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ASN Wikibase Occurrence # 259924
Last updated: 13 May 2021
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Time:17:42 UTC
Type:Silhouette image of generic P28A model; specific model in this crash may look slightly different
Piper PA-28-161 Cherokee Warrior II
Owner/operator:White Waltham Airfield Ltd
Registration: G-BZDA
MSN: 28-42087
Fatalities:Fatalities: 0 / Occupants: 2
Other fatalities:0
Aircraft damage: Substantial
Location:White Waltham Airfield, Maidenhead, Berkshire -   United Kingdom
Phase: Take off
Departure airport:White Waltham Airfield (EGLM)
Destination airport:
Investigating agency: AAIB
AAIB investigation to Piper PA-28-161, G-BZDA: Loss of power after takeoff, White Waltham, Berkshire, 13 September 2020. The AAIB Final Report was published on 13 May 2021, ansd the following is an excerpt from it:

"The accident flight was the fourth instructional flight of the day in G-BZDA for the instructor who was also the PIC (Pilot In Command). While his student undertook cockpit preparation, the instructor carried out a Transit Check in accordance with the PA-28 checklist. In addition to the Transit Check, he sampled fuel from both wing tank fuel drains and from the gascolator.

During the after-start checks it was noted that fuel pressure dropped when the fuel pump was turned off but stayed within the green range on the gauge, indicating to the instructor that the system was functioning satisfactorily.

The engine parameters were in the normal range during the before takeoff power check. On the takeoff roll the aircraft accelerated as expected but as G-BZDA climbed through 100 ft its engine abruptly ran down. The instructor took control, lowered the nose and looked for a suitable landing area while simultaneously transmitting a brief MAYDAY call.

The engine then recovered to full power, so the instructor gently raised the nose to climb away. He had just started cancelling the MAYDAY when the engine ran down for a second time and stopped. With a railway line ahead, the instructor turned the aircraft hard left towards open ground and executed a forced landing. Although the nosewheel collapsed during the landing, the student and instructor were unhurt and able to vacate the aircraft without assistance.

The airfield fire service were the first responders on scene and observed fuel leaking from the aircraft’s gascolator drain.

=AAIB Conclusion=
This accident resulted from the aircraft’s gascolator drain valve being inadvertently locked open after a fuel sample had been taken. The open drain caused partial fuel starvation leading to a loss of power when the aircraft was climbing shortly after takeoff.

The investigation found evidence dating back to 1975 that lockable gascolator drains were an identified hazard. The aircraft manufacturer changed their design standards in the late 1980s to eradicate the risk to new build aircraft and the New Zealand regulator later issued Airworthiness Directives as mitigation for older aircraft. G-BZDA was built to the revised design standard but had been fitted with a lockable drain valve at some point during its service life.

The investigation was not able to determine how, why or when this maintenance error had occurred. The commonality of wing and gascolator drain fittings was considered one possible error pathway for which maintenance procedures were the primary barrier

=Safety Action=
Following this event, the UK CAA undertook the following Safety Action. Safety Notice SN-2021/005 was released, highlighting to owners, operators and pilots, the risks associated with lockable gascolator drains and recommending replacement with ‘suitable, non-locking alternatives.’ This was later amended to include a recommendation that aircraft be checked for appropriate placarding at the next scheduled maintenance event.

Due to the lack of documentary evidence available to them regarding the decision not to replace EAD001-02-90, the CAA undertook to review the issue of lockable gascolator drains against current Airworthiness Directives criteria."

=Damage to Airframe=
Per the above AAIB Report: "Landing gear collapsed. Bent propeller blade and left wing root skin creased"


1. AAIB Final Report:
2. G-BZDA various photos 2007-2020:

Accident investigation:
Investigating agency: AAIB
Status: Investigation completed
Duration: 8 months
Download report: Final report

Revision history:

13-May-2021 16:49 Dr. John Smith Added
13-May-2021 16:49 Dr. John Smith Updated [Narrative]
13-May-2021 17:10 harro Updated [Accident report]

Corrections or additions? ... Edit this accident description