{"id":29747,"date":"2018-08-24T21:29:42","date_gmt":"2018-08-24T21:29:42","guid":{"rendered":"https:\/\/one.sightlinemg.com\/airforcetimes\/uncategorized\/2018\/08\/24\/gearbox-failures-ejection-seat-setting-mistakes-led-to-fatal-t-38-crash\/"},"modified":"2026-08-07T20:59:09","modified_gmt":"2026-08-07T20:59:09","slug":"gearbox-failures-ejection-seat-setting-mistakes-led-to-fatal-t-38-crash","status":"publish","type":"post","link":"https:\/\/one.sightlinemg.com\/airforcetimes\/news\/your-air-force\/2018\/08\/24\/gearbox-failures-ejection-seat-setting-mistakes-led-to-fatal-t-38-crash\/","title":{"rendered":"Gearbox failures, ejection seat setting mistakes led to fatal T-38 crash"},"content":{"rendered":"\n

The crash<\/a> of a T-38C Talon training aircraft in Texas last November, which killed one of its two pilots<\/a>, was caused by a dual failure of the trainer\u2019s troubled airframe mounted gearboxes, according to a new Air Force report.<\/p>\n\n\n\n

The Accident Investigation Board report<\/a> also found that the crew\u2019s distraction during checklist procedures resulted in an ejection seat not being armed, and led to the death of the requalification pilot, Capt. Paul Barbour.<\/p>\n\n\n\n

The plane crashed<\/a> about 12 miles northwest of Laughlin Air Force Base in Texas on Nov. 20. The instructor pilot, Capt. Joshua Hammervold, ejected and sustained mild injuries, said the report, which was finished in May and posted online Tuesday.<\/p>\n\n\n\n

Barbour, 32, of Van Nuys, California, was taking part in requalification training after returning from a non-flying overseas deployment, the report said. Both pilots were with the 87th Flying Training Squadron at Laughlin, part of Air Education and Training Command\u2019s 47th Flying Training Wing.<\/p>\n\n\n\n

The accident investigators found the input drive coupling shafts in both the left and right airframe mounted gearboxes on the T-38 sheared, which led to the crash.<\/p>\n\n\n\n

This was a long-standing problem with that T-38. The right gearbox had seven input coupling shaft shears over the previous 22 months, including the shear that led to its crash.<\/p>\n\n\n\n

\"\"
Capt. Paul Barbour was killed Nov. 20 when his T-38 Talon crashed in Del Rio, Texas. Barbour was the air crew flight equipment flight commander with the 47th Operations Support Squadron and an instructor pilot with the 87th Flying Training Squadron at Laughlin Air Force Base, Texas. (Courtesy photo from Barksdale Air Force Base)<\/figcaption><\/figure>\n\n\n\n

But those failures didn\u2019t happen frequently enough to signal maintainers to take a closer look, the report said. Additional scrutiny was only required if an aircraft had failures on back-to-back sorties, or happened twice in five sorties, the report said. The policies that were in place at the time had no rules requiring additional inspection or maintenance for an aircraft that needed seven coupling shaft replacements in less than two years.<\/p>\n\n\n\n

The report also said the left gearbox had five previous failures before the crash, but none were a sheared shaft.<\/p>\n\n\n\n

The president of the board, Brig. Gen. Joel Carey, concluded that a lack of maintenance guidance spelling out what should be done when the gearbox fails repeatedly was a substantial contributing factor in the mishap.<\/p>\n\n\n\n

Investigators also concluded the pilots of the T-38 didn\u2019t finish their standard checklist procedures, which led to Barbour\u2019s inability to eject. The report said Hammervold interrupted the normal flow of checklist call-outs and confirmations by saying, \u201cThis is where I usually go 60 as you\u2019re straightening out,\u201d and Barbour replied, \u201cOh, yeah!\u201d After that interruption, they didn\u2019t go back and finish the last two items \u2014 making sure the levers in both ejector seats were moved from safe to armed, and moving the inter-seat sequencing system, or ISS, from \u201csolo\u201d to \u201cboth.\u201d<\/p>\n\n\n\n

As a result, Hammervold\u2019s seat was armed, but Barbour\u2019s was not. And if the ISS had been moved to both, the report said, Hammervold would have been able to trigger Barbour\u2019s ejector seat alongside his, even though Barbour\u2019s lever was not in the right position.<\/p>\n\n\n\t