B-29 crews of the 307th Bomb Group report a fast-climbing unidentified jet off Holland (5 September 1948)
This file is a USAFE intelligence summary of 4 November 1948 (Top Secret control number 2-5317, dated 8 November 1948). Item 10 reports that on 5 September 1948, at 1402Z, aircraft of the 307th Bomb Group on "operation daggar" were flying at 30,000 ft off the west coast of Holland. They saw an unidentified aircraft at normal jet speed on heading 120. It then trailed smoke and condensation, accelerated suddenly and climbed. The report judged it a "single jet propelled A/C employing probably rocket assists with tremendous reserve power". It never came within identification range, and the evaluation was B-2. Item 14 of the same summary covers other reports, including one of a hovering object at Neubiberg for about thirty minutes, and quotes Swedish Air Intelligence on a Swedish lake crash and an uncharted crater. The writer said he was inclined not to discredit "this somewhat spectacular theory" entirely. *Method note: war.gov blocks this server. The 7-page file was read from the original PDF on the ufotransparency.com mirror; pages 4-5 were read from the page images.*
How plausible · High
A Top Secret USAFE intelligence summary records B-29 crews' report, rated B-2; it suggests a rocket-assisted jet, not demonstrated.
- ●●Access Bomber crews in flight.
- ●●No gain sought An intelligence summary.
- ●●Checkable details check out The summary is released.
- ●○Restraint "Probably" a rocket-assisted jet.
- ●○Character record Official, crews unnamed.
- ●○Independent convergence Several crews of the group.
Plausibility weighs how well an account fits where secrecy hides the documents by design, so missing records never count against it. Strength measures what is documented. Assessed 2026-10-23.
On the record
- USAFE intelligence summary item 10 (TT 1524, 4 November 1948): at 1402Z on 5 September 1948, 307th Bomb Group aircraft on "operation daggar" [sic], all at 30,000 ft, at 5155N/0355E off the west coast of Holland, saw an unidentified aircraft at normal jet speed on heading 120. It then made smoke and condensation trails and accelerated and climbed suddenly. (341_110448..., pp. 4-5, read from the page images)
- "single jet propelled A/C employing probably rocket assists with tremendous reserve power" (341_110448_Records_Relating_to_the_Collection_and_Dissemination_of_Intelligence_1948-1955-TS_CONT_No.2_2-5300-2-5399, p. 4; read from the page image); it never came within identification range; evaluation "B-2".
- Item 14 covers a hovering object at Neubiberg for about thirty minutes and quotes Swedish Air Intelligence on a crash in a Swedish lake and an uncharted crater. The writer says he is "inclined not to discredit entirely this somewhat spectacular theory". (pp. 4-5, read from the page images)
- Top Secret control "TS Cont. 2-5317", dated 8 November 1948. (p. 2)
Claims
Where
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Sources
- war.gov/ufo, PURSUE Release 01 listing (8 May 2026; not reachable from this server)
- Mirror file list for Release 01 (ufotransparency.com)
- 341_110448_Records_Relating_to_the_Collection_and_Dissemination_of_Intelligence_1948-1955-TS_CONT_No.2_2-5300-2-5399 (war.gov), mirror page with the official description
- 341_110448_Records_Relating_to_the_Collection_and_Dissemination_of_Intelligence_1948-1955-TS_CONT_No.2_2-5300-2-5399 original file, via mirror