When interrupted by interphone call from a cabin attendant, inadvertently placed in the 'emergency m...

Attributes
ACN	622433
Time
Date	200406
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	intersection : macey
State Reference	GA
Altitude	msl single value : 23000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : ztl.artcc
Operator	common carrier : air carrier
Make Model Name	DC-9 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent : holding
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : cfi pilot : atp pilot : multi engine
Experience	flight time last 90 days : 240 flight time total : 15000 flight time type : 4400
ASRS Report	622433
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 210 flight time total : 12000 flight time type : 6000
ASRS Report	622079
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne critical non adherence : company policies non adherence : clearance non adherence : far other anomaly other anomaly
Independent Detector	aircraft equipment other aircraft equipment : airspeed indicator
Resolutory Action	flight crew : returned to assigned altitude flight crew : regained aircraft control
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	ATC Human Performance Flight Crew Human Performance Aircraft
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While flying the macey arrival into atlanta, GA, we were issued holding instructions. Holding would be at the macey intersection. The airplane was slowed prior to arrival at the fix. As we entered the holding pattern, I was about to report to ATC our entry into holding. It was at this point that we received a call from the flight attendant. Although this call turned out to be routine, it came across as an emergency call from the cabin. This, naturally, got the attention of both crew members (myself and the captain). At this point, the captain called my attention to a vibration on the airplane. After a brief moment of investigation, we discovered that the source of the vibration was a loss of airspeed, which when combined with the bank angle of the aircraft, resulted in a stall of the airplane and a subsequent loss of altitude (approximately 500 ft) during the recovery process. Recovery, although initiated immediately, took more than 1 min. We tried to get a lower altitude from ATC but they were unable to accommodate the request due to other traffic holding below us. Once recovery was complete we returned immediately to our assigned altitude. The distraction, although momentary, was timed so as to divert attention from the task at hand. In hindsight it may have been prudent to emphasize the role of the captain to fly the airplane, while I answered a call that we thought was of an emergency nature, prior to answering the call! I'm not positive this would have prevented our situation but it may have been a good reminder of the priority of our tasks. Supplemental information from acn 622079: we were busy as we entered the holding pattern, so I decided to use a 'ballpark' holding speed versus looking one up. The ballpark speed -- vref +20 works in most sits, but not in this one. Lesson learned.

Original NASA ASRS Text

Title: WHEN INTERRUPTED BY INTERPHONE CALL FROM A CABIN ATTENDANT, INADVERTENTLY PLACED IN THE 'EMER MODE,' THE FLT CREW OF A DC9 IN A HOLDING PATTERN NEAR ATL FAILS TO MONITOR AIRSPD AND EXPERIENCE A STALL AND LOSS OF SEPARATION WITH ACFT BENEATH THEM.

Narrative: WHILE FLYING THE MACEY ARR INTO ATLANTA, GA, WE WERE ISSUED HOLDING INSTRUCTIONS. HOLDING WOULD BE AT THE MACEY INTXN. THE AIRPLANE WAS SLOWED PRIOR TO ARR AT THE FIX. AS WE ENTERED THE HOLDING PATTERN, I WAS ABOUT TO RPT TO ATC OUR ENTRY INTO HOLDING. IT WAS AT THIS POINT THAT WE RECEIVED A CALL FROM THE FLT ATTENDANT. ALTHOUGH THIS CALL TURNED OUT TO BE ROUTINE, IT CAME ACROSS AS AN EMER CALL FROM THE CABIN. THIS, NATURALLY, GOT THE ATTN OF BOTH CREW MEMBERS (MYSELF AND THE CAPT). AT THIS POINT, THE CAPT CALLED MY ATTN TO A VIBRATION ON THE AIRPLANE. AFTER A BRIEF MOMENT OF INVESTIGATION, WE DISCOVERED THAT THE SOURCE OF THE VIBRATION WAS A LOSS OF AIRSPD, WHICH WHEN COMBINED WITH THE BANK ANGLE OF THE ACFT, RESULTED IN A STALL OF THE AIRPLANE AND A SUBSEQUENT LOSS OF ALT (APPROX 500 FT) DURING THE RECOVERY PROCESS. RECOVERY, ALTHOUGH INITIATED IMMEDIATELY, TOOK MORE THAN 1 MIN. WE TRIED TO GET A LOWER ALT FROM ATC BUT THEY WERE UNABLE TO ACCOMMODATE THE REQUEST DUE TO OTHER TFC HOLDING BELOW US. ONCE RECOVERY WAS COMPLETE WE RETURNED IMMEDIATELY TO OUR ASSIGNED ALT. THE DISTR, ALTHOUGH MOMENTARY, WAS TIMED SO AS TO DIVERT ATTN FROM THE TASK AT HAND. IN HINDSIGHT IT MAY HAVE BEEN PRUDENT TO EMPHASIZE THE ROLE OF THE CAPT TO FLY THE AIRPLANE, WHILE I ANSWERED A CALL THAT WE THOUGHT WAS OF AN EMER NATURE, PRIOR TO ANSWERING THE CALL! I'M NOT POSITIVE THIS WOULD HAVE PREVENTED OUR SIT BUT IT MAY HAVE BEEN A GOOD REMINDER OF THE PRIORITY OF OUR TASKS. SUPPLEMENTAL INFO FROM ACN 622079: WE WERE BUSY AS WE ENTERED THE HOLDING PATTERN, SO I DECIDED TO USE A 'BALLPARK' HOLDING SPD VERSUS LOOKING ONE UP. THE BALLPARK SPD -- VREF +20 WORKS IN MOST SITS, BUT NOT IN THIS ONE. LESSON LEARNED.

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.

When interrupted by interphone call from a cabin attendant, inadvertently placed in the 'emergency mode,' the flight crew of a DC9 in a holding pattern near atl fails to monitor airspeed and experience a stall and loss of separation with aircraft beneath them.