The following is sent on behalf of the HAC Flight Safety Team – Flt Lt Sammy Nassiri and Flt Lt (Retd) Shane Sobral. It delivers the initial findings of the Local Investigation of the G-BSCZ EFATO and subsequent field landing. My thanks goes to them for this work. All members are to read and consider the recommendations before flying next.
In addition, please note all members are now in the RED for the HAC FOB update detailed in the email dated 8 Jan 23.
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Dear HAC Membership,
As all of you now will be aware, on 7 Dec 22 G-BSCZ suffered a loss of power on take-off resulting in an off-site forced landing. Both occupants were unharmed. The HAC Flight Safety Team have subsequently begun a Local Investigation (LI) into the incident, and as we near completion of the LI have put together a summary below of the key points to keep you informed and promulgate some initial recommendations without delay.
The summary below will mirror the format of the LI so the full report and can be easily followed when released.
What Happened?
On 7 Dec 22 G-BSCZ was conducting circuits as part of an instructional event. The first circuit was conducted without incident. Following a touch & go on the second circuit the engine stopped producing power at approximately 200ft AGL. The instructor took control and committed to a forced landing in an off-site crop field approximately 120 degrees to the port side. After a successful touch down, the nosewheel dug into the soft surface causing the aircraft to turn over in a forward direction resulting in it coming to a halt upside down. The instructor successfully shut down the aircraft and both occupants exited safely. The emergency services attended the scene and both instructor and student were medically cleared.
Why Did it Happen?
On 7 Dec 22 the United Kingdom was experiencing a Polar Maritime air mass and its associated wet and cold air. At RAF Halton on 7 Dec 22 the outside air temperature was forecast to be 4°C, dew point 0°C, and relative humidity 90%. The actual air temperature at the time of the incident was 3°C and the dew point 0°C. These environmental conditions are considered a Serious Icing Risk for all Power Settings (see the CAA Safety Sense Carb Icing chart below). Another HAC aircraft airborne at the time also reported symptoms of carb-icing.
Given the environmental conditions on the day and the additional report of carb-icing symptoms, it is highly likely that Carburettor Icing was the Cause. An in-depth check of the Avgas installation (and all other aircraft tanks) to rule out fuel contamination of water was conducted and deemed satisfactory.
In light of the available Meteorological data for the day, additional report of carb icing symptoms, and absence of any other abnormalities, the HAC Flight Safety Team deem Carburettor Icing as the Cause.
Recommendations
Our formal recommendations will be published in the full LI on 13 Feb 23. In the interim however we make the following recommendations to the membership:
- Re-familiarise yourself with the theory behind carb-icing and its associated symptoms. CAA Safely Sense Leaflet 14 provides excellent reading on Piston Engine Icing.
- In particular be cognisant of the environment factors (temperature, dew point and relative humidity) that make carb-icing more likely – the carb icing poster is located at the Ops Desk.
- Report any suspected carb-icing immediately to allow other crews to make informed decisions.
- Think about where the best options for forced-landings exist and at what heights they become the best or only option as you climb.
- Re-familiarise yourself with the bold-face EFATO actions for the aeroplane you’re flying.
- Request an instructor to fly with you to rehearse an EFATO if required.
If you have any questions in the interim please do not hesitate to stay in touch, and stay safe.
Kind Regards,
Sammy
Flt Lt S Nassiri BA (Hons), PgCert, RAF | FSO | Halton Aero Club | RAF Halton | Aylesbury | Buckinghamshire | HP22 5PG | Civ: 0129656178 |* MODNET: Sammy.Nassiri100@mod.gov.uk | * Internet: Sammy.Nassiri@haltonaeroclub.co.uk | HAC FS | CAA MOR | RAFSA VOR | ASIMS
