B737-800 captain reported airspeed indicator malfunction on approach. A go around was executed; and ...

Narrative:

We were descending on the approach to runway xy. At about 5 NM from the runway and decelerating for flaps 30; the red low speed barberpole began to rise up to our current airspeed which was 170 KIAS. At the same time the low speed (a)lpha warning indicated on the MCP panel and indicated 135 KIAS. With an unknown airspeed anomaly we elected to abandon the approach and go around. During the go around after flaps were selected to up; we both noticed that the flaps stopped retracting at about 9 degrees. The flap handle was up and the leading edge flap transit amber light was on. All indicators were green on the overhead flaps panel. I [let] ATC [know the situation] and got the QRH out to run the leading edge flaps transit checklist. I notified the flight attendants of our status and the decision to divert to [an airport with a longer runway.] ATC vectored us for an approach to runway xx. A full stop landing was made uneventfully. The airspeed indications and the barberpole low and high speed warnings indicated normally; and appeared to have been normal after about 5 minutes once we elected to go around.

Original NASA ASRS Text

Title: B737-800 Captain reported airspeed indicator malfunction on approach. A go around was executed; and flaps failed to retract. Flight diverted to a nearby airport with a longer runway.

Narrative: We were descending on the approach to Runway XY. At about 5 NM from the runway and decelerating for flaps 30; the red low speed barberpole began to rise up to our current airspeed which was 170 KIAS. At the same time the low speed (A)lpha warning indicated on the MCP panel and indicated 135 KIAS. With an unknown airspeed anomaly we elected to abandon the approach and go around. During the go around after flaps were selected to up; we both noticed that the flaps stopped retracting at about 9 degrees. The flap handle was up and the leading edge flap transit amber light was on. All indicators were green on the overhead flaps panel. I [let] ATC [know the situation] and got the QRH out to run the leading edge flaps transit checklist. I notified the flight attendants of our status and the decision to divert to [an airport with a longer runway.] ATC vectored us for an approach to Runway XX. A full stop landing was made uneventfully. The airspeed indications and the barberpole low and high speed warnings indicated normally; and appeared to have been normal after about 5 minutes once we elected to go around.

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.

Attributes
ACN	1288184
Time
Date	201508
Local Time Of Day	0001-0600
Place
Locale Reference	ZZZ.Airport
State Reference	US
Aircraft 1
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	Initial Approach
Route In Use	Visual Approach
Flight Plan	IFR
Component
Aircraft Component	Flap Control (Trailing & Leading Edge)
Person 1
Function	Captain Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Critical

B737-800 captain reported airspeed indicator malfunction on approach. A go around was executed; and flaps failed to retract. Flight diverted to a nearby airport with a longer runway.