3D visualization of China Eastern Airlines Flight MU5735's final minutes, built with Three.js.
This project reconstructs the flight trajectory of MU5735 (B-1791, Boeing 737-89P) on March 21, 2022, route KMG→CAN, using publicly available ADS-B and FDR data. The visualization covers the final 2 minutes and 13 seconds — from cruise at FL291 through the two-phase descent to impact at Teng County, Guangxi.
All data comes from publicly disclosed open sources. No classified or restricted information is used.
本重建所使用的全部数据均来自网上公开披露的开源信息，未使用任何保密或受限数据。
| Parameter | Data Type |
|---|---|
| Position (lat/lon) | Measured |
| Altitude (ft) | Measured |
| Ground Speed (kts) | Measured |
| Heading (°) | Measured |
| Vertical Speed (ft/min) | Measured |
- 27 data points selected from 397 granular ADS-B records
- Source: cathaypacific8747/mu5735 — Flightradar24 ADS-B granular data, publicly archived
- Flight path and timing are real recorded data / 航迹与时间为真实记录数据
- Original data provider: Flightradar24
Data from the last ~90 seconds of FDR recording before power loss at ~26,000 ft.
| Time (CST) | Event | Source |
|---|---|---|
| 14:20:38 | Engine 1 & 2 fuel switches RUN→CUTOFF (simultaneous) | FDR Fig 11 |
| 14:20:41 | AP-1/AP-2 Warn ON (~3s after cutoff) | FDR Fig 11 |
| 14:20:44 | Last stable flight parameters at FL291 | FDR Fig 11 |
| 14:20:45 | Roll passes −90° (left wing fully down) | FDR Fig 13 |
| 14:20:49 | Inverted — roll −180° / +180° wrap | FDR Fig 13 |
| 14:20:58 | Roll −270° cumulative (right wing fully down) | FDR Fig 13 |
| 14:21:01 | FDR power loss — engine N2 below generator threshold | FDR Fig 11 |
Pitch and Roll for the FDR-traced 21-second window (T = engine cutoff 14:20:38 CST → 14:20:59 CST; the FDR recording itself extends ~2 s further to power loss at 14:21:01) are traced directly from NTSB DCA22WA102 plots, not estimated:
| Parameter | Source plot | Profile traced from plot |
|---|---|---|
| Pitch | Fig 11 — Pitch Angle | Holds 0° to T+5s, smoothstep monotonic to −35° at T+21s (no oscillation) |
| Roll | Fig 13 — Roll Angle (zoomed) | Holds 0° to T+3s (AP active until disconnect), then continuous unidirectional left rotation: 0° → −180° at T+11s (8s, ~22.5°/s) → −270° cumulative at T+20s (9s, ~10°/s), held to T+21s. Display wraps at ±180° but physical rotation is monotonic. |
| Eng1/2 Cutoff SW | Fig 11 | Both switches RUN→CUTOFF at T+0 (simultaneous, manual) |
| AP-1/AP-2 Warn | Fig 11 | Both ON at T+3s |
| Rudder | Fig 12 | Untouched throughout (input remains at neutral) |
Key observation from FDR plots: Pitch and roll are smooth, monotonic, single-direction — not the chaotic oscillation suggested by "two pilots fighting for control." The aircraft was rolled deliberately and continuously to the left, accumulating ~270° of rotation while pitch decreased monotonically. Rudder was never used.
References:
- NTSB FOIA DCA22WA102 — U.S. National Transportation Safety Board, Freedom of Information Act release. Pages 25 (Fig 11 basic parameters), 27 (Fig 12 control surfaces), 28 (Fig 13 control forces + roll-angle zoom).
- CAAC Investigation Progress Reports — Civil Aviation Administration of China, publicly released investigation updates (中国民航局事故调查进展情况通报)
- Wikimedia Commons: China Eastern Airlines Flight 5735 — NTSB FDR documents archived
Cruise is held at a stable nominal attitude; the post-FDR dive is derived from the 3D trajectory tangent. The FDR window itself is traced from the NTSB plots — see §2.1 above (MEASURED, not estimated).
| Phase | Window (CST) | Heading (航向) | Pitch (俯仰角) | Bank (倾斜角) | Notes |
|---|---|---|---|---|---|
| Cruise 巡航 | up to 14:20:38 | ADS-B linear interp | Held at +2° AOA | 0° (wings level) | Visual altitude locked to ADS-B; no spline-derived attitude jitter |
| FDR-traced phase | 14:20:38 – 14:20:59 (21 s) | (see §2.1 — MEASURED, FDR-traced) | |||
| Post-FDR dive 断电后俯冲 | 14:20:59 – impact | 3D track from spline tangent — atan2(tan.x, −tan.z) | 3D FPA from spline tangent — asin(tan.y) + AOA from V/S magnitude | Coordinated turn — tB = −atan(v · ω / g), where ω is yaw-rate from centered finite-difference of track | All three axes derived from the same 3D velocity vector — nose visually follows the trajectory (no sideslip). FDR-end roll (cumulative −270°) is wrapped to equivalent +90° at boundary, then smoothly transitions to spline-derived bank |
Aerodynamic constraints applied across all phases:
| Constraint | Cruise | FDR window | Post-FDR dive |
|---|---|---|---|
| Pitch rate limit | ≤25 °/s | ≤30 °/s | ≤25 °/s |
| Roll rate limit | ≤60 °/s | ≤75 °/s | ≤60 °/s |
| Heading rate limit | ≤4 °/s | ≤50 °/s | ≤50 °/s |
| Yaw-rate cap (input to bank) | — | — | ≤35 °/s (spline plausibility) |
| Smoothing τ (low-pass) | 2.5 s | 0.7 s | 0.6 s |
| Other | Method | Applied Period |
|---|---|---|
| G-load (G载荷) | Approximation from vertical speed; FDR window adds oscillation envelope | Entire flight |
The following are not publicly available and cannot be used:
- Complete FDR readout (full parameter set)
- CVR (Cockpit Voice Recorder) transcript
- Actual continuous pitch / roll / AOA time series
- Control surface deflection time series
- Engine parameters (N1, N2, EGT, fuel flow)
- Final CAAC investigation report (not yet published as of 2025)
| Asset | Source | License |
|---|---|---|
| Aircraft 3D model | Boeing 737-800 GLTF | Flightradar24 B738 model |
| Satellite imagery | Google Maps satellite tiles (zoom 13) | Google Terms of Service |
| Impact coordinates | 23°19'25.5"N 111°06'44.3"E | CAAC official announcement |
| Three.js | r164.1 | MIT License |
| Time (CST) | Altitude | Event | Data Source |
|---|---|---|---|
| 14:20:38 | FL291 | Engine 1 & 2 fuel switches RUN→CUTOFF (simultaneous) | FDR Fig 11 |
| 14:20:41 | FL291 | AP-1/AP-2 Warn ON; sustained left aileron input begins | FDR Fig 11 |
| 14:20:44 | FL291 | Last stable flight parameters | FDR Fig 11 |
| 14:20:45 | FL291 | Roll passes −90° (left wing fully down) | FDR Fig 13 |
| 14:20:49 | FL291 | Inverted — roll wraps −180° / +180° | FDR Fig 13 |
| 14:20:58 | ~FL291 | Roll −270° cumulative — pitch ~−34° | FDR Fig 13 |
| 14:21:00 | 27,025 ft | Descent detected — V/S −21,696 ft/min | ADS-B |
| 14:21:01 | ~26,000 ft | FDR stops — generator power loss | FDR (NTSB) |
| 14:21:15 | 17,325 ft | Dive steepens — heading 91°→123° | ADS-B |
| 14:21:46 | 7,850 ft | First dive bottom — GS 590 kts | ADS-B |
| 14:21:56 | ~7,850 ft | Recovery — V/S +3,520 ft/min | ADS-B |
| 14:22:05 | 8,600 ft | Peak recovery altitude | ADS-B |
| 14:22:22 | 8,175 ft | Second dive begins | ADS-B |
| 14:22:36 | 3,225 ft | Last ADS-B signal — 376 kts | ADS-B |
| 14:22:38 | 0 ft | Impact — Teng County, Guangxi (witnesses: spiral/tumble) | CAAC / witnesses |
- Rendering: Three.js r164 with ES modules, logarithmic depth buffer, ACES filmic tone mapping
- Trajectory: CatmullRom spline (centripetal, open) through 27 ADS-B waypoints
- Attitude: Euler angles (YZX intrinsic order) — heading from ADS-B, pitch/roll from FDR (when available) or estimated from trajectory
- Cruise attitude model: Held at +2° AOA, wings level; visual altitude locked to ADS-B data to suppress spline Y-jitter (no shake along the green cruise line)
- FDR attitude model (FDR-traced from NTSB Fig 11/13, MEASURED): During FDR-traced window (t=268–289 s, 21 s), pitch follows a smooth monotonic smoothstep — held at 0° to T+5 s, then 0° → −35° by T+21 s; roll is a continuous unidirectional left rotation — held at 0° to T+3 s (AP still active), then 0° → −180° by T+11 s (~22.5°/s) → −270° by T+20 s (~10°/s), held to T+21 s. Traced directly from NTSB plots, not synthesized. Cumulative bank stored as unwrapped radians (Three.js Euler renders any value correctly); wrapped to [−π, π] equivalent at FDR end for smooth post-FDR transition
- Post-FDR attitude model (3-axis from velocity vector): All three axes derived from the same 3D spline tangent so the nose visually tracks the path. Heading = atan2(tan.x, −tan.z); Pitch = asin(tan.y) + AOA(V/S); Bank = −atan(v · ω / g) where ω is the yaw-rate from a centered finite-difference (±0.6 s) of the track angle, capped at 35°/s for spline plausibility. Final clamps: pitch ∈[−72°,+20°], bank ∈[−65°,+65°]
- Smoothing: Frame-rate-independent exponential low-pass with phase-tuned time constants (τ = 2.5s cruise, 0.7s FDR, 0.6s post-FDR)
- Rate limits: Per-axis aerodynamic clamps on smoothed output — pitch ≤25°/s (30°/s during FDR), roll ≤60°/s (75°/s during FDR), heading ≤4°/s cruise / ≤50°/s dive
- Terrain: Google satellite tiles at zoom 13, procedural elevation displacement
- UI: Bilingual (English / 中文), responsive layout for mobile and desktop
Open index.html in any modern browser. No build step, no server — all dependencies load from CDN (jsdelivr).
For local development, serve the directory over a static HTTP server (the GLTF model and texture tiles need same-origin or CORS):
python3 -m http.server 8000
# then open http://localhost:8000/Controls:
- Space — play / pause
- Drag — orbit camera
- Scroll / pinch — zoom
- Timeline bar — click to seek
- Camera modes — Tail / Free / Left / Right / Top
- Speed — 0.5× / 1× / 2× / 4× / 8×
- Next event — jump to next timeline marker, then pause
MU5735/
├── index.html # Single-file app (HTML + CSS + JS + SVG)
├── b738.glb # Boeing 737-800 GLTF model
├── README.md # This file
├── LICENSE # MIT
└── .github/workflows/
└── pages.yml # GitHub Pages auto-deploy on push to main
- ADS-B data: cathaypacific8747. MU5735 ADS-B granular data. GitHub. https://github.com/cathaypacific8747/mu5735
- FDR plots: U.S. National Transportation Safety Board. FOIA DCA22WA102 — FDR parameter plots. https://data.ntsb.gov/Docket?ProjectID=105683
- Investigation reports: Civil Aviation Administration of China. MU5735 investigation progress reports. http://www.caac.gov.cn/
- NTSB documents archive: Wikimedia Commons. Category: China Eastern Airlines Flight 5735. https://commons.wikimedia.org/wiki/Category:China_Eastern_Airlines_Flight_5735
- Impact site: CAAC official announcement — 23°19'25.5"N 111°06'44.3"E, Molang village, Teng County, Wuzhou, Guangxi
- Three.js: mrdoob. Three.js r164. https://github.com/mrdoob/three.js/
MIT — see LICENSE.
This visualization is created for educational and research purposes only. All data used comes from publicly disclosed open sources. No classified or restricted information is used. Attitude values during the post-FDR phase are estimates and may not reflect actual aircraft state.
This project is not affiliated with China Eastern Airlines, CAAC, NTSB, or any investigation authority.
本可视化仅用于教育和研究目的。所使用的全部数据均来自公开披露的开源信息，未使用任何保密或受限数据。FDR断电后的姿态数据为估算值，可能不反映飞机实际状态。本项目与中国东方航空、中国民航局、美国国家运输安全委员会及任何调查机构无关。