Rough Climb Over Tampa Bay
Carburetor ice, partial power loss, and a water-surrounded airport — the decision clock is short
The scenario
Departing Albert Whitted Airport (KSPG), St. Petersburg, FL — Runway 07, climbing out over Tampa Bay on a 062° heading. Elevation 7 ft MSL; the runway is essentially at sea level.
It is a hazy Florida afternoon in late spring: OAT 28°C, dew point 22°C, altimeter 29.92. Scattered clouds at 2,500 ft, light rain shower two miles to the northeast. Visibility 8 SM. Classic Gulf Coast conditions — warm, moist, and exactly the environment the FAA icing probability chart marks as 'serious icing at glide power, moderate icing at cruise power.'
You are 400 ft AGL, climbing through 79 KIAS (Vy), heading 062°, when the engine begins to run rough. Power is noticeably down — the tachometer is dropping. The water of Tampa Bay fills the windscreen ahead. KSPG's tower is part-time (0700–2100) and is open; you are in Class D airspace.
Aircraft: Piper PA-28-161 Warrior, solo, full fuel, within limits. Carbureted Lycoming O-320-D, fixed-pitch prop, steam panel, fuel selector on LEFT (you switched to LEFT on the run-up). Nothing was written up; the airplane was airworthy at departure.
Pilot: you — a Private pilot, current, roughly 200 hours total. You did not apply carburetor heat during the run-up because the engine ran smoothly. You did not apply it after takeoff because you were heads-down on the climb.
- {'label': 'Field', 'value': 'KSPG · Albert Whitted'}
- {'label': 'Runways', 'value': '7/25 · 18/36'}
- {'label': 'Elevation', 'value': '7 ft'}
- {'label': 'Aircraft', 'value': 'PA-28-161'}
- {'label': 'Dominant phase', 'value': 'Landing / Takeoff'}
The decision
Before we get into the decision tree — what do you already know about carburetor ice in the PA-28-161? (Pick all that apply; this records your baseline.)
What the record shows
What the NTSB files show
NTSB CEN12LA175 (2012): A Piper PA-28-161 on an instrument instructional flight experienced progressive engine power loss due to carburetor icing during climb through 6,500 feet. The probable cause was carburetor icing in conditions conducive to serious icing, with a contributing factor of limited carburetor heat valve travel from recent maintenance. The pilot did not apply carburetor heat proactively.
NTSB LAX03LA238 (2003): A Piper PA-28-161 experienced partial engine power loss during initial climb from Torrance due to carburetor icing. During a go-around attempt, the pilot failed to maintain adequate airspeed, resulting in a stall and collision with power lines and terrain. The probable cause was carburetor icing and the pilot's failure to use carburetor heat.
NTSB CEN09CA532 (2009): A Piper PA-28-161 on a personal return-to-airport flight lost engine power during descent due to carburetor icing one mile from the airport. The pilot made a forced landing in a corn field and sustained a broken arm. The probable cause was the pilot's failure to apply carburetor heat in icing-conducive conditions.
NTSB ATL04LA124 (2004): A Piper PA-28-161 on a personal flight lost engine power during climb in conditions favorable for carburetor ice formation, and the pilot made a forced landing on a beach. The probable cause was the pilot's failure to use carburetor heat when weather conditions were favorable for carburetor ice formation.
The local environment at KSPG makes this scenario particularly unforgiving: Runway 07's departure end is open water — Tampa Bay. An engine failure on the Runway 07 departure at low altitude is a ditching, not a field landing. There is no open field, no road, no park. The water is the off-field environment. This is not hypothetical; it is the NLCD ground cover off that runway end.
NTSB LAX89LA222 (1989, fatal): A Grumman AA-1C stalled on final approach to a coastal airport after an unstable low-altitude approach in gusting winds. The airplane impacted the water short of the runway. The mechanism — low altitude, low airspeed, pilot trying to stretch the approach to the runway — is the same trap that kills pilots who delay the ditching decision and try to glide to the runway instead.
The real accidents cited above occurred at other airports and in other aircraft — NOT at Albert Whitted Airport. KSPG has its own accident history (see field dominant patterns), but these specific events happened elsewhere. The scenario is localized to KSPG to make the off-field environment real and consequential for you as a student here.
The consistent thread across all these events: carburetor ice in the PA-28-161 is insidious. It builds gradually, the first symptom is roughness and a dropping tachometer (not a dramatic power cut), and by the time it is obvious, it may be too late for a comfortable recovery. The fix — full carburetor heat, immediately, at the first sign of roughness in conducive conditions — is simple. The failure is always a delay.
Key lesson — In warm, moist Gulf Coast air, the PA-28-161's carbureted O-320-D can accumulate serious carburetor ice even at cruise power and above-freezing temperatures. Apply full carburetor heat at the first sign of engine roughness or unexplained RPM loss. At low altitude over water, the decision window is measured in seconds — not minutes. Off Runway 07 at KSPG, the off-field environment is Tampa Bay: a delayed response means a ditching, not a field landing.
Debrief — teaching points
Carburetor ice forms in conditions you would not expect.
The FAA icing probability chart shows 'serious icing at glide power' at temperatures between roughly 20°C and 30°C when relative humidity is high — exactly the Gulf Coast afternoon conditions at KSPG. You do not need visible ice, freezing temperatures, or IMC. Warm, moist air at reduced power is the classic carb-ice environment. The PA-28-161's Lycoming O-320-D is carbureted; it has no fuel injection or alternate air system. Carburetor heat is the only tool.
The first symptom is subtle — a dropping tachometer and engine roughness.
In a fixed-pitch airplane like the PA-28-161, carburetor ice first shows as engine roughness and an unexplained RPM decrease. There is no dramatic power cut. Pilots who are not actively monitoring the tachometer miss the early warning. By the time the roughness is obvious, significant ice has accumulated. Scan the tachometer as part of your regular instrument scan, especially in conducive conditions.
Apply full carburetor heat — not partial — and expect an initial RPM drop.
When you apply carb heat to an iced carburetor, the RPM will drop further before it rises. This is expected and normal: the heat is melting ice and the resulting water is briefly disrupting combustion. Do not remove carb heat when the RPM drops — that is the heat working. Hold it full on. The RPM will recover as the ice clears, typically within 15–30 seconds depending on ice accumulation. Partial carb heat can worsen the situation by partially melting ice into water ingestion without fully clearing the restriction.
At KSPG Runway 07, an engine failure on departure is a ditching.
The off-field environment off Runway 07's departure end (heading 062°) is open water — Tampa Bay. There is no alternate landing surface. If the engine quits on the Runway 07 departure and altitude is insufficient to return to the airport, the outcome is a ditching. This is not a worst-case scenario; it is the geographic reality. Best glide is 73 KIAS. Doors unlatched before water contact. Master off just before impact. Flaps for slowest possible touchdown speed — impact energy rises with the square of touchdown speed, so the slowest possible speed matters most. Know this before you line up on Runway 07.
The PA-28-161 fuel selector is LEFT / RIGHT — tank management is your job.
Unlike some aircraft with a BOTH position, the PA-28-161 requires you to actively select LEFT or RIGHT. There is no BOTH. This means you must monitor fuel consumption and switch tanks during flight to maintain lateral balance and prevent fuel starvation. In this scenario, you were on LEFT at departure. If the engine had been starving for fuel (not the case here — it was carb ice), the first diagnostic step would be to switch tanks. Know your fuel selector position at all times.
Built from the real accident record
Scenario built from NTSB CEN12LA175 (2012 PA-28-161 carburetor ice / power loss), LAX03LA238 (2003 PA-28-161 carb ice / stall on go-around), CEN09CA532 (2009 PA-28-161 carb ice / forced landing), ATL04LA124 (2004 PA-28-161 carb ice / beach landing), and NYC03LA012 (2002 PA-28-161 improper carb heat use). Local-environment precedents LAX89LA222 (1989 stall on final, coastal), ERA10CA300 (2010 stall/spin on final turn), ATL92LA146 (1992 stall on short final). Anonymized and localized to KSPG.
NTSB reports: CEN12LA175 · LAX03LA238 · CEN09CA532 · ATL04LA124 · NYC03LA012 · LAX89LA222 · ERA10CA300 · ATL92LA146
ACS tasks: PA.I.F — Weather Information · PA.I.G — Cross-Country Flight Planning · PA.IX.C — Emergency Approach and Landing · PA.I.H — Human Factors · PA.II.B — Engine Starting / Systems Preflight
Relevant FARs: §91.3 · §91.13 · §91.185
Step through the full decision tree, make the calls, and see where each choice leads — then debrief it with your CFI.
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