An aircraft heard a garbled transmission saying 'cleared for takeoff.' the pilot assumed it was for ...

Narrative:

The pilot flying wanted to fly the aircraft and delegated the radio operation to me. We were in position for takeoff short of runway 32 in number 2 position. There were several aircraft arriving at the same time. The controller was transmitting on both lake hood and anchorage international airport's frequency at the same time on the same frequency. The tower informed us to standby instead of saying 'hold short of runway 32' for arriving traffic and the tower immediately transmitted to another aircraft. The number one aircraft was cleared for takeoff. A short time later both the pilot and I heard 'cleared for takeoff' with some background interference. While I entered the downwind on my 360 turn for altitude the controller tried to call me 3 times and the transmission was blocked by other aircraft on the same frequency 126.8. I received a call from the controller saying 'possible deviation when able contact anchorage tower; standby for phone number'. To prevent this occurrence in the future I would suggest that there be one controller for anchorage tower (118.3) and one controller for lake hood tower (126.8) especially when lake hood is busy. Transmitting on two frequencies at the same time is not a good operating practice and will lead to future problems. Also the term roger or standby should be readdressed as 'hold short of runway 32 at lake hood for arriving traffic' and make sure the pilot repeats the clearance in the order given. As an example; merrill field tower requires that the controller transmit hold short instructions and requires the pilot read back hold short instructions or the controller will say again repeat the hold short instructions prior to takeoff.

Original NASA ASRS Text

Title: An aircraft heard a garbled transmission saying 'cleared for takeoff.' The pilot assumed it was for their flight. The takeoff clearance was for a different aircraft. The adjacent airport Control Tower also controls this airport and was transmitting and receiving on two frequencies.

Narrative: The pilot flying wanted to fly the aircraft and delegated the radio operation to me. We were in position for takeoff short of Runway 32 in number 2 position. There were several aircraft arriving at the same time. The controller was transmitting on both Lake Hood and Anchorage International Airport's frequency at the same time on the same frequency. The tower informed us to standby instead of saying 'Hold Short of Runway 32' for arriving traffic and the tower immediately transmitted to another aircraft. The number one aircraft was cleared for takeoff. A short time later both the pilot and I heard 'Cleared for Takeoff' with some background interference. While I entered the downwind on my 360 turn for altitude the controller tried to call me 3 times and the transmission was blocked by other aircraft on the same frequency 126.8. I received a call from the controller saying 'Possible deviation when able contact Anchorage Tower; standby for phone number'. To prevent this occurrence in the future I would suggest that there be one controller for Anchorage Tower (118.3) and one controller for Lake Hood Tower (126.8) especially when Lake Hood is busy. Transmitting on two frequencies at the same time is not a good operating practice and will lead to future problems. Also the term Roger or Standby should be readdressed as 'Hold Short of Runway 32 at Lake Hood for arriving traffic' and make sure the pilot repeats the clearance in the order given. As an example; Merrill Field Tower requires that the controller transmit Hold Short instructions and requires the pilot read back Hold Short instructions or the controller will say again repeat the Hold Short instructions prior to takeoff.

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	1321863
Time
Date	201512
Local Time Of Day	1201-1800
Place
Locale Reference	LHD.Airport
State Reference	AK
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Small Aircraft High Wing 1 Eng Fixed Gear
Operating Under FAR Part	Part 91
Flight Phase	Takeoff
Route In Use	VFR Route
Flight Plan	None
Person 1
Function	Pilot Not Flying
Qualification	Flight Crew Instrument Flight Crew Flight Instructor Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 100 Flight Crew Total 30000 Flight Crew Type 10000
Events
Anomaly	ATC Issue All Types Deviation - Procedural Clearance

An aircraft heard a garbled transmission saying 'cleared for takeoff.' the pilot assumed it was for their flight. The takeoff clearance was for a different aircraft. The adjacent airport control tower also controls this airport and was transmitting and receiving on two frequencies.