# Aviation Accident Report: American Airlines Flight 9/Conclusion

CONCLUSION
Upon all of the evidence available to the Board at this time, we find that the facts relating to the accident involving NC 16015 which occurred near St. Louis, Missouri, on December 11, 1940, are as follows:
1. The accident, which occurred at approximately 2:47 p.m., December 11, 1940, to American Airlines' Trip 9 of that date, resulted in major damage to aircraft NC 16015 and injuries to two passengers and two members of the crew.
2. At the time of the accident, American Airlines held a currently effective and appropriate certificate of public convenience and necessity and an air carrier operating certificate.
3. Captain Susott and First Officer Phillips were physically qualified and held proper certificates of competency to operate as air carrier pilots over the route between Chicago, Illinois, and St. Louis, Missouri.
4. Aircraft NC 16015 was currently certificated as airworthy at the time of the accident.
5. Trip 9 was cleared by the company flight dispatcher in accordance with proper procedure from Chicago, Illinois, to St. Louis, Missouri.
6. At the time of departure from Chicago the gross weight of the airplane did not exceed the approved gross weight and its load was properly distributed with reference to the location of the center of gravity.
7. At the time of departure from Chicago to St. Louis, the airplane carried sufficient fuel to permit flight at normal cruising power to St. Louis and thereafter for about six hours, thus making available to Captain Susott a choice between a number of alternate airports.
​8. Trip 9 proceeded without incident from Chicago until it arrived over the St. Louis radio range station at 2.31 p.m. at an altitude of 1,600 feet.
9. Captain Susott then executed a standard instrument let-down-through procedure and broke out of the overcast east of the Lambert-St. Louis Airport at an altitude of 400 feet above the level of the airport.
10. The condition of the airport had been affected by the construction of 60-foot poles just north of the east end of the No. 1 runway, by the accumulation of mud on the No. 1 runway about 1,500 feet from its east end, and by the filling of a low area in the southeast portion of the airport; these conditions were known to Captain Susott.
12. The ceiling at the airport was 400 feet, with lower scattered clouds at 200 feet; the visibility was one mile and light rain was falling.
13. After breaking out of the overcast, Captain Susott planned to land toward the east on the No. 4 runway but was unable to do so because of the poor visibility resulting from the presence of low-lying scattered clouds west of the airport.
14. Captain Susott then attempted to land toward the west on the No. 1 runway but missed his approach and found himself headed directly toward the poles, previously referred to, which are located on the north side of the runway.
15. Captain Susott turned sharply to the left to avoid the poles and then to the right in an effort to line up on No. 1 runway. This maneuver placed him south of the runway, in spite of which he elected to continue to a landing on the turf beyond the fill in the southeast corner of the airport.
​15. The wheels of the aircraft first touched the ground approximately 1,875 feet from Coldwater Creek, which runs near the boundary of the airport on the south and west.
16. Due to the limited area available and the slippery condition of the turf, Captain Susott was unable to bring the aircraft to a stop before it rolled into the creek.
17. Aircraft NC 16015 and all of its equipment functioned normally during the entire flight.
18. The weather forecasts and observations upon which Captain Susott depended were made without substantial error.
19. The airway aids to navigation available for use by Captain Susott were functioning satisfactorily.
Probable Cause
Upon the basis of the foregoing findings of fact and upon all of the evidence available to us at this time, we find that the probable cause of the accident to NC 16015 (American Airlines' Trip 9) on December 11, 1940, was the clearly incautious attempt by the pilot to land the airplane under circumstances unfavorable to a safe landing.
Recommendation
The Board has recommended to the Administrator that the weather letters of competency issued by him to air carriers be amended to provide that when a solid cloud cover prevails at an altitude of 800 feet or less and the horizontal visibility is officially reported to be less than five miles, the height of the ceiling shall be from the base of the lowest cloud form ​officially reported. The Board suggested that this recommendation be made effective and enforced until such time as additional studies indicated that other action of a more fundamental and permanent character should be taken. The Board has been advised by the Administrator that this recommendation has been carried into effect.
BY THE CIVIL AERONAUTICS BOARD:
/s/ Harllee Branch Harllee Branch, Chairman
/s/ Oswald Ryan Oswald Ryan, Member
/s/ G. Grant Mason, Jr. G. Grant Mason, Jr., Member
/s/ George P. Baker George P. Baker, Member
(Mr. Edward P. Warner, Vice Chairman, did not take part in the adoption of this report and recommendation.)