MULTI ENGINE PERFORMANCE LOSS

When a Multi Engine Aircraft loses an engine in flight, it will experience a 50% power loss and an 80 to 90% loss in climb performance! Why is this?


Here's what you need to know.


ENGINE FAILURE EXAMPLE

Let's assume we are flying a Piper Seminole for our example today. However, the principle discussed below applies to all Multi Engine Airplanes.


The Piper Seminole is powered by 2 Lycoming Engines that are both rated at 180 Horsepower at 2700 RPM.


This means, with both engines operating, the aircraft is producing 360 total horsepower.


If one of our 2 engines fails, we will lose 180 horsepower leaving us with only 180 horsepower total. In other words, we just lost 50% of our power.







However, we may lose upwards of 90% of our climb performance!


This is because a Piper Seminole requires 160 horsepower to maintain level flight. Therefore, with both engines operating (360 horsepower total), we would have an additional 200 horsepower available for our climb performance.


With one engine inoperative, we are only working with 180 horsepower and level flight still requires 160 horsepower.


This means we now only have 20 horsepower available for climbing since the other 160 is being used to maintain level flight. This results in a 90% loss of climb performance!


See the depiction below for better understanding.







Author - Nate Hodell

CFI/CFII/MEI/ATP - Creator of wifiCFI - Owner of Axiom Aviation Flight School.


This information is included in the Multi Engine Other Factors Lessons on wifiCFI. Sign up today to watch videos, listen to podcasts, take lesson quizzes, join live webinars, print lesson quicktakes, and more by clicking this link >


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