Accident Boeing 707-330C ST-AKW,

ASN Wikibase Occurrence # 321425

Date:	Wednesday 21 October 2009
Time:	15:31
Type:	Boeing 707-330C
Owner/operator:	Sudan Airways
Registration:	ST-AKW
MSN:	20123/788
Year of manufacture:	1969
Total airframe hrs:	77484 hours
Cycles:	26888 flights
Engine model:	Pratt & Whitney JT3D-3B
Fatalities:	Fatalities: 6 / Occupants: 6
Aircraft damage:	Destroyed, written off
Category:	Accident
Location:	1,6 km NW of Sharjah Airport (SHJ) - United Arab Emirates
Phase:	Initial climb
Nature:	Cargo
Departure airport:	Sharjah Airport (SHJ/OMSJ)
Destination airport:	Khartoum-Civil Airport (KRT/HSSS)
Investigating agency:	GCAA
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
A Boeing 707 cargo plane, owned by Azza Transport, was destroyed when it crashed in a desert area immediately after takeoff from Sharjah Airport (SHJ). The airplane operated on Sudan Airways flight SUD2241 and was carrying air conditioning units, auto parts, computers and personal effects. The flight took off from runway 30 at 15:29. During initial climb, the core cowls of engine no. 4 separated and fell on the runway.

The aircraft continued in a shallow climb with level wings when the pilot informed the ATC that he lost engine no.4. He assumed this because the no. 4 Engine Pressure Ratio (EPR) manifold flex line had ruptured, leading to erroneous reading on the EPR indicator. The crew interpreted the EPR reading as a failure of no. 4 engine; accordingly they declared engine loss and requested the tower to return to the airport.
The aircraft went into a right turn, banked and continuously rolled to the right at a high rate, sunk, and impacted the ground with an approximately 90° right wing down attitude.

CAUSES:
(a) the departure of the No. 4 engine core cowls;
(b) the consequent disconnection of No. 4 engine EPR Pt7 flex line;
(c) the probable inappropriate crew response to the perceived No. 4 engine power loss;
(d) the Aircraft entering into a stall after the published maximum bank angle was exceeded; and
(e) the Aircraft Loss of Control ("LOC") that was not recoverable.

Contributing Factors to the Accident were:
(a) the Aircraft was not properly maintained in accordance with the Structure Repair Manual where the cowls had gone through multiple skin repairs that were not up to aviation standards;
(b) the Operator's maintenance system failure to correctly address the issues relating to the No. 4 engine cowls failure to latch issues;
(c) the failure of the inspection and maintenance systems of the maintenance organization, which performed the last C-Check, to address, and appropriately report,
the damage of the No. 4 engine cowls latches prior to issuing a Certificate of Release to Service;
(d) the Operator's failure to provide a reporting system by which line maintenance personnel report maintenance deficiencies and receive timely and appropriate guidance and correction actions;
(e) the Operator's quality system failure to adequately inspect and then allow repairs that were of poor quality or were incorrectly performed to continue to remain on the Aircraft; and
(f) the SCAA safety oversight system deficiency to adequately identify the Operator's chronic maintenance, operations and quality management deficiencies.

Accident investigation: