Crew of B727 vicinity of maj working through san francisco commercial radio for descent clearance be...

Attributes
ACN	405810
Time
Date	199806
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : maj
State Reference	FO
Altitude	msl bound lower : 20000 msl bound upper : 20000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zoa
Operator	common carrier : air carrier
Make Model Name	B727 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent other
Route In Use	enroute : other oceanic
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 220 flight time total : 6500 flight time type : 1500
ASRS Report	405810
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot non adherence : far
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	other
Situations
Navigational Aid	Unspecified

Narrative:

After starting descent to maj with cruise clearance, san francisco commercial radio called with clearance to FL210, no crossing restrs, however, cruise clearance was not canceled. Due to HF radio communications being difficult to understand (scratchy radio) and the delay in relaying requests -- or even just a reply from commercial radio, a couple times we thought commercial radio had not heard our request -- it took so long to get a readback. One other aircraft called commercial radio with a position report, which he allowed in full, apparently forgetting we were having a conversation with him. When ATC finally confirmed the cruise clearance was canceled, we were below FL200 and so canceled IFR (per our operations specifications). Commercial radio confirmed cancellation of IFR, then called back later with clearance to descend to FL200. We then reconfirmed we had already canceled IFR. Confusion arose from difficulty in understanding HF radio whether initial clearance was descend and maintain FL210 or call descending through FL210, with no cancellation of cruise clearance, exasperated by excessive delay in getting replies from commercial radio.

Original NASA ASRS Text

Title: CREW OF B727 VICINITY OF MAJ WORKING THROUGH SAN FRANCISCO COMMERCIAL RADIO FOR DSCNT CLRNC BECAME EXASPERATED BECAUSE OF POOR RADIO RECEPTION AND EXCESSIVE DELAYS RECEIVING REPLIES.

Narrative: AFTER STARTING DSCNT TO MAJ WITH CRUISE CLRNC, SAN FRANCISCO COMMERCIAL RADIO CALLED WITH CLRNC TO FL210, NO XING RESTRS, HOWEVER, CRUISE CLRNC WAS NOT CANCELED. DUE TO HF RADIO COMS BEING DIFFICULT TO UNDERSTAND (SCRATCHY RADIO) AND THE DELAY IN RELAYING REQUESTS -- OR EVEN JUST A REPLY FROM COMMERCIAL RADIO, A COUPLE TIMES WE THOUGHT COMMERCIAL RADIO HAD NOT HEARD OUR REQUEST -- IT TOOK SO LONG TO GET A READBACK. ONE OTHER ACFT CALLED COMMERCIAL RADIO WITH A POS RPT, WHICH HE ALLOWED IN FULL, APPARENTLY FORGETTING WE WERE HAVING A CONVERSATION WITH HIM. WHEN ATC FINALLY CONFIRMED THE CRUISE CLRNC WAS CANCELED, WE WERE BELOW FL200 AND SO CANCELED IFR (PER OUR OPS SPECS). COMMERCIAL RADIO CONFIRMED CANCELLATION OF IFR, THEN CALLED BACK LATER WITH CLRNC TO DSND TO FL200. WE THEN RECONFIRMED WE HAD ALREADY CANCELED IFR. CONFUSION AROSE FROM DIFFICULTY IN UNDERSTANDING HF RADIO WHETHER INITIAL CLRNC WAS DSND AND MAINTAIN FL210 OR CALL DSNDING THROUGH FL210, WITH NO CANCELLATION OF CRUISE CLRNC, EXASPERATED BY EXCESSIVE DELAY IN GETTING REPLIES FROM COMMERCIAL RADIO.

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.

Crew of B727 vicinity of maj working through san francisco commercial radio for descent clearance became exasperated because of poor radio reception and excessive delays receiving replies.