Adv tech medium large transport overweight takeoff.

Attributes
ACN	145629
Time
Date	199005
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : mdw
State Reference	IL
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	Mixed
Light	Night
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	climbout : takeoff
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 250 flight time total : 7000 flight time type : 2000
ASRS Report	145629
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	non adherence : far non adherence : published procedure other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

On 5/wed/90, air carrier flight xx taxied from the gate area at mdw to runway 4R for takeoff. Upon arriving at runway 4R, I advised the captain that we were over our allowable takeoff gross weight for that runway. At the time, temperature was 53 degrees F with altimeter setting of 29.34' and a headwind. Our actual weight was 111000#. Flaps 15 degrees with engine bleeds off for takeoff provided us with the highest allowable takeoff weight for runway 4R and that figure was 112000#. However, the low altimeter setting required a further reduction of 270# in allowable takeoff weight. The captain said he was not aware of corrections due to altimeter settings. At the same time, mdw tower cleared us for an immediate takeoff and the captain proceeded with the takeoff, even though we were not legal for takeoff on that runway. The problem was the captain was not up to date on current takeoff performance procedures. The procedures for adjusting weights due to altimeter setting had been in effect for only a few months. Before this procedure change took effect,altimeter settings had only affected takeoff power setting, not takeoff weights. A test or some classroom work should be sufficient to correct the situation.

Original NASA ASRS Text

Title: ADV TECH MLG OVERWEIGHT TKOF.

Narrative: ON 5/WED/90, ACR FLT XX TAXIED FROM THE GATE AREA AT MDW TO RWY 4R FOR TKOF. UPON ARRIVING AT RWY 4R, I ADVISED THE CAPT THAT WE WERE OVER OUR ALLOWABLE TKOF GROSS WT FOR THAT RWY. AT THE TIME, TEMP WAS 53 DEGS F WITH ALTIMETER SETTING OF 29.34' AND A HEADWIND. OUR ACTUAL WT WAS 111000#. FLAPS 15 DEGS WITH ENG BLEEDS OFF FOR TKOF PROVIDED US WITH THE HIGHEST ALLOWABLE TKOF WT FOR RWY 4R AND THAT FIGURE WAS 112000#. HOWEVER, THE LOW ALTIMETER SETTING REQUIRED A FURTHER REDUCTION OF 270# IN ALLOWABLE TKOF WT. THE CAPT SAID HE WAS NOT AWARE OF CORRECTIONS DUE TO ALTIMETER SETTINGS. AT THE SAME TIME, MDW TWR CLRED US FOR AN IMMEDIATE TKOF AND THE CAPT PROCEEDED WITH THE TKOF, EVEN THOUGH WE WERE NOT LEGAL FOR TKOF ON THAT RWY. THE PROB WAS THE CAPT WAS NOT UP TO DATE ON CURRENT TKOF PERFORMANCE PROCS. THE PROCS FOR ADJUSTING WTS DUE TO ALTIMETER SETTING HAD BEEN IN EFFECT FOR ONLY A FEW MONTHS. BEFORE THIS PROC CHANGE TOOK EFFECT,ALTIMETER SETTINGS HAD ONLY AFFECTED TKOF PWR SETTING, NOT TKOF WTS. A TEST OR SOME CLASSROOM WORK SHOULD BE SUFFICIENT TO CORRECT THE SITUATION.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.