Empty Side
A fuel selector, a silent engine, and the worst place to run out of options
The scenario
Field: Tampa International Airport (KTPA), Tampa, FL — elevation 26 ft MSL. You are inbound on a VFR flight from Gainesville, cleared by Tampa Approach for a visual approach to Runway 19L (8,300 ft, heading 182°). Class B airspace, towered field, 24-hour ATCT. You are number two behind a regional jet.
Aircraft: Diamond DA40, solo, within limits. Lycoming IO-360-M1A fuel-injected engine, constant-speed prop, G1000 glass panel. Fuel selector has two positions: LEFT and RIGHT — there is no BOTH.
Fuel state: You departed Gainesville with 30 gallons total — 15 left, 15 right. You have been running on the LEFT tank since engine start, 1 hour 22 minutes ago. You did not switch tanks during the flight. The G1000 fuel quantity pages show LEFT: 2.1 gal, RIGHT: 14.6 gal. You have been heads-down managing the approach briefing and ATIS.
Pilot: Private certificate, 210 hours total, 40 in type. You have flown into KTPA twice before, always with an instructor. Today is your first solo visit to a Class B airport. You are task-saturated.
Weather: Clear, visibility 10 miles, winds 190° at 9 knots. Density altitude near field elevation — no performance penalty. A textbook VFR day that lulls you into not checking the fuel selector.
- {'label': 'Field', 'value': 'KTPA · Tampa'}
- {'label': 'Runways', 'value': '10/28 · 19L/01R · 19R/01L'}
- {'label': 'Elevation', 'value': '26 ft'}
- {'label': 'Aircraft', 'value': 'DA40'}
- {'label': 'Dominant phase', 'value': 'Landing / Takeoff'}
The decision
On downwind / early final, before anything goes wrong — which of these is actually in your head right now? (Pick all that apply — no wrong answers; this records your starting mental model.)
What the record shows
What the NTSB files show
Fuel starvation from tank-switching failures is a recurring NTSB finding across all single-engine piston types — and it is almost entirely preventable. In NTSB GAA19CA534 (Piper PA-28, 2019), a pilot switched to the left tank during descent and then failed to switch back when power was lost, despite the right tank containing usable fuel. The airplane was landed on a road. In NTSB WPR24LA167 (Harvard MK IV, 2024), improper tank selection at low fuel levels combined with a malfunctioning selector produced a forced landing into a dirt berm. In NTSB WPR12LA023 (Cessna 185, 2011), the pilot inadvertently left the selector on the left tank during descent near Bend, Oregon, despite usable fuel in the right — forced landing on an unpaved road, noseup on rollout. In NTSB CEN25LA081 (Piper PA-24, 2025), fuel mismanagement on a ferry flight — no leaning, incorrect tank switching — produced power loss on approach.
These accidents did NOT occur at Tampa International Airport. They are cited here because the mechanism — running one tank to exhaustion while the other tank holds usable fuel — is directly applicable to the Diamond DA40's LEFT/RIGHT-only fuel system.
The DA40 has no BOTH position. Every flight requires the pilot to actively decide which tank is selected, monitor quantity in each tank independently, and switch on a planned interval. In a task-saturated environment — a first solo visit to a Class B airport, an ATIS to copy, a clearance to read back, a sequence to manage — fuel-system monitoring is exactly the task that gets dropped.
The off-field environment off KTPA Runway 19L is poor: dense development and medium development dominate the approach corridor. There are no open fields of meaningful size. An engine-out event on the 19L final at 5 nm is not a 'find a field' problem — it is a 'restart the engine immediately or land in urban Tampa' problem. The margin for error is zero.
Key lesson — The DA40's fuel selector has no BOTH — fuel management is an active, required task on every flight. Establish a tank-switching interval before departure, monitor each tank independently on the G1000 engine page, and run the fuel-starvation memory items (mixture, boost pump, fuel selector) the instant power becomes abnormal. In the dense urban environment off KTPA, there is no acceptable forced-landing option — the only acceptable outcome is a restart.
Debrief — teaching points
The DA40 has no BOTH — fuel management is always active.
Unlike a Cessna 172 with a BOTH selector, the Diamond DA40 requires the pilot to choose LEFT or RIGHT. There is no passive, always-correct position. If you depart on LEFT and never switch, you will exhaust the left tank while the right tank sits full. Establish a switching interval — every 30 minutes is a common discipline — and write it into your personal checklist. Verify the selected tank and its quantity at every phase change: runup, departure, cruise, top of descent, final.
Fuel-starvation memory items for a fuel-injected engine: mixture, boost pump, fuel selector.
The IO-360-M1A is fuel-injected — there is no carburetor heat, no carb-ice troubleshoot. When power is abnormal, the memory sequence is: mixture FULL RICH, boost pump ON, fuel selector to the other tank, throttle as needed. This sequence addresses the most common cause (wrong or empty tank) in the first 6–8 seconds. Do not spend those seconds on the throttle or the radio — the fuel selector is the most likely fix and it costs nothing to try.
Best glide is 73 KIAS — raising the nose below that makes things worse.
The DA40's best glide speed is 73 KIAS at gross weight. Flying slower than 73 KIAS increases the descent rate; it does not extend the glide. In a power-off situation, the instinct to raise the nose and 'stretch it' is aerodynamically backwards. Establish 73 KIAS, trim, and assess the geometry. The DA40's clean composite airframe glides well — but only at the right speed.
The off-field environment off KTPA Runway 19L is poor — there is no margin.
The approach corridor to KTPA Runway 19L (heading 182°) is dense Tampa urban development. USGS land-cover data shows mostly dense development and medium development with minimal open space. There is no 'best available field' in the traditional sense. A fuel-starvation event on the 19L final at low altitude is not recoverable by field selection — it is only recoverable by restarting the engine. This makes pre-arrival fuel-system verification at KTPA non-negotiable.
Task saturation in Class B airspace is a fuel-management risk.
A first solo visit to a Class B airport — ATIS, clearances, sequencing, traffic calls, approach briefing — consumes working memory. Fuel-system monitoring is a low-salience, periodic task that is easily crowded out by high-salience ATC tasks. Recognize this explicitly: before you enter the Class B, verify fuel selector position and quantity in each tank. Make it a hard gate, not an afterthought.
Built from the real accident record
Composite scenario built from NTSB fuel-starvation events in single-engine pistons (WPR24LA167, GAA19CA534, WPR12LA023, CEN25LA081). Localized to KTPA / Diamond DA40. Anonymized.
NTSB reports: WPR24LA167 · GAA19CA534 · WPR12LA023 · CEN25LA081
ACS tasks: PA.II.A — Pilot Qualifications / Preflight Preparation · PA.II.B — Airworthiness / Fuel and Systems · PA.IX.A — Emergency Approach and Landing · PA.I.H — Human Factors
Relevant FARs: §91.3 · §91.13 · §91.151
Step through the full decision tree, make the calls, and see where each choice leads — then debrief it with your CFI.
Open the interactive scenario →All sample scenarios · More Diamond DA40 scenarios · More scenarios at KTPA