Our pilot was a new aircraft owner and very proud of the mid-70s Piper Cherokee he had chosen for himself. It was very nicely equipped but lacking one thing he had convinced himself he wanted to have – a fuel totalizer. This is a device that is displays the amount of fuel consumed by the aircraft with extreme accuracy. This consumption is gauged by a sensor that is installed in the fuel line that keeps track of the amount of fuel flowing past it. With needle indicators being notoriously unreliable, our pilot insisted on the peace of mind having a totalizer installed would provide so installed it was.

One spring day our pilot planned a day trip with a friend about a two and a half hour flight away. It was a beautiful VFR day and the winds were expected to be favorable – at least on the way there. About an hour into the flight our pilot calculated that his ground speed was approaching 145 knots. He was excited since that was so much faster than the usual 110 or so knots he was becoming used to. His thrill was muted some when a Mooney blasted by him on the right, but he was still very pleased with the tailwinds he was enjoying.

After arriving ahead of schedule, our pilot and his guest spent the day as planned. They headed back to the airport early that evening to plan the return trip home. Those previous tailwinds would now end up being a headwind so he picked his altitude accordingly. He planned on 6,500 feet and filed his flight plan.

He had originally planned on simply reversing the route to get home but shortly into the flight with the sun having gone down, our pilot was faced with what seemed like an endless mass of featureless darkness ahead on that moonless night. With forecast scattered clouds along the planned route, our pilot decided he didn’t want to risk the chance of disorientation or inadvertent flight into a cloud so he opted to divert to the south about 30 miles where he could follow a major highway all the way home.

Our pilot contacted flight services to advise them of the diversion and to change the planned en route time. A short while later with the lights of the highway in sight he turned west on course. Almost immediately he noticed that some of the cars on the highway were actually driving a little faster than his humble Cherokee was flying. His ground speed at best was a modest 70 knots!

With his previous flight plan rendered essentially useless our pilot performed some quick calculations on the fly. With full tanks (which he fortunately had begun the flight with) he could lean out to get between five and a half and six hours endurance. He should have plenty of fuel, but SHOULD isn’t nearly as confidence inspiring as WILL. Now almost two hours into the flight and still a long way from home, our pilot was considering options. Land at an airport along the way or carry on?

The few airports in the remote area between points A and B were now closed for fuel. Accommodations could also be a problem if it came to staying put. Landing certainly wasn’t a convenient option but definitely a safe one. With landing as his backup plan, our pilot chose to remain in touch with flight services and closely monitor his trusty fuel totalizer to keep a close eye on the fuel remaining. As long as this number remained acceptable (including a broad buffer) then the flight could continue.

During the remainder of the flight, our pilot almost constantly performed fuel calculations just waiting for the number to break his threshold of comfort. All the while, his guest, in blissful ignorance, was either listening to music or napping.

About FOUR hours into the flight and now approximately 30 minutes from home, and the totalizer never once indicating a number our pilot wasn’t satisfied with, he was confident of his ability to reach their destination airport. Finally, much later than anticipated, the Cherokee safely touched down at home.

Our pilot parked the aircraft and dipped the tanks to check the levels. Perfectly in line with the totalizer, he found almost an hour of fuel remaining. Despite strong headwinds and a diversion, our pilot managed to remain legal and stay safe. He now never flies with any less than the legally required amount of fuel plus a sizable contingency – full tanks preferred. Just in case!

Fly safe(r).

Anthony Nalli is the Director of Canadian Development, General Aviation Collision Avoidance and President of SciDac Corporation/PCAS.ca. PCAS.ca is dedicated to the implementation of affordable collision avoidance devices in General Aviation with a mission to eliminate mid-air collisions and dramatically reduce close calls. Anthony can be reached at This e-mail address is being protected from spambots. You need JavaScript enabled to view it , 1-888-PCAS-123 (GTA: 416-225-9266), and www.PCAS.ca