Regulations & Safety
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.
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.
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Photo Credit: Xinhua