Subido por Elis Jose Marcano Inciarte

Controlled Flight into Terrain

A classic CFIT accident that occurred 25 years ago
changed the way we handle IFR flights, resulted in better
charting, and IFR changes. Some aspects of the accident
were so disturbing that, to this day, pilot examiners and
flight instructors drill new IFR pilots on what the phrase
"Cleared for Approach" means.
On December 1, 1974, TWA Flight 514, a Boeing 727-231
was en route from Indianapolis to Washington's National
Airport. Crosswinds at National were too much for the
north-south runway, and flights were being diverted to
Washington Dulles International Airport's Runway 12.
Weather observations at Dulles showed a 900 ft ceiling
and visibility of 3 to 7 miles in rain. Surface winds were
from 070° at 25 to 28 knots, with gusts as high as 49 kt.
At 10:42 a.m ATC cleared Flight 514 to Dulles via the
Front Royal VOR and to maintain FL290.
At 10:43 the flight was cleared down to FL 230 and to
cross 40 nm west of Front Royal at that altitude.
At 10:51 ATC gave the flight heading of 090° to intercept
the R300 of the ARMEL VOR, to cross a point 25 nm west
of ARMEL at 8000 and "...the 300 radial will be for the
VOR approach to Runway 12 at Dulles, altimeter 29.74.
The crew acknowledged. Cockpit voice recordings showed
that the VOR was tuned and altimeters properly set.
At 10:57 the crew again discussed the approach, including
Round Hill intersection, the final approach fix, VASI,
runway lights, and the airport diagram.
At 11:09:22 TWA 514 struck the west slope of Mount
Weather, about 25 nm from Dulles at an elevation of about
1670 ft. Seven crewmembers and 85 passengers perished
in the crash. There were no survivors. Testimony following
the accident indicated that ATC frequently vectored aircraft
off published routes and cleared them to descend below
altitudes published on the charts.
Ironically, as early as 1970, both the U.S. Air Force and
the airlines pointed out to the FAA that the statement
“Upon receiving an Approach Clearance, the pilot should
begin his descent to the Approach Altitude as soon as
possible” published in the February 1970 issue of the AIM
could be misinterpreted unless a specific altitude
restriction was included in the clearance. This statement
was deleted in May 1970; however the line used to indicate
a change was not drawn in that page. Some pilots,
including the TWA Crew, were not aware of this change.
The NTSB found the causes of the crash to be:
1. Flight crew's decision to descend to 1800 ft before the
aircraft had reached the approach segment where that
minimum altitude applied (See Appendix 1).
2. Flight crew's failure to adhere to the MSA depicted on
the IAP chart and to request a clarification of the clearance.
However, two of the five-member NTSB dissented,
identifying the cause to be the failure of ATC to issue
altitude restrictions in accordance with the ATC handbook.
At 11:01 the flight was cleared to 7000 ft and to proceed
inbound to ARMEL VOR and to expect the VOR/DME
approach to Runway 12.
At 11:04 the flight reported level at 7000, and five seconds
later the controller said, "TWA Five-Fourteen, you're
cleared for a VOR/DME approach to Runway One-Two."
The captain acknowledged this.
Worldwide implementation of pilot responsibilities and
actions after receiving an Approach Clearance.
(USA: CFR 14 91.175. PANAMA: Libro X Artículo 134)
GPWS since December 1975 is mandatory.
Modification of Automated Radar Terminal System
(ARTS) alerting ATC when aircraft deviate from
predetermined altitudes while flying in a Terminal Area.
Mandatory exchange incident reporting system between
airlines that is intended to identify unsafe operating
conditions in order that they can be corrected before an
accident occurs. The U.S.A FAA keeps oversight.
Introduction of the MSA symbol on Approach Chart.
10:51 “TWA 514 at 44 nm from FFR turn left heading
090 to intercept Radial 300 of the ARMEL VOR
Cross 25 nm inbound to ARMEL VOR at 8000”
10:59 “TWA 514 leaving 11000 for 8000”
11:01 “TWA 514 descend and maintain 7000”
11:02 “TWA 514 out of 10.000 for 7000”
11:01 “TWA 514 Proceed inbound to ARMEL,
Expect VOR/DME RWY 12”
11:04 “TWA 514 is maintaining 7000”
11:09 "514 Cleared VOR/DME Approach RWY12"
Cleared for VOR/DME RWY 12, TWA 514”