493
1951-APR-25 · Off Key West, Florida

Multi-aircraft Event — Cubana de Aviación CU493 / United States Navy Navy 39939

A Cubana de Aviación Douglas DC-4 and a U.S. Navy Beechcraft SNB-1 collided at 4,000 feet over the Naval Air Station at Key West. Both aircraft were operating under Visual Flight Rules (VFR) in clear weather. The DC-4 was on a scheduled flight from Miami to Havana, while the Navy aircraft was conducting a simulated instrument training flight. Following the collision, the Beechcraft disintegrated and fell into the sea, while the DC-4 remained airborne for several seconds before diving into the water. There were no survivors from either aircraft.

Aircraft 1
Cubana de Aviación — Flight CU493
Douglas DC-4 · CU-T188
Miami, FLHavana, Cuba
Souls 39 · Fatal 39
Aircraft 2
United States Navy — Flight Navy 39939
Beechcraft SNB-1 Kansan · 39939
NAS Key WestNAS Key West
Souls 4 · Fatal 4
Phase
Cruise
Cause
Human Factors (Operational)
Total Souls
43
Total Fatalities
43
Report
Final

Investigation Summary

The collision occurred at approximately 11:49 EST. The Cubana DC-4, named 'Estrella de Cuba', was cruising south at 4,000 feet as cleared by Air Traffic Control. Simultaneously, the Navy SNB-1 was performing a training mission that involved flying inbound on the east leg of the Key West Radio Range. Although the Navy flight was practicing 'blind' instrument flying, safety protocols required one pilot to maintain visual observation at all times. Investigation revealed that neither crew took evasive action, suggesting they were unaware of the other's presence until the moment of impact. The DC-4's left wing was sheared off opposite the outer engine, leading to the aircraft assuming a nose-down attitude before crashing into the ocean near the 'Little White House' presidential retreat.

Final Conclusions

The Civil Aeronautics Board (CAB) determined the probable cause was the failure of both flight crews to maintain sufficient vigilance to see and avoid other traffic while operating under Visual Flight Rules. Despite the Navy aircraft being on a training mission and the airliner being on a cleared airway, the clear weather conditions placed the primary responsibility for separation on the pilots' visual lookout.

Video Analysis

No video analysis linked for this case file yet.

Airframe & Maintenance

Cubana de Aviación CU493 — Douglas DC-4 · CU-T188

Airframe Hours
13,218
Last Major Check
1,317 hours since last major overhaul
Engines
Pratt & Whitney R-2000

United States Navy Navy 39939 — Beechcraft SNB-1 Kansan · 39939

Airframe Hours
2,264
Engines
Pratt & Whitney R-985-AN-1

Crew Experience

Cubana de Aviación CU493 — Douglas DC-4 · CU-T188

Captain

Total hours
12,158
On type
1,317

Javier Z. Bazan

First Officer

Total hours
4,557
On type
2,791

Jesus F. Pacheco

Systems & Failure Modes

i

Visual Flight Rules (VFR)

The regulatory framework requiring pilots to maintain their own separation from other aircraft by visual observation.

i

Key West Radio Range

The navigational aid the Navy aircraft was using to fly a specific heading (250 degrees) during its training mission.

Interesting Facts

  • 01The collision occurred in clear and calm weather conditions with excellent visibility.
  • 02The DC-4 crashed into the ocean approximately 1.7 miles southeast of the collision point.
  • 03The Navy Beechcraft disintegrated immediately upon impact and fell two miles west of the transport's wreckage.
  • 04The DC-4 was carrying 34 passengers and 5 crew members; the Navy aircraft carried 4 crew members.
  • 05Witnesses reported the DC-4's left wing was sheared off during the collision.

Safety Actions & Advisories

ATC Procedure Review

The CAB Chairman recommended that the Civil Aeronautics Administration review Air Traffic Control procedures and operational practices in the Key West area to prevent future conflicts between civilian and military traffic.

Location

Off Key West, Florida · 24.5352, -81.7943

Related Cases

Case ID · cubana-493-1951Last updated · Filed

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