A MD80 captain reported that on two flights the VHF frequency selector shifted several digits withou...

Attributes
ACN	899654
Time
Date	201007
Local Time Of Day	1801-2400
Place
Locale Reference	IAD.Airport
State Reference	DC
Environment
Light	Dusk
Aircraft 1
Make Model Name	MD-80 Series (DC-9-80) Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Takeoff Climb
Flight Plan	IFR
Component
Aircraft Component	VHF
Person 1
Function	Pilot Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Clearance Deviation - Track / Heading All Types

Narrative:

After takeoff on runway 19L from iad; we were given a frequency change to departure control. Check in was normal and we were assigned a vector for climbout. After approximately a minute; we noted a lack of radio chatter on the frequency and attempted a to call to departure control with no contact. We then noted the departure control frequency in the #1 VHF had shifted several digits off proper frequency with no pilot input. The proper frequency was reset and contact was made with the controller; who asked us 'where we had been' and issued us an immediate right turn on course. This anomaly happened once before on the inbound flight; but we thought one of us had inadvertently moved the dial. This was not the case leaving this time. No further frequency shifts occurred and the defective #1 VHF was written up on arrival.

Original NASA ASRS Text

Title: A MD80 Captain reported that on two flights the VHF frequency selector shifted several digits without pilot input. A loss of communications resulted for a short time after departure.

Narrative: After takeoff on Runway 19L from IAD; we were given a frequency change to Departure Control. Check in was normal and we were assigned a vector for climbout. After approximately a minute; we noted a lack of radio chatter on the frequency and attempted a to call to Departure Control with no contact. We then noted the Departure Control frequency in the #1 VHF had shifted several digits off proper frequency with no pilot input. The proper frequency was reset and contact was made with the Controller; who asked us 'where we had been' and issued us an immediate right turn on course. This anomaly happened once before on the inbound flight; but we thought one of us had inadvertently moved the dial. This was not the case leaving this time. No further frequency shifts occurred and the defective #1 VHF was written up on arrival.

Data retrieved from NASA's ASRS site as of April 2012 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 MD80 captain reported that on two flights the VHF frequency selector shifted several digits without pilot input. A loss of communications resulted for a short time after departure.