Date:	Saturday 18 August 2018
Time:	13:14
Type:	CZAW SportCruiser
Owner/operator:	Private
Registration:	G-CGJZ
MSN:	LAA 338-14962
Fatalities:	Fatalities: 0 / Occupants: 2
Other fatalities:	0
Aircraft damage:	Substantial
Category:	Accident
Location:	near Clacton-on-Sea, Essex -   United Kingdom
Phase:	Initial climb
Nature:	Training
Departure airport:	Clacton-on-Sea Airport (EGSQ)
Destination airport:	Maypole Airport (EGHB)
Investigating agency:	AAIB
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
AAIB investigation to CZAW SportCruiser, G-CGJS: Significantly damaged due to engine failure and subsequent forced landing, near Clacton-on-Sea, Essex, 18 August 2018. The incident was the subject of an AAIB Investigation, and the following is an excerpt from the AAIB Report:

"Synopsis:
The aircraft suffered an engine failure while climbing through 1,400 ft after takeoff, and a forced landing was carried out into a ploughed field. The aircraft was damaged but the occupants were not injured. The flywheel had detached due to failure of its attachment bolts which were found to have broken; fatigue was evident on at least one bolt. There was a discrepancy in the time intervals for replacement of the bolts in the engine manufacturer’s documentation.

History of the flight:
The pilot/owner had built the aircraft and it was first registered in 2010. He was carrying out a training flight with a class rating instructor to revalidate his licence. The weather conditions in south-east England were fine with a westerly wind of around 15 kt.

The flight started from Maypole Airfield, north-east Kent, where a few circuits were flown. It then continued to Clacton Airfield, where Runway 18 was in use, so that a crosswind landing and takeoff could be practised. The aircraft landed uneventfully at Clacton and was parked on the grass for a short while.

The aircraft took off from Runway 18 at Clacton at 13:10 hrs. The pilot reported leaving the circuit to the west and changed frequency to Southend Radar. While he was making his initial call to Southend Radar there was a “loud clank” from the engine and power was lost. The instructor took over the radio communications while the pilot continued to fly the aircraft.

A restart attempt was unsuccessful and the pilot, recognising that he could not return to Clacton, picked a series of three fields he thought would be suitable for landing. He decided to aim for the third field as it appeared to have the best surface and to be clear of a crop, but as he got nearer, he realised the field contained a crop of potatoes and the surface was deeply furrowed.

While the pilot focussed on flying, the instructor communicated with Southend Radar and advised they would be landing in a field. Southend Radar confirmed they had radar contact. The instructor monitored the pilot, reminding him of the wind and pointing out a field. However, it became apparent the pilot had selected a different field. The instructor pointed out that the chosen field was rough and suggested another, but the pilot was fully engaged with carrying out the landing and so, as he judged the landing would be safely made, the instructor decided not to interfere further.

The landing was completed into wind with full flap, and the pilot estimated the touchdown was at around 30 kt (20 kt groundspeed). On touchdown the aircraft decelerated rapidly, and the nose wheel snapped off as the aircraft slid to a halt. Both occupants were wearing full four-point harnesses and neither was injured. The pilot secured the aircraft before both occupants exited in the normal way through the hinged canopy. They walked a safe distance away and telephoned Southend ATC to advise they had landed safely.

In the meantime, Southend Radar had contacted a nearby aircraft and advised its pilot of the situation. He flew over to assist and reported that he could see the aircraft in a field, together with vehicles and people."

Conclusion:
The engine failed while the aircraft was climbing through 1,400 ft, and a successful forced landing was made. The engine flywheel had detached due to failure of its attachment bolts. The engine had completed 447 hours, which was within the service interval of 500 hours for replacement of the bolts, as published in a Service Bulletin on the engine manufacturer’s website and as followed by the pilot/owner. The engine manufacturer’s Maintenance Manual specified an interval of 100 hours for replacement of the bolts, but this was not reflected in the Service Bulletin. This discrepancy was resolved such that the documents only referred to the correct 100 hours replacement interval.

Damage Sustained to airframe:
Per the AAIB Report "Landing gear [damaged], engine cowling and minor damage to firewall". The aircraft was repaired and returned to service (with the same owner as before)

Unusually, the ATSB (Australian Transport Safety Bureau) was also involved. According to an ATSB statement (see link #3):

"As Australia is the State of Manufacture of the engine type involved, the AAIB requested an Accredited Representative from the Australian Transport Safety Bureau (ATSB) be appointed.

To facilitate this request, the ATSB initiated an external investigation under the provisions of the Transport Safety Investigation Act 2003.

On 2 May 2019, the AAIB advised the ATSB that the final investigation report was due for release and ATSB assistance was no longer required"

1. AAIB Report: https://assets.publishing.service.gov.uk/media/5f467caee90e07299030ce8b/CZAW_Sportcruiser_G-CGJS_05-19.pdf
2. https://www.planelogger.com/Aircraft/Registration/G-CGJS/
3. ATSB Investigation number AE-2018-076: https://www.atsb.gov.au/publications/investigation_reports/2018/aair/ae-2018-076
4. https://en.wikipedia.org/wiki/Clacton_Airport

G-CGJS: CZAW SportCruiser at the LAA Rally, Sywell, Northamptonshire (ORM/EGBK) 4 September 2021

Date/time	Contributor	Updates
29-Jul-2024 05:28	Dr. John Smith	Added
29-Jul-2024 05:29	ASN	Updated [Accident report, ]