Air carrier first officer reported beginning a descent during approach to jac believing he had been ...

Attributes
ACN	1390402
Time
Date	201609
Local Time Of Day	1201-1800
Place
Locale Reference	JAC.Airport
State Reference	WY
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Large Transport Low Wing 2 Turbojet Eng
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Route In Use	Vectors Visual Approach
Flight Plan	IFR
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Inflight Event / Encounter CFTT / CFIT

Narrative:

While on descent to jac in VMC weather I was cleared to the FAF of fapmo by a previous controller on the ILS to runway 19 which has an altitude of 9700 feet to intercept the glide slope. We were cleared to 14000 and told to report the field in sight for a visual approach. After reaching 14000 with the field in sight; showing a highest elevation of 9800 on the egpws and no clouds and very clear skies I thought we were on a visual and planned to descend to 11000 to be at the fix of quirt for a turn to final to allow for a normal descent approach. I dialed in 11000 and started a descent when ATC reported to me that he had an alert. I saw 13;500 on the altimeter and started back up to 14;000. We told him we thought we were on the visual and had the field in sight. We were switched to tower; cleared for the visual with the tower; and flew the ILS to a landing. I had visual conditions throughout this time period; briefed the elevations and used the egpws as a backup. My error was the transition between the ATC controlled section and the visual approach clearance.

Original NASA ASRS Text

Title: Air carrier First Officer reported beginning a descent during approach to JAC believing he had been cleared for a visual; resulting in an ATC low altitude alert.

Narrative: While on descent to JAC in VMC weather I was cleared to the FAF of FAPMO by a previous controller on the ILS to Runway 19 which has an altitude of 9700 feet to intercept the glide slope. We were cleared to 14000 and told to report the field in sight for a visual approach. After reaching 14000 with the field in sight; showing a highest elevation of 9800 on the EGPWS and no clouds and very clear skies I thought we were on a visual and planned to descend to 11000 to be at the fix of QUIRT for a turn to final to allow for a normal descent approach. I dialed in 11000 and started a descent when ATC reported to me that he had an alert. I saw 13;500 on the altimeter and started back up to 14;000. We told him we thought we were on the visual and had the field in sight. We were switched to tower; cleared for the visual with the tower; and flew the ILS to a landing. I had visual conditions throughout this time period; briefed the elevations and used the EGPWS as a backup. My error was the transition between the ATC controlled section and the visual approach clearance.

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.

Air carrier first officer reported beginning a descent during approach to jac believing he had been cleared for a visual; resulting in an ATC low altitude alert.