The Civil Aviation Authority of China (CAAC) released its preliminary report on the China Eastern crash in March. But most questions remain.
As expected, the Chinese aviation authority delivered its preliminary report on the China Eastern crash to ICAO this week. CAAC had previously stated that it would do so within ICAO’s desired 30-day deadline. In general, preliminary reports don’t contain conclusions or definitive statements about accidents or incidents. However, they often contain new factual information.
On this occasion, CAAC’s preliminary report contains some radar data on the China Eastern crash. Until now, the information we had about the aircraft’s path was derived from ADS-B data from the aircraft itself, as recorded by tracking sites. The preliminary report appears to refer to data from a ground radar station.
According to this information, the China Eastern 737 was cruising at 8,900 metres (29,200 feet). The aircraft was at this altitude until 14:20:55 local time on the 21st of March. It then started a rapid descent. The last time ground radar got a return from the aircraft was at 14:21:40, i.e. 45 seconds later. At this time, the plane was at 3,380 metres (11,100 feet).
The preliminary report into the crash states that the China Eastern crew were qualified and that the aircraft’s maintenance revealed no question marks. Also, the weather didn’t appear to be a factor and there were no dangerous goods on the aircraft.
China Eastern Crash Preliminary Report – A Notable Absence
In the briefing about its preliminary report, the authority also confirmed its ground findings. The main wreckage was in an area just 45 square metres (484 square feet) in size. It contained the horizontal and vertical stabilizer, the engines, both wings and parts of the fuselage (including the cockpit) and landing gear. More parts were in a second site, nearby. But the trailing edge of the right winglet was 12 kilometres (7.5 miles) away.
Unfortunately, the preliminary report into the China Eastern crash did not contain what most were looking for. In its briefing, the CAAC stated that the Cockpit Voice Recorder and Flight Data Recorder were still being processed. As we’ve already seen, the NTSB in the US has both the CVR and FDR in its Washington labs.
So over a month since the crash, the restoration of the data in the two devices is still in progress. However, the search and recovery crews at the site took over a week to find the FDR in particular. This was largely because of the terrain and challenging weather conditions. The preliminary report briefing revealed that much of the wreckage in the China Eastern crash was in a depth up to 2.7 metres.
The crash involves China Eastern flight MU-5735, from Kunming Changshui International (ZPPP) to Guangzhou Baiyun International (ZGGG) in China. The airline used a Boeing 737-800 for this flight, grounding the type after the crash. However, we recently saw that the airline returned this fleet to service. The country’s aviation authority had not requested this temporary grounding. No other airline in the country grounded its 737-800s.