Gulfstream G IV N450KK

Summary

On 10 April 2015 at about 22:45 local time, a Gulfstream G IV registered N450KK, operated by La Venezolana de Seguros CA, was involved in an accident near Caribbean Sea, Unknown. 2 people were on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

10 April 2015 at 22:45

Classification

Accident

Location

Caribbean Sea, Unknown

Coordinates

22.4167, -74.8333

Aircraft

Gulfstream G IV

Registration

N450KK

Category

Airplane

Year built

1993

Engines

2

Operator

La Venezolana de Seguros CA

Operating rule

Part 91: General Aviation

Purpose of flight

Positioning

Phase of flight

Not recorded

Route

Maiquetia → Fort Lauderdale

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ERA15LA328

Nobody was injured.

The in-flight failure of the cabin pressurization relief/safety valve (CPRV) due to an obstruction of the CPRV static port, which allowed the airplane to overpressurize. The reason for the initial overpressurization condition could not be determined.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The pilot and copilot were conducting a repositioning flight. According to the pilot, during cruise at flight level 430, they observed a red "9.8 CABIN DFRN" warning message, indicating a maximum cabin differential pressure of 9.8 pounds per square inch differential or greater, followed by a red "DOOR MAIN" indication. The pilots donned oxygen masks and referenced the airplane's emergency checklist. They then heard a loud "bam" sound in the cabin and immediately initiated a descent. The pilots opened the cabin pressure outflow valve manually and leveled the airplane at 12,000 ft mean sea level. The pilots continued the flight unpressurized and landed without further incident. The day after the accident, the airplane was flown for a short and uneventful repositioning flight, after which it was examined and structural airframe damage, including a cracked floor beam, dimpled areas in the floor boards, damaged structure between ribs, and damaged wing links, was found. An examination of the outer fuselage revealed that the cabin pressurization relief/safety valve (CPRV) static port, located above the CPRV, was completely plugged with a foreign material resembling dried dirt from a mud dauber. According to the airplane manufacturer, a blocked CPRV static port would render the CPRV inoperative due to its inability to measure the cabin-to-atmosphere pressure differential. The cockpit aural warning speaker was also found inoperative, which may have delayed the pilots' ability to recognize the overpressurization condition. The airplane's digital flight data recorder indicated that the crew acknowledged the initial warning message 89 seconds after its illumination. No other mechanical anomalies were found with the airplane's pressurization system. The airplane's structural damage was not repaired after the accident; therefore, the reason for the overpressurization condition could not be determined.

Quoted verbatim from the NTSB record.