NTSB Factual Report

HISTORY OF Flight

On January 21, 1998, at 1534 Eastern Standard Time, a Twin Commander 695A, N269M, collided with palm trees and the ground near Delray Beach, Florida. The personal flight was operated by the pilot under the provisions of Title 14 CFR Part 91 with an instrument flight plan filed. Visual meteorological conditions prevailed at the time of the accident. The airplane was destroyed, and there was a post impact fire. The commercial rated pilot and his two passengers were fatally injured. The flight departed Boca Raton, Florida, at 1530 EST.

On January 21, 1998, at 1419, a man who identified himself as the pilot of N269M, telephoned the Miami Automated International Flight Service Station (AIFSS), and filed an instrument flight plan. According to the Air Traffic Control Specialist, the pilot filed an instrument flight plan from Boca Raton, Florida, to Gwinnett County Airport, in Lawrenceville, Georgia. After the pilot filed the instrument flight plan, the pilot was given a standard weather briefing. According to a statement from the Air Traffic Control Specialist, he did not recall the exact content of the weather briefing (see-attached transcription of communication).

At 1528, the pilot of N269M called Palm Beach Approach Control and requested an instrument flight clearance to Lawrenceville. The pilot was issued the flight clearance as filed, and was assigned an initial altitude of 2000 feet. The pilot was instructed to hold for release, and to advise approach when N269M was number one for takeoff. At 1529, Palm Beach Approach released N269M for takeoff after the pilot confirmed that he could execute a northbound departure. The pilot also advised Palm Beach approach that he would be in clouds almost immediately after takeoff.

At 1531, the pilot reported airborne to Palm Beach Approach. Palm Beach Approach instructed the pilot to climb and maintain 5000 feet. The pilot was also instructed to fly a 320-degree magnetic heading. After takeoff, radio communications between the pilot and Palm Beach Air Traffic Control Tower, was routine. Approximately five minutes into the flight, the radar controller assigned the flight a 320-degree magnetic heading. At about the same time, the radar controller noticed that N269A was in a left turn to the southwest, and questioned the pilot concerning the assigned heading, The controller stated that the pilot "sounded extremely strained" and replied, "N269M is in trouble." Radar altitude data showed a rapid loss of altitude for N269M; the last radar altitude data showed the flight at 2800 feet. The radar target display went into a coast mode, and radar contact was lost with N269M. No further radar or radio contact was recorded from N269M.

PERSONNEL INFORMATION

The pilot held a commercial pilot certificate with single engine land, multi engine land, and instrument airplane ratings. His latest medical certificate, a second class, was issued on December 10, 1997, and contained a limitation that he must wear corrective lenses for distant vision and must possess glasses for near vision to exercise the privileges of his airman's certificate. The pilot's last flight review was August 8, 1997. The flight review was taken a Twin Commander Model 695A airplane. The pilot had accumulated approximately 1,500 hours of total pilot time. The review of the pilot's records also showed that the pilot had accumulated a total of 843 hours in the Twin Commander 695A; within 90 days of the accident, the pilot had flown 72 hours in the Twin Commander.

AIRCRAFT INFORMATION

N269M was owned by Airplanes of Boca, and the pilot. Additional information on the airplane is located in the factual report on page 2 under the "Aircraft Information" data field.

METEOROLOGICAL INFORMATION

The weather at the time of the accident was visual meteorological conditions (VMC) with rain, thunderstorms, turbulence and gusty winds in the vicinity. Additional information about the weather is contained on pages 3 and 4 under the section titled Weather Information.

During the preflight weather briefing, the pilot was briefed on existing and forecasted for his intended route of flight. The pilot was informed of a high pressure system that was dominating the weather across the south of Florida. There were rain showers. There were also isolated moderated to heavy rain showers west of Boca Raton with the heavier showers west of Boca Raton. The pilot was also told that once he started north those showers would no longer be a factor. south of Boca Raton in the area of Fort Lauderdale. The shower activity was associated with a stationary front, in the area. The pilot was also told that the weather he saw at Boca Raton was part of this system. Boca Raton and Fort Lauderdale areas reported rain shower activity with isolated moderate to heavy showers west of Boca Raton.

There is no weather reporting facility available at Boca Raton. However, a pilot that landed at the Boca Raton Airport at the approximate time that N269M departed, reported that the weather during the approach, landing, and north of the airport, "looked very bad". Other pilots flying into the Boca Raton area reported observing weather conditions on their airborne weather radar that ranged from areas of moderate to heavy rain. One pilot, flying an airplane with an on board lightning strike finder stated that he had no indications of lightning in the immediate Boca Raton area.

Another pilot, flying a Cessna Caravan, enroute to Boca Raton, was issued an approach clearance for the VOR Approach. The pilot declined the approach from the west and elected to continue south around an area of convective activity. Upon arriving at Boca Raton, he requested the current weather. He stated that a pilot taxing for takeoff responded to his request. The pilot on the ground at Boca Raton told the Cessna Caravan pilot that there were low ceilings and very heavy rain north of the airport. The pilot also provided Cessna Caravan pilot with additional weather information for the other quadrants of the airport. At approximately 1530, while on final to runway 5, the Cessna Caravan pilot noticed a Twin Commander in the runup area, and subsequently watched the Twin Commander takeoff. The Cessna Caravan pilot did not report seeing other airplanes in the runup area or taxing for takeoff (see attached pilot reports of weather conditions).

Weather radar data from the Miami Weather Surveillance Radar-1988, Doppler (WSR-88D) showed a large, intense convective cell just west of Boca Raton between 1530:15 and 1535:57. Moderate to very heavy rain showers were associated with the convective activity. The Federal Aviation Administration National Track Analysis Program (NTAP) was employed to assist in defining the severity of reported weather conditions. A review of the NTAP data showed that N269M was 3.5 to 4.0 miles north of the core of the large convective cell. The WSR-88D data at 1536:04 to 1541:46, showed that the area of convection west of Boca Raton had shifted slightly to the north and had intensified. The reflectivity values of the WSR-88D data ,in the core of the cells, ranged from 35 dBZ (VIP level 2) for the smaller cell to 50.5 dBZ (VIP level 5) for the larger cells.

WERCKAGE AND IMPACT INFORMATION

An examination of the accident site disclosed that the airplane was destroyed by impact forces with the ground and post crash fire. Further on-site examination also disclosed areas of post-impact fire to the main fuselage and the wing assembly. The airplane wreckage was located in a stand of palm trees west of Delray Beach. An examination of the accident site disclosed that, aircraft wreckage debris was scattered over an area approximately 375 feet long and 125 feet wide. The airplane impacted the soft terrain in a nose down attitude. Other wreckage debris was scattered on a westerly magnetic heading beyond the main wreckage.

The main wreckage was located in a five-foot crater 20 feet northwest of several freshly damaged palm trees. Wreckage debris recovered from the fresh crater included airframe components from the nose section, wing assemblies, powerplants, fuselage and the empennage. Above the rim of the crater, the airframe was compressed to a height of about four feet. Additional aircraft wreckage was scattered 300 feet northwest of the main wreckage.

The major sections of the airplane, the left and right outboard sections of the wings, parts of the left and right ailerons, parts of the flaps, left and right horizontal stabilizers, part of the left and right elevator, rudder horn, and lower rudder, were located at the accident site. All major components of the airframe were also located within the layout of the wreckage path. Parts of all major assemblies were found at the crash site.

Debris from both engines and both propellers was recovered from the crater. During the engine teardown, the following findings were discovered on both engines:

1. Broken blades on both the first and second stage impellers 2. First and second stage compressor impeller blades were bent opposite the direction of rotation 3. Rotational score marks on the first and second stage compressor impeller blades, with corresponding rotational scoring on the second stage compressor shroud 4. Second and third stage turbine rotor blades were also bent opposite the direction of rotation 5. There were platform rubs on all stages of turbine rotor blades, with corresponding score marks on the turbine stator/rear support.

The follow-up examination, of the propeller assemblies failed to yield blade angle information.

MEDICAL AND PATHOLOGICAL INFORMATION

The postmortem examination of the pilot was conducted by Dr. Jon R. Thogmartin at the office of the Palm Beach County Medical Examiner in Palm Beach, Florida. A toxicological examination of the pilot was performed by the Toxicological and Accident Research Laboratory of the Federal Aviation Administration in Oklahoma City, Oklahoma. The Toxicology report stated that no ethanol was detected in the muscle specimen. Carbon monoxide and cyanide analysis could not be performed due to lack of a suitable specimen.

ADDITIONAL INFORMATION

Radar data recovered from Miami tower was used to generate a plot of the track for N269M after it departed Boca Raton. Recovered data included distance, east and north of Boca Raton, flight altitude, and total time of the flight (see attached plots of radar data).

The airplane wreckage was released to Mr. Michael Barrett, insurance adjuster, for United States Aviation Underwriters, Orlando, Florida.

Additional parties to the investigation included:

Steven G. Macon, AlliedSignal Aerospace, Phoenix, AZ,

Roger Alderman, Twin Commander Aircraft Corp, Arlington, WA

Roger W. Stallkamp, Hartzell Propeller Inc., Piqua, OH,

Mona Tindall, FAA Fort Lauderdale FSDO, Fort Lauderdale, FL,

Paul Werner Jr., FAA/MIDO, Vandalia, OH,

Tom McCreary, Hartzell Propeller Inc. Piqua, OH.

NTSB Probable Cause

The pilot flew into known convective meterological conditions and lost control of the airplane. Factors were low clouds, and moderate to heavy rain.