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NTSB Releases Flight Data on China Eastern Flight 5735 Crash

NTSB FOIA release reveals manual engine shutdown and control inputs in China Eastern Airlines Flight 5735 crash; CAAC final report pending.

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This article is based on original AirPro News reporting and analysis of newly released public FOIA documents from the National Transportation Safety Board (NTSB).

On April 29, 2026, the U.S. National Transportation Safety Board (NTSB) released critical technical data regarding the fatal March 2022 crash of China Eastern Airlines Flight 5735 (MU5735). The release, prompted by a Freedom of Information Act (FOIA) request filed by a Chinese citizen in January 2026, provides the first public, data-backed insight into the final moments of the Boeing 737-800 aircraft.

According to the newly public Flight Data Recorder (FDR) download report, originally compiled in July 2022, the aircraft experienced a deliberate manual shutdown of both engines at cruising altitude. This was immediately followed by severe manual flight control inputs that forced the plane into a fatal dive. This data release occurs against a backdrop of delayed official reports from the Civil Aviation Administration of China (CAAC), which is leading the Investigation under international protocols.

We have reviewed the released documents, which were published on the NTSB’s official FOIA reading room on May 1, 2026, and subsequently mirrored on Wikipedia and GitHub. The findings offer essential technical context to an aviation tragedy that claimed the lives of all 132 passengers and crew members on board, marking it as the deadliest aviation accident in China since 1994.

Technical Findings from the FDR Data

Sequence of Events at 29,000 Feet

The NTSB’s July 2022 “Combined Download Report” details the final 90 seconds of recorded flight parameters. The data reveals a sequence of deliberate actions rather than a mechanical failure. According to the NTSB FOIA release, the incident began at a cruising altitude of 29,100 feet.

“while cruising at 29,000 ft., the fuel switches on both engines moved from the run position to the cutoff position.”

, NTSB Combined Download Report, July 2022

The FDR data plots show that this action occurred simultaneously or within one second of each other. Moving these switches to the cutoff position is a highly specific, multi-step physical action. It requires a pilot to lift and pull the switches over a mechanical detent, making an accidental deployment highly improbable.

Power Loss and Flight Control Inputs

The immediate result of the fuel cutoff was a rapid drop in engine core speed (N2) and a total loss of thrust. Following this power loss, the NTSB data indicates that the autopilot was disengaged.

Approximately three seconds later, the FDR recorded that the control yoke was pushed forward violently. This manual input initiated a steep, nose-down pitch. The data also shows continuous left-roll inputs, resulting in an inverted barrel roll maneuver, while the rudder remained in a neutral position.

The FDR ceased recording at approximately 26,000 feet, about 23 seconds after the fuel switches were cut. The NTSB report notes that the FDR relies on engine-driven generators and lacks a backup battery. Consequently, it powered down when the engines spooled down, leaving the final plunge to the ground unrecorded by this specific device.

The Investigation and Official Stances

The Role of the CAAC and NTSB

Under International Civil Aviation Organization (ICAO) Annex 13 guidelines, the CAAC is the lead investigative authority for the MU5735 crash, which occurred on March 21, 2022, in Teng County, Guangxi. The NTSB serves as a technical advisor representing the state of the aircraft’s Manufacturers, Boeing.

The CAAC has yet to release a final investigation report. While ICAO guidelines expect a final report or an annual interim statement, the CAAC has deviated from this standard. In response to an open government information request on May 19, 2025, the CAAC explained its withholding of the report.

Releasing an annual interim report might “endanger national security and societal stability.”

, CAAC response to an open government information request, May 2025

Previously, in statements released in 2022 and 2024, the CAAC confirmed that no mechanical, structural, or systemic faults were found with the Boeing 737-800 aircraft.

Cockpit Voice Recorder Status

Unlike the FDR, the Cockpit Voice Recorder (CVR) is equipped with a backup battery and captured the entire event until impact. The NTSB FOIA response indicates that the CVR audio was successfully downloaded in excellent quality and handed over entirely to the CAAC. The NTSB did not retain any audio files, and the contents remain classified by Chinese authorities.

AirPro News analysis

The release of this FDR data highlights a significant transparency gap between the U.S. FOIA process and the CAAC’s ongoing withholding of the final report. U.S. federal law (49 U.S.C. § 1114(f)) mandates the release of certain technical data after specific criteria or timeframes are met, which ultimately forced the publication of these raw technical plots despite the CAAC’s reluctance to publish an interim update.

While the data strongly indicates deliberate manual inputs, specifically the fuel cutoff and the subsequent yoke push, we must avoid definitively diagnosing the motive. Without access to the CVR audio, which remains under the exclusive control of the CAAC, assigning psychological intent or confirming theories of hijacking or pilot suicide remains speculative. The empirical evidence confirms the mechanical steps of how the aircraft entered its fatal dive, but the underlying reason remains officially unanswered.

Frequently Asked Questions (FAQ)

What is a fuel control switch?

A fuel control switch manages the flow of fuel to the aircraft’s engines. Moving it to the “cutoff” position mid-flight stops fuel flow, shutting down the engine. It requires a specific, deliberate physical action to bypass a safety detent, preventing accidental activation.

Why did the Flight Data Recorder stop at 26,000 feet?

The FDR on the Boeing 737-800 relies on engine-driven electrical generators. When the engines were shut down and spooled down, the generators stopped providing power. Because the FDR lacks a backup battery, it powered off before the aircraft reached the ground.

Where can the public view these NTSB documents?

The documents are available in the NTSB’s official FOIA reading room under Document DCA22WA102. They have also been archived on Wikimedia Commons and translated on various GitHub repositories.

Sources:

Photo Credit: Xinhua

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Regulations & Safety

Global Aerospace Issues Hangar Foam Suppression Safety Guidelines

Global Aerospace updates hangar fire suppression guidelines, citing 200+ accidental foam discharges and the shift to PFAS-free alternatives.

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Global Aerospace has issued updated safety and risk mitigation guidelines for aviation hangar fire suppression systems, highlighting the severe financial and environmental toll of accidental foam discharges. The aviation insurer published the comprehensive best practices on August 24, 2026, detailing the industry transition toward alternative fire protection technologies.

The guidance arrives alongside the introduction of the 2026 edition of National Fire Protection Association (NFPA) 409. This updated standard governs hangar fire protection and introduces critical changes to align requirements with modern aircraft design and growing environmental concerns regarding chemical suppressants.

The financial and human cost of accidental discharges

Fire suppression standards established in the mid-1970s heavily prioritized foam systems to combat large fuel-spill fires. However, Global Aerospace reports that these systems frequently cause more damage than the fires they are designed to prevent. Over the last two decades, more than 200 unnecessary foam discharges have occurred in aviation facilities.

These accidental activations have resulted in tens of millions of dollars in total damages, with the average per-incident cost reaching hundreds of thousands of dollars. Beyond property damage to aircraft and hangar infrastructure, accidental discharges pose severe life-safety risks to personnel.

The insurer cited a fatal 2014 incident at Eglin Air Force Base as a primary example of these hazards. Following a broken sprinkler pipe, the hangar filled with approximately 17 feet of foam in minutes, resulting in the death of one contractor.

Shifting standards and environmental-impact liabilities

Aviation insurers are increasingly processing claims that extend beyond immediate property damage to include long-term health risks and environmental restoration. This liability shift is largely driven by the presence of perfluoroalkyl substances (PFAS) in older aqueous film-forming foams (AFFF).

To mitigate these chemical risks, the aviation industry is actively transitioning toward fluorine-free foams and alternative fire suppression technologies. Global Aerospace highlighted the growing adoption of ignitable liquid drainage floor assemblies and optical flame detection systems, such as multi-spectrum infrared detectors. These alternatives eliminate hazardous chemicals and significantly reduce the likelihood of false alarms.

While the 2026 edition of NFPA 409 provides the framework for these modern systems, the updated standards must be adopted by local fire marshals before facilities can implement the changes.

Operational risk mitigation strategies

For facilities still operating legacy high-expansion foam (HEF) or AFFF systems, Global Aerospace recommends strict operational protocols to minimize the risk and impact of an accidental discharge. The insurer advises operators to protect all aircraft openings and secure sensitive electronics during maintenance operations.

In the event of a discharge, the guidelines stress the importance of keeping hangar doors closed to contain the foam and prevent environmental contamination outside the facility. Additionally, Global Aerospace recommends conducting all system testing and maintenance during off-hours to limit personnel exposure and operational disruption.

AirPro News analysis

The publication of these guidelines by a major aviation insurer underscores a broader industry reality: insurance providers are often the primary catalyst for operational safety upgrades. While regulatory bodies like the NFPA set the baseline standards, the financial pressure of uninsurable environmental liabilities tied to PFAS contamination is forcing hangar operators to modernize. We expect the transition to optical flame detection and drainage floor assemblies to accelerate rapidly as insurers begin pricing the risk of legacy foam systems out of the market.

Sources: Global Aerospace

Photo Credit: Global Aerospace

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Regulations & Safety

NTSB Preliminary Report: Ryanair 737-800 Engine Failure

NTSB confirms fan-blade-out on Ryanair 737-800 shattered cabin window, partially ejecting a passenger during climb from Thessaloniki.

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This is a developing story. Information may change as official details are released.

This is original reporting and analysis by AirPro News.

On August 13, 2026, the National Transportation Safety Board (NTSB) issued its preliminary report on a July 10 uncontained engine failure aboard a Ryanair Boeing 737-800, confirming that a fan-blade-out event shattered a cabin window and caused a rapid decompression. The incident resulted in a 61-year-old male passenger being partially pulled through the shattered window before being secured by fellow passengers.

The event occurred during climb out from Thessaloniki International Airport (SKG) in Greece. The flight, operated by Ryanair subsidiary Malta Air, was bound for Memmingen, Germany (FMM). The NTSB is currently investigating potential similarities between this event and a fatal 2018 engine failure, while the agency has also publicly addressed premature speculation regarding the cause by Ryanair leadership.

Flight 1879 rapid decompression

According to the NTSB preliminary report, the Boeing 737-800 was climbing when the right-hand CFM56-7B engine experienced a fan-blade-out event. Debris from the engine struck the fuselage and shattered a window at row 11. The resulting rapid decompression pulled a passenger partially outside the aircraft. The passenger sustained neck and shoulder injuries as well as friction burns, but no fatalities occurred.

Reporting by The Air Current indicates the failure happened at an altitude of approximately 15,000 feet. Passengers described a sudden and violent disruption to the flight. A passenger told AP News that the cabin was quiet before a loud noise resembling a bursting tire occurred, adding that they knew immediately the aircraft had lost pressure due to the sudden loss of altitude.

Initial reports following the July 10 incident suggested the failure occurred in the airspace of the Republic of North Macedonia. However, flight path analysis confirmed the event took place in Greek airspace. The Hellenic Air and Rail Safety Investigation Authority officially delegated the investigation to the NTSB on July 16, 2026.

Maintenance history and preliminary findings

The NTSB preliminary report notes that bird remains were found inside the damaged engine. Flight crews had reported four suspected bird strikes to the aircraft’s number two engine in the 12 months preceding the accident. The report states that bird remains were found in two of those previous cases.

Maintenance records indicate that the fan blades on the failed right engine underwent ultrasonic inspections in November 2025 and May 2026. No damage was found during either inspection. The official cause of the July 10 failure remains under investigation by the NTSB, with participation from the Federal Aviation Administration (FAA), Boeing, and CFM International, a joint venture between GE Aerospace and Safran.

Regulatory protocols and historical precedent

The investigation has generated friction between the NTSB and Ryanair regarding public communications. On August 7, 2026, NTSB Chair Jennifer Homendy issued a letter to Ryanair CEO Michael O’Leary after he told investors the investigation was focused on foreign object damage rather than aircraft age or maintenance. Homendy stated that the NTSB had made no such determination and noted that O’Leary’s comments violated International Civil Aviation Organization (ICAO) Annex 13 protocols governing accident investigations.

The aviation industry is closely monitoring the investigation due to the aircraft and engine types involved. The Air Current reported that the event closely mirrors the April 2018 Southwest Airlines flight 1380 uncontained engine failure, which also involved a Boeing 737-700 and a CFM56-7B engine. That incident resulted in one passenger fatality after a shattered window caused partial ejection, leading the FAA to mandate engine inlet redesigns by July 2028.

The NTSB addressed the historical context directly in its preliminary report:

The investigative team is aware of previous … events with similar engine models that resulted in damage to engine inlets or cowlings and fuselage structures. Determination of any relevant similarities or details between this accident and previous events remains under investigation.

AirPro News analysis

We observe that the public rebuke of a major airline CEO by the NTSB is a rare and significant enforcement of ICAO Annex 13 communication protocols. Operators typically defer entirely to the investigating authority to avoid compromising the integrity of an active probe. The NTSB’s swift correction underscores the agency’s zero-tolerance policy for operator speculation, particularly when an event involves high-profile safety concerns like uncontained engine failures.

The CFM56-7B is one of the most widely used commercial aviation engines in the world. Any investigation involving a fan-blade-out event on this powerplant will naturally draw intense regulatory scrutiny, especially given the precedent set by the 2018 Southwest Airlines accident. While the discovery of bird remains introduces foreign object damage as a variable, we expect investigators will rigorously examine the efficacy of the ultrasonic inspections conducted in November 2025 and May 2026 to understand how the blade failure propagated.

Sources: National Transportation Safety Board

Photo Credit: NTSB

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Regulations & Safety

FAA Installs New Surface Radar at Newark Airport

The FAA unveiled a new SMR-4 radar at Newark Liberty as part of a $30 million infrastructure upgrade targeting runway safety.

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U.S. Transportation Secretary Sean P. Duffy and Federal Aviation Administration (FAA) Administrator Bryan Bedford unveiled a new Surface Movement Radar-Systems Model 4 (SMR-4) at Newark Liberty International Airport (EWR) on August 11, 2026, replacing a 30-year-old legacy system.

The installation is part of a broader $30 million infrastructure upgrade at the New Jersey hub designed to prevent runway incursions and reduce delays. According to the FAA press release, the SMR-4 allows air traffic controllers to track aircraft and ground vehicles across runways and taxiways in all weather and visibility conditions.

Newark’s infrastructure modernization

The $30 million funding allocation for EWR spans a three-year period and targets critical technological vulnerabilities. During the summer of 2025, the Airports experienced severe delays that prompted the FAA to deploy Software patches, expedite fiber deployment, and rebalance flight volumes. To date, 90% of the airport’s legacy copper wiring has been replaced with high-speed fiber.

“Since the start of this administration, we have been working towards building a modern system that will serve America’s skies for generations,” Duffy stated. “From replacing Newark’s ancient copper wire to investing $30 million into new infrastructure and bringing new radar online, we are delivering real safety and efficiency enhancements at one of our nation’s busiest airports.”

The FAA has set a target deadline of summer 2027 for EWR to install new electronic information displays, upgraded voice switches, and a new long-range radar system.

National surface awareness rollout

The EWR installation is one of five SMR-4 systems deployed nationwide to date. The agency has accelerated its broader technological overhaul over the past year, replacing 60% of all copper wires in its national network and converting 363 radio sites. The FAA also transitioned 19 air traffic control towers to electronic flight strips and installed 151 IP voice switches at control towers across the country.

Bedford emphasized the operational volume driving the upgrades. “Newark sees well-over a thousand flights per day, and the new Surface Movement Radar will help controllers keep those flights safe at this major U.S. hub,” Bedford said, describing the deployment as a step toward modernizing the national airspace.

The push for enhanced surface surveillance follows a fatal runway incursion at LaGuardia Airport (LGA) on March 22, 2026. In that event, Air Canada (AC) Express Flight 8646, operated by Jazz Aviation using a Bombardier CRJ900, collided with an airport firefighting vehicle on Runway 4. The National Transportation Safety Board (NTSB) confirmed two pilot fatalities and 39 injuries. The NTSB is leading the ongoing Investigation, and no official cause has been determined.

In response to surface safety concerns, the FAA has installed 96 new Surface Awareness Initiative systems nationwide over the past year to provide controllers with better situational awareness.

AirPro News analysis

The FAA’s rapid deployment of 96 Surface Awareness Initiative systems and the ongoing SMR-4 rollout represent a tangible shift toward proactive technological intervention in ground operations. While the NTSB has not yet concluded its investigation into the March 2026 LaGuardia runway incursion, the agency’s aggressive timeline for replacing legacy copper wiring and installing surface tracking tools indicates that regulators are prioritizing immediate situational awareness upgrades for air traffic controllers. We view the $30 million targeted investment at EWR as a template the FAA is likely to replicate at other high-density hubs where legacy infrastructure limits operational capacity during low-visibility conditions.

Sources: Federal Aviation Administration

Photo Credit: Federal Aviation Administration

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