Read the…

Experience the thrills and defeats of an authentic deep sea adventure as you immerse yourself in the CATALYST 2 Mission Log. More>>

Waitt Institute

The Waitt Institute is a non-profit research organization that serves as an exploration catalyst, enabling scientific pioneers to transform the ways in which discoveries are made. More »

Search Stragegy Refinement

Narrowing the search area

Search Strategy Refinement

AE - Amelia Earhart

BHP - Brake Horse Power

CFIT - Controlled Flight Into Terrain

EON - End of Navigation Point

FN - Fred Noonan

GPH - US Gallons Per Hour

LOP - Line of Position

L487 - Lockheed and Kelly Johnson Report 487

SFC - Specific Fuel Consumption (lbs/BHP/hr)

Search Grid and Scenarios
The challenge to identify a starting point in the overall search grid requires a detailed fuel consumption analysis and a consideration of lost aircraft location theories.
We agree with Long and other researchers that NR 16020 was not lost en route, did not land at Howland or Baker Island, and lacked sufficient fuel (shown later) to reach any other land mass. Therefore, we focus on a failure to arrive scenario, where the aircraft possibly crashed, experienced a Controlled Flight Into Terrain (CFIT) event, or exhausted its fuel supply.

A crash event could result from a loss of control, or a mechanical malfunction.

A CFIT event is an inadvertent collision with terrain (water), often involving a loss of situational awareness, but with the aircraft flying normally in terms of configuration, speed and attitude.

Flying over smooth water conditions reported by Itasca, is a challenge.

Depth perception is more difficult than while flying over rougher seas.

A fuel exhaustion event could produce a survivable, controlled water ditching.

Various calculations result in sufficient fuel at 1912 GMT to conduct a 1.5-4.0 hour search, but more likely a search in the range of 1.5-3.1 hours. After 2013 GMT, the total absence of radio communications is unusual, supporting two possibilities.

1.  The aircraft may have impacted the water prior to fuel exhaustion.

2.  Fuel exhaustion precluded further radio communications. This could result from a mission fuel over-burn for unknown reasons. For example

a. Zero fuel at 2030 GMT would indicate a mission over-burn of 71 gallons.

b. Zero fuel at 2100 GMT would indicate a mission over-burn of 51 gallons.

These examples represent a 2.4 to 3.5 GPH variance in total fuel consumption from planning calculations. The per-engine fuel use variance of 1.2 to 1.75 GPH is certainly possible.

A search strategy requires calculation of where the aircraft is in time and space, and how much fuel and time remained, after arriving in the Howland area at 1912 GMT.

Reference Grids
Reference points are plotted in the search grids, including the Path C End of Navigation (EON) point and a 2013 GMT position.

There is evidence that winds in the final 8.5 hours of the mission either decreased in headwind component, and/or shifted direction to come from slightly left of course and at reduced strength.

In order to address the effects of winds that may not have been detected or accounted for by AE and FN, an analysis was completed for a range of possible wind values. This analysis applied various realistic wind values to fixed headings the crew could have maintained. The resulting End of Navigation points are contained in the existing search grid.

The Search Plan is oriented along a 337-157 degrees magnetic compass heading, perpendicular to the planned magnetic ground track from Lae to Howland. The Search Plan accounts for possible cross-track error en route, as well as subsequent Line of Position (LOP) ground tracks in the terminal area as functions of true or magnetic tracks.

The LOP established by FN at Howland sunrise in preparation for AE’s “about 100 miles out” position report at 1815 GMT, was 337-157 degrees true.

We assess AE did not fly the LOP initially, nor until at least 1928 GMT (”…circling…”), when they reported flying the LOP at 2013 GMT.


This report is 61 minutes after initial arrival at where they thought Howland Island was, following an initial search of the area. After the “circling” report at 1928 GMT, they likely commenced flying the LOP tracks in a rectangular pattern, progressing further east on each LOP, while attempting to contact Itasca and visually acquire Howland Island.

Anxiety was reported in AE’s 2013 GMT radio transmission. It would be possible that under the circumstances, AE flew northwest on a heading of 337 degrees magnetic.
not accounting for a magnetic variation correction to FN’s LOP if it was indeed in degrees True.

The 10-degree difference between true and magnetic courses in search grid orientation was constructed to examine positional effects on search operations.

The effect of this orientation is insignificant.

Back To Top