Beech 1900 altitude deviation in turbulence near cos.

Attributes
ACN	458098
Time
Date	199912
Day	Sat
Local Time Of Day	1801 To 2400
Place
State Reference	CO
Altitude	msl bound lower : 18500 msl bound upper : 19000
Environment
Flight Conditions	IMC
Weather Elements	Turbulence
Light	Night
Aircraft 1
Controlling Facilities	artcc : zdv.artcc
Operator	common carrier : air carrier
Make Model Name	Beech 1900
Operating Under FAR Part	Part 121
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 300 flight time total : 2000 flight time type : 300
ASRS Report	458098
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : excursion from assigned altitude inflight encounter : turbulence inflight encounter : weather non adherence : clearance non adherence : far non adherence : published procedure other anomaly other
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to assigned altitude
Supplementary
Problem Areas	Flight Crew Human Performance Weather Environmental Factor
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

It was my first officer's leg from den to laa. We were level at FL190, about 30 NM southeast of the black forest VOR, colorado springs, on a vector (heading) towards lamar (laa). We were encountering moderate chop, right in the top of turbulent wispy-like clouds. My first officer pulled the power back a bit to reduce the airspeed, and as he was adjusting the power, and in combination with strong downdrafts and updrafts, he proceeded to lose 500 ft of altitude. I was looking outside at the time, and as I looked back inside, his altimeter showed FL185. I said some profanity, and 'get back up there quick!' he said 'I'm trying,' or something like that, and added the power back and not so expeditiously climbed back up to FL190. Once I saw that we were so far off our altitude. I turned the transponder to standby. I returned the transponder back to altitude once within 200 ft of our assigned altitude. The controller did not say anything to us, query us, or anything of the sort.

Original NASA ASRS Text

Title: BEECH 1900 ALTDEV IN TURB NEAR COS.

Narrative: IT WAS MY FO'S LEG FROM DEN TO LAA. WE WERE LEVEL AT FL190, ABOUT 30 NM SE OF THE BLACK FOREST VOR, COLORADO SPRINGS, ON A VECTOR (HDG) TOWARDS LAMAR (LAA). WE WERE ENCOUNTERING MODERATE CHOP, RIGHT IN THE TOP OF TURBULENT WISPY-LIKE CLOUDS. MY FO PULLED THE PWR BACK A BIT TO REDUCE THE AIRSPD, AND AS HE WAS ADJUSTING THE PWR, AND IN COMBINATION WITH STRONG DOWNDRAFTS AND UPDRAFTS, HE PROCEEDED TO LOSE 500 FT OF ALT. I WAS LOOKING OUTSIDE AT THE TIME, AND AS I LOOKED BACK INSIDE, HIS ALTIMETER SHOWED FL185. I SAID SOME PROFANITY, AND 'GET BACK UP THERE QUICK!' HE SAID 'I'M TRYING,' OR SOMETHING LIKE THAT, AND ADDED THE PWR BACK AND NOT SO EXPEDITIOUSLY CLBED BACK UP TO FL190. ONCE I SAW THAT WE WERE SO FAR OFF OUR ALT. I TURNED THE XPONDER TO STANDBY. I RETURNED THE XPONDER BACK TO ALT ONCE WITHIN 200 FT OF OUR ASSIGNED ALT. THE CTLR DID NOT SAY ANYTHING TO US, QUERY US, OR ANYTHING OF THE SORT.

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.