PA-18 seaplane instructor pilot reported the engine quit in the traffic pattern because of suspected...

Attributes
ACN	1368053
Time
Date	201606
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	PA-18/19 Super Cub
Operating Under FAR Part	Part 91
Flight Phase	Initial Approach
Route In Use	Visual Approach
Flight Plan	None
Component
Aircraft Component	Engine
Person 1
Function	Instructor
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Instructor Flight Crew Sea Flight Crew Multiengine Flight Crew Instrument
Experience	Flight Crew Last 90 Days 135 Flight Crew Total 2430 Flight Crew Type 195
Events
Anomaly	Aircraft Equipment Problem Critical Inflight Event / Encounter Fuel Issue

Narrative:

While on base leg of traffic pattern engine stopped. Suspected fuel exhaustion. Purchased more than enough fuel for mission and had fuel in tanks when started. Aircraft either burned more than planned fuel or FBO did not pump the final amount ordered. Training took place over 2 days. Aircraft started with approximately 10-15 gallons. We purchased a total of 80 gallons over the 2 days and flew 7.8 on the hobbs meter. Much of that was spent at idle and reduced power learning to taxi and handle the aircraft on the water. Flight time was much less and the aircraft has never burned more than 10 gallons per hour. I know this because I have purchased [20] gallons; flown for 2 hours and had more remaining than I started with.

Original NASA ASRS Text

Title: PA-18 seaplane instructor pilot reported the engine quit in the traffic pattern because of suspected fuel exhaustion.

Narrative: While on base leg of traffic pattern engine stopped. Suspected fuel exhaustion. Purchased more than enough fuel for mission and had fuel in tanks when started. Aircraft either burned more than planned fuel or FBO did not pump the final amount ordered. Training took place over 2 days. Aircraft started with approximately 10-15 gallons. We purchased a total of 80 gallons over the 2 days and flew 7.8 on the Hobbs meter. Much of that was spent at idle and reduced power learning to taxi and handle the aircraft on the water. Flight time was much less and the aircraft has never burned more than 10 gallons per hour. I know this because I have purchased [20] gallons; flown for 2 hours and had more remaining than I started with.

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.