Citation flight crew experienced an HF radio issue that resulted in a clearance deviation.

Attributes
ACN	1696020
Time
Date	201910
Local Time Of Day	0601-1200
Place
Locale Reference	KZAK.ARTCC
State Reference	HI
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Cessna Citation Undifferentiated or Other Model
Operating Under FAR Part	Part 91
Flight Phase	Climb
Route In Use	Oceanic
Flight Plan	IFR
Person 1
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument
Experience	Flight Crew Last 90 Days 40 Flight Crew Total 8700 Flight Crew Type 500
Events
Anomaly	ATC Issue All Types Aircraft Equipment Problem Less Severe Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Published Material / Policy Deviation - Procedural Clearance

Narrative:

Enroute to ZZZ on R576 on a daytime flight in VMC (visual meteorological conditions). Flight planned altitude was FL430 to dadie waypoint then climb to FL450 by dialo waypoint. Approaching dadie the pilot flying confirmed the plan to initiate a constant mach climb to FL450 by dialo and asked for FL450 to be set in the altitude preselect which was accomplished. The pilot monitoring initiated the required voice position report via HF to [oakland oceanic]. Communication was difficult on the primary HF (high frequency) frequency and it took several exchanges to confirm the position report. The PF (pilot flying) was monitoring VHF (very high frequency) frequencies 123.45 and 121.50 during the position report and initiated a climb to FL450 assuming the pilot monitoring had communicated the climb to FL450. Due to the distraction of the HF position report the pilot monitoring neglected to request a climb to FL450 and focused on completing the navigation log following the HF communication. Upon reporting the next position report at dialo [oakland oceaninc] queried the altitude which was confirmed as FL450 and the crew realized they had not received clearance confirmation to make the flight planned climb from FL430 to FL450. ATC re-cleared the flight to maintain FL450 and reiterated a clearance was required to initiate the climb. The confusion caused by the difficulty with the HF communication associated with the position report at dadie contributed to the error.

Original NASA ASRS Text

Title: Citation flight crew experienced an HF radio issue that resulted in a clearance deviation.

Narrative: Enroute to ZZZ on R576 on a daytime flight in VMC (Visual Meteorological Conditions). Flight planned altitude was FL430 to DADIE waypoint then climb to FL450 by DIALO waypoint. Approaching DADIE the Pilot Flying confirmed the plan to initiate a constant mach climb to FL450 by DIALO and asked for FL450 to be set in the altitude preselect which was accomplished. The Pilot Monitoring initiated the required voice position report via HF to [Oakland Oceanic]. Communication was difficult on the primary HF (High Frequency) frequency and it took several exchanges to confirm the position report. The PF (Pilot Flying) was monitoring VHF (Very High Frequency) frequencies 123.45 and 121.50 during the position report and initiated a climb to FL450 assuming the Pilot Monitoring had communicated the climb to FL450. Due to the distraction of the HF position report the Pilot Monitoring neglected to request a climb to FL450 and focused on completing the navigation log following the HF communication. Upon reporting the next position report at DIALO [Oakland Oceaninc] queried the altitude which was confirmed as FL450 and the crew realized they had not received clearance confirmation to make the flight planned climb from FL430 to FL450. ATC re-cleared the flight to maintain FL450 and reiterated a clearance was required to initiate the climb. The confusion caused by the difficulty with the HF communication associated with the position report at DADIE contributed to the error.

Data retrieved from NASA's ASRS site 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.