Engine Failure on Climb — Sarasota Bradenton
Carburetor ice, marginal climb performance, and a low-altitude engine-out decision over mixed terrain — the window closes fast in a 150-hp Cessna
The scenario
Departing Sarasota Bradenton International Airport (KSRQ), Runway 04, climbing out on a 038° heading. Elevation 30 ft MSL. It is a warm, humid Florida morning in late spring: OAT 28°C, dew point 21°C, altimeter 29.91. Scattered clouds at 2,500 ft, light rain shower three miles to the northeast. Visibility 9 SM. The conditions are classic Gulf Coast — 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 78 KIAS (Vy), heading 038°, when the engine begins to run rough. Power is noticeably down — the tachometer is dropping. The terrain ahead is mixed: medium development, wooded wetland, low-density residential. KSRQ's tower is open (0600–0000 local); you are in Class C airspace. The aircraft is a Cessna 172M — a 150-hp Lycoming O-320, carbureted, fixed-pitch prop, fixed gear. Climb performance is marginal at best in these conditions.
Aircraft: Cessna 172M, solo, full fuel, within limits. Carbureted Lycoming O-320, fixed-pitch prop, steam panel (attitude + heading vacuum-driven), fuel selector on BOTH. Nothing was written up; the airplane was airworthy at departure.
Pilot: you — a Private pilot, current, roughly 220 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, monitoring airspeed and altitude.
- {'label': 'Field', 'value': 'KSRQ · Sarasota Bradenton'}
- {'label': 'Runways', 'value': '4/22 · 14/32'}
- {'label': 'Elevation', 'value': '30 ft'}
- {'label': 'Aircraft', 'value': 'C172M'}
- {'label': 'Dominant phase', 'value': 'Takeoff / Landing'}
The decision
Before we get into the decision tree — what do you already know about the C172M's climb performance and carburetor icing? (Pick all that apply; this records your baseline.)
What the record shows
What the NTSB files show
NTSB ERA09LA379 (2009): A Cessna 172M student pilot on a solo instructional flight experienced engine power loss during the base-to-final turn in the traffic pattern. The ambient conditions were 75°F OAT and 55°F dew point — conducive to serious icing per the FAA icing probability chart. The pilot made a forced landing in a field. The probable cause was listed as 'partial loss of engine power for undetermined reasons,' but the conditions and symptoms are consistent with carburetor icing.
NTSB DFW05CA237 (2005): A Cessna 172M lost engine power during initial climb due to carburetor icing and made a forced landing in a field. The pilot stalled while maneuvering to avoid a fence. The probable cause was the pilot's failure to maintain airspeed, with contributing factors including loss of engine power due to carburetor icing and high density altitude. This accident illustrates the compounding effect of the C172M's marginal climb performance in high-density-altitude conditions — when the engine is already struggling, a stall is just seconds away.
NTSB CEN22LA309 (2022): A Cessna 172M experienced engine power loss during cruise flight near Friend, Nebraska due to a stuck exhaust valve. The pilot performed a forced landing in a field between corn crops, resulting in substantial fuselage damage. This case shows that not all engine failures are icing-related — mechanical failures (valve stiction, throttle cable failure, weight/balance) can also force an off-airport landing.
NTSB WPR13LA035 (2012): A Cessna 172M on an aerial photography mission experienced a loss of engine power when the pilot applied full throttle during climb. The accident resulted from failure of the throttle control cable outer jacket, which fragmented and prevented proper throttle control. A forced landing was necessary.
NTSB CHI07LA177 (2007, fatal): A Cessna 172M departed approximately 243 pounds over gross weight and out of balance. During initial climb, the engine lost power at 100–150 feet AGL; the aircraft stalled and impacted terrain. The probable cause was the pilot's improper aircraft weight and balance, and his failure to maintain sufficient airspeed to avoid a stall during takeoff-initial climb. This accident underscores the C172M's marginal climb capability — overweight and out-of-balance, the airplane cannot climb; add a stall, and the outcome is fatal.
The real accidents cited above occurred at other airports and in other aircraft — NOT at Sarasota Bradenton International Airport. KSRQ has its own accident history (dominant patterns: loss of control ground 19.2%, forced landing 15.4%, runway excursion 11.5%, hard landing 11.5%, loss of control inflight 11.5%), but these specific events happened elsewhere. The scenario is localized to KSRQ to make the off-field environment real and consequential for you as a student here.
The consistent thread across all these events: the C172M's 150-hp O-320 is at the edge of its capability, especially in warm, humid, high-density-altitude conditions. Carburetor icing is insidious — it builds gradually, the first symptom is roughness and a dropping tachometer, 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 C172M'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 marginal terrain, the decision window is measured in seconds — not minutes. Off Runway 04 at KSRQ, the off-field environment is mixed (medium development, wooded wetland, low-density residential) — a forced landing there is workable but tight. Off Runway 22, the environment is low-density development and open water — a forced landing there is a ditching. Know the terrain before you depart.
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 KSRQ. You do not need visible ice, freezing temperatures, or IMC. Warm, moist air at reduced power is the classic carb-ice environment. The C172M's Lycoming O-320 is carbureted; it has 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 C172M, 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.
The C172M's 150-hp O-320 is marginal on climb, especially in high-density-altitude conditions.
The C172M is not a high-altitude, high-performance airplane. In warm, humid Gulf Coast conditions, expect best-rate climb of 300–400 fpm at gross weight. Add an engine anomaly, and the margin evaporates. A stall is just seconds away if you lose airspeed trying to maintain altitude. Best glide is 65 KIAS — that is the speed to fly immediately if power is lost. Do not try to climb out of trouble; descend to best glide and manage the emergency.
Know the off-field environment off each runway end before you depart.
Off Runway 04 at KSRQ, the off-field environment is marginal — medium development, wooded wetland, low-density residential. A forced landing there is workable but tight. Off Runway 22, the environment is low-density development and open water — a forced landing there is a ditching. Off Runway 14 and 32, the environment is poor — dense development, medium development, marsh. Know these facts before you line up on the runway. If you depart Runway 04 and lose the engine at 350 ft AGL, you are committed to a forced landing in marginal terrain — there is no return to the airport.
Proactive carb heat use in conducive conditions is not optional.
The C172M 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°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 marginal terrain is waiting too long.
Built from the real accident record
Scenario built from NTSB ERA09LA379 (2009 C172M carburetor ice on base-to-final), DFW05CA237 (2005 C172M carb ice on initial climb, stall during avoidance), CEN22LA309 (2022 C172M stuck exhaust valve forced landing), WPR13LA035 (2012 C172M throttle cable failure), and CHI07LA177 (2007 C172M overweight/out-of-balance stall on climb). Anonymized and localized to KSRQ.
NTSB reports: ERA09LA379 · DFW05CA237 · CEN22LA309 · WPR13LA035 · CHI07LA177
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 · PA.III.A — Takeoff and Departure Climb
Relevant FARs: §91.3 · §91.13 · §91.185 · §91.207
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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