CEDAR KEY, FL, USA
N196DA
Diamond Aircraft Industries DA20-A1
The pilot did not ensure that the fuel valve was on nor did he activate the electric fuel boost pump before takeoff. The low fuel warning light illuminated on takeoff roll with sufficient runway remaining to abort the takeoff. The pilot elected to continue the takeoff. The airplane experienced a loss of engine power and a forced landing was initiated. The airplane collided with trees, and crashed while maneuvering to a forced landing area. The engine was removed and mounted in a test stand. The engine started immediately and sustained normal operations. The mechanical fuel pump functioned normally in all operating conditions. The low fuel warning light did not flicker or illuminate when using any combination of the mechanical or electric fuel pump. With the fuel valve turned to the off position the engine would run for about 2.4 minutes at full power before losing power.
On September 4, 1999, at about 1845 eastern daylight time, a Diamond DA20-A1, N196DA, registered to Sky King Aviation, operating as a 14 CFR Part 91 personal flight, crashed while making a forced landing back to George T. Lewis Airport, Cedar Key, Florida. Visual meteorological conditions prevailed and no flight plan was filed. The airplane sustained substantial damage. The private pilot reported no injuries. The flight was originating at the time of the accident. The pilot stated he did not conduct any performance data for his departure from George T. Lewis Airport. The departure runway is 2,335 feet long. He started the airplane engine, conducted an engine run-up, taxied out to runway 23, and back taxied down the runway for departure. The takeoff roll was normal. Before reaching rotation speed, the low fuel pressure warning light illuminated about half way down the runway. He checked and verified that the fuel selector valve and electric fuel pump were in the on position. He elected not to abort the takeoff and the airplane became airborne at about 1,800 feet. As soon as the airplane was airborne the engine started to sputter. He made a hard right turn in an attempt to return to the departure runway. Halfway through the turn the engine quit, the stall warning horn activated, due to low airspeed and high angle of bank. He realized he was going to over shoot runway 05. He lowered the nose to regain airspeed, and made a hard left turn towards the runway. The next he remembered was the airplane being on the ground with smoke in the cockpit. He turned the fuel selector valve off, and was assisted out of the airplane by a person who came to render assistance. A witness stated he observed the airplane on the takeoff roll. The airplane took off and was at about 15 feet when the engine sputtered. It looked like the pilot was going to set the airplane back down on the runway, but he continued the takeoff. He flew out over the water, made a 180-degree turn and over flew the runway. The airplane was observed to make a hard left bank, the left wing collided with the tie down area, the airplane turned sideways, took out a light-box sign, hit another airplane, a tree, and came to a complete stop. Examination of the airframe and flight controls by the FAA revealed no evidence of a precrash mechanical failure or malfunction. The electrical fuel switch was in the off position. The engine-driven fuel pump was removed from the airplane. Battery power was reconnected and the electrical fuel pump switch was turned on to validate pump operation. The electrical fuel pump did not produce any noise normally heard when the switch is turned on. Power was then turned off and the battery was disconnected. The FAA inspector asked the pilot if he had conducted a performance takeoff stopping distance calculation as part of his preflight preparation. The pilot stated no. The pilot was asked to calculate the weight and balance of the airplane and takeoff distance required given the following criteria: temperature 74 degrees, dew point 64, wind 310 at 4 knots. The pilot incorrectly calculated the weight and balance and takeoff distance. With continued assistance from the FAA, the pilot calculated the takeoff/stopping decision distance to be 1,100 feet. At this point of the ground roll, the pilot had 1,225 feet of runway remaining. The inspector stated, "It is my opinion that the pilot could have safely aborted the takeoff if he had acted responsibly when the fuel light had illuminated." (For additional information see FAA Inspector statement, an attachment to this report.) On September 7, 1999, the NTSB investigator-in-charge received a fax from the registered owner of the accident airplane. He stated that another airplane that was used by his flight school had experienced an intermittent engine roughness that would last for a second or more. After numerous inspections by the maintenance facility on the field they could not determine the cause. Inspections included pressure checks on the engine-driven fuel pump and the electric backup fuel pump. A change of all spark plugs and any related electrical items related to ignition, draining of the entire fuel tanks and inspection, replacement of fuel filters, and removal and inspection of the fuel lines. All inspections were found to be without fault. The registered owner stated further test flights revealed the problem was increasing and the fuel pressure warning light began to illuminate prior to the engine roughness. He suspected an engine-driven fuel pump intermittent failure Rotech of Canada was contacted and a new fuel pump was ordered and installed. The pump lasted about 4 hours and was replaced again. Rotech was contacted and another fuel pump was ordered and replaced. After 10 hours, the pump yielded the same results and was replaced. At this time N196DA began having the same symptoms. A fuel pump was ordered and replaced without any further incident. (For additional information see letter dated September 7, 1999, an attachment to this report.) A Diamond Aircraft Field Service Representative examined the aircraft on September 13, 1999, after the wreckage had been released by the NTSB to the registered owner on September 6, 1999. The examination was conducted at a salvage yard. The field representative concluded, "Visual inspection: All airframe fuel system components, located below the fuel tank and aft of the spar bridge appeared undamaged from impact of the accident. In addition, all components were properly installed and secured, including the electrical wiring and electrical ground terminal. Operational Check: When power was applied to aircraft's main bus and the "fuel pump" was selected on, the electric boost pump operated normally." (For additional information see Diamond Aircraft Field Service Report an attachment to this report.) Review of Diamond DA20 KATANA Airplane Flight Manual states on page1-2 Paragraph 1.3 WARNINGS, CAUTIONS, AND NOTES states, "The following definitions apply to warnings, cautions, and notes used in the Flight Manual: WARNING means that the non-observation of the corresponding procedure leads to an immediate or important degradation of the flight safety." Chapter 4 Normal Operating Procedures, paragraph 4.4 Normal Operation Checklist, 4.4.2. Before Starting Engine, 7. Fuel Shut-off Valve, OPEN. Paragraph 4.4.14. Engine Shut-down, does not instruct the pilot to turn the fuel shut-off valve to the off position when the flight is completed. Title 14 CFR Section 91.7 (b) states, "The pilot in command of a civil aircraft is responsible for determining whether that aircraft is in condition for safe flight. The pilot in command shall discontinue the flight when un-airworthy mechanical, electrical, or structural condition occur." The flight manual does not address the loss of fuel pressure on the ground; however, it states the following on page 3-4, "III. LOSS OF FUEL PRESSURE 1. Electric Fuel Pump ON, and land at nearest suitable airport 2. If Fuel Pressure Land at nearest suitable airport. Be Warning Light prepared for engine failure and Does not extinguish emergency landing" The engine fuel pump and electric fuel pump from N196DA was removed from the airplane and forwarded to the NTSB investigator-in-charge (IIC). The IIC forwarded the components to NTSB headquarters and were hand carried to Rotec Canada for further analysis. A Kodiak Research representative obtained the engine assembly from Quality Aircraft Salvage in Groveland, Florida. The engine was shipped to Rotec Research Canada Ltd. for testing and evaluation. The engine assembly was mounted onto a test stand to determine if the engine had suffered a mechanical failure. The original fuel pump was installed on the engine. Inspection of the fuel pump found no discrepancies and the pump did not rattle internally as originally suspected by the aircraft owner. The engine was pulled through by hand and found to be resistive and sticky. Investigation revealed the starter had failed. The starter was replaced and the engine was cranked over to establish oil pressure. The stator winding, triggers, and coils were impedance tested to confirm serviceability. An engine start was attempted. The engine started immediately and effortlessly. A high audible whine coming from the gearbox was noted. The engine was warmed and taken to mid power (3750 RPM) to perform a magneto check. The magneto check was within limits. The engine was accelerated to full power rpm of 5,800. The engine was run at cruise and various power settings with no hesitation or stoppage. The engine test stand fuel supply shut-off valve was changed to the off position. After several minutes (about 2.4), the fuel low pressure light illuminated and the engine ran for about 50 more seconds at full power before losing power. The fuel shut-off valve was turned back on and the engine recovered full power immediately. The fuel shut-off valve was activated again and the engine was operated at idle for 4 minutes before the fuel low pressure light illuminated. The fuel supply (shut-off supply valve opened) was restored and the engine recovered immediately. (See NTSB Powerplant Teardown Report of Investigation an attachment to this report.) A spectrum analysis of the engine was performed to determine vibration amplitudes of the engine. The engine was started and warmed to operating temperature, and then accelerated to 5,000 engine rpm for reading of the spectrum analysis. The result was the engine gearbox was producing overall vibration amplitudes of 21.68 inches-per-second in the 600-12,000 frequency range and overall vibration amplitudes of 29.17 in the 600-60,000 frequency range. These amplitudes are the most severe recorded to date of a 912 engine. A baseline engine will typically produce overall vibration amplitudes of 0.5 inches-per-second. A visual inspection was conducted on the gearbox. The PTO drive gear had evidence of severe gear spalling. Visual inspection of the Main drive gear showed that the drive gears had several deep pits on the tooth surfaces and severe spalling. A review of the engine logbooks was conducted to verify engine oil type, viscosity, frequency of oil changes, and maintenance performed with respect to the gearbox. The results were as follows: 1. Engine TTSN shown as 1297.0 as of August 23, 1999. Airframe total time shown as 2228.6. 2. Engine oil change intervals were at every 100 hours. 3. Majority of engine life on oil type Havoline SAE30HD. This oil is rated to a maximum climatic operating range of 85 degrees F. Aircraft was being operated in Florida. 4. Fuel pump changed at 651.9 TTSO of engine. No reason given for change of fuel pump. No record of serial numbers, on or off, recorded. 5. No entries could be found of references made in the engine log to reflect a monitoring of gearbox condition i.e. verification and recording of friction torque levels. 6. Gearbox was rebuilt by Lockwood Aviation at 540.6 hour TTSO. Gearbox TTSO 756.4. Rotech Research Canada Ltd., concluded in their Summary of Results: The engine started immediately and sustained normal operations. The mechanical fuel pump functioned normally in all operating conditions tested. At no time did the low fuel pressure warning light illuminate or flicker when using any fuel pump combination i.e. mechanical, electrical or both. No mechanical problem could be found to substantiate the cause of the engine stoppage reported by the pilot. The loud whine from the gearbox indicated severe gear set wear was present. The fuel pump's close proximity to the gearbox meant that the fuel pump was subject to high and severe vibration amplitudes caused by severe gear set wear. Engine logs indicate that the fuel pump was previously changed and therefore had been subjected to high vibrations for only a short time. The mechanical fuel pump was found to be serviceable. The excessive spalling of the gear set caused high vibration amplitudes to be pronounced at the gearbox and subsequently transmitted through the engine and accessories. Primarily, spalling is the result of operation of the engine with oils of low viscosity and high oil temperatures. The customer's choice of single grade oil was a minimum standard to all published criteria on lubrication of the 912 engine. The further choice of the 30-grade oil put the climate limitations for the oil at 30 degrees C (86 degrees F). The geographic location of the customer would most probably put the engine oil at its high limit capability. The 100-hour oil change intervals exceeded the minimum recommended interval by the manufacturer. This may have further taxed the oil's capabilities to maintain its viscosity and provide the necessary load bearing and lubrication required to prevent spalling. Overall maintenance of the engine was poor with a number of apparent defects that were unrelated to the accident. (For additional information see Final Report Engine Stoppage on Diamond Katana N196DA Engine S/N 44122760 an attachment to this report.) The engine assembly was returned by Rotech Research Canada Ltd; to Quality Aircraft Salvage, Groveland, Florida, on September 12, 2000. The components retained by the NTSB for further analysis were returned to Quality Aircraft Salvage, Groveland, Florida, on July 12, 2000.
The pilot's failure to follow the checklist (turn Fuel Valve-On, and activate electric fuel boost pump) and the pilot's decision to continue flight with a known unairworthy condition (illumination of low fuel pressure warning light on takeoff roll) with sufficient runway remaining to abort the takeoff. This resulted in a subsequent loss of engine power on initial takeoff climb, forced landing, and in-flight collision with trees and terrain.
Source: NTSB Aviation Accident Database
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