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On January 28, 2012, about 1408 eastern standard time, a Cessna T210M, N761HW, registered to and operated by Pinnacle Sales LLC, sustained substantial damage during a forced landing shortly after takeoff from St. Petersburg-Clearwater International Airport (PIE), Clearwater, Florida. Visual meteorological conditions prevailed at the time and no flight plan was filed for the 14 Code of Federal Regulations (CFR) Part 91 personal local flight from PIE. The private pilot, the sole occupant, sustained minor injuries. The flight originated from PIE about 1403.
The pilot stated that during his preflight inspection of the airplane he did not visually check the fuel tanks nor did he use the available dipstick to determine the quantity of fuel in the wing fuel tanks. With battery power applied, the left fuel quantity gauge indicated about 25 gallons, and the right fuel quantity gauge indicated slightly more than 1/3 capacity or approximately 15 gallons. After engine start he taxied to the approach end of runway 36R where he performed an engine run-up, checking the magnetos and propeller; no discrepancies were noted.
The pilot further stated that during the takeoff roll with the fuel selector positioned to the right tank position, he noted the fuel flow reading was satisfactory. After takeoff he retracted the landing gear, turned left to a heading of about 270 degrees and applied rudder trim to center the ball of the turn coordinator reporting that the flight had been uncoordinated for about 10 seconds. While continuing to climb on a westerly heading he reduced the fuel flow from 41 gallons-per-hour (gph) to 36 gph, and at about 1,600 feet mean sea level, the engine quit. He turned both auxiliary fuel pump switches on for 2 seconds in an attempt to restore engine power but that was not successful. He did not perform any other actions to restore engine power and reported he did not move the fuel selector. He then declared an emergency with air traffic control, trimmed for best glide airspeed between 80 and 85 knots, and turned right to return to the departure airport. While maneuvering with the flaps and landing gear retracted, he cleared one set of power lines then banked right to avoid another set. The left wing then collided with a tree followed by the right wingtip contacting the ground. He rolled to a wings level attitude and the airplane impacted the ground sliding about 110 yards before coming to rest upright. He remained in the airplane for 3 to 4 minutes then evacuated it and after fire rescue arrived was asked to shut off the fuel selector because of fuel leakage at the right side of the airplane forward of the co-pilot’s seat area. He did so, but the fuel leakage continued.
A witness reported seeing the airplane flying in a westerly heading about 2,000 to 2,500 feet, followed by hearing the engine rev, sputter, and then quit. He observed the airplane in a sharp bank as if flying to return to the departure airport, then heard the engine operating but reported it sounded as if it was “feathering.”
The pilot held a private pilot certificate with ratings for airplane single engine land and sea, airplane multi-engine land, and instrument airplane. He was issued a third class medical certificate on June 1, 2010, with a restriction to have available glasses for near vision. He listed on the NTSB Pilot/Operator Aircraft Accident/Incident report having a total time of 1,756 hours, of which 1,376 were in the accident make and model airplane.
The airplane was manufactured in 1977 by Cessna Aircraft Company as model T210M, and was designated serial number (S/N) 21062279. It was certificated under Part 3 of the Civil Air Regulations and originally powered by a Continental Motors, Inc. (CMI) formerly Teledyne Continental Motors TSIO-520-R engine and equipped with a McCauley constant speed propeller.
At manufacture, the gravity fed fuel supply system consisted of a 45 gallon total capacity fuel tank installed in each wing. Each wing tank is plumbed by 3/8 inch fuel lines installed in the front and rear door posts to separate approximately 1 gallon reservoir tanks installed in the cockpit beneath the floor forward of the pilot and co-pilot seats. The fuel is then plumbed from each reservoir tank to the fuel selector valve, forward to the auxiliary fuel pump, to the fuel strainer, engine-driven fuel pump, fuel metering unit, fuel manifold, and finally to the fuel injector nozzles. Excess fuel and vapor are returned from the fuel vapor ejector on the engine-driven fuel pump, through a check valve to the appropriate reservoir tank on the side selected by the fuel selector valve. The fuel selector valve is a three-position valve labeled “Left On”, “Right On”, and “Off.” The airplane was also equipped with a combination analog manifold pressure and fuel flow (pressure) gauge.
Since manufacture, the airplane was modified in accordance with (IAW) numerous Supplemental Type Certificates (STC’s). Specifically, an 18-gallon aft baggage compartment fuel tank was installed in November 1998 in accordance with (IAW) STC SA515NE. The aft baggage compartment fuel tank supplied fuel to the right fuel tank via hoses and an electric pump controlled by the pilot. The control switch and quantity gage were installed directly aft of the fuel selector handle. In April 2010, a J.P. Instruments EDM 800 indicator was removed and a JPI EDM 830 was installed IAW STC SA2586NM. The FAA 337 form indicates the installation was a change of the display only.
On November 29, 2011, the airplane was modified IAW STC SA02918CH, by installation of a Continental Motors, Inc., IO-550-P6B engine rated for 310 maximum continuous horsepower at 2,700 rpm, and a Hartzell constant speed propeller HC-J3YF-1RF with F7693DF+2 propeller blades. The original exhaust and turbocharger components were retained by the STC, although dual intercoolers were installed. The fuel injection system is from the Continental TSIO-550-C engine which utilizes larger fuel injection nozzles and lower fuel pump pressures than the originally installed engine, and the modified induction system is similar to the TSIO-550-C, G, and K engines. The STC also modified the operational characteristics of the split rocker-type auxiliary fuel pump switch, resulting in the yellow or right side of the switch operating the auxiliary fuel pump at only low speed. The red, or left side of the switch operates the auxiliary fuel pump only at high speed. The STC also replaced the -8 size hose from the fuel strainer to the fuel pump inlet fitting but the line size remained the same. The engine installation results in a manifold pressure limit of 31 inches, with allowance for momentary excursions to 33 inches for cold oil. The fuel flow/pressure normal operating green arc range is 5 to 18 GPH, the caution range is 18 to 30 GPH, and the maximum fuel flow limit is 37 GPH which equates to a maximum metered fuel pressure limit of (13.6 psi).
The flight manual supplement associated with the STC engine installation supplied to the pilot incorrectly listed the maximum fuel pressure limit in the limitations section and also in the powerplant markings table. The STC holder reported that as part of the STC installation process for the accident airplane, the combination analog manifold pressure and fuel flow (pressure) gauge was removed and sent to a facility to be remarked so as to coincide with the fuel flow/pressure limitations of the STC. However, the facility did not mark it as instructed. The fuel flow/pressure portion of the gauge was required to have red line radials at 3.0 and 13.6 psi, a green arc normal operating range of 5 to 18 gallons-per-hour (GPH), a yellow arc caution range of 18 to 30 GPH, and a white arc normal climb range of 34 to 37 GPH. The pilot/owner was reportedly instructed about the instrument issue but later reported to NTSB that he had always used the JPI for fuel flow and found it to be very accurate. Additionally as part of the STC installation, an incorrect magnetic pickup for the JPI was provided to the STC holder and installed, resulting in erratic rpm reading at high rpm; however, the pilot reported that he uses an electronic tachometer installed IAW a STC for engine rpm.
Following the engine installation in December 2011, a maintenance facility inspected the airplane due to a complaint about poor idling. Maintenance personnel inspected the airplane and noted maintenance discrepancies (chafing, etc.) attributed to the engine installation. As a result of the poor idling, the maintenance facility adjusted the low unmetered fuel pressure, reset the idle mixture, and also twice adjusted the high side fuel flow. The first adjustment of the high side fuel flow was due to a pilot report of fuel flow exceedance, and the second adjustment 2 days later by the same facility was to correct for a low fuel flow condition. The write-up for the second adjustment also indicated that the manifold pressure was adjusted, and those adjustments were performed with the oil temperature between 170 and 180 degrees.
At the time of the accident the airplane had been operated for approximately 42 hours since the STC engine was installed.
A surface observation weather report taken at PIE at 1353, or approximately 15 minutes before the accident, indicates the wind was from 310 degrees at 9 knots, the visibility was 10 statute miles, and clear skies existed. The temperature and dew point were 20 and 09 degrees Celsius, respectively, and the altimeter setting was 30.14 inches of Mercury.
The airplane was equipped with an Aspen electronic flight display (EFD) 1000, a Garmin GPS Map 495 GPS receiver, and a JP Instruments (JPI) EDM 830; however the Aspen EFD does not record any data. The data from the EDM was provided by the pilot-in-command to the Federal Aviation Administration (FAA) and National Transportation Safety Board, while the Garmin GPS was sent to the NTSB Vehicle Recorder Division for readout.
According to the NTSB Factual Report concerning the readout of the GPS, the accident flight from takeoff to accident was recorded as a track log. A plot of the track log tabular data was overlayed onto a Google earth Plot, and the GPS Factual Report with raw data is included in the NTSB Public Docket for this case.
The JPI EDM recorded data from the accident flight begins after engine start with the first time stamp index point indicating the engine was operating at 986 rpm, the fuel flow was 3.4 GPH, and the fuel used was 44.3 gallons. The last time stamp index point indicates the rpm was 1, the fuel flow was 0 GPH, and the fuel used was 46.5 gallons. A total of 129 index points were recorded with an index point being recorded approximately every 6 seconds. The recorded data included fuel flow, rpm, manifold pressure, and calculated fuel used along with other engine parameters. Review of the data indicates that during takeoff power application, the fuel flow increased above 37 GPH, and remained above that value for 6 data points. During that time the manifold pressure was between 31.4 and 32.0. The highest recorded value of 41.1 GPH was noted at 2 of the data points, and then the fuel flow at the next data point 6 seconds later was 37.4 GPH. The fuel flow then decreased to about 36 GPH, and remained at that value for about 15 data points or approximately 1 minute 30 seconds. During this time the manifold pressure was between 30.7 and 31.4. The fuel flow decreased to about 16 GPH, with a corresponding decrease in engine rpm, then decreased to 0 GPH, with an engine rpm at that data point of 1,351 rpm. The fuel flow then increased to 31.0 GPH (the highest value after the decrease to 0 GPH), though the engine rpm at that data point was 1,149, and the manifold pressure was 29.1. The fuel flow again decreased to 0, with corresponding decrease of engine rpm, with the last recorded engine rpm of 1. No rapid fluctuation of fuel flow was noted.
WRECKAGE AND IMPACT INFORMATION
The airplane impacted in a grassy open field; the accident site was located at 27 degrees 54 minutes 31.42 seconds North latitude and 082 degrees 43 minutes 10.45 seconds West longitude, or 1.7 nautical miles and 266 degrees from the center of PIE Airport.
A PIE Airport Operations Supervisor who was on duty at PIE on the date and time of the accident reported he responded to the accident site after being notified of the accident. After arrival he reported observing fuel leaking on the right side of the airplane which was being treated by local fire rescue; however, the individual did not identify the location of the leak nor could he confirm how much fuel leaked out. The pilot was asked to shut off all fuel related valves that could stop the spill and he complied with the request.
Examination of the airplane at the accident site was performed by a FAA airworthiness inspector who reported that visual inspection of the left fuel tank revealed it to be “almost full”; however, the tank was later drained and found to contain 29 gallons. The right fuel tank only had residual fuel, the right reservoir tank was reported to be ruptured, and the auxiliary fuel tank was full by gauge indication. The firewall and tunnel for the nose landing gear were bent. The inspector removed the engine-driven fuel pump and noted the drive coupling was undamaged. . The airplane was recovered for further examination.
Further inspection of the fuel injection system components revealed residual fuel at the inlet fittings of the fuel manifold valve and engine-driven fuel pump. Inspection of the air induction system revealed no obstructions, and inspection of the engine revealed no evidence of preimpact failure or malfunction. The lower spark plugs were removed and did not appear to be lead fouled. The aircraft’s battery and fuel pump were turned on with the fuel injector lines loosened at each fuel injector nozzle and the inlet fuel line at the engine-driven fuel pump loosened; fuel came out of the loosened connections. The magneto P-leads checked satisfactory.
Examination of the cockpit revealed an analog combination manifold pressure and fuel flow gauge was installed on the co-pilot’s side of the instrument panel just to the left and slightly above the control yoke. The faceplate of the fuel flow side of instrument depicted red line radial markings of 3.0 and 23.0 psi, green arc ranges between 36 and 105 PPH and 175 and 205 PPH, and yellow arc range between 105 and 175 PPH. A placard indicating, “Refer to Original Fuel Flow Instrument for Primary Information” was also located on the co-pilot’s side of the instrument panel below the engine gauges and also to the right of the analog combination manifold pressure and fuel flow gauge.
Additional examination of the engine was performed by a representative of the engine manufacturer with FAA oversight, and examination of the airframe was also performed by the FAA airworthiness inspector. Using shop air, the right fuel supply system was found to be intact with the exception of a broken line between the right reservoir tank and the fuel selector valve where the line passed through a lighting hole of adjacent structure. The right wing fuel cap did not seal to the sealing surface of the wing. With battery power applied and the wing tanks empty, the left and right fuel quantity gauges indicated zero fuel when the selector was placed to the left and right positions. The wing panels were then opened and the float in each tank was raised to signify a full tank and both fuel quantity gauges responded appropriately to the full position smoothly. Inspection of the fuel selector valve revealed it was able to be rotated; however, the detents could not be felt. Further inspection of the fuel selector revealed the lack of detent feel was attributed to dirt and debris building up on top of the selector valve causing the balls to stick; disassembly inspection of the fuel selector revealed no obstructions. Inspection of the right wing fuel vent revealed no obstructions, and inspection of the alternate air door revealed it operated normally. The engine was removed from the airplane and sent to the manufacturer’s facility for an engine run.
At the manufacturer’s facility a test club propeller was installed and the engine was installed in a test cell for attempted engine runs with NTSB and/or FAA oversight. Because of the configuration of the engine, the test cell louvers could not be lowered on the top portion of the engine changing cooling characteristics. The engine was started and allowed to warm up then full throttle was applied and at about 2,300 rpm, the fuel to air ratio went rich, black smoke was coming from the exhaust, and the engine quit. The engine-driven fuel pump was removed and placed on a test bench which indicated at an unboosted condition the outlet pressure was greater than specified. The remaining fuel injection components were bench tested and no evidence of preimpact failure or malfunction was noted. The fuel injection components were reinstalled and additional engine runs were then performed all yielding the same results pertaining to running rich at 2,300 rpm. That condition was later attributed to negative pressure created at the turbocharger inlet caused by propeller blast past the turbocharger due to the orientation of the turbocharger and engine in the test cell. A 180-degree induction pipe
was connected to the turbocharger inlet to simulate the actual aircraft installed configuration and an exhaust tail pipe was connected to the exhaust side of the turbocharger. The engine was started and found to operate normally. No evidence of preimpact failure or malfunction was noted to the engine, or its systems.
TESTS AND RESEARCH
At the request of the NTSB, ground based testing was performed using N4789K, a 1979 Cessna P210N, S/N P2100320, owned and operated by the STC holder. The ground based testing was requested in order to determine the affect of excessive fuel flow on engine performance, and also to determine the affect different oil temperatures have on fuel flow, rpm, and manifold pressure. The testing was performed by the STC holder on November 11, 2012. The airplane utilized for the testing was equipped with the same engine and propeller as the accident airplane. Although the turbocharger installed on N4789K was different from the turbocharger installed on the accident airplane, the STC holder reported that they use the same operating engine parameters for the test airplane as the accident make and model airplane. With respect to the fuel supply system, the airplane used for the testing was similar to the accident airplane including the dimension of the fuel supply lines in the forward and aft door posts, and also pertaining to the excess fuel/vapor return lines to the reservoir tanks.
The testing of N4789K was performed at the Pickaway County Memorial Airport (CYO), Circleville, Ohio, which has a surveyed field elevation of 685 feet, and was recorded by two cameras mounted in the cockpit. The engine was started about 1557 eastern standard time, and while at the run-up area the automated terminal information service (ATIS) from Ross County Airport (RZT), Chillicothe, Ohio, at 1559, indicated the temperature was 20 degrees Celsius (same as the ATIS for the accident flight), the dew point was minus 3 degrees Celsius, and the altimeter setting was 30.17 inches of Mercury. The RZT Airport is located about 5 nautical miles south-southwest of the CYO Airport.
Although only ground based testing was requested using N4789K, the STC holder actually initiated takeoff and applied takeoff power when the oil temperature was indicating 129 degrees (within 4 degrees of the temperature during takeoff of the accident flight). With full power applied, the camera recorded exceedances for fuel flow (40.4 GPH), rpm (2,725), and manifold pressure (33.2 inches of Mercury), although no degraded engine performance was noted. The STC holder continued the takeoff remaining in the traffic pattern and climbed to 2,500 feet mean sea level (msl) during the downwind leg. The pilot returned for landing and landed uneventfully with the oil temperature indicating 161 degrees. He immediately returned to the approach end of the runway and initiated takeoff applying full throttle with the oil temperature indicating 166 degrees. With full power applied an exceedance of engine rpm was noted, while the maximum fuel flow was recorded to be 37.4 GPH and the manifold pressure was recorded to be 31.1 inches of Mercury; no degraded engine performance was noted. The pilot returned for an uneventful landing.
Further ground based engine run testing was performed with FAA oversight of a 1979 Cessna T210N, N4888C, which was also modified by installation of the same make and model engine installed in the accident airplane. The testing was approved by the airplane owner, and was executed by the STC holder. The STC holder reported that they use the same operating engine parameters for the test airplane and accident make and model airplane. With respect to the fuel supply and excess fuel/vapor return systems, the airplane used for the testing was similar to the accident airplane with the exception of the dimension of the fuel supply lines in the forward and aft door posts. The dimension of the aluminum lines in the test airplane forward door post was 3/8 inch while the aluminum line in the aft door post was ½ inch. The testing was performed on April 3, 2013, also at Pickaway County Airport (CYO), Circleville, Ohio. The airplane was equipped with a JPI EDM, and two cameras were installed in the cockpit to record the readings of the JPI EDM. The weather at RZT Airport about the time of the testing indicated the temperature and dew point were 40 and minus 13 degrees Fahrenheit, respectively, and the altimeter setting was 30.40 inches of Mercury. Prior to the ground based test, the STC holder adjusted the manifold pressure and fuel flow to levels exceeding normal operating parameters to demonstrate the consequences or lack of consequences of excessive fuel flow and manifold pressure. The testing revealed that with the oil temperature at about 110 degrees Fahrenheit and all cylinders above 200 degrees F, full throttle application resulted in 34.9 inches manifold pressure and fuel flow reached a high of about 47 GPH. Observers outside said there was no smoke or indications the fuel flow was too high. The FAA inspector who witnessed the ground based testing reported that there were no indications to indicate engine failure due to excessive fuel flow.
Civil Aeronautics Regulation (CAR) Part 3, titled “Airplane Airworthiness; Normal, Utility, and Acrobatic Categories” contains design criteria for certification of the airplane and its systems. Section 3.434, which pertains to the fuel flow rate of gravity fuel systems, indicates that the fuel flow rate for gravity systems (main and reserve supply) shall be 150 percent of the actual takeoff fuel consumption of the engine.
The airplane’s type certificate data sheet indicates that the airplane’s takeoff horsepower rating is 310 limited to 5 minutes, and the maximum fuel limit is 186 PPH. Using the 150 percent criteria from section 3.434 of CAR 3, the airplane’s fuel supply system was designed to deliver fuel flow rate of 279 PPH, which correlates to 46.5 GPH.
Following engine installation IAW the STC, the JPI recorded a total of 67 separate data files either associated with a flight or only ground based operations. Further review of the data files revealed that 25 of the data files associated with a flight reflect fuel flow exceedance, while no fuel flow exceedance was noted during 9 of the data files associated with a flight. The highest recorded fuel flow was 44.3 GPH, which occurred during a flight on December 1, 2011, or 2 days after the STC engine and propeller were signed off as being installed.
Section 4 of the Pilot’s Operating Handbook (POH) contains in part checklists for preflight inspection, before takeoff, and takeoff. The before starting engine and before takeoff checklists both indicate to place the fuel selector on the fuller tank. Section 3 of the POH contains a checklist for engine failure during flight, which stipulates to move the fuel selector valve to the fuller tank, followed by placing the mixture control to full rich. The auxiliary fuel pump switch should be turned on for 3 to 5 seconds with the throttle ½ open, then off, and to place the ignition switch to the both (or start position) if the propeller is stopped. The final step of the checklist indicates to advance the throttle slowly.
The FAA Approved Airplane Flight Manual Supplement for the airplane indicates that an engine-driven fuel pump failure will be evidenced by a sudden reduction in the fuel flow/pressure indication prior to the loss of power when operating on a tank which contains an adequate supply of fuel. The supplement indicates that with fuel flow decrease while operating on a tank with an adequate supply of fuel, to immediately move the left half of the auxiliary fuel pump switch to the on position, and manual leaning of the fuel/air ratio may be required. Section 7 of the supplement titled Systems Descriptions indicates that in the event that the engine-driven fuel pump is functioning, and the auxiliary fuel pump switch is placed in the on position, an excessively rich fuel/air ratio may be produced requiring the fuel to air ratio be reduced by pulling on the mixture control. Further review of the supplement revealed information concerning vapor formation indicating fuel flow fluctuations greater than 0.9 GPH are consistent with vapor formation.
Correlation of the GPS Factual Report and the data downloaded from the GPS along with the data downloaded from the JPI EDM 830 was performed. The estimated point of takeoff power application by the GPS data occurred about 1404, while the JPI data indicates that point was about 1403:36, or a difference of approximately 24 seconds. The data from the GPS indicates that the left turn to the west-southwesterly direction began about 1405, or about 1 minute after takeoff power was applied. The airplane turned to a west-southwesterly heading and continued in that direction until about 1406:43. While in a west-southwesterly heading and climbing, the fuel flow was recorded to be about 36 GPH until about 1406:12. At the next 2 data points at 1406:18, and 1406:24, the fuel flow was recorded to be 16 GPH, then decreased to about 2 GPH, while the flight continued climbing in a west-southwesterly heading with decreasing groundspeed for about 18 seconds, or until 1406:43. About that time a right descending turn was initiated; the fuel flow at that point was about 1 GPH. The flight proceeded on a southeasterly heading with the fuel flow decreasing to less than 1 GPH and remaining less than 1 GPH until 1407:54, at which time after completion of the right turn, the fuel flow increased to 26.2 GPH, and remained above that value for the next 42 seconds, or until 1408:42, at which time the fuel flow decreased to 2.9 GPH. About that time the airplane was descending and changing heading to a southerly direction, in preparation for the forced landing.
Documents from the engine manufacturer pertaining to vapor return indicate that the maximum vapor return for the original installed engine (TSIO-520-R) is 101 PPH, while the maximum vapor return for the STC installed engine is approximately 59 PPH, a reduction of nearly 42 percent. Further, the total fuel flow, which is the required maximum fuel flow for the engine plus the vapor return amount for the original engine installed was 287 PPH, while the total fuel flow for the STC installed engine is 276 PPH, a decrease of approximately 4 percent.
The airplane was fueled last on January 9, 2012, while at Fort Myers, Florida. The pilot fueled the airplane himself filling the tanks while following the procedures in the POH, adding 36.49 gallons of 100 low lead (100LL) fuel. At the time of the fueling, the JPI data indicated 33 gallons fuel had been used. The JPI EDM 830 was reset after fueling, and after fueling the K-factor was reset (re-programmed), and the 4 previous flights were used to determine what to reset the K-factor to. Prior to the accident flight, the JPI data files indicated the airplane had been operated on 4 flights totaling approximately 2 hours 54 minutes, and had also been operated on the ground using 44.2 gallons of fuel since being reset after the last fueling.
On September 9, 1981, Cessna Aircraft Company developed Service Information Letter (SIL) SE81-33, titled Fuel Vapor, applicable to the accident airplane. The SIL indicated the purpose was to instruct owners and operators about the facts about fuel vapor and to announce the availability of a service kit that installed an additional vapor return line between the fuel reservoir tank and the main wing fuel tank. The accident airplane did not have the service kit installed, nor was it required to have the service kit installed.