Rough Climb Out of Tampa
Partial power loss in a carbureted Lycoming, dense development all around, and a decision clock measured in seconds
The scenario
Departing Tampa International Airport (KTPA), Runway 10, climbing out on a 092° heading. Elevation 26 ft MSL; the runway is essentially at sea level. You are a Private pilot with 240 hours total, current and proficient. Solo flight, full fuel, within limits.
It is a warm, humid Florida afternoon in late spring: OAT 29°C, dew point 23°C, altimeter 29.91. Scattered clouds at 2,800 ft, light rain shower visible two miles to the south. Visibility 9 SM. This is the classic Gulf Coast environment — warm, moist air at reduced power — that the FAA icing probability chart marks as 'serious icing at glide power, moderate icing at cruise power.' You are in Class B airspace; KTPA tower is active 24 hours.
You are 500 ft AGL, climbing through 75 KIAS (just above Vy of 73 KIAS), heading 092°, when the engine begins to run rough. The tachometer is unwinding — power is noticeably down. Off the Runway 10 departure end, the off-field environment is dense development, open parks, and wooded wetland — marginal forced-landing terrain. KTPA tower is aware you are climbing out; you are in contact.
Aircraft: Cessna 172N, solo, full fuel, within limits. Carbureted Lycoming O-320, fixed-pitch prop, steam panel, fuel selector on BOTH. The airplane was airworthy at departure; nothing was written up. 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.
Pilot: you. You have 240 hours total, mostly local VFR. You know the C172N well. You did not brief yourself on the carburetor ice risk in these conditions, and you did not proactively apply carb heat on departure. That is the decision you are about to face the consequences of.
- {'label': 'Field', 'value': 'KTPA · Tampa'}
- {'label': 'Runways', 'value': '10/28 · 19L/01R · 19R/01L'}
- {'label': 'Elevation', 'value': '26 ft'}
- {'label': 'Aircraft', 'value': 'C172N'}
- {'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 C172N? (Pick all that apply; this records your baseline.)
What the record shows
What the NTSB files show
NTSB CEN24LA362 (2024): A Cessna 172N encountered light rain and carburetor ice at 1,800 ft AGL. The engine ran rough and lost power. The probable cause was carburetor ice formation in conditions conducive to serious icing, with insufficient time and altitude for carburetor heat to clear the accumulated ice. The pilot had not applied carburetor heat proactively in conditions that clearly warranted it. This event occurred at a different airport — not KTPA.
NTSB CEN14LA276 (2014): A Cessna 172N on a cross-country flight experienced engine roughness and power loss at cruise altitude in conditions conducive to carb icing. The pilot made a forced landing on an island; the aircraft nosed over in soft sand. The pilot survived. The probable cause could not be determined due to premature aircraft release — but the conditions and symptoms are consistent with carburetor ice. This event occurred at a different airport — not KTPA.
NTSB ANC26LA001 (2025): A Cessna 172 on an instructional flight experienced progressive engine power loss during training maneuvers despite carburetor heat application. The pilot made a forced landing on a road; the aircraft struck a rock during landing roll and nosed over. Atmospheric conditions indicated serious icing conditions in pressure-type carburetors. This event occurred in Alaska — not at KTPA.
The local environment at KTPA makes this scenario consequential: Runway 10's departure end is surrounded by dense development, parks, and wooded wetland — marginal forced-landing terrain. An engine failure on the Runway 10 departure at low altitude is not a ditching, but it is a forced landing into difficult terrain. There is no open field, no road, no clear park. The development is the off-field environment. This is not hypothetical; it is the USGS NLCD ground cover off that runway end.
NTSB CEN14LA374 (2014): A Cessna 172N on a personal local flight experienced partial engine power loss during cruise and made a forced landing to a cornfield near Rockville, Indiana. The accident resulted from partial loss of engine power due to failure of the dual magneto system caused by loose mounting screws, with improper maintenance during the annual inspection as a contributing factor. This event occurred in Indiana — not at KTPA.
The consistent thread across all these events: partial power loss in the C172N can result from carburetor ice, magneto failure, fuel contamination, or exhaust valve failure. The first symptom in a fixed-pitch airplane is often roughness and a dropping tachometer — not a dramatic power cut. By the time it is obvious, the decision window is measured in seconds. The fix — immediate full carburetor heat, immediate return to the airport, or immediate forced-landing preparation — depends on the cause and the altitude. Early recognition and decisive action are the entire lesson.
Real accidents cited above occurred at other airports and in other aircraft — NOT at Tampa International Airport. KTPA has its own accident history (see field dominant patterns), but these specific events happened elsewhere. The scenario is localized to KTPA to make the off-field environment real and consequential for you as a student here.
Key lesson — In warm, moist Gulf Coast air, the C172N's carbureted O-320 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 dense development, the decision window is measured in seconds — not minutes. Off Runway 10 at KTPA, the off-field environment is marginal terrain; a delayed response means a forced landing into difficult ground, not a comfortable return to the airport.
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 KTPA. You do not need visible ice, freezing temperatures, or IMC. Warm, moist air at reduced power is the classic carb-ice environment. The C172N's Lycoming O-320 is carbureted; it has no alternate air system. Carburetor heat is the only tool. Proactive application in conducive conditions is not optional — it is the correct procedure.
The first symptom is subtle — a dropping tachometer and engine roughness.
In a fixed-pitch airplane like the C172N, 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. At 500 ft AGL, a 10-second delay in recognizing and responding to a dropping tachometer costs you 100 feet of altitude — altitude you may not have.
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 KTPA Runway 10, an engine failure on departure is a forced landing into marginal terrain.
The off-field environment off Runway 10's departure end (heading 092°) is dense development, parks, and wooded wetland — marginal forced-landing terrain. There is no alternate landing surface. If the engine quits on the Runway 10 departure and altitude is insufficient to return to the airport, the outcome is a forced landing into difficult ground. This is not a worst-case scenario; it is the geographic reality. Best glide is 65 KIAS. Doors unlatched before landing. 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 10.
Proactive carb heat use in conducive conditions is not optional.
The C172N POH and the FAA Pilot's Handbook of Aeronautical Knowledge both recommend applying carburetor heat when conditions are conducive to icing — before the symptom appears. In a Gulf Coast summer departure, with OAT near 28–30°C and dew point near 22–24°C, that means applying carb heat during the run-up check (and confirming the expected RPM drop, then recovery) and considering its use during climb in visible moisture or high humidity. Waiting for the roughness to appear at 500 ft AGL over dense development is waiting too long.
Built from the real accident record
Scenario built from NTSB CEN24LA362 (2024 C172N carburetor ice / power loss), CEN14LA276 (2014 C172N engine roughness / forced landing), ERA09LA517 (2009 C172N total power loss), ANC26LA001 (2025 C172N progressive power loss despite carb heat), WPR15LA086 (2015 C172N partial power loss / mountainous terrain), CEN14LA374 (2014 C172N magneto failure), WPR14LA099B (2014 water-contaminated fuel / forced landing), and WPR12LA306 (2012 C172N exhaust valve failure). Localized to KTPA; real events occurred at other airports.
NTSB reports: CEN24LA362 · CEN14LA276 · ERA09LA517 · ANC26LA001 · WPR15LA086 · CEN14LA374 · WPR14LA099B · WPR12LA306
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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