An air carrier MD80 flight crew had the aircraft depart its assigned altitude then when they attempted to climb, it suddenly pitched up and overshot the altitude. They suspect tail icing.

Home

Browse by month

Random

Latest

About

Contact

Attributes
ACN	391293
Time
Date	199801
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : bdf airport : ord
State Reference	IL
Altitude	msl bound lower : 10900 msl bound upper : 11400
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : ord
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	cruise other cruise other
Route In Use	arrival other arrival star : star
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
ASRS Report	391293
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	391292
Events
Anomaly	aircraft equipment problem : critical altitude deviation : excursion from assigned altitude inflight encounter : weather other anomaly
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : declared emergency flight crew : overcame equipment problem flight crew : regained aircraft control other
Consequence	Other
Supplementary
Primary Problem	Weather
Air Traffic Incident	other

Narrative:

On arrival into ord during moderate icing the aircraft left altitude hold at 300 KTS and started an uncommanded 500-700 FPM descent. I noticed at 10900 ft and selected 700 ft pitch up on the vsi. The aircraft was slow to respond at first, but then pitched up into a 3000 FPM climb. The captain had selected tail deice at approximately the same time I selected 700 ft up on the vsi. The autoplt was disconnected and I returned the aircraft back down to 11000 ft, 300-400 ft deviation, considerable forward pressure was required to level the aircraft, yet it appeared to be in trim once level. Suspect icing on tail even though we had cycled it at least 3 times. No comment from approach. Supplemental information from acn 391292: first officer pushed forward the same time I did and the aircraft climbed to approximately 11350 ft before we started a descent to 11000 ft and leveled off. Approach did not say anything if they noticed. Suspect icing on tail. Addition to previous report titled the same. We had been selecting tail deice every 10 mins prior to the incident due to the moderate icing.

Original NASA ASRS Text

Title: AN ACR MD80 FLC HAD THE ACFT DEPART ITS ASSIGNED ALT THEN WHEN THEY ATTEMPTED TO CLB, IT SUDDENLY PITCHED UP AND OVERSHOT THE ALT. THEY SUSPECT TAIL ICING.

Narrative: ON ARR INTO ORD DURING MODERATE ICING THE ACFT LEFT ALT HOLD AT 300 KTS AND STARTED AN UNCOMMANDED 500-700 FPM DSCNT. I NOTICED AT 10900 FT AND SELECTED 700 FT PITCH UP ON THE VSI. THE ACFT WAS SLOW TO RESPOND AT FIRST, BUT THEN PITCHED UP INTO A 3000 FPM CLB. THE CAPT HAD SELECTED TAIL DEICE AT APPROX THE SAME TIME I SELECTED 700 FT UP ON THE VSI. THE AUTOPLT WAS DISCONNECTED AND I RETURNED THE ACFT BACK DOWN TO 11000 FT, 300-400 FT DEV, CONSIDERABLE FORWARD PRESSURE WAS REQUIRED TO LEVEL THE ACFT, YET IT APPEARED TO BE IN TRIM ONCE LEVEL. SUSPECT ICING ON TAIL EVEN THOUGH WE HAD CYCLED IT AT LEAST 3 TIMES. NO COMMENT FROM APCH. SUPPLEMENTAL INFO FROM ACN 391292: FO PUSHED FORWARD THE SAME TIME I DID AND THE ACFT CLBED TO APPROX 11350 FT BEFORE WE STARTED A DSCNT TO 11000 FT AND LEVELED OFF. APCH DID NOT SAY ANYTHING IF THEY NOTICED. SUSPECT ICING ON TAIL. ADDITION TO PREVIOUS RPT TITLED THE SAME. WE HAD BEEN SELECTING TAIL DEICE EVERY 10 MINS PRIOR TO THE INCIDENT DUE TO THE MODERATE ICING.

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.