Date:	Monday 6 March 2023
Time:	22:36 UTC
Type:	Boeing 737-301 (BDSF)
Owner/operator:	West Atlantic UK
Registration:	G-JMCU
MSN:	23513/1327
Year of manufacture:	1986
Fatalities:	Fatalities: 0 / Occupants: 2
Aircraft damage:	None
Category:	Serious incident
Location:	Aberdeen International Airport (ABZ/EGPD) -   United Kingdom
Phase:	Take off
Nature:	Cargo
Departure airport:	Aberdeen International Airport (ABZ/EGPD)
Destination airport:	East Midlands Airport (EMA/EGNX)
Investigating agency:	AAIB
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
West Atlantic UK flight NPT28E, a Boeing 737-301 (BDSF), departed runway 34 at Aberdeen Airport with flap 1 set instead of the planned flap 5 used in the takeoff performance calculations. The crew noticed the incorrect flap setting after takeoff, whilst attempting to retract the flaps in the normal sequence. Calculations performed afterwards indicated that on this occasion the aircraft’s performance on takeoff was adequate with flap 1 set. However, it is not safe to take off without confirming that flap is set correctly, because the aircraft may not achieve the required performance.


Conclusion
An incorrect flap selection was made and not detected before takeoff. A combination of poor weather conditions and time pressure may have influenced the pilot’s performance.
It is necessary to check the actual flap position set, because the green configuration light indicates only that flap more than zero is set.

Weather about the incident time (2236Z):
EGPD 062050Z AUTO 31007KT 9999 SCT020 BKN037 00/M02 Q1000
EGPD 062220Z AUTO 33008KT 9999 FEW019 SCT026 BKN031 00/M01 Q1000 TEMPO 2000 SHSN BKN010
EGPD 062250Z AUTO 35009KT 9999 -RA SCT006 BKN020 M01/M01 Q1000 RESN TEMPO 2000 SHSN BKN006

AAIB

Date/time	Contributor	Updates
08-Feb-2024 10:05	ASN	Added
08-Feb-2024 10:07	ASN	Updated [Location, Narrative]
08-Feb-2024 10:08	ASN	Updated [Total occupants]