DHL Expreso B752 at San Jose on Apr 7th 2022, hydraulic failure results in runway excursion

Last Update: October 1, 2023 / 07:57:55 GMT/Zulu time

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Photo of DHL Air HP-2010DAE, Boeing 757-200 — DHL Air HP-2010DAE, Boeing 757-200 (Photo credit: Aero Icarus / Flickr / License: CC by-sa)

Incident Facts

Date of incident
Apr 7, 2022

Classification
Accident

Airline
DHL Air

Flight number
D0-7216

Departure
San Jose, Costa Rica

Destination
Guatemala City, Guatemala

Aircraft Registration
HP-2010DAE

Aircraft Type
Boeing 757-200

ICAO Type Designator
B752

Airport
Juan Santamaria International Airport, San Jose

Airport ICAO Code
MROC

Costa Rica's CETAC released their final report in Spanish only (Editorial note: to serve the purpose of global prevention of the repeat of causes leading to an occurrence an additional timely release of all occurrence reports in the only world spanning aviation language English would be necessary, a Spanish only or no release does not achieve this purpose as set by ICAO annex 13 and just forces many aviators to waste much more time and effort each in trying to understand the circumstances leading to the occurrence. Aviators operating internationally are required to read/speak English besides their local language, investigators need to be able to read/write/speak English to communicate with their counterparts all around the globe).

The report concludes the probable causes of the accident were:

Fatigure and Stress in individual wires in the cross section of flexible hydraulic retraction hose of the left hand main landing gear downward locking actor.

Inadvertent synchronized movement of right hand reverse thrust lever and left engine control thrust lever as a reaction to muscle memory.

The main findings of CETAC were:

During the flight the crew received a left hydraulic system low quantity indication followed by a left low hydraulic system pressure indication. The crew properly followed the non-normal procedures for the low hydraulic pressure and showed good CRM.

The aircraft was intact prior to impact.

The aircraft touched down normally and initially rolled out normally until reaching abeam taxiway D where a loss of control occurred with heavy braking on the main landing gear, the aircraft veered to the right, exited the runway to the south of taxiway K, ran over uneven terrain causing the collapse of the landing gear and fracture of fuselage amongst other damage.

All damage to the airframe was attributable to impact forces.

The engine fan blades show both engines were running.

Flight crew fatigue was not a factor. Alcohol and drug tests on both flight crew were negative (no substances found). Both crew were properly licensed and experienced.

According to the non-normal procedures the left hand hydraulic failure meant, left hand thrust reverser, autobrakes, rudder ratio, spoilers 3,5,8 and 10 and nose wheel steering were inoperative.

Air Traffic Control was instrumental in assisting the crew to manage a successful landing and did NOT contribute in any way to the runway excursion.

The airport was not a factor in the hydraulic failure or runway excursion. However, due to the layout of the airport any accident in area of taxiway K could block the deployment of emergency services.

The other hydraulic systems and PTU were operating normally.

The throttle quadrant was operating normally.

The acceleration of the left engine while the aircraft was slowing down through 60 knots over ground is consistent with the left throttle lever movement. Both throttle levers were found in the idle position after the accident consistent with the "SHUTDOWN" procedure.

The left hydraulic failure was caused by multiple failure modes of wire strand fracture, material delamination, fatigue and ductile separation as well as cracks and voids in individual wires in the cross section of the left hand main landing gear down-lock actor retraction hose due to material fatigue and stress.

On landing the speedbrakes were manually brought to the UP position but were not retracted again consistent with the hydraulic failure procedure.

Prior to reaching taxiing speeds the left hand throttle lever angle began to increase to 81 degrees, the left hand N1 increased to 92% N1 at 60 knots over ground associated with an longitudinal acceleration of 0.6G, the master warning activated. The crew achieved the desired results of the non-normal checklists with the exception of the left hand throttle lever advancing just prior to loss of control and the runway excursion. A failure of the throttle system was ruled out. The inadvertent synchronous movement of right hand reverser thrust lever and left hand engine control thrust lever is considered probable.