Lazy Hazy Steamy Flight over Water

Very Poor Visibility in VFR Flight Conditions

Weather is good but the visibility is down. What can happen over water on a lazy, hazy, steamy flight into the sun in the Summer?

In Michigan - plenty. Mid-afternoon, returning from a popular amusement park called Cedar Point, on a flight to a shore line destination to the West you reach cruising altitude in level flight. Suddenly you discover you can't determine where the horizon is because of very limited visibility caused by humid hazy air facing into the sun. You look down - below you the blue of the water gives you a sensation of sky. You look up - and the blue sky looks exactly as the water below.

Now you wonder what is the actual attitude of your airplane? Yep! You are disoriented. If you are instrument rated you can file an instrument flight plan and proceed to your destination after you  I-dent and receive clearance form the Center to fly to your destination.

Trusting your instruments, the sensation (illusion) of attitude confusion disappears and you make your destination.

If you don't have an Instrument Rating the flight could end tragically. It doesn't have to if you recognize that apparent IFR conditions could occur even if the forecast called for normal VFR flight.

This may require you to reschedule your flight or pick another route where the direction of the plane is not facing into the sun and your flight path is not over water. a flight plan is not a bad idea either.

Ask questions, before the flight, about flying in those conditions if you are a low time pilot.

Safety Oriented Checks to do Before Starting the Engine

Safety Checks - Pre Flight 

1. Check the oil dipstick.
2. Actually remove the gas caps and stick your finger in to see if they are topped off.
3. Check all hinges that attach things to the tail and wing structures.
4. Check for fatigue cracks.
5. Chocks.
6. Check and drain a cup of fuel and inspect for water.
7. Check for oil and brake fluid leakage.
8. Check the weather.
9. File a VFR of IFR Flight Plan.
10. Visit the FSS for updates on navigation equipment, pilot reports, etc.
11. Are you rested?
12. Make sure all control surfaces have immobilizers removed.
13. Check, for example, are there any bird's nests that are are under your cowling.
14.  While under the engine cowling check for loose wires, leaks of any kind, loose parts or accessories.
15. Be sure and close the cowling attachments after inspecting.
16. Pitot tube okay? If covered, did you remove the cover?
17. Running lights okay? Strobe? Operate them to make sure. 
18. Aerials. Cracked? Missing? Bent?
19. Propeller. Nicks, gouges, tip broken off, loose?

This is a possible complete outer inspection. Help me out and add to the listed items. Everything helps for safety.

Start a list of Cockpit Checks. It's a lifesaver.

Six Probe Cylinder Head Gauge and its Use

Six Probe Cylinder Head and EGT Gauge Use - Good

Lets begin with the aircraft engine. If you have a six cylinder engine you can, in normal flight at cruising speed, find the hottest running cylinder and, for safety back off 25 to 50 degrees.

Why is this so important? High temperatures, not controlled, can damage engine valves. If you can determine the hottest running cylinder using the two gauges above, and you back off 25 degrees on the cylinder that is the hottest running of the six (by testing each cylinder separately) you know for sure all the cylinders are running below the peak leaning point of the hottest running cylinder.

Why would you want to do this? An efficient leaning procedure, in aircraft at normal level flight and cruise speed, is attained by gradually leaning the engine until the RPMs decline a bit then enriching the mixture approximately 25 degrees. If you don't have a cylinder head temperature gauge this becomes a guessing game learned with experience. It will result in an engine that is running with near peak efficiency but you are not really sure.

Doing this, without a six probe gauge, may leave one or more cylinders above peak leaning temperature and make valve damage possible on those valves . This can occur after enriching the mixture 25 degrees. You really don't know, without testing, which cylinder is running the hottest when you lean them out together without  testing each cylinder alone.

If you can find that hottest running cylinder,and you back off on the mixture control on that cylinder 25 degrees, you know the other cylinders are safe even though they may operate at a temperature cooler than the 25 degrees of the leanest cylinder. You are sacrificing a little efficiency for the longevity of the valves in the engine.

I will discuss the EGT in a future blog and combine the two in diagnostic procedures that could save you labor costs and part replacement costs. 

Safety Shorts On Mixture Control

Mixture Control Smarts

The mixture control adjusts the mixture of fuel and air, for combustion characteristics in aircraft engines.

If too much fuel reaches the combustion chamber for detonation the mixture setting is 'rich."

If too little fuel reaches the combustion chamber for detonation the mixture setting is "lean."

A "rich" mixture" will use more fuel and, generally, have a cylinder head temperature "cooler" than a "lean" mixture".

To stop the idling engine, after landing, and before shutting down the plane to leave it, you pull the mixture control all the way out. The very mixture will starve the engine and cause it to stop.

Now for the fun and safety issues. In this blog I will cover two that may save a life or two.

Sometimes when you taxi up to a small terminal a child may dart out from the waiting area to great you. They can't see the rapidly rotating propeller.

No matter where you are, pull out the mixture control and shut off the magnetos. That may or may not stop the engine. If it does stop the engine you may have prevented a very tragic accident.

Do not do anything until the child and the parents have safely set their offspring behind the safety fence. Then you can resume the procedure to park the plane.

Second safety issue is carburetor icing. In a normally aspirated engine the vanes that regulate the amount of air/fuel mixture may ice shut. When a gas expands rapidly the surrounding environment cools. If there is moisture in the air the actual temperature may reach below 32 degrees F and the moisture may change state to ice and starve the engine. This results in a sputtering engine on its way to stopping.

Lean out the engine quickly until it backfires. The backfire may dislodge the ice buildup and the engine will begin to run again.

Your instructor can elaborate on carburetor icing with you in a ground school setting or show the proper technique in flight.

Net effect, you can find your airport and land. Safety at last.