1 December 1974 - TWA 514

The crew descended below minimum altitude during a runway 12 VOR/DME approach to Washington-Dulles. The aircraft struck high ground at 1800ft.
PROBABLE CAUSE: "The crew's decision to descend to 1800ft before the aircraft had reached the approach segment where that minimum altitude applied. The crew's decision to descend was a result of inadequacies and lack of clarity in the air traffic control procedures which led to a misunderstanding on the part of the pilots and of the controllers regarding each other's responsibilities during operations in terminal areas under instrument meteorological conditions. Nevertheless, the examination of the plan view of the approach chart should have disclosed to the captain that a minimum altitude of 1800ft was not a safe altitude.

The following is the CVR transcript.
Voices are identified thus: Capt--Captain, FO--First Officer, and FE--Flight Engineer.

The National Transportation Safety Board did not quote all items verbatim except what is considered pertinent. The "nonpertinent" comments here are copied directly from the report.

11:04 Capt: "Eighteen hundred [feet] is the bottom."
FO: "Start down. We're out here quite a ways. I better turn the heat down [probably referring to cabin heat]."
11:06:15 FO: "I hate the altitude jumping around." Then he commented that the instrument panel was bouncing around.
11:06:15 Capt: "We have a discrepancy in our VORs, a little but not much. Fly yours, not mine."
11:06:27 Capt discusses the last reported ceiling and minimum descent altitude and concluded: "...should break out."
11:06:42 FO: "Gives you a headache after awhile, watching this jumping around like that."
11:07:27 FO: "...you can feel that wind down here now."
Capt: "You know, according to this dumb sheet [referring to the instrument approach chart] it says thirty-four hundred to Round Hill--is our minimum altitude." The FE asked where the captain saw that, and the captain replied, "Well, here. Round Hill is eleven-and-a-half DME."
FO: "Well, but...."
Capt: "When he clears you, that means you can go to your...."
Unidentified: "Initial approach."
Unidentified: "Yeah."
Capt: "Initial approach altitude."
FE: "We're out of twenty-eight for eighteen."
Unidentified: "Right; one to go." [meaning 1,000 feet more before reaching the supposed level-off altitude of 1,800]
11:08:14 FE: "Dark in here."
FO: "And bumpy too."
11:08:25 Altitude alert horn sounds.
Capt: "I had ground contact a minute ago."
FO: "Yeah, I did too."
11:08:29 FO: "...power on this [expletive]."
Capt: "Yeah, you got a high sink rate."
FO: "Yeah."
Unidentified: "We're going uphill."
FE: "We're right there, we're on course."
Two voices: "Yeah."
Capt: "You ought to see ground outside in just a minute. Hang in there, boy."
FE: "We're getting seasick."
11:08:57 Altitude alert horn sounds.
FO: "Boy, it was--wanted to go right down through there, man."
Unidentified: "Yeah."
FO: "Must have had a [expletive] of a downdraft."
11:09:14 Radio altimeter warning horn sounds and stops.
FO: "Boy!"
11:09:20 Capt: "Get some power on."
Radio altimeter warning horn sounds again and stops.
At 11:09:22 TWA 514 struck the west slope of Mount Weather, about 25 nautical miles from Dulles at an elevation of about 1,670 feet. Seven crewmembers and 85 passengers perished in the crash. There were no survivors.