Controller cleared crew to climb and maintain FL220, readback accepted. On handoff altitude again ac...

Attributes
ACN	114169
Time
Date	198906
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : roa
State Reference	NC
Altitude	msl bound lower : 20000 msl bound upper : 21000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : ztl
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 120 flight time total : 10000 flight time type : 900
ASRS Report	114169
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 6500 flight time type : 1400
ASRS Report	114067
Events
Anomaly	altitude deviation : overshoot other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance
Consequence	Other
Supplementary
Primary Problem	Ambiguous
Air Traffic Incident	other

Narrative:

We received and acknowledged a clearance from ZDC to climb to and maintain FL220. I was handed off to ZTL when passing thru FL185. On initial contact I advised ZTL climbing to FL220. ZTL responded by 'turn left 150 degree slow to 280 KTS for intrail spacing into clt' and did not acknowledge my climb clearance to FL220. Approximately 2 min later ZTL said I show you at FL210 and something to the effect that I was cleared to FL200. I said ZDC had cleared us to FL220. ZTL said to descend to FL200 now as he had another flight descending to 220. ZDC and ZTL both failed to hear or respond to my call and acknowledgement of clearance to FL220. Both centers had ample opportunity to correct the problem before it occurred, by failing to listen for and respond to both my readback clrncs. ZTL was not prepared to hear or respond to my initial callup in that he was preoccupied with intrail restrictions into clt, and he was not prepared to listen to or understand my altitude readback. It is apparent that one or more failures in the system occurred: 1) ZDC issued incorrect altitude. 2) I misunderstood the clearance altitude. 3) ZDC and ZTL failed to hear and/or correct altitude. 4) phonetically similar sounding clrncs as cleared to 200 or descend to 220-200 are easily misunderstood. I suggest that the word 'to' be deleted from ATC phraseology when associated with altitude or heading. I.e., turn to 270-070 climb to 220-200.

Original NASA ASRS Text

Title: CTLR CLEARED CREW TO CLIMB AND MAINTAIN FL220, READBACK ACCEPTED. ON HANDOFF ALT AGAIN ACCEPTED BY CTLR. LATER QUESTIONED ABOUT ALT AND CLEARED TO FL200 AND DESCEND.

Narrative: WE RECEIVED AND ACKNOWLEDGED A CLRNC FROM ZDC TO CLIMB TO AND MAINTAIN FL220. I WAS HANDED OFF TO ZTL WHEN PASSING THRU FL185. ON INITIAL CONTACT I ADVISED ZTL CLIMBING TO FL220. ZTL RESPONDED BY 'TURN LEFT 150 DEG SLOW TO 280 KTS FOR INTRAIL SPACING INTO CLT' AND DID NOT ACKNOWLEDGE MY CLIMB CLRNC TO FL220. APPROX 2 MIN LATER ZTL SAID I SHOW YOU AT FL210 AND SOMETHING TO THE EFFECT THAT I WAS CLRED TO FL200. I SAID ZDC HAD CLRED US TO FL220. ZTL SAID TO DSND TO FL200 NOW AS HE HAD ANOTHER FLT DESCENDING TO 220. ZDC AND ZTL BOTH FAILED TO HEAR OR RESPOND TO MY CALL AND ACKNOWLEDGEMENT OF CLRNC TO FL220. BOTH CENTERS HAD AMPLE OPPORTUNITY TO CORRECT THE PROBLEM BEFORE IT OCCURRED, BY FAILING TO LISTEN FOR AND RESPOND TO BOTH MY READBACK CLRNCS. ZTL WAS NOT PREPARED TO HEAR OR RESPOND TO MY INITIAL CALLUP IN THAT HE WAS PREOCCUPIED WITH INTRAIL RESTRICTIONS INTO CLT, AND HE WAS NOT PREPARED TO LISTEN TO OR UNDERSTAND MY ALT READBACK. IT IS APPARENT THAT ONE OR MORE FAILURES IN THE SYSTEM OCCURRED: 1) ZDC ISSUED INCORRECT ALT. 2) I MISUNDERSTOOD THE CLRNC ALT. 3) ZDC AND ZTL FAILED TO HEAR AND/OR CORRECT ALT. 4) PHONETICALLY SIMILAR SOUNDING CLRNCS AS CLRED TO 200 OR DSND TO 220-200 ARE EASILY MISUNDERSTOOD. I SUGGEST THAT THE WORD 'TO' BE DELETED FROM ATC PHRASEOLOGY WHEN ASSOCIATED WITH ALT OR HDG. I.E., TURN TO 270-070 CLIMB TO 220-200.

Data retrieved from NASA's ASRS site as of August 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.

Controller cleared crew to climb and maintain FL220, readback accepted. On handoff altitude again accepted by controller. Later questioned about altitude and cleared to FL200 and descend.