The Search for Amelia, 2009
The Waitt Institute CATALYST 2 Mission assembled a diverse team of experts from multiple backgrounds and institutions to identify new search options for Amelia Earhart’s Electra.
To re-evaluate known information about the flight and re-think Earhart’s last flight leg from a pilot’s perspective, these experts used historical data, aircraft specifications and radio signals to retrace Earhart’s most likely route in a flight simulator.
A New Look at Amelia Earhart’s Last Flight
Flight Reconstruction Team Lead Christopher Nutter and Research Assistant Michael DiBello get up close and personal with a near replica of Earhart’s Electra.
Rather than begin at the end of Earhart’s flight and ask what went wrong, the team began at Lae and attempted to determine Earhart’s most likely flight path and fuel exhaustion point from known data. This flight reconstruction was integrated with known radio calls and information obtained on the ground from observers at Lae, the Itasca and elsewhere along the route.
Flight Profile Modeling
This included research into more than a dozen published books, numerous research reports, aircraft manuals, over 8,000 pages of data and in excess of 2,200 documents in archival collections. The analysis team then utilized advanced software for aircraft flight profile modeling that wasn’t available when earlier investigations were conducted.
After determining several potential profiles for the flight based on Earhart’s flying characteristics, the Electra’s known performance statistics and an analysis of the fuel consumption during the flight, the team analyzed numerous points in the flight path.
Insights and Creative Links
When fused and integrated, this extensive array of data provided new insights and creative links among previously discrete and unconnected data. One of the Waitt Institute team’s findings was a possible mistake in the logging of Earhart’s location by the radio operator at Lae in the first third of the flight. This transposition of coordinate numbers suggests an initial southerly route and departure from the straightline course to Howland in order to avoid weather in the north.
Further, the fuel consumption analysis suggested that there was a failure of the Cambridge Fuel Analyzer on board. The loss of this instrument, as well as the longer flight path, would have drastically reduced Earhart’s amount of fuel upon arrival in the vicinity of Howland and caused her to run out of fuel much earlier than expected.
Probable Flight Paths
As a result of this research, the flight reconstruction team established the most probable path for the Electra from Lae, New Guinea, to a point determined to be Earhart’s End of Navigation (EON) point. This EON is the location where Earhart reported, “We must be on you,” referring to the point in the flight where she and Noonan believed Howland should be located.
Beyond this point, Earhart most likely flew a search pattern to look for the island, but it is difficult to determine exactly what that search pattern was from known information, primarily her radio calls. Rather than add conjecture to a flight reconstruction based heavily on solid data and proven analysis methods, the team calculated the most probable EON point, and determined a search area based on the expected limits of Earhart’s own search for Howland Island beyond this EON point.
New Search Pattern
This reconstruction resulted in a search area defined into a search grid, which was then used to create a search pattern. Three separate flight paths were defined and evaluated, each terminating in a high confidence End-of-Navigation (EON):
A - Least likely
B - Possible
C - Most likely
The highest confidence Path C resulted from rigorous recalculation, aerodynamic performance and fuel consumption assessments, and significant cross-validation of results and conclusions.
The Search Area
The reconstruction of Earhart’s flight path resulted in a highest probability location for Earhart’s fuel exhaustion point, an area roughly half the size of New Jersey. This search area entails 2,520 square nautical miles (3,250 square miles) directly to the west of Howland Island and oriented nearly north and south along Earhart’s reported 337‐157 position path.
To further refine the search area for efficient AUV operations, the Waitt Institute sonar analysis team worked with the reconstruction team to break down the larger search box into smaller boxes representing the area one AUV can fully map in one programmed sortie. These smaller boxes cover 28 square nautical miles each (eight nautical miles by three and a half nautical miles), and most hit depths of more than three miles below the ocean’s surface.
When creating these individual AUV sortie boxes, the sonar analysis team took into account the bottom topography and the overall size and direction of the search area. They then combined that data with the most efficient pattern and search methodology used by the AUVs to scan an area of seafloor.
Scheduling AUV Runs for Maximum Efficiency
Robin Littlefield of Woods Hole (WHOI) discusses AUV operations.
Deep Ocean Transponders (DOTs)
The CATALYST AUVs utilized Deep Ocean Transponders (DOTs) during their sorties that acted as acoustic tracking beacons to assist the AUV in locating its relative position along the seafloor. The deployment and recovery of these DOTs is time consuming and dangerous in water depths down to 6000 meters. By arranging the search area to incorporate an efficient DOT strategy, the sonar analysis team was able to cut in half the number of DOTs used per sortie.
Effectively, the boxes were laid such that both CATALYST AUVs could survey in adjacent boxes, using the same pair of DOTs on two separate sorties. In the final grid, the AUV operations team searched the boxes in numerical order, sending each vehicle down on their relative side of the numbered box, labeled as “a” and “b.” As one vehicle was searching box 6a, the other was able to search box 6b using the same DOTs, creating an efficient, leap‐frog search pattern.
Learn more: Re-Navigation Research Executive Summary