Serious incident Aerospatiale AS 355F Ecureuil 2 G-BOSN, Wednesday 4 October 2023
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Date:Wednesday 4 October 2023
Type:Silhouette image of generic AS55 model; specific model in this crash may look slightly different    
Aerospatiale AS 355F Ecureuil 2
Owner/operator:Helicopter Services
Registration: G-BOSN
MSN: 5266
Fatalities:Fatalities: 0 / Occupants: 6
Other fatalities:0
Aircraft damage: Minor
Category:Serious incident
Location:Near Gunnersbury Park, Chiswick, West London -   United Kingdom
Phase: En route
Nature:Passenger - Non-Scheduled/charter/Air Taxi
Departure airport:White Waltham Airfield (EGLM)
Destination airport:White Waltham Airfield (EGLM)
Investigating agency: AAIB
Confidence Rating: Accident investigation report completed and information captured
Aerospatiale AS 355F Ecureuil 2 G-BOSN sustained minor damage on 4 October 2023 when the right forward and rear doors opened in flight over Gunnersbury Park in West London. The incident was the subject of an AAIB Investigation, published on 11 April 2024, and the following is an excerpt from the AAIB Report:

"The helicopter was taking six persons (five passengers plus pilot) on a commercial sightseeing tour of London when, approximately 20 minutes into the flight, the cabin doors on the right side of the helicopter opened unexpectedly. The pilot could see the rear door had swung open and was “still attached but being held fully open by the airflow.” The forward door was also ajar.

Concerned by the risk of the rear door detaching, he elected to make an immediate landing at the nearby Gunnersbury Park.

After shutting the helicopter down the pilot saw there was minor skin damage on the rear door and that its window was cracked. The crack was contained, with no loose fragments, and appeared to have been caused by the window striking the baggage compartment hinge when the door swung backwards as it opened

While on the ground at Gunnersbury Park, the pilot assessed the reason for the doors opening was they had likely not been securely locked before departure. He could not recall checking the rear door’s locking pins were correctly located when he initially closed it. He also reported that because he “closed the front door from a seated position which is slightly awkward [he] might not have properly secured it to the rear door.”

After checking the passengers were happy to continue, the pilot re-closed the doors, checked their locking pins were correctly located, and continued the flight as planned.

The pilot reflected that a more thorough check of all four doors’ security prior to the initial departure would likely have prevented the incident"

=Damage sustained to airframe=
Per the AAIB Report "Minor damage to right rear cabin door"

Gunnersbury Park is a park between Acton, Brentford, Chiswick and Ealing, in West London, England.

Accident investigation:
Investigating agency: AAIB
Report number: 
Status: Investigation completed
Duration: 6 months
Download report: Final report


1. AAIB Final Report:

History of this aircraft

G-BOSN was built in 1982 and was previously N2109L (US Registry) and 5N-AYL from September 1989 to December 1999. It was G-BOSN from 22.8.1988 to 11.9.1989, returning to UK registry as G-BOSN on 17.1.2000.

The same helicopter was also involved in an incident at Hedsor House, Bourne End, Buckinghamshire on 2 March 2021 (see separate ASN entry)

Other occurrences involving this aircraft

2 March 2021 G-BOSN Helicopter and Pilot Services Ltd 0 Hedsor House, Bourne End, Buckinghamshire min



Aerospatiale AS 355F Ecureuil 2 G-BOSN over Blackbushe Airport, Hampshire (EGLK) on 31.10.2019: EGLK - Aerospatiale AS355 F1 Ecureuil 2 - G-BOSN

Revision history:

27-Oct-2023 09:53 harro Added
31-Oct-2023 06:45 Dr. John Smith Updated
11-Apr-2024 10:10 Dr. John Smith Updated [Total occupants, Nature, Source, Narrative]
11-Apr-2024 10:10 ASN Updated [Accident report]

Corrections or additions? ... Edit this accident description

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