Vliegtuigongeval op 06 FEB 1996 met Boeing 757-225 TC-GEN

Home » Database » 1996

Accident

Last updated: 20 June 2013

Status:	Definitief
Datum:	06 FEB 1996
Tijd:	23:47
Type:	Boeing 757-225
Vloog voor:	Alas Nacionales
Gehuurd van:	Birgenair
Registratie:	TC-GEN
Constructienummer:	22206/31
Bouwjaar:	1985
Aantal vlieguren:	29269
Aantal vluchten:	13499
Motoren:	2 Rolls Royce RB211-535E4
Bemanning:	slachtoffers: 13 / inzittenden: 13
Passagiers:	slachtoffers: 176 / inzittenden: 176
Totaal:	slachtoffers: 189 / inzittenden: 189
Schade:	Vernield
Gevolgen:	Written off (damaged beyond repair)
Plaats:	26 km (16.3 mijl) NE van Puerto Plata, Dominican Republic (Atlantische Oceaan)
Fase:	Kruisvlucht (ENR)
Soort vlucht:	Internationale charter
Vliegveld van vertrek:	Puerto Plata-La Union International Airport (POP/MDPP), Dominicaanse Republiek
Vliegveld van aankomst:	Gander Airport, NF (YQX/CYQX), Canada
Vluchtnummer:	301

Beschrijving:
Flight ALW 301 departed Puerto Plata for a charter flight to Frankfurt via Gander and Berlin at 23:42 LT. At 80 knots on take-off the captain found out that his air speed indicator (ASI) wasn't working properly. The co-pilot's indicator seemed to work fine. While climbing through 4700 feet the captain's ASI read 350 knots (real speed was about 220kts); this resulted in an autopilot/autothrottle reaction to increase the pitch-up attitude and a power reduction in order to lower the airspeed. At that time the crew got 'Rudder ratio' and 'Mach airspeed' advisory warnings. Both pilots got confused when the co-pilot stated that his ASI read 200 knots decreasing while getting an excessive speed-warning, followed by a stick shaker warning. This led the pilots to believe that both ASIs were unreliable.
Finally realizing that they were losing speed and altitude they disconnected the autopilot (which, fed by the captain's faulty ASI, had reduced the speed close to the stall speed) and applied full thrust. At 23:47:17 an aural GPWS warning sounded. Eight seconds later the aircraft struck the ocean.
The incorrect ASI readings were possibly caused by an obstructed pitot tube, which had left uncovered for 3-4 days prior to this flight.

PROBABLE CAUSE: "The crew's failure to recognize the activation of the stick shaker as a warning of imminent entrance to the stall, and the failure of the crew to execute the procedures for recovery from the onset of loss of control."

Bronnen:
» Air Safety Week 12.02.1996 (p. 1)
» Aviation Week & Space Technology 12.02.96(33,34)
» Flight International 14-21.02.96(4)
» NTSB Safety Recommendations A-96-15 through -20
» Erroneous Airspeed Indications Cited in Boeing 757 Control Loss (Flight Safety Foundation - Accident Prevention October 1999)
Sample newspaper article from Newspaperarchive.com

Veiligheidsmaatregelen

NTSB issued 6 Safety Recommendations

Show all AD's and Safety Recommendations

Foto's

Kaart

Deze kaart geeft het vliegveld van vetrek weer en de geplande bestemming van de vlucht. De lijn tussen de vliegvelden geeft niet de exacte vliegroute weer.
De afstand tussen Puerto Plata-La Union International Airport en Gander Airport, NF bedraagt 3524 km (2203 miles).

This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.

languages:

Boeing 757

3^e ongeval
1050 built
zwaarste ongeval

safety profile

Atlantische Oceaan

2^e zwaarste ongeval (toen het plaatsvond)
4^e zwaarste ongeval (op dit moment)

»safety profile

Issued: 31-MAY-1996	To: FAA	A-96-015
ISSUE AN AIRWORTHINESS DIRECTIVE TO REQUIRE THAT THE BOEING 757/767 AIRPLANE FLIGHT MANUAL BE REVISED TO NOTIFY PILOTS THAT THE SIMULTANEOUS ACTIVATION OF THE "MACH/SPD TRIM" & RUDDER RATIO" ADVISORIES IS AN INDICATION OF AN AIRSPEED DISCREPANCY. (Closed - Acceptable Alternate Action)
Issued: 31-MAY-1996	To: FAA	A-96-016
REQUIRE THAT THE BOEING COMMERCIAL AIRPLANE GROUP MODIFY THE CREW ALERTING SYSTEM OF THE BOEING 757/767 TO INCLUDE A "CAUTION" ALERT WHEN AN ERRONEOUS AIRSPEED INDICATION IS DETECTED. (Closed - Acceptable Action)
Issued: 31-MAY-1996	To: FAA	A-96-017
REQUIRE THE BOEING COMMERCIAL AIRPLANE GROUP TO MODIFY IT BOEING 757/767 OPERATIONAL MANUAL TO INCLUDE A DETAILED EMERGENCY PROCEDURE ADDRESSING THE IDENTIFICATION & ELIMINATION OF AN ERRONEOUS AIRSPEED INDICATION. (Closed - Acceptable Action)
Issued: 31-MAY-1996	To: FAA	A-96-018
ISSUE A FLIGHT STANDARDS INFO BULLETIN TO DIRECT PRINCIPAL OPERATIONS INSPECTORS TO ENSURE THAT THE OPERATING MANUALS OF THEIR BOEING 757/767 OPERATORS INCLUDE A DETAILED EMERGENCY PROCEDURE ADDRESSING THE IDENTIFICATION & ELIMINATION OF AN ERRONEOUS AIRSPEED INDICATION. (Closed - Acceptable Action)
Issued: 31-MAY-1996	To: FAA	A-96-019
ISSUE A FLIGHT STANDARDS INFO BULLETIN TO NOTIFY PRINCIPAL OPERATIONS INSPECTORS OF THE CIRCUMSTANCES OF THIS ACCIDENT & TO HAVE THEM ENSURE THAT TRAINING PROVIDERS EMPHASIZE THE IMPORTANCE OF RECOGNIZING AN AIRSPEED INDICATION MALFUNCTION DURING THE TAKEOFF ROLL. (Closed - Acceptable Action)
Issued: 31-MAY-1996	To: FAA	A-96-020
ENSURE THAT ALL BOEING 757/767 TRAINING PROVIDERS INCLUDE AN EFFECTIVE SCENARIO IN THE FLIGHT SIMULATOR DURING WHICH THE STUDENT IS TRAINED TO APPROPRIATELY RESPOND TO THE EFFECTS OF A BLOCKED PITOT TUBE. (Closed - Acceptable Action)