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ASN Wikibase Occurrence # 146423
Last updated: 10 September 2021
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Date:17-JUN-2012
Time:16:08
Type:Silhouette image of generic A320 model; specific model in this crash may look slightly different
Airbus A320-232
Owner/operator:JetBlue Airways
Registration: N552JB
MSN: 1861
Fatalities:Fatalities: 0 / Occupants: 154
Aircraft damage: None
Category:Incident
Location:near McCarran Intl. Airport - LAS/KLAS, Las Vegas, NV -   United States of America
Phase: Initial climb
Nature:Passenger - Scheduled
Departure airport:Las Vegas, NV (LAS)
Destination airport:New York, NY (JFK)
Investigating agency: NTSB
Narrative:
Before the Airbus A320-232 departed on the incident flight, one flap control computer channel was inoperative and deferred for maintenance, which was in accordance with the Federal Aviation Administration (FAA)-approved minimum equipment list. During landing gear retraction after takeoff, the Green hydraulic system on the airplane lost pressure, and the flight warning computer detected a flight control flaps system fault followed by a reservoir overheat condition for the Yellow hydraulic system 2 minutes later. Normal inhibition of alerts and warnings from the flight warning computer prevented notification of the faults to the flight crew until the airplane was climbing out of 1,500 above ground level. The crew subsequently experienced a period of high workload as they received multiple aural and visual warnings on the flight deck.

The captain, who was the pilot flying, transferred airplane control to the first officer and began to accomplish the abnormal procedures that were displayed on the electronic centralized aircraft monitor. Accomplishing the manufacturer-recommended procedures included turning off the Green and the Yellow hydraulic systems' engine-driven pumps and the power transfer unit (PTU), resulting in low pressure in the Yellow hydraulic system (in addition to the existing low pressure in the Green hydraulic system), the airplane's reversion to alternate law in which flight envelope protections are reduced (most critically, stall protection), and autopilot and autothrust disconnection. The crew attempted to raise the flaps from position 1 (the takeoff position) to 0, but the flaps remained at position 1 because the loss of the Green hydraulic system and subsequent loss of the remaining flap control computer channel resulted in the flaps being inoperable.

At this point, of the airplane's three hydraulic systems, only the Blue hydraulic system was providing useable pressure. The flight crew coordinated with air traffic control to enter a holding pattern at 12,000 feet to accomplish checklists, communicate with company maintenance and dispatch, and calculate landing distance performance using the procedures in the quick reference handbook. During this time, the captain recognized that the Yellow hydraulic system reservoir was no longer in an overheat condition and followed the appropriate procedures to restore the Yellow hydraulic system. It was restored about 36 minutes after takeoff and remained operative for the rest of the flight.

To calculate landing distance performance with two inoperative hydraulic systems, the captain initially calculated a required landing distance of over 11,000 feet. After recovery of the Yellow hydraulic system, the captain calculated a revised landing distance of about 8,500 feet.

The flight control flaps system fault required a higher-than-normal landing speed, and the Green hydraulic system malfunction resulted in loss of normal braking, loss of nosewheel steering on the ground, and loss of the ability to retract the landing gear once extended. Due to the system malfunctions and the inability to raise the landing gear in the event of a go-around, the flight crew decided to remain in the holding pattern to burn fuel and reduce aircraft weight below the maximum landing weight of 142,200 pounds. The airplane landed 3 hours 35 minutes after takeoff and was towed to the gate.

Postincident examination of the airplane found a leak in the Green hydraulic system, in the right main landing gear door retraction flexible hydraulic line due to a kink in the line and a collapsed sidewall. An article in the June 2007 issue of Safety First, Airbus' safety magazine published for use by operators' flight and ground crews, described a scenario in which a leak in the Green hydraulic system results in that system's loss of fluid, which can lead to the loss of the Yellow hydraulic system. As the hydraulic pressure decreases and reaches a 500 psi differential between the Green and Yellow system, the PTU, by design, automatically activates and operates at maximum speed in an effort to
Probable Cause: 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.

Sources:

NTSB
https://flightaware.com/live/flight/JBU194/history/20120617/2053Z/KLAS/KLAS
http://aerossurance.com/safety-management/a320-hydraulic-incident/

Accident investigation:
cover
  
Investigating agency: NTSB
Status: Investigation completed
Duration: 2 years and 9 months
Download report: Final report
Other occurrences involving this aircraft

29 Jun 2015 N552JB JetBlue 0 Charleston, SC non

Location

Media:


Images:

Photo of N552JB courtesy AirHistory.net


Fort Lauderdale - Hollywood International (KFLL / FLL)
19 February 2020; (c) Lewis Grant

Revision history:

Date/timeContributorUpdates
22-Jun-2012 00:13 ebakni Added
25-Jun-2012 04:05 RobertMB Updated [Aircraft type, Registration, Cn, Operator, Location, Departure airport, Destination airport, Source, Narrative]
15-Apr-2015 21:59 Aerossurance Updated [Time, Total occupants, Source, Damage, Narrative]
21-Dec-2016 19:28 ASN Update Bot Updated [Time, Damage, Category, Investigating agency]
28-Nov-2017 20:17 ASN Update Bot Updated [Other fatalities, Departure airport, Destination airport, Source, Narrative]
17-Jun-2021 20:33 Aerossurance Updated [Location, Source, Embed code]

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