Inadvertently selecting app mode vice VOR/localizer to intercept the localizer while on autopilot re...

Attributes
ACN	1126007
Time
Date	201310
Local Time Of Day	0601-1200
Place
Locale Reference	L30.TRACON
State Reference	NV
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Route In Use	Visual Approach
Flight Plan	IFR
Component
Aircraft Component	Autoflight System
Person 1
Function	First Officer Pilot Not Flying
Experience	Flight Crew Last 90 Days 154
Person 2
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Clearance

Narrative:

On left base visual to 25L with the autopilot on; looking over left shoulder to spot traffic and the runway; the captain selected the approach mode instead of the localizer button. This caused the airplane to climb 500 feet above altitude. As soon as the engines started to spool; I informed the captain that we were about to start climbing out of our assigned altitude. He was not sure what to do; as he started pushing buttons to get the airplane to level off. After a few moments of letting him try to solve the solution; I asked him to turn off the autopilot; which he eventually did; and returned the aircraft to its intended flight path. He completed the visual approach with a slight overshoot. I should have intervened right away; instead of waiting for him to figure out the automation. I'll be less respectful of positional authority; and more respectful of the possible consequences.

Original NASA ASRS Text

Title: Inadvertently selecting APP mode vice VOR/LOC to intercept the localizer while on autopilot resulted in a glide slope capture and a climb out of their cleared altitude for a B737NG flight crew.

Narrative: On left base visual to 25L with the autopilot on; looking over left shoulder to spot traffic and the runway; the Captain selected the approach mode instead of the LOC button. This caused the airplane to climb 500 feet above altitude. As soon as the engines started to spool; I informed the Captain that we were about to start climbing out of our assigned altitude. He was not sure what to do; as he started pushing buttons to get the airplane to level off. After a few moments of letting him try to solve the solution; I asked him to turn off the autopilot; which he eventually did; and returned the aircraft to its intended flight path. He completed the visual approach with a slight overshoot. I should have intervened right away; instead of waiting for him to figure out the automation. I'll be less respectful of positional authority; and more respectful of the possible consequences.

Data retrieved from NASA's ASRS site as of July 2013 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.

Inadvertently selecting app mode vice VOR/localizer to intercept the localizer while on autopilot resulted in a glide slope capture and a climb out of their cleared altitude for a B737NG flight crew.