Aircraft: Cessna 150. Injuries: None. Location: Mansfield, Mass. Aircraft damage: Substantial.
What reportedly happened: The accident happened during a training flight. According to the flight instructor, during climb out when the airplane reached 250 feet AGL, the airplane stopped climbing and began to descend.
The flight instructor assumed control of the airplane and verified the position of the engine controls, but could not get the airplane to climb. The airplane came down in trees off the departure end of the runway.
After the accident, the airplane was removed from the trees by local authorities and placed inverted on the ground. As a result, all residual fuel drained from the airplane, and no fuel was available for testing.
The engine was removed and placed in a test cell where it started immediately, accelerated smoothly, and ran continuously at rated power.
Atmospheric conditions at the time of the accident were conducive to serious icing at any power setting, and the flight instructor stated that he ensured that the carburetor heat control was in its cold position during the takeoff.
Investigators determined that based on the conditions, it is likely that the loss of engine power was related to the accumulation of carburetor ice during takeoff.
Probable cause: The pilots’ failure to apply carburetor heat during takeoff, which resulted in a partial loss of engine power due to the formation of carburetor ice.
NTSB Identification: ERA13LA034
This October 2012 accident report is are provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Intake hose clamps can back off over time and if not checked and retightened as needed can leak air into intake and cause a too lean of a mixture that can cause power loss on the o-200A engine.
not enough information.!
Did the aircraft conduct a glide approach and was carb heat selected?
what is the heat source for the carb ht in a C150?
if this was a Touch and Go or Go Around was full power selected prior to closing carb ht? At low power settings very little heat is available at the exhaust but with full power selection heat is almost instantanious. Check the C150 POH.
Well, I’ve been retired for almost a couple of years …. and getting bored. Maybe I need to take a guv’ment job.
Hey! NTSB personnel are government employees. Need more be said?
I share your frustration, Dale, but mine is more with the article itself. There’s several key details that aren’t presented here. I hate to be too hard on the author, but I believe the article as posted is very typically lacking in important details and is a poorly chosen example. I’ve long ago realized that it’s very easy to get the wrong impression by reading the Readers Digest style snippets that are posted here. To get the full story, you have to click the NTSB Investigation number link, and on the following page click the Full Narrative link.
Reading the Full Narrative we learn that this was not the initial take off as one might easily assume from this article, but was at least the 3rd time around the pattern. It also states that carb heat was applied for the preceding landing and was then closed and full power applied for takeoff. The aircraft reportedly was climbing at 600 fpm before it “stopped climbing”. So we’re left to assume, as the NTSB has assumed, that the carb iced up during the aprox 30 second climb out with an OAT of 10 C (50F, I believe).
This still leaves me scratching my head as to what we’re supposed to learn from this. If we accept the NTSB’s assumption as Gospel, then I suppose the take away is that rapid onset carb icing really can happen, even at these seemingly moderate temperatures. I can’t speak for all pilots, but I’m not sure that applying carb heat would have even crossed my mind in the short time before the plane settled into the trees. And given their proximity to the ground, should it even have been applied, if it had occurred to the CFI? Would he have been able to put it into the trees in the same way, which apparently allowed them both to climb down and walk away? I’m just not sure. And I’m also just not sure this type of accident report is the best choice for these articles, unless someone else can help me understand what we’re supposed to learn from it.
Huh ?? Who are they hiring at the ‘NTSB” these days? Normal engine operating protocol dictates that one never uses carburetor heat on takeoff (except perhaps in a ’39 Luscombe, with the fuel tank in the rear, but that is discussion for another time).
If there is any probability for carb ice on takeoff, (which may have ALREADY been in the venturi) one burns this off BEFORE the takeoff …. not while on takeoff. In fact I have encountered carb ice build up while taxiing out to the runway (generally early morning hours when conditions were ripe, in my locale) …. I always told students to leave the carb heat out for 30 seconds or so, during runup and mag check, to be sure all the ice is gone …. that’s BEFORE takeoff. Yes, it can become habitual to just pull carb heat momentarily to check it’s operation, not being aware that there could be ice buildup while taxiing.
In all my years of flying and instructing, (soloed in ’54 and instructing since ’60) I have NEVER encountered carb icing conditions so “severe’ that one needed to use carb heat on during FULL POWER application on takeoff. Whether this is true or not, I have been told (and read in the books) that carb icing is minimal, if non-existent, during full power application. But of course, I’ve been on this earth long enough to “never say never”..
My thought exactly. I have never had the need to use carb heat for takeoff, it would be the last thing on my mind to apply. However, on landing always if needed.
Something is amiss here.