1969 — March 5, PR Int. Airlines plane crash, Sierra de Luquillo Mts., San Juan, PR –all 19

— 19 NTSB. AAR. Puerto Rico International Airlines… San Juan, PR, March 5, 1969. 1970.
— 19 Planecrashinfo.com. “1969. Accident Details…San Juan, Puerto Rico, Mar 5, 1969.”

Narrative Information

National Transportation Safety Board Synopsis:

“Puerto Rico International Airlines (FRIWJR), N563PR, a De Havilland Heron 114-2, a regularly scheduled air taxi passenger flight from St. Thomas, Virgin Islands, to San Juan, Puerto Rico, crashed in the Sierra de Luquillo mountains while being vectored for an ILS approach to Runway 7 at the San Juan International Airport, at approximately 1738, March 5, 1969. The aircraft was destroyed. The accident was fatal to all 19 occupants aboard the aircraft: two crewmembers and 17 passengers.

“The flight was operating on an IFR clearance and flying in actual IFF weather conditions. Following the transfer of control from San Juan Air Route Traffic Control Center to San Juan Approach Control, the flight was given an erroneous position report. Indications are that the flight complied with the subsequent radar vectors and altitude assignments until the accident became unavoidable.

“The aircraft was not equipped with a radar transponder or distance measuring equipment (DME).

“The Board determines that the probable cause of this accident was the vectoring of the aircraft into mountainous terrain, under IFR conditions, without adequate obstruction clearance altitude by a controller who, for reasons beyond his control, was performing beyond the safe limits of his performance capability and without adequate supervision.

“Shortly after the accident, the Board made certain recommendations to the Federal Aviation Administration dealing with the operation of aircraft without distance measuring or transponder equipment in instrument flight conditions in the San Juan area. A review of approach control procedures in locations with a similar topography was also recommended. In response to these recommendations the FAA took several actions which satisfied the intent of the Board.” (NTSB 1970, 1)

Puerto Rico International. Airlines (PRINAZR), Flight 277, a De Havilland Heron 114-2, N563E3, was a regularly scheduled air taxi passenger flight from St. Thomas , Virgin Islands, to the San Juan, Puerto Rico, International Airport.

“At 1715 on March 5, 1969 PRINAIR 277 departed St. Thomas on an Instrument Flight Rules (IFR) clearance to San Juan via Route 2 to Isla Verde intersection, to maintain 4000 feet…. The flight proceeded initially under the control of the San Juan Air Traffic Control Center (ARTCC).

“At 1718:40, the Center advised San Juan Approach Control that PRINAIR 277 was estimating Isla Verde intersection at 1738, maintaining 4,000, and that it would be a radar handoff from the east on Route 2.

“At 1730:50, the Center identified to Approach Control the radar target of PRINAIR 277, which was then 27 miles east of San Juan on Route 2. When this was accomplished, and the radar target verified by the approach controller, a center-to-approach control handoff was effected.

“At 1732:05, PRINAIR 277 contacted San Juan Approach Control and advised that the flight was maintaining 4,000. Approach Control replied: “PRINAIR two seven-seven San Juan Approach Control radar contact three miles east of Isla Verde fly a heading of two five zero for a vector to IIS final maintain four thousand.” When this transmission was made by the trainee controller working the AFH (Arrival Radar) position, the aircraft was actually observed by him on the radarscope 3 miles east of the Fajardo intersection. It should be noted that the Isla Verde intersection is located about 10 miles west of the Fajardo intersection; both intersections are part of the Route 2 structure.

“The controller, who was working the coordinator position in the Terminal Radar Approach Control. (TRACON) room, noticed this error but made no comment. When interviewed, he referred to this error as “a slip of the tongue’ and indicated that he did not consider this a case of misidentification since there was no target on the radarscope 3 miles east of the Isla Verde intersection. Furthermore, he pointed out the target on the radarscope to the AR-1 controller, who acknowledged. The coordinator also stated that he assumed that the instructor controller, who was supervising the AR-1 controller as part of the latter’s facility checkout, had caught this mistake.

“The instructor controller indicated that he was not aware of the error in phraseology and that he was given collateral duties immediately following PRINAIR 277’s handoff.

“At 1732:25, PRINAIR 277 acknowledged by stating: “Okay we’ll maintain four thousand and we’re turning to a heading of two five zero.’…

“A t 1733:15, Approach Control issued a clearance for PRINAIR 277 to descend to and maintain 3,000 feet. PRINAIR 277 acknowledged.

“At 1737:25, PRINAIR 277 asked for a lower altitude.

“A t 1737:35, Approach Control issued the following: “PRINAIR two-seven-seven San Juan Approach Control turn left heading two-two-zero continue to maintain three thousand vectors to IC3 final.” PRINAIR 277 acknowledged as follows: “Ah left heading two-two-zero for two seventy seven and we’re at three thousand at the present time.’ [This was the last communication from 277.] ….” (NTSB 1970, 3)

“The aircraft came to rest near the top of a knoll in the Sierra de Luquillo mountains at an elevation of approximately 2,400 feet. This knoll is located in a dense rain forest and bordered on the northeast and south by ridges at or above 3,000 feet….” (NTSB 1970, 8)

“The indication that PRINAIR Flight 277 followed given instructions to the letter for about 5 minutes suggests that the accident vas the end result of a chain of conditioning events, rather than one single error or deficiency….” (NTSB 1970, 9)

“At 1732:05, the crew received an erroneous position report from the AR-1 controller which put the aircraft 10 miles farther west than it actually was. This “slip of the tongue” in itself was not a critical error, although it may have affected the controller’s later action. To go uncorrected, this error required the passive cooperation of three parties: (a) the AR-1 controller’s direct supervisor (the instructor controller)… (b) the coordinator who noticed the error but expected that it would be caught by the instructor, and (c) the aircraft crew who acknowledged the erroneous position report without further comment.” (NTSB 1970, 9-10)

Sources

National Transportation Safety Board. Aircraft Accident Report. Puerto Rico International Airlines, Inc. De Havilland Heron 114-2, N563PR Sierra De Luquillo San Juan, Puerto Rico March 5, 1969 (NTSB-AAR-70-9). Washington, DC: NTSB, adopted April 24, 1970, 32 pages. At: http://libraryonline.erau.edu/online-full-text/ntsb/aircraft-accident-reports/AAR70-09.pdf

Planecrashinfo.com. “1969. Accident Details…San Juan, Puerto Rico, Mar 5, 1969.” Accessed 3-28-2022 at: http://www.planecrashinfo.com/1969/1969-10.htm