Weather conditions at the time included a 1,200-foot ceiling - nothing that should have posed a problem for the Learjet and its crew. The pilots had planned to fly the ILS 18 instrument approach, but a navigational glitch put the aircraft off course, and the pilots executed a missed approach. Apparently thinking the ILS was out of service, the pilots opted for the VOR 25 approach, and received their approach clearance. At approximately 10:02 a.m. local time they called for the procedure turn on the approach's outbound leg.
Lebanon tower fully expected to hear the pilots report inbound on the approach within a few minutes. That call never came. Nine minutes later, after repeated, unsuccessful attempts to contact the inbound Lear, the controllers notified authorities.
Lebanon Municipal Airport lies along the Connecticut River, which forms the boundary between Vermont and New Hampshire. Surrounded by rugged, mountainous terrain, with numerous peaks rising to nearly 3,500 feet MSL, radar contact is often spotty below 4,000 to 5,000 feet MSL. Dotted with obstacle symbols, the approach plate only begins to describe the tortuous maze of mountains surrounding the airport. With a cold front expected to arrive around midnight, rescuers would have to work fast to find the downed pilots. What ensued was a monumental search effort that encompassed the resources of the Civil Air Patrol (CAP), National Guard, State Police, and a host of volunteers too numerous to mention.
Forces at the Ready
The CAP is an all-volunteer auxiliary to the U.S. Air Force that provides a broad spectrum of assistance ranging from disaster relief to environmental monitoring, emergency response, wildlife management, and health and human services. It's not unusual for CAP members to assist hurricane or blizzard victims, to monitor rivers, forests, and wildlife, or to transport human bone marrow or transplant organs. But the CAP's most widely known mission is searching for lost aircraft.
The CAP's function in search and rescue (SAR) operations varies depending on the state and the particular situation. The Air Force has overall responsibility to coordinate search and rescue efforts in the inland portions of the continental United States. The Air Force Rescue Coordination Center (AFRCC) carries out this responsibility, and as an auxiliary to the Air Force, the CAP is called upon to provide the resources for many of SAR activities.
Often times, SAR operations fall within the jurisdiction of a state, and through formal agreement with the state, the CAP provides its services. Sometimes the CAP coordinates the SAR operation, and at other times the CAP provides their services to another agency charged with the responsibility of conducting the search. The New Hampshire Department of Fish and Game had jurisdiction over the search and rescue operation in Lebanon, and the CAP wasn't called in until the following day. But when CAP squadron leader and mission pilot Keith Neilson received the call, he was ready to go.
A Search Begins
A search can be initiated in any one of several ways. Sometimes, the first indication of a downed aircraft is when a satellite picks up an aircraft's ELT (emergency locator transmitter) signal. Depending on the crash site's location, it can take from 45 seconds to more than 2.5 hours for AFRCC to verify the signal and triangulate its approximate location. Then come calls to local airports and ATC facilities to see if they have any reports about problems or missing aircraft. Volunteers may call area FBOs if it's believed the signal may be coming from a parked aircraft. Roughly 97 percent of all the ELT signals in the U.S. are false alarms, so the search never leaves the airport. But once it's known that the signal is real, search crews begin their efforts.
A rescue effort may be underway much sooner if a pilot has filed and activated a VFR flight plan. If the pilot hasn't closed the flight plan within 30 minutes of his (or her) estimated time of arrival (ETA), Rescuers make a phone search to find out whether the aircraft arrived at its destination. If this doesn't locate the aircraft, a ground and/or air search begins.
In the best of circumstances, aircrews may be on their way within minutes of being called. But as Neilson explains, "CAP pilots must balance the urgency of the minute with the overall safety of the mission. We can't jeopardize the safety of our crews." In mountainous terrain, an air search may have to wait until daylight. Inclement weather conditions can also force a delay.
A pilot's best bet for a timely rescue comes when flying on an IFR flight plan. If an aircraft disappears from radar, ATC takes immediate action to note its last known location and initiate a search. Because the Learjet was on an IFR flight plan, the search and rescue machinery kicked into high gear quickly.
Tools of the Trade
Finding a downed aircraft is no simple task. It takes a well-rehearsed, coordinated effort on the part of a well-trained team of individuals, says Col. Bill Hines, commander of CAP's Colorado Wing. The effort requires a cadre of personnel composed of ground crews, pilots, observers, technicians, communications experts, and safety personnel, to name a few. Local SAR units, state police, the Sheriff's Department, National Guard, and other agencies often pool their efforts in locating a missing aircraft.
Knowing where to look for a downed aircraft is key to a timely rescue. "One of the most important tools we have for locating a downed aircraft," Hines says, "is called NTAP, for National Track Analysis Program." Developed by an air traffic controller/CAP volunteer several years ago, the program analyzes ATC radar data to trace the flight path of a missing aircraft.
"Knowing the time and location of departure, aircraft speed, and initial direction of travel, NTAP can sort through the maze of radar tracks and find the ones most likely to be the missing aircraft." The analysis can take 24 to 72 hours, but the resulting data often pinpoints the location of a missing aircraft, even if it wasn't on a flight plan or using its transponder. If an aircraft was on an IFR flight plan or receiving flight following from ATC, NTAP data is usually available within hours. In the case of the missing Lear, radar coverage at the altitudes being flown was sketchy, and even NTAP couldn't locate the crash site.
Another important tool for ground searchers is the "Little 'Elper," a handheld receiver that homes in on an ELT signal much like an airplane's ADF points to a radio beacon. Once within range, ground crews can triangulate on the signal and quickly locate the crash site. Unfortunately for the Lear pilots, Federal Aviation Regulation 91.207 says turbojet aircraft aren't required to have an ELT, and their aircraft didn't have one - so there was no ELT signal to lead rescuers to them.
"Interviews are another tool for gathering critical information," Hines says. "We call people who know the pilot and try to develop a profile of his flying habits. We try to find out if the pilot is likely to follow roads, VOR airways, or if he uses GPS to fly direct from point to point. This information helps us determine where to search."
The pilot's flight plan, position reports, prevailing weather, proximity of airports and navaids, aircraft performance, and reported sightings all form important clues in developing a search plan. Because the Lear was executing a published instrument approach procedure, the searchers had a general idea where to look, but many variables could have affected its actual flight path.
Tactical Factors
The rescuers had their work cut out for them in Lebanon. Without a precise search location and with no ELT signal to home in on, they had to rely on a visual search of a relatively large area. Worse than the proverbial needle in a haystack, they were looking for a white aircraft in mountainous terrain covered with fresh snow. Poor visibility, mountain obscuration, and periods of freezing rain complicated the air search, and deep snow on the precipitous terrain slowed the ground search to a crawl.
SAR missions use several types of aerial search patterns, and the type used depends on several factors including terrain, weather, visibility, and the circumstances surrounding the loss of the aircraft. Searchers may fly over the lost aircraft's route of flight in a "track crawl" search pattern. To search a relatively large, flat area several aircraft may fly a "parallel track" or "parallel sweep" pattern. Sometimes, aircraft fly a "creeping line" search, where they fly back and forth across the search area, progressing in the missing aircraft's direction of travel. Depending on the situation, search pilots use VORs, NDBs, Loran, GPS, and DME to establish various search patterns.
One of the most difficult and potentially dangerous patterns is a contour search. Often used in mountainous terrain, a contour search takes the search aircraft along elevation contours. Such a search may begin near the mountain's peak, with the aircraft circling the mountain at close proximity at descending elevations.
Aircraft from a six-state region participated in the Learjet search in Lebanon, and they scoured the mountainous terrain in precise formation. "The plan was to have A-10s flying search patterns at 2,000 feet, the CAP flying their grids at 1,000 feet, and National Guard helicopters flying contour searches at 500 feet," Neilson explains. "Unfortunately, there were clouds between 1,000 to 2,000 feet, so the A-10s weren't able to participate. The visibility was only three to five miles, and we were flying 10-mile legs, so we didn't have good visual references. We used Loran and GPS grids and flew at half-mile intervals. The freezing rain started about an hour and a half into a four-hour search, and we had to call it quits."
The search efforts continued for two weeks, with inclement winter weather causing frequent interruptions. The SAR mission never found any signs of the Learjet or its pilots.
The Learjet crash illustrates the importance of having an ELT, but that alone isn't enough to ensure a timely rescue. If the ELT battery is in poor condition, or if the antenna is damaged in the crash, the signal may be weak or unusable. Depending on the geographic location, it may take hours for satellites to triangulate on the location.
Missing, but Not Missed
Several years ago, a family of five aboard a Piper PA-32 Cherokee Six was on its way from Dallas, Texas, to Aspen, Colorado, for the Christmas holiday. With meticulous preflight planning, a complete weight and balance, and thorough weather briefing, the family took off at 8:30 a.m. and headed west. The weather was perfect with clear skies and light winds aloft, even in the mountains. Only isolated snow showers were expected.
They stopped in Dalhart, Texas, for fuel, rechecked the weather, and departed for Aspen around noon. By 2:30 p.m., they were flying over Buena Vista, Colorado, threading their way northwest through high, rugged terrain where the peaks rise to more than 13,000 feet MSL.
The wind was blowing out of the southwest at about 20 knots, creating updrafts on the southwestern slopes, and turbulence and downdrafts on the eastern slopes of the mountains and ridges along the route. As the Cherokee Six clawed its way through a pass, a sudden downdraft overpowered the aircraft and forced it down on the snow-covered slopes.
The pilot did a fine job maintaining control and made a textbook forced landing on the north slope of Mt. Yale at a dizzying elevation of almost 12,000 feet MSL. All the passengers suffered injuries in the jolting crash, but none were life threatening. Fearing for their safety, the pilot, dressed only in blue jeans, a sweater and heavy coat, set out to get help. The others huddled in the intact fuselage and waited for help to arrive.
Even with an ELT, the family had two strikes against it. First, in spite of his attention to detail, the pilot didn't file a flight plan. Nobody was looking for them. Nobody even knew they were missing. With no survival equipment on board, they would have to endure the long wait with no food, water, or heat.
Two days later an airliner reported a weak ELT signal near Buena Vista. A search team was summoned, but foul weather and agonizingly rugged terrain hampered rescue efforts, and it took rescue crews three days to reach the site. The four people who stayed with the airplane had survived five days and nights of freezing temperatures, and were rushed to a nearby hospital where they recovered. Sadly, the pilot never made it out for help. The victim of an avalanche, his body was found nine months later.
Lessons Learned
Although tragic, these accidents provide valuable lessons for all pilots. First is the importance of a flight plan. Had the Cherokee pilot filed a flight plan, he would have had no reason to leave the aircraft. A search would have begun within hours, rather than days after the crash.
As with the Learjet crash, the Cherokee accident highlights the effect of weather on search and rescue operations. If the weather makes flight operations unsafe, a ground search is the only option. In snow-covered, mountainous terrain, a ground search can be excruciatingly slow. If conditions are too severe, even ground crews must turn back rather than place searchers at high risk. When traversing inhospitable terrain, survival equipment is a must.
It's been nearly two years since the Learjet disappeared near Lebanon. The official search ended long ago, but volunteers continue the search. The tragic loss has raised the question of whether ELTs should be required on all aircraft, including those, such as turbojets, exempted by FAR 91.207. Regardless of what regulations say, an ELT represents an important piece of safety equipment.
These incidents also highlight the need for pilots to be aware of the problems searchers encounter looking for downed aircraft, and to take the precautions necessary to maximize the chances of being located if an emergency forces them out of the sky. After making a successful forced landing, we might think the worst is over. But unless someone knows we're missing, and has the tools and resources to find us, our troubles may have only just begun.
To learn more about search and rescue operations, and survival, see page 83.
Save Yourself: Tips for Helping Rescuers Find You
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