A B747-400 flight crew at FL350 has a problem with ATC when requesting a block altitude of FL350-FL370. ATC expected them to accept the climb to FL370 after the crew had rejected the climb since their request for a block altitude had been deferred by ZOA, ca.

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Attributes
ACN	504740
Time
Date	200103
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : zoa.artcc
State Reference	CA
Altitude	msl bound lower : 35000 msl bound upper : 37000
Environment
Flight Conditions	IMC
Weather Elements	Turbulence
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zoa.artcc tower : ord.tower
Operator	common carrier : air carrier
Make Model Name	B747-400
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	cruise : level cruise : enroute altitude change
Route In Use	enroute : pacific
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
ASRS Report	504740
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	504727
Events
Anomaly	altitude deviation : undershoot inflight encounter : turbulence non adherence : clearance other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance controller : issued advisory
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Flight Crew Human Performance Airspace Structure Weather ATC Facility ATC Human Performance
Primary Problem	ATC Human Performance

Narrative:

While on trk 14 just past W170 we encountered light to moderate turbulence. We contacted oakland via control/pilot data link communication and asked for FL370 and in the free text asked for a block FL350-FL370. They cleared us to FL370. We rejected that request and in the free text again asked for a block FL350-FL370. They responded 'unable due to traffic request deferred' so we maintained FL350. Mins later oakland requested we confirm altitude. We responded FL350. They responded we were issued a clearance to climb to FL370. We informed them we received message that request for FL370 was deferred and confirm now cleared to FL370. They cleared us to FL370 and we climbed. After reaching FL370, we reported level without any further incident. Supplemental information from acn 504727: CRM issues include an ambiguous clearance and should have been clarified vice assumed. Safety issues include being at an altitude which ATC has cleared us from.

Original NASA ASRS Text

Title: A B747-400 FLC AT FL350 HAS A PROB WITH ATC WHEN REQUESTING A BLOCK ALT OF FL350-FL370. ATC EXPECTED THEM TO ACCEPT THE CLB TO FL370 AFTER THE CREW HAD REJECTED THE CLB SINCE THEIR REQUEST FOR A BLOCK ALT HAD BEEN DEFERRED BY ZOA, CA.

Narrative: WHILE ON TRK 14 JUST PAST W170 WE ENCOUNTERED LIGHT TO MODERATE TURB. WE CONTACTED OAKLAND VIA CTL/PLT DATA LINK COM AND ASKED FOR FL370 AND IN THE FREE TEXT ASKED FOR A BLOCK FL350-FL370. THEY CLRED US TO FL370. WE REJECTED THAT REQUEST AND IN THE FREE TEXT AGAIN ASKED FOR A BLOCK FL350-FL370. THEY RESPONDED 'UNABLE DUE TO TFC REQUEST DEFERRED' SO WE MAINTAINED FL350. MINS LATER OAKLAND REQUESTED WE CONFIRM ALT. WE RESPONDED FL350. THEY RESPONDED WE WERE ISSUED A CLRNC TO CLB TO FL370. WE INFORMED THEM WE RECEIVED MESSAGE THAT REQUEST FOR FL370 WAS DEFERRED AND CONFIRM NOW CLRED TO FL370. THEY CLRED US TO FL370 AND WE CLBED. AFTER REACHING FL370, WE RPTED LEVEL WITHOUT ANY FURTHER INCIDENT. SUPPLEMENTAL INFO FROM ACN 504727: CRM ISSUES INCLUDE AN AMBIGUOUS CLRNC AND SHOULD HAVE BEEN CLARIFIED VICE ASSUMED. SAFETY ISSUES INCLUDE BEING AT AN ALT WHICH ATC HAS CLRED US FROM.

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.