The placards and instructions in the POH of our aircraft are there for our protection… usually. When you are taking part in normal flight, the instructions on placards and in the POH are there to help you keep the plane flying. As an example, if you are flying a Beech Bonanza, chances are you have a placard that states “Turning type takeoffs prohibited”. The purpose of this placard is to help pilots avoid making a mistake — in Bonanzas with unbaffled fuel tanks, a turning type takeoff can cause fuel to slosh away from the fuel pickup, causing a loss of power on takeoff.
However, if you are in an emergency situation, some of the instructions on the placards that were put there to protect you may cause you to make a key mistake, and not perform a maneuver that you need to in order to safely land the airplane.
THE SETUP — You are a pilot, flying around in your 1974 Cessna 172. The plane is flying well, and you notice an airport passing below you as you cruise at 2,500 feet above the ground. Suddenly, the engine goes quiet — leaving you with a glider… and a decision.
FOLLOW THE CHECKLIST — You follow your emergency checklist for engine out, making sure your mixture is at rich, your throttle is in, and your fuel is selected to BOTH in this model. You pump the primer in an effort to get the windmilling engine to restart, while you dial back the trim to reach your best glide speed. As you turn back to the airport, you notice that by luck you have a straight-in to the runway, but that your altitude is WAY HIGH.
As you glance down at the panel, you see the ominous placard: ‘SLIPS PROHIBITED.’ You try S-turns to lose altitude instead, but unable to shed the extra altitude without a slip, you land long and plunge off the end of the runway into a ditch.
IT DIDN’T HAVE TO HAPPEN THIS WAY. The placard on the mid-1970s Cessna 172 was to protect the plane from fuel unporting, the same as the Beech placard. With the high wing and the right combination of fuel conditions and attitude, you could slip hard enough to unport the fuel pickup, and cause the engine to quit. Cessna took the easy approach, and BANNED SLIPS in certain models.
The pilot in command has the authority to deviate from the Federal Air Regulations, including placards on the instrument panel, when needed for flight safety. Had the pilot slipped the plane in the example above, he would have been able to make the near end of the runway, and would have avoided the accident.
IT CAN HAPPEN TO YOU — Here is another example. On his FAA ATP checkride, our intrepid pilot noticed that, while on long final over the ocean, he had mismanaged the fuel to his twin. The tanks ran dry, and the engines quit, leaving him and his instructor with a good case of the sweats as the plane started to descend towards water.
“LANDING WITH THE FUEL SYSTEM SELECTED TO THE TIP TANKS IS PROHIBITED” said the placard. Having nothing to lose, our pilot exercised his emergency authority, and selected the tip tanks. A few moments later, power returned to both engines, and our pilot stabilized his approach and safely landed. He flunked the checkride, but then, he didn’t go swimming either. A water landing is no laughing matter, and no matter how smooth the pilot, few planes ever survive the event.
By thinking outside the box in an emergency, our pilot saved the plane, and possibly the life of both himself and his FAA examiner.
NOTE: EMERGENCY USE ONLY. Electing to ignore posted warnings must be used in emergencies only. As we have said, the placards on your panel and limitations in your POH are there to keep you safe in NORMAL FLIGHT. If your flight departs the norm and becomes an emergency, you should consider ignoring the rules.