Never Again Online: An Inadequate Preflight Inspection Can Kill

March 1, 2009

After any maintenance, an incomplete exterior and interior preflight inspection of your aircraft systems can endanger your life.  It is often difficult to be thorough because your normal check list procedure is inadequate.

Early Thursday morning on September 6, 2007, I flew my Cessna 182 from the Boulder City Nevada airport to the North Las Vegas Airport using the Showboat approach through the Las Vegas Class B airspace to have my two-year-old Garmin 1000 glass cockpit system updated as directed by a Cessna owner advisory.  It was a beautiful clear day with a light wind out of the northwest, so the North Las Vegas tower cleared me for a straight in approach to land on runway 30 Right before taxiing to the authorized Cessna dealer where I left my plane for the day.

When I returned after dark that evening, I completed a thorough exterior preflight inspection, checked to make sure the new Garmin CD was in the POH, replaced the old Garmin cockpit reference guide with the new one, and verified that the appropriate avionics entry had been prepared and entered in the maintenance record. After picking up the ATIS information, calling for clearance and getting permission to taxi to the active runway, I taxied to the run up area to do a thorough run up. I did the normal interior preflight inspection before spending 10 minutes exploring the updated Garmin system for any changes to the four main windows and their respective sub-windows to make sure I understood the new system and its new features.  This inspection was done with the Garmin display lighting turned clear up so as to make any new features stand out.

After feeling comfortable that I understood the modified Garmin 1000 presentation, I called the tower when I was holding short of Runway 7.  The tower cleared me for an immediate departure on Runway 7 and to make a left turn when able to 340 at or below 4,400 feet msl consistent with the clearance and delivery. The tower also confirmed I was VFR.

After taking off and turning north to 340 while climbing to 4,400 feet, I remember thinking how incredibly dark it was and being vaguely uncomfortable that something was not correct about the MFD, but I was focused on setting up the autopilot to fly a 340 course and climb to and maintain 4,400 feet just below the Class B’s 4,500-foot floor.  Once the autopilot was set, I again asked myself: Why is it so dark? What is different about the MFD? Why hasn’t the North Las Vegas Tower instructed me turn east and change frequency to Nellis Tower for clearance into Class B?

Finally it dawned on me what was different about the MFD. The Cessna dealer had installed the modified Garmin 1000 software, but had not reset my individual preferences on the Map Page which meant that the TAWS (a visual only terrain awareness system) was not displayed.  Therefore I didn’t know if I was within 100 feet of the ground shown by a red display, within 1,000 feet of the ground shown by a yellow display or greater than 1,000 feet agl given how black the night was. I immediately pushed the Map button followed by the Terrain button which produced a Map Page with yellow directly beneath me but red within 15 seconds ahead of me.  North Las Vegas clearance or not, I quickly turned to an easterly heading to avoid the mountainous terrain north of the North Las Vegas Airport.

I then realized that one of the reasons it had been so dark was that I was flying away from the lights of Las Vegas on a moonless night, but the main reason was that I had not dimmed my cockpit lighting including the PFD and MFD lighting after familiarizing myself with the new aspects of the Garmin upgrade following the run up. When I dimmed all the cockpit lighting and my eyes began to adjust, it only further frightened me when I realized how close to the ground I was.

The following thoughts then went through my mind. Why had North Las Vegas Tower not warned me of the higher terrain? After all, they had their radar and had to be keeping an eye on me for traffic reasons and Class B reasons. Surely they understand that flying at night, while not IFR, simulated IFR flight in many respects; but….North Las Vegas Tower had cleared me VFR.  Suddenly I had a broader understanding of visual fight rules. VFR meant I, not North Las Vegas Tower, was responsible for not only aircraft avoidance and Class B avoidance but also terrain avoidance.  North Las Vegas Tower had no obligation to me because I was not in their airspace, or on an IFR flight plan.

The mistakes I made included not performing a thorough enough preflight internal inspection following a software upgrade, forgetting to dim the cockpit lights after playing with the new toy, not fully understanding visual flight rules, and thinking I was somehow under positive control because I was speaking to a tower near restricted airspace.  As a result of this experience I have resolved to always have my maiden flight after any kind of maintenance be in the daylight hours, which would have prevented this near mishap, making it more likely that I will be around another day to fly the beautiful skies of the West regardless of the surprises the avionics hold.

Rex Lewis is a private pilot with more than 500 hours flying experience in his G1000-equipped Cessna 182. He has been flying since 2006.