jeffquitney
patreon
Ditching of a B-24 Airplane into the James River 1944 NACA
🕑 Added 2019-11-08 01:36:43 +0000 UTCmore at http://quickfound.net/
'Experimental ditching test conducted by NASA Langley Researcher. The B-24 was ditched into the James River on September 20, 1944. A pilot flew the plane into the water and the B-24 definitely experienced damage.'
Originally a public domain film from NASA, slightly cropped to remove uneven edges, with the aspect ratio corrected, and one-pass brightness-contrast-color correction & mild video noise reduction applied.
https://crgis.ndc.nasa.gov/crgis/images/8/85/2009Ditching.pdf
In 1943 the Army and Navy requested that Langley undertake a major study of ditching with a view to providing procedural recommendations to operational military units as well as to provide designers of new military aircraft with valuable data. The resulting research effort at Langley was extremely broad, including: structural tests to determine the structural load limits of actual aircraft such as the Boeing B-17 Flying Fortress, the Consolidated B-24 Liberator, and the Martin B-26 Marauder; measurement of the stresses imposed on structures during landings in calm and rough seas; and observations of aircraft behavior during ditching as replicated by free-flight models in Tow Tank 2. Virtually every U.S. bomber and fighter configuration was evaluated in simulated ditching tests to determine the most desirable airplane attitude and configuration for ditching. Major questions required answers, such as whether to deflect wing trailing-edge flaps or extend the landing gear, whether bomb-bay doors should be opened to partially absorb the impact, and whether one wing tip should be allowed to hit the water first to slew the airplane around to absorb energy.
The B-24 bomber, in particular, had exhibited appalling ditching behavior in operational service. When ditched, the airplane suffered massive structural failure and a diving tendency with a poor record for survivability of the crew. Extensive testing of a B-24 model in the towing tank faithfully replicated the undesirable ditching characteristics and permitted the evaluation of many modifications to improve the aircraft as well as recommendations for ditching procedures of operational aircraft. In addition to studies conducted in the Langley laboratories, the NACA provided instrumentation for two experimental ditching tests by the Army Air Forces in Virginia and Florida.
The test in Virginia was conducted by the Army Air Forces in the James River near Newport News in 1944 and was followed by additional B-24 model tests in the Langley towing tank for comparison of accelerations during the ditching impact. Excellent agreement was obtained between the model and full-scale results, providing additional confidence in the Langley testing procedure. Tests in a structures research laboratory at Langley showed that the bomb-bay doors of the B-24 had only one-fifth as much strength as the rest of the bottom structure, and door failure was known to be a major factor in the unacceptable ditching characteristics of the airplane. Working with the Army Air Forces, Langley designed and evaluated stiffening ribs that were distributed to the operational squadrons in 1944 for implementation prior to ditching. The ribs could be rapidly installed by the crew in a few minutes during preparations for the landing.
Daily Press of Newport News, Virginia
Thursday, September 21, 1944
https://crgis.ndc.nasa.gov/crgis/images/1/1c/1944-09-21_Daily_Press_Article_on_B-24.pdf
...Handling the controls of the large bomber was Major Julian A. Harvey of the AAF proving grounds and serving as co-pilot was Col. Carl F. Greene of Langley Field, liaison for the army with the Langley Memorial laboratories of the NACA.
The bomber made several dry runs before it came in at 100 miles per hour for the ditching in the calm waters parallel to the James River Bridge while several ranking navy and army officers crowded rails of a fleet of army craft lining the course. Official cameras recorded the ditching for a minute study.
Tail Strikes First
With her four motors throttled back and landing wheels up, the bomber was skillfully set down on the water, the tail end of the fuselage striking first. The bomber, which as the “Ellen Mae” served well the army air forces before being consigned to the advancement of aviation research, set up a thick enveloping spray as the nose of the ship struck the water. Planing for a few feet, the ship “porpoised” and buried the nose, wings and motors deep. The deceleration was terrific and it seemed minutes before the nose reappeared in the matter of a few seconds. The impact broke loose the nose, the break coming about six feet to the rear of the pilot’s compartment at the leading edge of the bomb bay doors, but the fuselage was not severed...
