Hello everyone and welcome back to my aviation blog. Today I want to talk about the use of your Pilot’s Operating Handbook or POH. Lately I have seen many posts on Facebook on the different aircraft pages I belong to that make me scratch my head. It’s mostly about power settings and speed in cruise flight. The people posting are asking other pilots who fly the particular model if they need to see a mechanic or not about how the airplane is performing when it is performing normally in the given situation. The answer to all the questions I have seen can be found right in your POH. One question I found particularly head banging was if it was normal for a stock Cessna 182 to only rev at 2400 RPM at full throttle. Both 182’s I fly tell you what the max rpm is right on the back of the front cover which is supposed to be 2400 unless you have had an upgrade in horsepower done on the engine. In aviation we De-rate engine horsepower by limiting RPM. For example, the skydivers Cessna 182 I fly has the P-PONK conversion which allows the engine to rev at 2700 RPM upping the horsepower from 235 to 270.
Your POH has every piece of information you need to successfully fly your airplane. Weight and balance, normal procedures, emergency procedures, checklists and a lot more information. Power settings in cruise are among the wealth of information contained in the POH. This is the most asked question I find on Facebook, speeds at altitudes with certain power settings. The most common mistake in an airplane with a constant speed propeller I see is running an extremely low RPM and wondering why the speed is so low. You should look at your POH and choose what kind of fuel burn you want given your cruising altitude and distance to cover and choose a power setting for your desired flight from the POH. This way you don’t risk running the engine in a way that can damage it or not getting the desired / expected performance out of the aircraft.
When transitioning to a new type of aircraft you should always study the POH. You should also stay current with your POH in an aircraft you have been flying forever as well. Be careful about advice you get from Facebook. There is a number of people who believe that running your engine at a high Manifold Pressure and low RPM is a good idea. That is false. The engine manufacturer, aircraft manufacturer, and every mechanic I have ever talked to about this all said that it is bad to do that. When all the pro’s say it’s a bad thing, it most likely is. Running your aircraft like that is the same thing as giving a car with a manual transmission full throttle and never taking it out of first gear. All you’re doing is creating a massive amount of power that you aren’t using. When your engine is producing a massive amount of power that you aren’t using, you’re setting yourself up for an engine failure. Social media is a great place to share stories and pictures about flying a specific type of airplane however always double check any operational settings or limitations someone suggests with your POH. A big trigger for me is when someone says that doing something we have done a certain way forever is wrong and that actually the opposite is true.
So to recap, your POH is a very useful tool that all pilots should stay familiar with. That is also your go to when transitioning into a new type of aircraft. It can also answer most all of your questions pertaining to how to fly your aircraft. Remember to double check your POH after getting advice from people on social media because you don’t know who these people are and they may or may not be right. Be careful out there and don’t get caught up in aviation myth when seeking aviation facts.
Until next time, everyone remember to stay safe out there flying and keep the greasy side down. Remember if you have any questions or comments on what you have read or want to request a topic for me to cover feel free to email me at the address below or leave a comment.
Flight Operations Manager / Head Pilot
Winterset Aviation Services