John Denver plane crash - Essay Example

Accident Investigation Report on John Denver Plane Crash Flight History At around 1640 of October 12, 1997, the pilot, a middle-aged male Caucasianarrived at the Monterey Peninsula Airport to conduct a practice flight on his plane, an Adrian Davis Long-EZ model with markings N555JD. At 1702 Pacific daylight time, the pilot contacted ground control and obtained a taxi-for-takeoff clearance from the hangar. At 1709, the pilot reported to the local controller that he was ready for takeoff on runway 28, and requested to stay in the traffic pattern for some touch-and-go landings. The plane was cleared for takeoff at 1712, and the pilot performed three touch-and-go landings before departing the traffic pattern about 1727. At this time the controller asked the pilot to recycle his transponder code and the latter did so. At around 1728 Pacific daylight time, the plane was flying in a westerly direction when it began to lose altitude, went into a steep nose-down descent, and hit the water. Witnesses said they heard a strong "pop" and a reduction in engine noise level just before the airplane's impact with the water. Visual meteorological conditions prevailed from start to the end of flight. The point of impact was an area in the Pacific Ocean off Pacific Grove, California. The airplane was destroyed and the pilot, the sole occupant, received fatal injuries. Rescue workers from the area were dispatched to the site to recover the pilot's body, secure the crash site, and recover the wreckage. An autopsy on October 13, 1997 by the Monterey County Medical Examiner revealed that the cause of the pilot's death was multiple blunt force trauma. Investigation of the Accident This report summarizes the findings of the National Transportation Safety Board (NTSB, 1999; AW, 1999) and several reports (CNN, 1998; CIR, 1999) on the probable causes of the accident that killed John Denver: human factors (Sumwalt, 1997) or aircraft design and integrity. Air traffic control records. The pilot did not file a flight plan. The Air Traffic Control (ATC) tapes revealed no distress calls from the pilot, who did not indicate any aircraft or engine malfunctions. A certified audio re-recording of the transmissions between the accident airplane and the Monterey ATC Tower local control position was subjected to audio spectrum analysis to identify background sound signatures that could be associated with engine trouble. Analysis of nine transmissions between 1714 and final transmission at 1728:06 showed engine speed harmonics between 2,100 and 2,200 revolutions per minute (rpm). Accident Witnesses. Of twenty witnesses interviewed: Four saw the airplane as it was flying west; five observed the airplane in a steep bank, with four of those reporting the bank was to the right (north). Twelve saw the airplane in a steep nose-down descent, of whom six saw the airplane hit the water near Point Pinos some 150 yards offshore. The airplane was flying at an altitude estimated at 350-500 feet over the residential area. Pre-flight Witnesses. Two pre-flight witnesses gave important testimonies related to the accident. The first was an aircraft maintenance technician who assisted the pilot in removing the airplane from a hangar. He observed the pilot perform a preflight check for 20 minutes and borrow a fuel sump cup to drain a fuel sample to check for contaminants. He did not observe the pilot visually verify the quantity of fuel aboard the airplane, nor did he see the pilot check the engine oil level. The technician and the pilot talked about the location of the cockpit fuel selector valve handle behind the pilot's left shoulder and its resistance to being turned. They attempted to extend the reach of the handle with a pair of vice grip pliers, but this did not work, as the pilot could not reach the handle. The pilot said he would use the autopilot in-flight to hold the airplane level while he turned the fuel selector valve. The technician observed that the fuel selector handle was in a vertical position (meaning that the right tank was in use). The maintenance technician noticed that the fuel sight gauges were visible only to the rear cockpit occupant. When the pilot asked the technician about the quantity of fuel shown, the technician answered that he had "less than half in the right tank and less than a quarter in the left tank." The technician estimated the fuel quantity based on the assumption that the gauge presentation was linear, then provided a shop inspection mirror to the pilot so that he could look over his shoulder at the fuel sight gauges in-flight. The mirror was recovered in the wreckage. According to the technician, the pilot declined an offer of fuel service since he would be flying for only about an hour. The pilot then got in the airplane and proceeded with his preflight duties, including checking the operation of the control surfaces. The technician went into the hangar to put away his tools and heard the engine start, but the engine soon quit. He walked out of the hangar and observed the pilot turn in his seat to the left, toward the fuel selector location. The technician believes the pilot changed the fuel selector and restarted the engine. The second pre-flight witness was another Long EZ pilot (hereinafter referred to as the "checkout" pilot), who gave the accident pilot a half hour of ground and flight checkout routine in the accident airplane in Santa Maria, California before the pilot flew the same airplane to Monterey the day before the accident. They performed two touch-and-go landings and some slow flight maneuvers, and discussed the aircraft systems, including the fuel selector location. He made arrangements with the pilot to relocate the fuel selector handle as soon as possible. He also saw a pillow at the back of the pilot's seat to assist him in reaching the rudder pedals. Wreckage recovery and analysis. An underwater video was taken on the wreckage site and revealed broken rock structures that were free of normal underwater growth. All major structural components of the airframe were found in a fragmented state on the ocean floor near the engine. An examination of the engine, gear and valve train, cylinder compression, carburetor, electronic ignition system, and other engine accessories found no discrepancies. During investigation, all aircraft extremities were accounted for in the examination, and all recovered control system push-pull tubes and associated bell cranks were examined, with overload signatures evident and no unusual operating condition noted. No battering or over-travel signatures were observed. The steel and aluminum rods connecting the handle to the fuel selector valve were found bent. The rods were straightened to determine the handle position relative to the valve position. The fuel tanks of the airplane were extensively damaged, but investigators observed that the fuel tanks were empty, a condition that would happen only if the plane went on a prolonged descent with just a few gallons of fuel in the tank. The recovered wreckage was examined for evidence of a possible bird strike. There were no leading edge canard or wing sections intact, the canopy was destroyed, and only fragments of the Plexiglas were recovered. Bird feathers were found commingled in the recovered wreckage. The curator of the local Museum of Natural History was asked to view the feathers during the wreckage examination. A seat cushion determined to be from the accident airplane was found torn open. According to the cushion material tag, it was filled with goose feathers, but the curator found duck feathers in the cushion. The cushion feathers matched those found in the wreckage. Pilot Information. The pilot's logbook was not recovered, but an investigation of the pilot's airman and medical records revealed that as of June 13, 1996, he had logged a total flight time of 2,750 hours, held a private pilot certificate with airplane ratings for single and multi-engine land, single engine sea, and gliders. He also held an instrument airplane rating and a Lear Jet type rating. A certified true copy of the pilot's FAA medical record files were obtained and reviewed, showing that on November 6, 1996, the FAA Civil Aeromedical Certification Division sent the pilot a letter by certified mail, return receipt requested, acknowledging receipt of his June 13, 1996 medical application and stating that the pilot's "continued airman medical certification remains contingent upon total abstinence for use of alcohol." The letter informs the pilot that he did not meet the medical standards prescribed in Federal Aviation Regulations and that he was not qualified for any class of medical certificate at that time. The letter further states that if the pilot did not voluntarily return his certificate, his file would be sent to the FAA's regional office for appropriate action. The letter was returned unclaimed to the FAA on December 2, 1996. FAA did not follow-up until March 25, 1997 when the agency sent a second letter by certified mail again notifying the accident pilot that he was medically disqualified. The letter was received, but the signature of the person who signed for the mail was illegible. During the accident pilot's autopsy, the FAA's Civil Aeromedical Institute in Oklahoma City, Oklahoma obtained samples for toxicological analysis. Tests were negative for all screened drugs and ethanol. This rules out the pilot's condition as a cause. Aircraft Information. The airplane engine was a 150-hp Lycoming O-320-E3D consuming 8.5 to 10 gallons of fuel per hour depending on the power setting. This engine required the installation of 50 pounds of ballast in the nose. The airplane's designer testified that although the only engines approved by the factory for installation are the Continental models O-200 or O-240, or the Lycoming O-235, the airplane's design allowed up to 200 hp engines and an additional weight of 50 percent above the prototype limit. The pilot who sold the airplane to the accident pilot disclosed that no ballast was installed in the nose, although two batteries, totaling 40.8 pounds, were relocated in the nose section, one directly in front of the foremost bulkhead and the other just behind it. The airplane was bought by its original owner on March 5, 1994 and sold to the accident pilot on September 27, 1997. The checkout pilot flew the plane (see above) from Santa Ynez to Santa Maria, California where, on October 11, 1997, he and the accident pilot had a half hour flight orientation before the accident pilot flew the plane to Monterey. At Santa Maria, the airplane was sanded, primed, and painted, adding 30 pounds to the plane's empty weight and bringing its total weight to 1,091 pounds without changing the center of gravity (CG) at 110.0 inches. Based on the weight and balance document and estimates of the airplane's probable fuel load at the accident flight's departure from Monterey, gross weight and CG conditions were estimated at 1,310 pounds and 103.65 inches. At the time of the accident, the airplane would have had a gross weight of approximately 1,280 pounds with a CG at 103.63 inches. According to the manufacturer, the design gross weight limit is 1,425 pounds and the CG range is from the forward limit of 98 inches to the rear limit of 103 inches. During the investigation, the manufacturer flew the same profile as that believed to have prevailed during the accident flight (start, taxi, run-up, takeoff, three touch-and-goes, and a pattern departure) in a Lycoming O-320-equipped Long-EZ and measured the fuel consumed at 3.6 gallons. After running one tank dry, a time interval of 6 to 8 seconds was measured between changing the fuel selector and resumption of engine power. Fuel Selector. The plane's original design located the fuel selector just aft of the nose wheel position window between the pilot's legs, but for personal reasons the first owner of the plane moved the fuel selector handle to the bulkhead behind the pilot's left shoulder. The selector valve was installed inside the engine firewall 45 inches aft of the selector handle. A steel and aluminum tubing connected by a universal joint joined the valve to the handle. The airplane had two 26-gallon fuel tanks in the wing roots that contain usable fuel. The fuel quantity is determined by viewing non-linear sight gauges located in the rear cockpit at the wing roots. The sight gauges show an amount of actual fuel supporting a red float. Post-accident examination of the airplane revealed the sight gauges were not marked or calibrated for quantity. According to other pilots who were familiar with the airplane, to change the fuel selector one had to: 1) Remove his hand from the right side control stick if he was hand flying the aircraft; 2) Release the shoulder harness; 3) Turn his upper body 90 degrees to the left to reach the handle; and 4) Turn the handle to another position. Two pilots shared their experiences of having inadvertently run a fuel tank dry with nearly catastrophic consequences because of the selector and sight gauge locations. The original owner claimed that when he changed tanks in-flight, he would engage the autopilot and use his right hand to reach behind his left shoulder to the selector handle. The owner said that when he sold the plane, the handle was easy to turn, and that the checkout pilot had removed the selector valve for cleaning and lubricating after the sale. The checkout pilot claimed to have simulated changing tanks using the selector on one occasion on the ground and that he was not pleased with the location, and because of the difficulties of using the selector, he said he had never used the selector in flight. Post accident wreckage examination by investigators revealed that the selector handle was not placarded or marked for any operating position. According to the checkout pilot, the handle in the right position was for the left tank, the handle in the down position was for the right tank, and the off position was up. The fuel selector, linkage, universal joint, handle, and handle-bearing block were recovered. The brass 3-port Imperial fuel selector valve assembly was examined and found in an intermediate position, which was half open between the engine feed line and the right tank fuel supply line. The port to the left tank was observed to be open about 10 percent to the engine feed line. The valve was frozen in place and could not be moved. The fuel valve was plumbed into an engine test cell, with the fuel supply connected to the valve's right tank fuel port. At that point, the left tank port was open to the atmosphere and was subsequently capped. An exemplar Lycoming O-320 engine was installed in the test cell, started and run to maximum power. The half-open right port position had negligible effect on the engine power output; however, when the cap was removed from the left port (simulating the effect of an empty left tank) the fuel pressure dropped to less than one-half, and within a few seconds the engine quit because the fuel/air mixture resulted in a vapor state. Crash investigators discovered that every time the pilot attempted to switch fuel tanks in a Long EZ plane and turn his body the 90 degrees required to reach the valve, the natural tendency was to extend his right foot against the right rudder pedal to support his body as he turned in the seat. Pressing on the right rudder pedal moves the right rudder in an outboard direction, producing increased drag and a subsequent yawing moment. The designer claimed that the plane has a very strong spiral mode, and that the rudders and side stick controller are very sensitive to slight movements, with a inch movement enough to cause a roll initiation. Fuel Tank. The checkout pilot who flew the airplane from Santa Ynez to Santa Maria for repainting estimated that before his departure, 4 to 5 gallons of fuel were in the two tanks, and he stated that he added 10 gallons of fuel to each tank. The checkout pilot said that he did not update the plane's fuel monitoring instrument after refueling because he was not familiar with the procedure. The flight to Santa Maria lasted 20 minutes and was estimated to have consumed 4 gallons of fuel. During the accident pilot's 30-minute checkout at Santa Maria, the checkout pilot estimated that 5 gallons of fuel were consumed. The checkout pilot stated that the pilot flew the airplane from Santa Maria to Monterey, with about 15 gallons of fuel onboard. There were 10 gallons of fuel in the right tank and 5 gallons in the left tank. He noted that the selector was located on the right tank (in the down position) before the pilot's departure from Santa Maria. The investigation estimated the amount of fuel required to fly to Monterey from Santa Maria ranged from 6.4 to 9.1 gallons, depending on power settings used. Estimates for fuel used during the checkout flight at Santa Maria ranged from 2.5 to 3.6 gallons. The accident flight was estimated to have consumed 3.0 to 4.3 gallons, for a combined total consumption of 11.9 to 17.0 gallons of fuel. Fuel records disclosed that the airplane was not refueled at Monterey Airport. Conclusions Given the facts, two probable causes of the accident were determined: first, the pilot's diversion of attention from the operation of the airplane while switching the fuel selector handle, and second, his inadvertently stepping on the right rudder resulted in the loss of airplane control while attempting to manipulate the fuel selector. The Board also identified several other factors that may have caused the crash: the pilot's inadequate pre-flight planning and preparations and specifically his failure to refuel the airplane, the builder's error of locating the unmarked fuel selector handle in a hard-to-access position and inadequate marking of the fuel quantity sight gauges, and the inadequate transition training of the pilot given his lack of total experience in this type of airplane. The checkout pilot's negligence in not emphasizing to the accident pilot the inconvenience of the fuel selector may also have been a contributing factor. Reference List AW (Aviation Web). (1999). Report on the John Denver Crash. Retrieved February 12, 2006, from http://www.avweb.com/other/ntsb9905.html CIR ("Crash Investigation Report.") (1999). Updated January 3, 2005. Retrieved February 14, 2006, from http://www.john-denver.org/default.aspid=364 CNN (1998). John Denver crash points to fuel problems. (June 23, 1998 edition) Retrieved February 13, 2006, from http://www.cnn.com/SHOWBIZ/Music/9806/23/ denver/index.html NTSB (National Transportation Safety Board) (1999). Public Meeting on Aircraft Accident involving John Denver/In-Flight Collision with Terrain/Water on October 12, 1997 at Pacific Ocean near Pacific Grove, CA, No. LAX-98-FA008 held January 26, 1999. Retrieved February 14, 2006, from http://www.ntsb.gov/publictn/1999/ABR9901.htm Sumwalt III, R. L. (1997). Mishaps and human factors. Adapted from the author's paper titled "Integrating human factors: the future of accident investigation" presented at the ISASI 1997 International Seminar in Anchorage, Alaska, October 1997. Read More