F/FB-111 Escape Injury Mechanism Assessment.
Abstract
All F/FB-111 ejections, for the period October 1967 to June 1977, have been reviewed from an orthopedic biomechanical point of view. A suggested radiographic method for identifying and classifying the unique spinal injury patterns in the F/FB-111 is presented. A type of fracture due to hyperextension of the upper thoracic spine, previously unidentified in the clinical and operational environment and having clinically unfamiliar features, is described. F/FB-111 spinal injuries have been classed as (a) hyperextension injuries, (b) hyperflexion injuries, and (c) combination hyperextension/hyperflexion injuries. Hyperextension injuries are due to the direction of force application of the powered inertia reel, and they occur during the powered inertia reel retraction phase of the ejection sequence. Hyperflexion injuries are due to the ineffectiveness of the upper torso harness, and they occur following ground landing impact. Combination injuries (hyperextension/hyperflexion) are common. The mechanism of spinal injury in most aircrewmen is best understood and most often diagnosed by a combination of careful aircrew questioning, clinical history, and thorough roentgenographic assessment. The operational, clinical, and roentgenographic features should be complementary. A new technical order has been incorporated into the F/FB-111 emergency escape procedures. The severity and frequency of hyperflexion injuries have been reduced. The design deficiency in the configuration of the support and restraint system has been identified, with the result that corrective action has been initiated.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1977
- Accession Number
- ADA052337
Entities
People
- Leon E. Kazarian
Organizations
- Air Force Research Laboratory