DHL de Guatemala Flight 7216

DHL de Guatemala Flight 7216 was an international cargo flight between Costa Rica's Juan Santamaría International Airport and Guatemala City's La Aurora International Airport. On 7 April 2022 (2022-04-07), the Boeing 757 suffered a hydraulic failure, and crashed on landing at the Costa Rican airport. Neither of the two pilots were injured.^[1]

DHL de Guatemala Flight 7216

HP-2010DAE, the Boeing 757 involved in the accident, three months before the crash
Accident
Date	7 April 2022 (2022-04-07)
Summary	Hydraulic failure followed by runway excursion
Site	Juan Santamaría International Airport 9°59′42.1074″N 84°12′9.36″W (approx.)[1]
Aircraft
Aircraft type	Boeing 757-27A (PCF)
Aircraft name	Ciudad de David
Operator	DHL de Guatemala for DHL Aero Expreso
IATA flight No.	L37216
ICAO flight No.	JOS7216
Call sign	YELLOW 7216
Registration	HP-2010DAE
Flight origin	Juan Santamaría International Airport, San José, Costa Rica
Destination	La Aurora International Airport, Guatemala City, Guatemala
Occupants	2
Crew	2
Fatalities	0
Injuries	0
Survivors	2

Background

Aircraft

The aircraft involved was a 22-year-old Boeing 757-27AF registered HP-2010DAE, with serial number 29610 and line number 904. The aircraft was first delivered to Far Eastern Air Transport in December 1999 as a passenger aircraft. The aircraft was leased to EVA Air from May 2002 to January 2004 before returning to Far Eastern Air Transport. The aircraft was withdrawn from service and later converted into a freighter aircraft in October 2010.^[2] DHL Aero Expreso took possession in November 2010.

Crew

The captain, age 58, had logged 16,381 flight hours, including 6,233 hours on the Boeing 757. The first officer, age 43, had 10,545 flight hours including 2,337 on the Boeing 757.^[3]

Crash

Flight path of Flight 7216

The flight took off at 9:34 AM local time (UTC−6:00) from Juan Santamaría International Airport to La Aurora International Airport to deliver cargo. However, while flying over the Costa Rican town of Mueller San Carlos, the pilot declared an emergency due to hydraulic problems, and returned to the terminal, after flying a holding pattern to empty its fuel tanks, and touched down at 10:24 am local time. At 10:25, the aircraft entered a right turn that the crew could not control, leading to the aircraft leaving the runway.^[3]

Investigation

The final report by the Costa Rican Technical Council for Civil Aviation (CETAC) was released on 22 September 2023, a year and a half after the accident.

Hydraulic failure

Fatigue and wire stress damage in the left landing gear hydraulic actuator hose caused loss of hydraulic fluid, leading to failure of the left hydraulic system.^[3]: 109 Failure of this particular system meant that the autobrake, left thrust reverser, rudder ratio, four of the twelve spoilers, and nose wheel steering were not functional.^[3]: 108 The flight crew followed correct procedures for this emergency per the aircraft manual. During the initially successful landing sequence, flight crew properly applied right thrust reverse, manual spoilers and brakes, using rudder and differential braking for steering.^[3]: 107

Runway excursion

As the aircraft was slowing toward 60 knots, right reverse thrust was deactivated, while left forward thrust simultaneously increased to 91%.^[3]: 109 The asymmetric thrust caused the aircraft to accelerate and enter a right turn the crew could not control. The aircraft departed the runway to the right, spun 180 degrees, finally coming to rest with its left main landing gear collapsed, fuselage broken into two pieces, and left engine still producing thrust. Both throttles were later found in the idle position according to correct shutdown procedure.^[3]: 110 There was no post-crash fire, and the crew exited with assistance from emergency responders without serious injury.^[3]: 107

Explanations

Investigators explored three hypotheses to explain the left engine's increased thrust:

1. Mechanical failure in the throttle system was rejected by a Boeing analysis which showed the engine control had correctly responded to a manual throttle input.^{[3]: 105–106}
2. Mistaking the left throttle for the speedbrake control was considered, but rejected, since the flight data recorder showed the left throttle and right reverser levers had been moved simultaneously.^{[3]: 105–106}
3. Synchronous inadvertent manipulation of the left throttle and right thrust reverse levers due to "muscle memory" was considered the most likely cause.^[3]: 110

Recommendations

The report recommended that the FAA make compliance with Boeing's service bulletin 757-29-0056 mandatory instead of voluntary. The bulletin, published over 20 years prior on 8 February 2001, addressed improvements to the hydraulic hoses that had failed on the accident aircraft. DHL was further encouraged to replace the hoses more frequently than recommended by Boeing, and to institute maintenance training that emphasizes installation of flexible hydraulic hoses in a manner that minimizes kinking and stress fatigue.^{[3]: 111–112}

Aftermath

The aircraft was written off as a result of the crash, the 12th hull loss of the Boeing 757.^[4] In December, the remains of the fuselage were preserved by the airport as a training aid for fire fighters.^[2]