A B737-700 captain reported a near-stall incident in climb when the aircraft dropped out of VNAV int...

Attributes
ACN	1002383
Time
Date	201204
Local Time Of Day	1801-2400
Place
Locale Reference	DEN.Airport
State Reference	CO
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Climb
Flight Plan	IFR
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 271 Flight Crew Type 7500
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy Inflight Event / Encounter Other / Unknown

Narrative:

During climb; I was the pilot flying and after receiving a climb clearance and dialing the new altitude in the altitude preselect window; I failed to notice VNAV had disengaged and vertical speed had engaged. As I noticed the airspeed low and was disengaging the autopilot and auto throttles; the airspeed low aural warning sounded briefly as I was advancing power and lowering the nose of the aircraft. Airspeed recovered quickly and the flight was completed without further event. All ATC clearances were adhered to. Aircraft did not stall. Airspeed quickly recovered after lowering the nose of the aircraft. In retrospect; I have seen the VNAV disengage numerous times on company aircraft. Monitoring the FMA closer would have prevented this from occurring.

Original NASA ASRS Text

Title: A B737-700 Captain reported a near-stall incident in climb when the aircraft dropped out of VNAV into Vertical Speed mode. Reporter stated this is not an uncommon occurrence.

Narrative: During climb; I was the pilot flying and after receiving a climb clearance and dialing the new altitude in the Altitude Preselect window; I failed to notice VNAV had disengaged and Vertical Speed had engaged. As I noticed the airspeed low and was disengaging the autopilot and auto throttles; the Airspeed Low Aural Warning sounded briefly as I was advancing power and lowering the nose of the aircraft. Airspeed recovered quickly and the flight was completed without further event. All ATC clearances were adhered to. Aircraft did not stall. Airspeed quickly recovered after lowering the nose of the aircraft. In retrospect; I have seen the VNAV disengage numerous times on Company aircraft. Monitoring the FMA closer would have prevented this from occurring.

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.

A B737-700 captain reported a near-stall incident in climb when the aircraft dropped out of VNAV into vertical speed mode. Reporter stated this is not an uncommon occurrence.