Accident Lockheed L-100-30 Hercules 7T-VHG,

ASN Wikibase Occurrence # 322119

Date:	Sunday 13 August 2006
Time:	20:15
Type:	Lockheed L-100-30 Hercules
Owner/operator:	Air Algérie
Registration:	7T-VHG
MSN:	4880
Year of manufacture:	1981
Total airframe hrs:	31889 hours
Cycles:	13173 flights
Engine model:	Allison 501-D22A
Fatalities:	Fatalities: 3 / Occupants: 3
Aircraft damage:	Destroyed, written off
Category:	Accident
Location:	SW of Piacenza - Italy
Phase:	En route
Nature:	Cargo
Departure airport:	Algiers-Houari Boumediene Airport (ALG/DAAG)
Destination airport:	Frankfurt International Airport (FRA/EDDF)
Investigating agency:	ANSV
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
An Air Algérie Lockheed L-100-30 Hercules cargo plane was destroyed when it crashed near Piacenza in Italy. All three crew members were killed.
The aircraft departed departed Algiers Airport, Algeria, at 16:05 UTC on a cargo flight to Frankfurt, Germany. The aircraft carried a load of 3696 pounds. The flight climbed to the cruising altitude of FL240 and crossed the Mediterranean Sea towards St. Tropez, France. The aircraft continued towards Italy.
Around 17:52 UTC the co-pilot, in conversation with the flight engineer, reported distant cloud formations. The subject of the subsequent conversations was again the existing weather conditions and a possible presence of ice. Later, around 18:04, near the MONEB reporting point, the crew talked about a large cloud formation that was exactly on the route the aircraft would have to travel to the next navigation point, called ABESI. The commander, at this point, suggested to assume a heading of 020° to avoid the cloud formation. At 18:05 the crew was instructed to contact Milano ACC.
The flight received confirmation that they could proceed towards the ABESI point and that they could avoid any cloud formation at their discretion. In the following minutes the crew discussed the possible approach routes and the possible runway in use at the destination airport.
At 18:14 the co-pilot reported the inefficiency of the autopilot system. From this moment on, the situation on board became excited and conversations in the cockpit denoted the crew's difficulty in maintaining control of the aircraft. During this phase of the flight, during which the acoustic overspeed warning activated in the cockpit. There was a loss of altitude of the aircraft with increasing speed. At 18:14:47 UTC the CVR recording was interrupted and after 32 seconds, at 18:15:19, the aircraft hit the ground in an agricultural land called Ca'degli Ossi, near Besurica, a residential area located in the south-west outskirts of Piacenza.

CAUSES:
The very high state of fragmentation of the wreck and the substantial absence/utilisation of FDR data made the safety investigation very difficult and therefore could not acquire some indisputable certainties on certain aspects.
The indications resulting from the examination of the acquired evidence and from the many technical analyses carried out lead to believe that the accident occurred because of the loss sudden control of the aircraft, induced, reasonably speaking, by a technical problem in the flight control system, which the pilots were unable to counter/manage and which the safety investigation could not detect with absolute certainty.

Accident investigation: