Jetblue A320 at Las Vegas on Jun 17th 2012, two hydraulic systems failed

Last Update: March 27, 2015 / 00:31:05 GMT/Zulu time

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Photo of Jetblue N552JB, Airbus A320 — Jetblue N552JB, Airbus A320 (Photo credit: Aero Icarus / Flickr / License: CC by-sa)

Incident Facts

Date of incident
Jun 17, 2012

Classification
Incident

Airline
Jetblue

Flight number
B6-194

Departure
Las Vegas, United States

Destination
New York JFK, United States

Aircraft Registration
N552JB

Aircraft Type
Airbus A320

ICAO Type Designator
A320

A Jetblue Airbus A320-200, registration N552JB performing flight B6-194 from Las Vegas,NV to New York JFK,NY (USA) with 149 passengers and 5 crew, was climbing out of Las Vegas' runway 25R when the crew levelled off at 13,000 feet reporting multiple hydraulic problems, a few minutes later the crew declared emergency reporting they had lost two hydraulic systems. They needed to burn off fuel and entered a holding at 12,000 feet for about 3 hours and landed safely on runway 25R about 3:30 hours after departure and stopped on the runway.

The runway was closed for about 30 minutes until the aircraft was towed off the runway.

A replacement Airbus A320-200 reached New York with a delay of 8 hours.

The airline reported the yellow hydraulic system had been lost.

The Aviation Herald however learned on Jun 20th that the green hydraulic system had been lost followed by an overheat indication of the yellow hydraulic system prompting the crew to report the failure of two hydraulic systems. The crew actioned the relevant checklists and were able to recover the yellow hydraulic system.

On Oct 4th 2012 the NTSB reported the aircraft suffered a dual hydraulic system failure after departure from Las Vegas. The crew actioned the relevant checklists and was able to restore one of the failed systems, burned off fuel and returned to Las Vegas for a safe landing. The aircraft was towed to the gate. There were no injuries, the aircraft sustained minor damage to the hydraulic system. An investigation is ongoing.

On Mar 26th 2015 the NTSB released their final report concluding the probable cause of the incident was:

the failure of the right main landing gear door retraction flexible hydraulic line in the Green hydraulic system, which led to prolonged operation of the power transfer unit and subsequent overheating and loss of pressure in the Yellow hydraulic system, resulting in the airplane's operation with only one hydraulic system. Contributing to the incident was the lack of incorporation of aircraft manufacturer service bulletins that describe procedures for aircraft modifications intended to prevent this occurrence.

The NTSB reported the aircraft had departed under minimum equipment list requirements with one flap computer inoperative. During gear retraction the green hydraulic system lost pressure, the flight warning computer detected a flight control flap system fault, 2 minutes later a yellow hydraulic reservoir overheat indication activated, the indications however were inhibited until the aircraft climbed through 1500 feet AGL. The NTSB wrote: "The crew subsequently experienced a period of high workload as they received multiple aural and visual warnings on the flight deck."

The captain handed control to the first officer and began to work the related checklists which required to shut down the green and yellow engine driven pumps and the power transfer unit (PTU). This however produced the loss of yellow hydraulic pressure, the reversion to Alternate Law and the disconnection of autopilot and autothrust. The crew attempted to raise the flaps from 1 to 0 degrees, however, due to the loss of green hydraulic system and the deactivated flaps computer the flaps were inoperative.

With only the blue hydraulic system remaining available the crew coordinated with ATC to enter a hold to work the related checklists, communicate with engineering and dispatch and compute landing distance. While in the hold the captain noticed that the yellow hydraulic system no longer indicated overheat and followed the checklists to restore the yellow hydraulic system and managed to bring the yellow hydraulic system online again 36 minutes after departure. The crew had already determined they needed 11,000 feet of runway for landing with two hydraulic systems inoperative, with the recovery of the yellow system they now needed 8,500 feet only.

With the loss of the green hydraulic system there was no possibility to retract the landing gear once it was extended, even in case of a go around, there was no nose wheel steering available and there was need for landing at a higher than normal speed. The crew therefore decided to remain in the hold to burn off fuel until being below maximum landing weight and landed safely at a higher speed than normal about 3.5 hours after departure. The aircraft was towed off the runway.

A post flight examination found a leak in the flexible green hydraulic line at the right main gear door retraction mechanism, the line showed a kink and a collapsed side wall.