Engine Roughness on the Climb-Out
Partial power loss after takeoff, the temptation to turn back, and why the 'impossible turn' at 200 feet is unrecoverable
The scenario
Departing Tampa Executive Airport (KVDF), Tampa, FL — Runway 05, climbing out on a 42° heading. Elevation 22 ft MSL. Non-towered field; you are on CTAF (122.8). The runway is short (5,000 ft) and the field is surrounded by medium development, wooded wetland, and pasture to the north and east.
It is a warm, humid Florida morning in late spring: OAT 26°C, dew point 21°C, altimeter 29.94. Scattered clouds at 2,500 ft, light rain shower two miles to the northeast. Visibility 8 SM. The conditions are classic for carburetor icing in the Continental O-200 — warm, moist air, reduced power on climb. The FAA icing probability chart marks this as 'serious icing at glide power.'
You are 200 ft AGL, climbing through 68 KIAS (Vy, best rate of climb), heading 042°, when the engine begins to run rough. Power is noticeably down — the tachometer is dropping. The field is behind you. Ahead and to the left is wooded wetland and pasture; to the right, medium development. You have seconds to decide.
Aircraft: Cessna 150M, solo, full fuel (26 gallons), within limits. Carbureted Continental O-200, 100 hp, fixed-pitch prop, steam panel, fuel selector on BOTH. 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 focused on the climb and scanning the engine instruments. You are now at 200 ft AGL with a rough engine and a decision window measured in seconds.
- {'label': 'Field', 'value': 'KVDF · Tampa Executive'}
- {'label': 'Runways', 'value': '5/23 · 18/36'}
- {'label': 'Elevation', 'value': '22 ft'}
- {'label': 'Aircraft', 'value': 'C150'}
- {'label': 'Dominant phase', 'value': 'Landing / Takeoff'}
The decision
Before we get into the decision tree — what do you already know about engine failure at low altitude in the C150? (Pick all that apply; this records your baseline.)
What the record shows
What the NTSB files show
NTSB CEN23FA401 (2023, FATAL): A Cessna 150K on an instructional flight experienced partial engine power loss due to fuel system blockage. The flight instructor failed to maintain adequate airspeed after the power loss, and the airplane stalled during a descending left turn at low altitude. The probable cause was fuel starvation and the instructor's failure to maintain airspeed.
NTSB CEN23FA077 (2023, FATAL): A Cessna 150H on an instructional flight conducted a night visual approach to a non-towered airport. The flight instructor failed to apply carburetor heat after a loss of engine power due to carburetor icing. The airplane descended below safe altitude and impacted a farm field 1.2 miles short of the runway.
NTSB CEN17FA281 (2017, FATAL): A Cessna 150F on a personal local flight conducted intentional low-altitude maneuvering over a lake when the engine sputtered. The pilot lost control and impacted the water. The probable cause was the pilot's failure to maintain clearance from the lake during a low-level maneuver.
NTSB WPR09FA326 (2009, FATAL): A Cessna 150 on a personal flight from Lake Tahoe Airport entered a spin seconds after takeoff at approximately 100 feet AGL. The probable cause was partial loss of engine power due to a malfunctioning carburetor and the pilot's failure to maintain adequate airspeed while maneuvering. High density altitude was a contributing factor.
The regional precedents are equally stark: NTSB WPR17FA152 (2017, Jansen Pazmany PL-2), LAX93LA048 (1992, Rans S-10), ERA14FA123 (2014, Williams Sonex), and SEA90LA162 (1990, Vaden SA102) — all experienced engine power loss shortly after takeoff and all attempted a steep 180° turn back to the runway at low altitude. All resulted in stall/spin at 100–200 feet AGL. All were fatal.
The consistent thread: the 'impossible turn' — a steep 180° turn back to the runway at low altitude after engine failure — is unrecoverable in light aircraft. The C150's light wing loading makes it particularly stall-sensitive on the base-to-final turn; a steep bank with a failing engine and decaying airspeed is the setup for a stall/spin. At 200 feet AGL, there is no altitude for recovery.
The real accidents cited above occurred at other airports and in other aircraft — NOT at Tampa Executive Airport (KVDF). KVDF has its own accident history (see field dominant patterns: LOSS_OF_CONTROL_GROUND 18.4%, HARD_LANDING 18.4%, FORCED_LANDING 15.8%, LOSS_OF_CONTROL_INFLIGHT 13.2%), but these specific fatal events happened elsewhere. The scenario is localized to KVDF to make the off-field environment real and consequential for you as a student here.
The lesson is unambiguous: after engine failure at low altitude, maintain wings level and accept a forward landing in the off-field environment ahead. The runway is behind you; the ground ahead is your landing spot. Attempting a steep turn back to the runway is the fatal trap.
Key lesson — In warm, moist Gulf Coast air, the Continental O-200 in the C150 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. If engine failure occurs at low altitude, maintain wings level, establish 60 KIAS best glide, and accept a forward landing in the off-field environment ahead. The 'impossible turn' — a steep 180° turn back to the runway at 200 feet AGL — is unrecoverable and is the fatal trap that kills pilots who attempt it.
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 morning conditions at KVDF. You do not need visible ice, freezing temperatures, or IMC. Warm, moist air at reduced power is the classic carb-ice environment. The Continental O-200 in the C150 is carbureted; it has no alternate air system. Carburetor heat is the only tool. Apply it proactively in conducive conditions — before the symptom appears.
The first symptom is subtle — a dropping tachometer and engine roughness.
In a fixed-pitch airplane like the C150, 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 200 feet AGL, you have seconds to act.
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.
The 'impossible turn' at low altitude is unrecoverable — accept a forward landing instead.
The C150's light wing loading makes it gust- and stall-sensitive on the base-to-final turn. A steep 180° turn back to the runway at 200 feet AGL with a failing engine and decaying airspeed is the setup for a stall/spin. At that altitude, there is no recovery. The NTSB accident corpus is full of this pattern: pilots who attempt the 'impossible turn' and stall/spin at 100–200 feet AGL. The correct response after engine failure at low altitude is to maintain wings level, establish 60 KIAS best glide, and accept a forward landing in the off-field environment ahead. The runway is behind you; the ground ahead is your landing spot.
Off Runway 05 at KVDF, the off-field environment is wooded wetland and pasture — a forced landing there is survivable.
The off-field environment off Runway 05's departure end (heading 042°) is mostly wooded wetland and pasture — not ideal, but far better than attempting a steep turn back to the runway at 200 feet AGL. The C150's light wing loading and fixed gear make it relatively forgiving in soft terrain. A controlled forced landing in pasture, flown at 60 KIAS best glide with flaps for slowest possible touchdown speed, is a survivable outcome. Attempting the 'impossible turn' is not.
Built from the real accident record
Scenario built from NTSB CEN23FA401 (2023 C150K fuel starvation / stall on attempted turnback), CEN23FA077 (2023 C150H carburetor ice / loss of control), CEN17FA281 (2017 C150F engine roughness / loss of control), WPR09FA326 (2009 C150 carburetor malfunction / spin at low altitude), and regional precedents WPR17FA152, LAX93LA048, ERA14FA123, SEA90LA162 (all attempted low-altitude 180° turns ending in stall/spin). Anonymized and localized to KVDF.
NTSB reports: CEN23FA401 · CEN23FA077 · CEN17FA281 · WPR09FA326 · WPR17FA152 · LAX93LA048 · ERA14FA123 · SEA90LA162
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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