Qantas B738 at Perth on Dec 4th 2012, windshear on takeoff run past V1

Last Update: May 17, 2013 / 13:45:07 GMT/Zulu time

Bookmark this article
Incident Facts

Date of incident
Dec 4, 2012

Classification
Report

Airline
Qantas

Flight number
QF-718

Aircraft Registration
VH-VZL

Aircraft Type
Boeing 737-800

ICAO Type Designator
B738

A Qantas Boeing 737-800, registration VH-VZL performing flight QF-718 from Perth,WA to Canberra,AC (Australia), was preparing for departure from Perth's runway 06 when the crew received ATIS information indicating winds were coming from 060 degrees at 8 knots, weather conditions were CAVOK with temperature at 37 degrees C. The aircraft lined up runway 06 with the first officer being pilot flying and the captain pilot monitoring, both pilots checked both windsocks visible showing headwinds for departure from runway 06, the aircraft was cleared for takeoff and accelerated for takeoff. Between V1=137 knots and Vr (V rotate)=139 knots the indicated airspeed no longer increased, the captain noticed a tail wind component of 20-25 knots was indicated on the navigation display, firewalled the throttles, the aircraft rotated and the first officer flew a windshear escape manoeuvre. The aircraft climbed out to safety and continued to Canberra for a safe landing.

Tower advised the following departure of the pilot report of windshear on the runway and added that the tower instruments were now showing a threshold 06 wind of 060 degrees at 10 knots, an airfield center wind of 280 degrees at 15 knots signifying a substantial windshear about mid runway. Departures from runway 06 were temporarily halted.

Australia's Transportation Safety Board released their final report into the abbreviated investigation releasing following safety message:

This incident serves as a reminder to pilots that significant wind changes can occur during takeoff, can be difficult to predict, and can occur in the absence of thunderstorm activity. The wind conditions at each end of a runway may differ significantly so that headwind conditions can exist at one end and tailwind conditions at the other end.

Although it did not assist in this case, it is important to monitor the available windsocks before takeoff as it is the final opportunity to detect wind changes before the take-off roll begins.

The ATSB reported that cumulonimbus cloud were about 20-30nm from the aerodrome at the time of the occurrence, there was no indication of an impending change of winds.

The airport anemometer recordings, averaged over a minute, showed a significant change of wind exactly at the time of the takeoff roll of QF-718 with the wind suddenly changing from about 100 to 135 degrees at 7 knots to 227 degrees at 18 knots and further changing to 271 degrees at 25 knots a minute later. The actual anemometer reading just after the aircraft became airborne was 282 degrees at 25 knots.

Radar recordings showed the aircraft passed the end of the runway at a height of 10 feet. the crew did not receive a windshear alert, the quick access recorder did not record a windshear alert. The ATSB stated with regards to windshear alerts: "New warnings were inhibited after the aircraft reached 100 kt until it was over 50 ft above ground level."

The quick access recorder showed the airspeed stagnated at 134 knots for about 3-4 seconds, just below V1, at that point autothrottle was disconnected and maximum thrust was set, ground speed however was smoothly increasing at that time.

The ATSB reported: "The aircraft was equipped with two CFM56-7B24/3 engines, which enabled takeoffs to be planned up to a maximum thrust of 24,200 lbs (24K). In addition, during takeoff, there was a ‘take-off bump’ feature where ‘fire-walling’ the thrust levers could temporarily provide 27,300 lbs (27K) thrust irrespective of whether a 24K thrust setting had been selected."
Aircraft Registration Data
Registration mark
VH-VZL
Country of Registration
Australia
Date of Registration
Kllgklgkhkqe h Subscribe to unlock
Airworthyness Category
Hdchpkgipjdn picle Subscribe to unlock
TCDS Ident. No.
Manufacturer
THE BOEING COMPANY
Aircraft Model / Type
737-838
ICAO Aircraft Type
B738
Year of Manufacture
Serial Number
Maximum Take off Mass (MTOM) [kg]
Engine Count
Engine
LbkejphicppbknncfpchecAkbnmplicpifj gfbp nqbe Subscribe to unlock
Main Owner
CmlnimpeAebplmjhdhnhbemg flmdpqpp pbddpAcdqAplih e eAbqpAfljmdpgjcjffnApAped Subscribe to unlock
Main Operator
HfpAglpAbicfqjdgppqpfmfiqikngmAncjbdglqlAAdejA AmfhbApflfmnlnqmdmikfhmnnmidncd Subscribe to unlock
Incident Facts

Date of incident
Dec 4, 2012

Classification
Report

Airline
Qantas

Flight number
QF-718

Aircraft Registration
VH-VZL

Aircraft Type
Boeing 737-800

ICAO Type Designator
B738

This article is published under license from Avherald.com. © of text by Avherald.com.
Article source

You can read 2 more free articles without a subscription.

Subscribe now and continue reading without any limits!

Are you a subscriber? Login
Subscribe

Read unlimited articles and receive our daily update briefing. Gain better insights into what is happening in commercial aviation safety.

Send tip

Support AeroInside by sending a small tip amount.

Related articles

Newest articles

Subscribe today

Are you researching aviation incidents? Get access to AeroInside Insights, unlimited read access and receive the daily newsletter.

Pick your plan and subscribe

Partner

Blockaviation logo

A new way to document and demonstrate airworthiness compliance and aircraft value. Find out more.

ELITE Logo

ELITE Simulation Solutions is a leading global provider of Flight Simulation Training Devices, IFR training software as well as flight controls and related services. Find out more.

Blue Altitude Logo

Your regulation partner, specialists in aviation safety and compliance; providing training, auditing, and consultancy services. Find out more.

AeroInside Blog
Popular aircraft
Airbus A320
Boeing 737-800
Boeing 737-800 MAX
Popular airlines
American Airlines
United
Delta
Air Canada
Lufthansa
British Airways