This is the reader-friendly version of this article. The academic version if this article can be found here:
The 157–337 Line
Reconstructing Amelia Earhart’s Final Search for Howland Island
Part Two of the Neapolis Forgotten Paths Earhart Investigation
By Douglas Estill
The Neapolis Forgotten Paths Research Institute
At 8:43 on the morning of July 2, 1937, Amelia Earhart transmitted what would become the final confirmed radio message received from the Lockheed Electra NR16020.
The aircraft had been in the air for approximately twenty hours. Earhart and navigator Fred Noonan believed they had reached the vicinity of Howland Island, but they could not see it.
Attempts to obtain a usable radio bearing had failed.
Then Earhart transmitted a navigational statement that has puzzled investigators ever since:
“We are on the line 157 337.”
An official Coast Guard dispatch subsequently rendered the remainder of the message as:
“We are now running north and south.”
Then NR16020 disappeared.
Those numbers—157 and 337—may represent the most important navigational clue Earhart and Noonan left behind.
They do not tell us where the Electra was.
But they may tell us something almost as important.
They tell us how Fred Noonan was trying to find Howland Island.
A Line Across the Pacific
The numbers 157 and 337 were reciprocal compass directions.
A heading of 157 degrees points approximately south-southeast.
Its reciprocal, 337 degrees, points approximately north-northwest.
Together they describe a single line extending in opposite directions across the chart.
For Noonan, this was not an arbitrary line.
It was almost certainly associated with celestial navigation.
As sunrise approached during the final portion of the Lae-to-Howland flight, Noonan could use an observation of the rising sun to establish a line of position.
A celestial observation does not necessarily tell a navigator, “You are here.”
Instead, it can establish something more like:
You are somewhere along this line.
That distinction is critical to understanding what happened next.
Finding a Two-Mile Island After Crossing an Ocean
Howland Island presented an extraordinary navigational problem.
Earhart and Noonan had crossed roughly 2,550 miles of open Pacific.
At the end of that journey they were required to find an island only a few miles long, extremely low, and surrounded by an enormous expanse of ocean.
A relatively small navigational error accumulated during the overnight flight could place the Electra north or south of Howland without either pilot ever seeing it.
The problem was especially dangerous because celestial navigation could help Noonan determine a line upon which he believed the aircraft was located without necessarily telling him exactly where on that line the aircraft had arrived.
This created a classic navigational problem.
Suppose Noonan had calculated a line of position passing through or near Howland.
The Electra could intercept that line north of the island.
It could intercept it south of the island.
Or it could arrive almost directly upon Howland.
Until the island appeared—or another navigational fix became available—Noonan might not know which of those possibilities was correct.
“We Must Be on You”
At approximately 7:42 a.m., Earhart transmitted:
“We must be on you but cannot see you.”
She also reported that the aircraft was flying at approximately 1,000 feet and that its gasoline supply was running low.
The strength of Earhart’s transmissions convinced personnel aboard the Coast Guard cutter Itasca that the Electra was somewhere nearby.
But “nearby” in radio terms was not the same thing as knowing the aircraft’s position.
The Electra could hear neither the information it needed nor obtain a usable bearing.
The crew of Itasca could hear Earhart.
Earhart apparently could not reliably hear them.
Two-way communication had effectively collapsed at precisely the moment when it was most desperately needed.
The Radio Bearing That Failed
At approximately 7:58, Earhart again called Itasca.
She indicated that the aircraft was circling and requested that the ship transmit a long count on 7500 kilocycles so she could attempt to obtain a bearing.
The attempt failed.
Several minutes later Earhart reported receiving Itasca’s signal but being unable to obtain a minimum.
That statement is enormously important.
Earhart’s receiver was working.
She could hear the signal.
But her direction-finding system could not tell her which direction the signal was coming from.
The distinction meant everything.
Had Earhart obtained a usable bearing to Itasca, she could have turned toward the cutter and Howland Island.
Instead she possessed a signal without a direction.
Somewhere nearby was the ship.
Somewhere nearby was the island.
But she still did not know where.
Then Noonan Took Over
Once radio direction finding failed, the problem returned to navigation.
And this is where the 157–337 line becomes central.
At 8:43 Earhart announced that the aircraft was “on the line.”
This was not the language of random wandering.
It suggests that Earhart and Noonan were operating according to a navigational plan.
They had a line of position.
They believed Howland lay somewhere on or near that line.
And according to the official Coast Guard dispatch, they were running north and south along it.
In practical terms, the Electra appears to have begun searching the line.
But Which Direction First?
Here we encounter one of the great unanswered questions of the Earhart disappearance.
Did they turn toward 337 degrees first?
Or toward 157 degrees?
Earhart never told Itasca.
The phrase “running north and south” describes movement along the line, but it does not establish which direction was searched first, how far the Electra traveled in either direction, or whether the aircraft reversed course.
Those distinctions are not minor.
They determine where NR16020 could have gone.
If Earhart initially flew northwest along 337 degrees, she moved away from the Phoenix Islands and into open ocean north and northwest of Howland.
If she flew southeast along 157 degrees, she moved toward a very different geography.
Baker Island lay relatively close to Howland.
Farther along the southeastern direction lay islands of the Phoenix group.
Among them was Gardner Island, today known as Nikumaroro.
The difference between 337 and 157 therefore becomes much more than a compass heading.
It becomes a fork in the disappearance.
The Search Pattern
There is another possibility that deserves consideration.
Earhart’s statement that the aircraft was running north and south may describe exactly what the words imply: a deliberate search along the line.
Imagine the situation from the cockpit.
Noonan believes Howland lies somewhere along the 157–337 line.
The aircraft reaches that line but the island is not visible.
The logical response is to search along it.
Fly one direction for a calculated distance.
If Howland does not appear, reverse course.
Cross the estimated position.
Continue in the opposite direction.
Such a maneuver would explain several otherwise disconnected pieces of the radio record.
At 7:42 Earhart believed they should be upon Howland.
At 7:58 she reported circling while attempting to obtain a radio bearing.
At approximately 8:03 she reported receiving Itasca’s signal but being unable to determine its direction.
At 8:43 she reported being on the 157–337 line.
That sequence resembles an escalating attempt to solve the same navigational problem.
First, visually locate Howland.
Then obtain a radio bearing.
When that fails, return to the celestial line of position and search it.
How Far Could They Search?
Here the question examined in Part One—The Earhart Fuel Paradox—becomes essential.
If Earhart literally possessed only thirty minutes of fuel at approximately 7:42, then the Electra should have exhausted its fuel before the 8:43 transmission.
Yet the aircraft was still transmitting.
Therefore, whatever the exact fuel quantity aboard NR16020, the surviving radio chronology demonstrates that the aircraft remained operational beyond the deadline implied by the disputed half-hour-fuel report.
That does not tell us whether Earhart had twenty minutes, an hour, or several hours remaining after 8:43.
But it prevents us from assuming that the search ended simply because an estimated fuel clock reached zero.
And every additional minute of endurance enlarges the geographical area that must be considered.
The Problem of Visibility
There was another enemy aboard the Electra that morning.
It was not mechanical.
It was visual.
Howland Island rises only slightly above the Pacific.
From 1,000 feet, Earhart’s theoretical horizon extended many miles.
But seeing the horizon is not the same thing as seeing Howland.
Cloud shadows, haze, scattered showers and sunlight reflecting from the ocean could make a tiny, low island extraordinarily difficult to distinguish.
Even a modest positional error could therefore produce a cruel navigational situation.
Earhart and Noonan might have passed remarkably close to Howland without ever seeing it.
Indeed, the strength of the radio transmissions heard aboard Itasca strongly suggested to those listening that the Electra was nearby.
Near enough to communicate.
Not necessarily near enough to see the island.
A Search Without a Reference Point
The most revealing aspect of the final message may be what Earhart did not provide.
She did not give a latitude.
She did not give a longitude.
She did not report seeing land.
She did not report seeing Itasca’s smoke.
She did not announce a course toward another island.
She gave a line.
That suggests Noonan possessed one reliable navigational dimension but lacked the second coordinate necessary to establish a precise fix.
The Electra was somewhere on—or believed itself to be somewhere on—the 157–337 line.
Where on that line remained the problem.
The Decision
At some point, searching for Howland had to end.
Fuel was finite.
Daylight was increasing.
Radio direction finding had failed.
Noonan therefore faced a decision that every navigator dreads.
Continue searching for the intended destination?
Or abandon the destination and navigate toward the best available alternate?
If NR16020 remained airborne long enough, the 157-degree direction offered something the 337-degree direction increasingly did not.
Land.
Southeast of Howland lay Baker Island and, much farther away, islands of the Phoenix group.
Northwest offered predominantly open ocean.
That does not prove Earhart turned southeast.
It does establish why the southern direction cannot simply be dismissed.
What the Final Transmission Actually Tells Us
Nearly nine decades of speculation have sometimes asked the 157–337 transmission to reveal more than it can.
It does not tell us Earhart’s exact position.
It does not prove she flew to Gardner Island.
It does not prove she crashed near Howland.
It does not tell us which end of the line she searched first.
But it does establish something important.
At the time of the last confirmed communication, Earhart and Noonan apparently still possessed a navigational strategy.
They were not simply lost.
They had a line of position.
They believed Howland was associated with that line.
And they were attempting to use it.
The Final Unknown
At 8:43 the microphone aboard NR16020 opened for the last confirmed transmission.
Earhart reported the 157–337 line.
She indicated that they were running along it.
Then the Pacific went silent.
For the searchers aboard Itasca, the disappearance had begun.
For Earhart and Noonan, however, something else may have begun.
A decision.
One direction led northwest.
The other led southeast.
One offered almost nothing but ocean.
The other eventually offered islands.
Which direction did Fred Noonan choose?
That question cannot presently be answered from the surviving radio log.
But the search conducted after Earhart disappeared provides another source of evidence.
Because ships and aircraft soon began looking across enormous stretches of the central Pacific.
Where they searched—and perhaps more importantly, why they searched there—reveals what the Navy and Coast Guard themselves believed might have happened after that final transmission.
Previously in the Earhart Investigation
The Earhart Fuel Paradox: Was Amelia Earhart Really Running Out of Fuel?
The surviving radio record raises an important question about the conventional fuel-exhaustion timeline and how much endurance NR16020 may actually have possessed when Earhart failed to locate Howland.
Next in the Earhart Investigation
The Search That Went Everywhere: Reconstructing the Navy and Coast Guard Hunt for Amelia Earhart
Within hours of the final transmission, the disappearance became an expanding military search involving the Coast Guard cutter Itasca, surface vessels, battleship aircraft and eventually the carrier Lexington.
But the search did not expand randomly.
Its changing geography reveals how American commanders interpreted the evidence—and how radio reports, navigational assumptions and false leads repeatedly changed where they believed Amelia Earhart might be.
RELATED ARTICLES:
Reader-friendly article version: The Fuel Paradox
AMELIA EARHART SERIES PART ONE
Full academic article version: The Fuel Paradox