Using a single-engine airplane for long-distance, literally cross-country trips, usually isnt a good choice. That is, of course, until you survey all the other choices-including the airlines-and decide the flexibility and utility of using a personal airplane is the only way to go. Often, of course, the flight is the trips purpose, not the act of getting to a destination. Watching various landmarks and other magnificent scenery slide underneath the wings-albeit relatively slowly-makes up for the time it can take, especially when headed west into prevailing winds. I have a few such trips under my belt and wouldnt hesitate to launch on another one-even if just for fun-if a good reason popped up. That said, flying from one U.S. coast to the other in a personal airplane isnt for the faint of heart. Among other factors, planning and preparation are critical; so is monitoring weather and continually evaluating the go/no-go equation. Its very easy to take off, climb to a higher-than-normal cruising altitude and sit back, becoming lulled into a false sense of security and oblivious to changing weather, fuel consumption and availability, and a host of other factors. On the long-distance, cross-country flights Ive taken, a relatively new element also is introduced: fatigue. Even if using supplemental oxygen at what might otherwise be considered non-oxygen altitudes, being “cooped up” in a personal airplane for double-digit hours in a single day is fatiguing. I recall one such flight after which I was too tired to push the airplane back into its hangar, and simply left it on the apron for the FBOs rampies to put away. Couple the relative boredom of a long flying day with fatigue and poor weather, and the risk of something bad happening increases. Throw in some turbulence to wear you down further, and a pilot can be much more prone to making a critical mistake at a critical time. Heres an example of what can happen. Background On March 1, 2009, at about 2300 Pacific time, a Diamond DA-40 impacted the waters of the Pacific Ocean while its pilot was executing an RNAV/GPS approach to Runway 14 at Arcata Airport, Arcata/Eureka, Calif. The well-qualified commercial pilot/CFI and his passenger were killed and the airplane was destroyed. Night visual conditions prevailed. The pilot was on an IFR flight plan and had been issued a clearance for the approach. The multi-leg flight originated in Florida the day before. According to the airplane owner, the pilot said he was building time, and he and his passenger were going to Las Vegas. As the flight neared Arcata, the pilot advised ATC flight conditions included moderate-to-severe turbulence. About two minutes later, ATC advised the pilot other aircraft had reported light to moderate turbulence while on the ILS approach into Arcata. There also was moderate to heavy precipitation along the route. On several occasions during the flights let-down into the Arcata area, the pilot exhibited fatigue signs, including incorrect readbacks, misunderstanding clearance elements and an inability to maintain assigned altitudes.After clearing the pilot for the approach and to change frequencies, the controller continued to monitor the flight. After noticing the flight descended early on the RNAV (GPS) approach, the controller made several attempts to contact the flight, to no avail. The last mode C radar target from the airplane was recorded about one-tenth of a mile outside the final approach fix, at 300 feet above the ocean surface. It should have been no lower than 2100 feet msl. Investigation For almost two weeks after the accident, about a dozen pieces eventually identified as being from the specific airframe washed ashore on nearby beaches. The single longest piece of the airplane was comprised of the left wings leading edge and forward upper wing skin, which measured about seven feet long, starting at the wing root, and was about nine inches wide. It had torn loose from the aft area of the upper wing skin along a very irregular and jagged line. Observed weather at the Arcata Airport at 2253 Pacific time included winds from 190 degrees at eight knots, six statute miles visibility, light rain, fog, scattered clouds at 1900 feet, a broken ceiling at 2800 feet and an overcast ceiling at 3400 feet. Since neither major aircraft components nor the occupants were located, investigators focused on the pilots duty day and the flight time accumulated as the airplane traveled from Florida to California. The NTSB noted the elapsed time from the pilots arrival in Florida to conduct a checkride in the accident aircraft before renting it (at 0800 on Saturday morning) until impact with the ocean off Arcata, Calif., (at 2300 on Sunday night) was 42 hours. During that 42-hour period, according to the NTSB, the pilot accumulated about 22 hours and 45 minutes of flying time, and was “on duty” for 30 hours and 45 minutes. As part of the investigation, the NTSB obtained weather briefing records from both Duats providers and from Lockheed Martin Flight Service. None of the three providers recorded the pilot seeking a weather briefing on the day of the accident. Probable Cause The NTSB determined the probable cause(s) of this accident to include: “The pilots failure to maintain proper altitude and glidepath while executing a night instrument approach. Contributing to the accident was the pilots fatigue.” Given the lack of available wreckage to study, theres not much else they could conclude. But, were left to wonder why a relatively qualified pilot and flight instructor would end up flying a perfectly good airplane into the ocean. Certainly fatigue is a factor. Anyone who has flown a single-engine airplane across the U.S. in two days can attest to the weariness. This DA40 was equipped with a Garmin G1000 glass-panel system, with which the pilot was familiar. The NTSB report is silent on whether it was equipped with a functioning autopilot, which would have reduced the pilots workload. Also not known is to what extent, if any, the passenger assisted with flying duties. The NTSB report also is silent on whether the passenger was a certificated pilot-he presumably wasnt-or whether he was a student or “wannabe.” After more than 22 hours of flying in 42 hours, shooting a relatively simple GPS approach in visual conditions shouldnt have been that difficult. Fatigue made it impossible.