Rough Climb Over Clearwater
Carburetor ice, partial power loss, and dense development off both runway ends — the decision window is tight
The scenario
Departing Clearwater Air Park (KCLW), Clearwater, FL — Runway 16, climbing out on a 155° heading. Elevation 71 ft MSL; the runway is essentially at sea level.
It is a hazy Florida afternoon in late spring: OAT 27°C, dew point 21°C, altimeter 29.92. Scattered clouds at 2,500 ft, light rain shower one mile 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 350 ft AGL, climbing through 72 KIAS (near Vy), heading 155°, when the engine begins to run rough. Power is noticeably down — the tachometer is dropping. The terrain ahead is dense development — low-density residential, medium development, scattered parks. KCLW is non-towered (CTAF); you are in Class G airspace below the overlying Tampa Class B (3,000 MSL floor).
Aircraft: Piper PA-28-180, solo, fuel tanks balanced (left and right roughly equal), within limits. Carbureted Lycoming O-360-A, fixed-pitch prop, steam panel, fuel selector on LEFT. Nothing was written up; the airplane was airworthy at departure.
Pilot: you — a Private pilot, current, roughly 180 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 and the initial climb was smooth.
- {'label': 'Field', 'value': 'KCLW · Clearwater Air Park'}
- {'label': 'Runways', 'value': '16/34'}
- {'label': 'Elevation', 'value': '71 ft'}
- {'label': 'Aircraft', 'value': 'PA-28-180'}
- {'label': 'Dominant phase', 'value': 'Landing / Approach'}
The decision
Before we get into the decision tree — what do you already know about carburetor ice in the PA-28-180? (Pick all that apply; this records your baseline.)
What the record shows
What the NTSB files show
NTSB DEN07CA035 (2006): A Piper PA-28-180 on a personal flight lost engine power on base leg due to carburetor icing. The pilot attempted a forced landing on a road, swerved to avoid oncoming car lights, and struck a tree, resulting in substantial damage. The probable cause was carburetor icing in conditions conducive to serious icing, with contributing factors including unsuitable terrain and the tree obstacle. The pilot did not apply carburetor heat proactively.
NTSB ATL03LA148 (2003): A Piper PA-28 on a personal flight experienced engine power loss during takeoff climb after extended ground operation in conditions favorable for carburetor icing. The probable cause was the pilot's failure to apply carburetor heat prior to takeoff, allowing ice to form in the induction system.
NTSB NYC02FA025 (2001, FATAL): A Piper PA-28-180 on a personal cross-country flight experienced engine failure due to carburetor icing and made a forced landing into trees near Mansfield, Ohio in darkness. The probable cause was the pilot's improper use of carburetor heat, with contributing factors including night conditions, trees, and the pilot's impairment from ingestion of an over-the-counter antihistamine.
The local environment at KCLW makes this scenario particularly unforgiving: both Runway 16 and Runway 34 departure ends are surrounded by dense development — low-density residential, medium development, scattered parks. An engine failure on either departure at low altitude is a forced landing into houses, roads, and obstacles — not open field. The off-field environment is the geographic reality. This is not hypothetical; it is the NLCD ground cover off those runway ends.
The real accidents cited above occurred at other airports and in other aircraft types — NOT at Clearwater Air Park. KCLW has its own accident history (see field dominant patterns: forced landing 22.2%, loss of control 18.5%, gear-up landing 18.5%), but these specific carburetor ice events happened elsewhere. The scenario is localized to KCLW 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-28-180 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-28-180's carbureted O-360-A 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 development, the decision window is measured in seconds — not minutes. Off either runway at KCLW, the off-field environment is dense development: a delayed response means a forced landing into houses and obstacles, 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 KCLW. You do not need visible ice, freezing temperatures, or IMC. Warm, moist air at reduced power is the classic carb-ice environment. The PA-28-180's Lycoming O-360-A is carbureted; it has no fuel injection, no 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-28-180, 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 KCLW, an engine failure on either runway departure is a forced landing into development.
The off-field environment off both Runway 16 (heading 155°) and Runway 34 (heading 335°) departure ends is dense development — low-density residential, medium development, scattered parks. There is no open field, no water, no clear alternate surface. If the engine quits on either departure and altitude is insufficient to return to the airport, the outcome is a forced landing into houses and obstacles. 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 either runway.
The PA-28-180 fuel selector is LEFT / RIGHT — no BOTH position. Active tank management is required.
Unlike some Cessnas, the PA-28-180 has no BOTH position on the fuel selector. You must actively switch between LEFT and RIGHT tanks to avoid starvation. Running a selected tank dry is the signature PA-28-180 fuel starvation trap. In this scenario, the fuel selector is on LEFT at departure; if you had been on a near-empty tank, the engine roughness could have been fuel starvation, not carb ice. Always verify fuel quantity and selector position during the preflight and run-up. Know which tank you are on and plan your tank switches before flight.
Proactive carb heat use in conducive conditions is not optional.
The PA-28-180 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 27°C and dew point near 21°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 350 ft AGL over development is waiting too long.
Built from the real accident record
Scenario built from NTSB DEN07CA035 (2006 PA-28-180 carburetor ice / forced landing), ATL03LA148 (2003 PA-28-180 carb ice on takeoff climb), NYC02FA025 (2001 PA-28-180 carb ice / forced landing), and local-environment precedents. Anonymized and localized to KCLW.
NTSB reports: DEN07CA035 · ATL03LA148 · NYC02FA025
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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