Cash-Landrum Incident -- The Sound of the Craft: Acoustic Analysis
Cash-Landrum Incident -- The Sound of the Craft: Acoustic Analysis
What the Witnesses Described
The Cash-Landrum witnesses described the sound of the diamond-shaped craft as very loud, jet-like, and roaring -- comparable to a large jet engine or industrial turbine. This acoustic description is one of the more specific and analytically useful physical characteristics reported, because sound signatures are relatively distinctive among different propulsion systems.
Acoustic Signatures of Known Propulsion Systems
| Propulsion Type | Sound Signature | Consistent With Witnesses' Description? |
|---|---|---|
| Conventional jet turbine (aircraft) | High-frequency whine; turbine scream; directional; frequency changes with power setting | Partially; the "jet-like" description is consistent but conventional jets don't hover as described |
| Rocket engine | Loud roar; broad frequency spectrum; very intense at close range | The "roaring" description is consistent; but conventional rockets don't hover indefinitely |
| Nuclear thermal engine | The specific sound depends on the reactor type; a gas-core or open-cycle nuclear thermal engine could produce an intense broad-spectrum roar | Potentially consistent; open-cycle nuclear engines vent hot gas that would produce intense acoustic output |
| CH-47 Chinook helicopter | Distinctive "wop-wop-wop" double beat; very recognizable | The Chinooks were separately identified; the "jet-like roar" appears to describe the diamond-shaped craft, not the helicopters |
| Electric/magnetic propulsion | Typically quiet at operational frequencies | Inconsistent; the loud roar argues against purely electromagnetic propulsion |
The Sound as Evidence
The acoustic evidence from Cash-Landrum is relatively unusual: most UFO reports describe silent or near-silent craft. The very loud, jet-like roaring sound described by the witnesses is a specific characteristic that:
- Argues against the craft being an ordinary electrostatic or electromagnetic phenomenon
- Is consistent with a heat-engine type propulsion (something burning or venting hot gas)
- Is consistent with the flames-from-the-base observation (a system venting propulsive hot gas would also be noisy)
- Is consistent with the "craft in distress" hypothesis (a malfunctioning engine would be noisier than a properly operating one)
The sound description, combined with the visual description of flames from the base, creates a coherent physical picture of a thermally intense propulsion system operating under stress.
The Helicopters' Acoustic Profile
Vickie Landrum's specific identification of CH-47 Chinooks by their sound as well as their silhouette adds acoustic evidence to the visual identification. The CH-47's characteristic "double beat" rotor sound is unique and unmistakable to experienced listeners. Her sound-based identification of the helicopter type -- at night, under stress -- is another element of specificity that supports the credibility of her account.
