Preflight after Maintenance
--Every aircraft component has a life cycle the end of which will require replacement.
--New means as originally built.
--Serviceable means within the allowable tolerances for continued use.
--Go over with mechanic all work done and evaluated
--Confirm that all work has been properly documented and endorsed by AI.
--Was 337 or STC needed and approved by FSDO
--Written record of changed parts, pressure values, instrument readings and standards maintained.
--Determine what you should look for and expect as check pilot.
--Use billing sheet to determine accuracy of written record.
--Use maintenance notes as guide to preflight procedure.
--Determine what you will do in your maintenance flight
--Pilot/owner becomes responsible party once out of sight.
--Confirm latest weight and balance papers.
--Aircraft papers must be visible.
--Take second party as recorder of data.
--Start
–Pre-takeoff and runup readings (warm-up)
--Vy initial climb readings
--Cruise climb readings
--Level cruise readings for power and airspeed
--Climb to altitude and level checks
--Cruise descent settings
--Arrival settings and instrument readings
--Post landing readings and shutdown.
--Pull cowling for final engine check for oil and security of accessories.

Risk
Some of us certainly wonder why so many pilots keep right on flying, knowing that the papers and TV are a constant reminder source of the serious risks involved. It must be because there is a factual discrepancy included in the 'official' cause that couldn't be determined. If the cause is indeterminate then pilots are unable to see how any pilot anticipation or preventive measures could have made a difference.

There is, however, very positive evidence that a careful and complete preflight is a powerful protective shield around subsequent flying activity. Preflights seem to work as they are supposed to. We are now ready to go through the preflight. Every effort is made to minimize the wasted time and movement about the aircraft while maximizing a through inspection. As though walking up to the C-150 for the first time we unchain the left wing. Note right main tire for yellow chalk mark showing that refueling has taken place since last flight. (This is so that we don't have to walk over to it again when we roll the aircraft tires for inspection.) We use a single key to open the door and place it on the floor below the trim wheel. (A single key is not as likely to result in an accidental turning off of the magnetos as is a key ring full of keys.) (Placing the key on the interior cowling has caused many a key to disappear down the defroster hole.)

Landing Gear Checks:
Brakes for fluid, leaks, wear, softness
Wheels for cracks and bolt security
Airworthiness depends on inflation
Low tires are likely FAA violation
Inflation and wear, cuts and flats
Use valve as clock measure (as place of tire damage)
Disks for rust and wear
Pads for thickness.

Tires as a Safety Factor
Tire wear is more related to abuses and under inflation than hours of flight. Heat is tire's greatest enemy. Under-inflation causes more heat and damage than over-inflation. Use aircraft inflation recommendation rather than tire maker's suggestion. Measure pressure only when cold. A new tire should be inflated again one day after installation because of stretching. System failures are more related to manners of use rather than hours of aircraft operation. An under-inflated tire bulges and covers more surface. Visually easy to detect this condition internally causes heat friction, which over a short time will destroy the tire. Over-inflation must be judged by becoming familiar with the surface covered with normal inflation and then judging accordingly.

Wheels are two halves bolted together. Wheel cracks are most common cause of wheel failure. Keep wheels clear makes cracks more visible. Do not brush wheels with stiff brushes or scrapers. Brakes are designed to dissipate heat without loss of braking effectiveness. The distance between the brake disk and the pad housing is a measure of pad wear. Soft brakes are indicative of air in the fluid lines. An aircraft that pulls to one side may be caused by a dragging brake. Any unusual brake feel or sound is a cause for concern.

A tire has a red dot as a balance mark indicating the lightest point. The tube has a yellow line on it that indicates the heaviest point usually near the tube valve stem. Proper installation should align these two markings.

Braking is most efficient in slowing the aircraft and minimizing heat when braking is sufficient to make the slowness if the wheels slightly less than the speed of the tire. The tire friction will produce drag without slipping. Excess braking will produce skidding and reduced braking effect. Most poor brake use occurs during taxi. Many pilots tend to taxi too fast and use the brakes instead of reduced power to slow and control the aircraft. The constant use of brakes during taxi creates the most damaging heat in the system.

Fuel may be ordered by radio using 122.95. This is the universal frequency used at airports with towers for Unicom services such as ordering a taxi or fuel. At CCR we normally use Chevron and call the truck as "Chevron one". If the truck fails to answer contact "Chevron Base". Give your location as "East Ramp Golf two Cessna 618". With the new aircraft cover you should check the logbook to ascertain if any remark is there that would make the aircraft less than airworthy.

Preset radios and transponder. Remove the control lock, turn on the master, check the fuel gauges, and say, "Clear flaps" before lowering the flaps. (Get fuel as necessary.) The "regulations" requires that a fuel gauge be accurate ONLY when reading full and empty. Open right door and get fuel sump cup. Drain and check fuel in left tank. Place sump cup in right seat. (You don't need to carry it) Check wheel faring (brake lines if visible), front and back side of left flap and antennas. Check empennage, horizontal and vertical stabilizer, elevator hinges and movement on left side. Remove tail chain. Check rudder hinges and movement. Check elevator (under side, too) and trim hinges and movement on right side. Check empennage. Check back side of right flap, front and back of right flap hinges, counterweight and movement. Wing tip and right leading edge. Unchain right wing, check underside of right flap and drain right wing sump. Return sump cup. Check right fuel tank and cap.

Check nose wheel faring, strut, and damper, inside engine compartment, loosen oil stick with left hand, remove with right hand, clean with left hand, re-insert and check for 4 quarts minimum. Pull fuel strainer with right hand and clean left hand with gasoline. Oil stick can be hung on prop blade while adding oil. (Be sure not to lose seal off lid of bottle into engine.) Don't make oil cap too tight. Check leading edge of propeller, spinner mounting plate for cracking, and cowling inlets. Make sure air filter is secure and intact. Watch for 'working rivets, those that have gray powder around them. Roll aircraft at least 40 inches to check tires. If diagonal cord shows in a smooth area the tire is unsafe for flight. Check static air hole, overflow, pitot tube, and stall warner. Don't blow into any aircraft instrument intake hole. Check left fuel tank and cap. Check left leading edge and tip. Check left aileron front back, movement and counterweight. Rocking the wings and gently moving horizontal stabilizers is a good way to pick up internal damage via sound. Do the 'squat test' to make sure everything is clear of the aircraft. The only difference in pre-flighting a C-172 is the luggage door and alternator belt.

The preflight requires the student to be aware of the possible causes of accidental propeller movement. That the key may possibly be removed from other than the off position. That the magneto can be otherwise grounded and allow a short movement of the propeller to start the engine. That, while there is no absolute safe way to turn the propeller, backwards is the safest. (Do not turn propeller of C-150 backwards). The only time you can have too much fuel is when you are on fire. From full tanks the maximum safe flight time of a C-150 is three hours. The tanks are full and the caps are tight only when checked by the pilot. No C-150 flight should be undertaken with less than four quarts of oil. Failure to monitor a radio frequency prior to transmitting as well as being poorly prepared to talk impinge on the flight safety of everyone. Poor use of the radio is the most common failing of the incompetent pilot.

Throughout the first preflight the instructor keeps up a running commentary into the tape recorder as to the why's, wherefore's and how to's for each check. On successive flights additional operational checklists are added. The first student effort is usually pages long. The second effort is more concise. For the third effort the instructor provides a twice folded 4 x 6 card cut half way through one fold. This card can be made into a compact but complete checklist covering all operations from preflight to shutdown. Arrows can be used below each list to indicate direction to fold card. Emergency list is in outlined red. Finally the pilot developed list is cross-checked with the manual approved one to make sure that all items are covered.

Where the student has previous flight experience the same process is used but the pilot is allowed to build on his experience. I feel it is vital that a pilot have his own personally developed checklist for every aircraft flown. Build on first learned skills and habits. The published and universal lists omit or rearrange the order of items so that mistakes often occur. The checklist must contain all items from the aircraft manual BUT there are many supplementary items of radio, transponder, leaning, taxiing, braking, and clearing that are not mentioned. Time is never wasted giving a careful preflight.

Seating
Confirm ability to get full use of rudder and brakes. Use cushions as required. Adjust so you can see instruments, over the glare shield, under the wing of Cessnas and below the aircraft. Don't sit where head movements are required to see instruments related to IFR control. Be aware that having to reach to rotate head can induce vertigo. Always confirm locking of seat rails. Consistent setting of the seat will make your flying more consistent.

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