Daily and Pre-Flight Inspections

Inspect like your life depends on it.... Because it does!

Daily inspections are a crucial part of flight operations and are required by Recreational Aviation Australia prior to the first flight of the day. A properly performed daily inspection by a trained pilot follows a standard procedure and permits detection of conditions that render an aircraft un-airworthy. However, some complacency (a theme discussed last week) and a lack of understanding of the standard procedure may prevent it from being totally effective among less experienced pilots.  

There is a difference between the daily inspection and the pre flight inspection, also known as the walk around
A daily inspection must be carried out using approved maintenance data
 (manufacturers daily inspection checklist) and recorded prior to the first flight of each day. For subsequent flights that day, the pilot in command must carry out a pre-flight inspection or carry out another daily inspection should it be deemed necessary. The pre-flight inspection is usually an abbreviated form of the daily inspection. 

The Daily inspection must consist of the making of checks set out in the aircraft flight manual 
These inspections are not intended to waste energy, be a mundane exercise, or be completed at record speed. They are designed to identify issues on the ground, so they are not issues in the air. A 2010 study conducted by NASA analysed data of US accidents between 1988 and 2004, and they found inadequate inspection practices to be a contributing factor in 54 loss of control accidents among general aviation operations. Back at home a number of occurrences are reported to RAAus where a daily inspection, carried out in accordance with the manufacturer’s checklist may have prevented the aircraft from landing other than back at the airstrip.  

A number of manufacturers require the engine cowls to be removed to enable a thorough inspection of the engine
Removing the cowls enables inspection for cracks, fuel and coolant hose integrity and 
to ensure nothing is chaffing on the exhaust. A number of occurrences may have been prevented should the checklist have been followed and a thorough daily inspection carried out. RAAus Airworthiness Notice AN270810-1 requires that all engine cooling hoses/clamps are inspected at each daily inspection and may be a difficult task to complete with the cowling on. 

Many factors influence the outcome of a daily inspection
Weather, time pressures, stress, and fatigue to name a few. Awareness of their presence and actions to mitigate their effects are paramount to properly completing the procedure. A daily inspection may appear to be a simple task, but it is more than glancing at a checklist and wiggling flight controls. These inspections require an understanding of normal and abnormal conditions. For the flight, it is the start of the aeronautical decision-making process. If unsure of what a checklist item refers to or whether the item is airworthy or not, enlist the help of a Level 2 Maintenance Authority Holder or CFI for assistance. 

The daily inspection is a systematic and thorough look at the aircraft in accordance with the manufacturers approved checklist. It does not matter where your inspection begins, as long as all areas of the checklist are covered. If your aircraft does not have a manufacturers checklist you may use the schedule in the RAAus Technical Manual or CASA schedule 5  

Whilst compiling this article we came across a very recent story for an Aero Club Newsletter. This is also very timely considering the recent aircraft hibernation due to the COVID-19 pandemic. The aircraft in this story is a light twin engine aircraft however is still extremely relevant to any RAAus machine. Thanks to Rob Parker for allowing us to share. 

Importance of a thorough daily inspection

Story by Rob Parker

Having already completed a daily inspection and signed the maintenance release I thought I was good to go. Wrong! One of the engine throttle levers had seized. I asked the engineers to look at the aircraft. When they removed the right hand engine cowling, they found the seized throttle cable and when they removed the left-hand engine cowling a bird escaped and flew away. The bird nest in the back of the engine certainly was not visible from the front air intake of the engine cowling and was also not visible from the rear of the engine cowling when I looked up through the open cowl flaps. It’s a great reminder to have an extra thorough look over your aircraft before taking her skyward.  

So, I thought about what could have happened once I became airborne with the nest embedded in the engine. It would have overheated, and I may have had to perform an inflight engine shutdown. Not a big deal, as I have another engine to take me to an airport, paddock or road and perform a landing and walk away.  

What about an inflight fire? This aircraft like many light twin engine aircraft does not have engine fire suppression (fire bottles). If the uncontained fire burns through the main wing spar, then it will most likely be a fatal event. The wing will separate from the aircraft and you will soon be following the wing to the ground at an uncomfortable rate of knots.  

All of this drama because of something that you couldn’t see. 

Please be safe, please have an extra special look over your aircraft before flying. Please pay for a maintenance professional to take a closer look at your aircraft if you are in doubt about anything.

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A Final Thought

One fantastic habit to build into your pre-flight routiene is to conduct a final 360 degree walk around the aircraft every time you go to get into the cockpit. This can be done EVERY TIME you leave the aircraft, even if you only walk away for a minute. 

A final walk around before getting in to the aircraft will allow you to identify anything you may have missed during your daily or pre-flight inspection. It will also ensure that nothing has changed since this inspection was complete!

99% of the time there will be nothing to find, but 15 seconds added on to your flight routiene may just save a whole lot of embarrasment, or worse, that 1% of the time when something goes unnoticed.


RAAus Technical Manual example checklist: 

Approaching the aircraft – check undercarriage and tyres for integrity;  


Internal checks: 
 

  • Master switch - off  

  • Ignition switches – off  

  • Throttle – closed  

  • Stall warning horn (if fitted and capable of testing)  

  • Rudder pedal system integrity  

  • Elevator, aileron, rudder controls – check for full, free and correct movement  

  • Trim controls – run through full range and set to neutral  

  • Check operation of flaps (if applicable)  

  • Check seats, seat belts and attachment points  

  • Ensure load is secure  

  • Look for and remove any foreign objects  

  • Registration current  

  • Cockpit Warning notice(s) in place.  

  • Instrument checks: fuel gauges, altimeter to airport elev or QNH, compass etc.  


General: 
 

  • Tubes - Check for bends, dents, scratches, etc.  

  • Wires - Check wire ends for bolt and/or other fastener security  

  • Check for twisted or jammed swages or securing mechanism  

  • Check cables are free of kinks, frays, abrasions, broken strands etc.  

  • Check cables are free of sagging but not so tight that they ‘twang’ when plucked  

Note: Whether you conduct the inspection clockwise or anticlockwise is an individual choice. The important matter is that the checks must be conducted in a systematic manner.  


Fuel system 
(this may be conducted as a separate check or as part of the walk around)  

  • Check venting system clear  

  • Fuel caps secure  

  • Fuel drain check for water or debris  

  • Fuel line for secure clamps  

  • Check security and integrity of tanks  

  • Check fuel level and correct fuel type (sufficient for flight)  


Left & Right Wing
 

  • Wing attachment points and bolts  

  • Fabric integrity  

  • Lift/compression struts  

  • Check each compression strut for dents or distortion  

  • Rigging cables and attachment points  

  • Wing tip/nav light  

  • Fabric ties, attachments and compression struts along trailing edge  

  • Attachment points for struts  

  • Aileron (& flap if appropriate) connections and hinges  

  • Mass balances (if fitted)  

  • Rigging cables and attachment points along trailing edge  

  • Surface of wing – damage, ice  


King Post 
(Vertical tube(s) positioned above the wing providing support for wire braced wings):  

  • Security of attachment/s  

  • All cables for condition and attachment points  


Undercarriage: 
 

  • Correct inflation of tyres  

  • Attachment points, oleo struts, bungee cords  

  • Wheel rim and tyre condition  

  • Brakes and pads - check for fluid leaks  


Flying and Landing Wires: 
 

  • Check for cable condition and attachment points.  


Windscreen: 
 

  • Secure and clean  


Emergency Parachute System (BRS) 
(if fitted):

  • Inspect as per manufacturer’s instructions. Check expiry or repack date 


Engine: 
 

  • Ignition off  

  • Engine controls and operation  

  • Air filters clean and secure  

  • Loose bolts/ nuts  

  • Integrity of electrical connections  

  • Integrity of spark plug caps  

  • Loose or damaged parts  

  • Throttle cable seated properly 

  • Coolant system 

  • Integrity of exhaust system 

  • Top of carburettor tight – rubber mount secure Fuel leaks  

  • Sediment in fuel filter 

  • Oil levels, no oil leaks. 

  • Reduction gear secure - no oil leaks 

  • Reduction V-belt drive - check for wear, proper tracking and correct tension  


Propeller: 
 

  • Cracks, chips or nicks 

  • Propeller firmly attached 

  • Spinner- nil cracks-secure 

  • In-flight adjustable propeller actuation (if possible to check with engine off)  


Tail Surfaces: 
 

  • Tail booms and braces 

  • Control systems rods and cables 

  • Horizontal stabiliser and attachment points Elevator hinges and linkages 

  • Fin and attachment points 

  • Rudder hinges and linkages 

  • Tubing for dents or distortions. 

  • Cables for fraying, loose thimbles or kinks.  

  • Rigging cables for tension 

  • mass balances 

  • trim devices