Swenson and Culick
Swenson, G., Culick, F.E.C.
Analysis of Amelia Earhart’s Final Flight - July 2, 1937
This research is well done. The engineering assessments are based on L487 and wind tunnel testing performed in 1935 and contained in a test report, GALCIT Report No. 161P. Standard aerodynamics equations are applied to determine performance.
Assumptions underlying this research include:
1. The magnitude of headwinds and their constant velocity throughout the entire flight.
This value, from Long, was 26.5 mph.
2. A constant true air speed flown throughout the entire flight.
This value, From Long, was 161.5 mph.
3. Initial fuel load.
This initial value was reported by Chater and Collopy.
Swenson and Culick, et al, applied adjustments for temperature and volume to arrive at an initial fuel load of 1080 gallons, vice the value of 1100 gallons reported by Collopy.
4. Flight Path.
The authors used the path constructed by Long.
The authors used In-flight position reports as the basis for reconstructing the vertical flight path profile between Lae and Howland Island.
6. Ship Sighting.
The authors addressed the relative reliability in the 1030 ship sighting report by AE
They concluded that the vessel observed was either the USS Ontario, or SS Myrtlebank.
Their assessment is based on assumed aircraft ground speed and time to the ship sighting, and a projection forward to the Howland area arrival time. This helps to establish a time abeam Nauru Island, in their path reconstruction.
The authors’ work is very credible. They presented a good baseline fuel consumption analysis, and created numerous alternate scenarios as functions of headwind, fuel consumption and error tolerance. Their assumptions for headwind, aircraft true air speed, initial fuel load, fuel consumption and endurance are appropriate given the scarcity of facts. Their conclusions are valuable and interesting in assessing boundary values for mission parameters.
The authors’ choice to use Long’s 26.5 mph headwinds is prudent and replicated by virtually all researchers. Similarly, assuming aircraft true airspeed of 161.5 mph is considered valid.
Swenson and Culick and Long plot AE’s flight path at the ship sighting as passing over the assumed ship’s position, which very slightly affects distance, timing, and position.
Swenson and Culick do not project this path point, slightly north of the great circle direct route from Lae to Howland (Path A), to an end point north of Howland, as Long does.
Swenson and Culick’s path from the ship sighting converges to Path A as it proceeds direct to Howland from the ship sighting point.
The Swenson and Culick, et al, conclusions below, are validated as follows
- Initial fuel load and preflight planning should have enabled flight for 20 hours 38 minutes.
- Actual mission time to initial arrival near Howland was 19 hours 12 minutes.
- This should have allowed post-arrival endurance of 1 hour 16 minutes.
- The ship sighted was SS Myrtlebank, based on assumed average headwind and aircraft ground speed and time, and projecting those parameters forward to an estimated arrival at Howland at 1912 GMT.
- AE was within 100 miles [units not specified] of Howland based on radio strength.
- “…AE’s flight…ended in the ocean short of her intended landing place.”