot was observed to taxi about 1-2 miles away from the seaplane base and the takeoff was initiated from a point abeam the Garrison Bight Channel just north of the Fleming Key. The flight departed into the wind and was about 60 feet above the water about abeam the Salt Pond Keys. The D.O.M. stated that he then diverted his attention and he further stated that he watched the takeoff because the engine was near the time required to be overhauled.

According to radar data from the Key West Naval Air Station, four secondary radar returns each 5 seconds apart were recorded. The airplane was first observed at 1236.52 while at 100 feet, heading 174 degrees and on the 106 degree radial and 2.4 nautical miles from the Key West Very High Frequency OmniDirectional Range Station (VOR). The next secondary radar return indicated that the airplane was at 200 feet on a heading of 131 degrees. The third secondary radar return indicated that the airplane was at 100 feet on a heading of 177 degrees. The final radar return indicated that the airplane was at 100 feet; on the 111 degree radial and 2.6 nautical miles from the VOR; heading was not available. Calculations determined that the approximate indicated airspeed was 54 knots using the change in time and distance between the radar targets and 6 knots of wind from 120 degrees recorded at the Key West International Airport at 1240. The airplane Pilot's Operating Handbook indicates that the indicated stall speed at gross weight with the flaps retracted and at a 45-angle of bank is 54 knots.

Review of a transcript of communications with the Key West International Airport, Air Traffic Control Tower (ATCT), revealed that the pilot contacted the tower and stated that the flight was departing Key West "I'd like to go Cow Key Channel (which is over water) along the shoreline westbound to the Tortugas." The controller advised the pilot of the wind direction and velocity and also provided the altimeter setting, and advised the pilot to advise when the flight was airborne. The pilot acknowledged the clearance then advised that the flight was airborne. The controller acknowledged the pilot transmission and initially cleared the flight to proceed southbound then advised the pilot to make a right turn to pass behind another airplane that was preparing to depart from the airport.

Numerous witnesses near the accident site observed the airplane flying towards the island and all stated that when the flight was near beach, the airplane began banking to the right which increased to about a nearly wings vertical angle of bank. One witness observed the airplane begin a climbing right turn before the airplane pitched nose down. The airplane was then observed to pitch nose down and impact the water nose and right wing low. The airplane then rolled inverted and came to rest about 20 yards from a seawall in about 6 feet of water with the left float out of the water. Witnesses and CFR personnel near the crash site jumped into the water and helped to recover the occupants.

Personnel information

Information pertaining to the pilot-in-command is contained in the NTSB Factual Report-Aviation and Supplement U. Additionally, review of the company records revealed that he began his initial ground training with the company on November 15, 1995. His initial flight training with the company was completed 3 days later, and his airman competency/proficiency check flight was accomplished with an FAA operations inspector on November 21, 1995. Review of his pilot logbook revealed a break in flying from 1991 to 1993. The last entry in his logbook was the FAA checkride entry which occurred in November 1995. The two entries before that were dated in 1993 and were flown in the accident airplane. According to FAA personnel, the pilot did not have any previous accidents or incidents and he did not have any enforcement action pertaining to violation of any FAR'S. He was prescribed medication to control transient essential hypertension; however, he indicated on his last medical application dated November 15, 1995, that he was not taking any medication. On that application he indicated that he had flown 0 hours in the previous 6 months and his last medical was in 1993.

Information pertaining to the pilot-rated passenger in the right front seat is contained in Supplement E.

Aircraft information

Information pertaining to the airplane is contained in the NTSB Factual Report-Aviation and Supplements A and B. Review of the engine maintenance records revealed that the engine had accumulated 1,612.1 hours since rebuild by the engine manufacturer. The right magneto had accumulated 1,503 hours since new at the time of the accident and had been reinstalled on the engine on December 12, 1995. The left magneto had accumulated 302 hours since new at the time of the accident and was installed on October 10, 1995. The engine manufacturer recommends overhaul every 1,700 hours and the magneto manufacturer recommends overhaul not to exceed the engine overhaul time. Additionally, review of the inspection checklist for the last 100-hour inspection which was completed 2 days before the accident revealed that the mechanic did not initial that he had checked the landing gear group which requires in part inspection of the bottom of the floats for leaking around rivets. Review of the discrepancy and repair list for that inspection revealed that he did document repair to a loose pump tube for one of the compartments for the right float and the water rudders were rigged.

Communications

Air traffic control communications with the Key West International Airport Control Tower were recorded and a transcript is an attachment to this report.

Wreckage and impact information

Examination of the crash site revealed that the airplane was inverted in about 6 feet of water about 20 yards from a seawall. The right wing and engine assembly were separated from the airframe. During recovery of the airplane six inflatable type packaged life preservers were recovered. The airplane was taken to a nearby facility for further examination.

Examination of the elevator and rudder flight controls revealed control cable continuity from the cockpit to the control surfaces. The right wing aileron flight control cables were found to exhibit evidence of overload failure. Approximately 5 feet of the right float was observed to be displaced upward and the entire length of the float was observed to exhibit evidence of impact damage. Water was found in all float compartments. Examination of the aft bottom section of the right float revealed numerous damaged rivets which join the keel to the bottom skin panel near the aft bulkhead. The keel was pulled away from the skin panel and corrosion was observed between the keel