To the Letter


 

Forced landing straight ahead
Dear Editor,

While reading an article in Aviation Safety Letter 1/2007, about a small airplane that crashed in Brantford, Ont., I was reminded of one of my own experiences. Here it is in a few words. My intention is to share with other pilots these critical moments that can save lives.

In August 2001, while taking off from a private runway belonging to the Escapade au Réservoir Gouin outfitting company, I experienced a loss of power that was significant enough to force me to land in the middle of a forest at the end of the runway.

Several factors are always at play during such an event. First, the aircraft, a Cherokee 6-260, was almost at its maximum load capacity, that is, 3 360 lbs (the maximum allowable take-off weight is 3 400 lbs). In addition, the centre of gravity was near the maximum allowable aft position.

Under normal circumstances, the aircraft would have had enough power and capacity to take off with a similar load. I have actually been able to do it without any trouble under other circumstances.

Nevertheless, even if the limits listed in the aircraft operating manual (AOM) had allowed me to take off, I was confronted with an abnormal situation following a loss of power, which prevented the aircraft from recovering from ground effect. There was a wall of trees at the end of the sand and dirt runway.

Since the loss of power occurred after the wheels had left the ground, I did not have enough distance to interrupt the takeoff without violently crashing into the wall, which was the fast-approaching forest. So, I decided to conduct a forced landing in the forest straight ahead.

Let me assure you that my heart stopped for a second when I realized that there would be nothing left of my aircraft after this event. What saved my life, and the lives of my five passengers, was that I did not attempt any turns or manoeuvres to try to stay in the air. I was content with letting the aircraft glide straight ahead, keeping the wings horizontal and closely monitoring the speed to avoid stalling.

The aircraft landed in a forest of coniferous trees, which probably helped limit the amount of damage, and except for a few scratches and bruises, nobody was injured.

Fortunately, my pre-flight briefing to the passengers allowed for a very quick evacuation of the aircraft. A fire started in the engine bay within seconds after the crash, but everyone on board was safe and sound before the fire reached the cockpit.

I am convinced that keeping the aircraft in horizontal flight during the descent saved all of our lives. A stall at low altitude is fatal most of the time.

According to the observations made on the aircraft debris, the loss of power was apparently caused by a fire that started in the engine bay during the ground roll on takeoff. The aircraft was completely destroyed in the fire, but the six occupants are safe and sound.

Michel Perrier
Montréal, Que.


Small screw, big problem
Dear Editor,

I am a commercial pilot working for a private company on a Cessna 206 (seaplane configuration). I would like to share with your readers an experience I had in the summer of 2006, in order to make pilots and aircraft maintenance engineers (AME) aware of the importance of paying attention to detail.

After having had major changes made to the avionics, the owner of the Cessna 206 returned the aircraft to service. After three months of operation and approximately 100hr of flight, an annual inspection had to be carried out. During the inspection, it was found that a 1/8-in. stainless steel cable, which was connected to the flight controls and then went through a pulley system under the console and attached to the elevator, had been half-cut at the aforementioned pulley.

The AME investigated further, and found that a small screw had fallen from avionics equipment and became stuck between the pulley and the cable. Since this type of pulley had a "groove" so that the cable did not come out, the screw became trapped, and each time the pilot operated the flight controls, the cable rolled over the screw, which slowly but surely began cutting the cable.

If it weren’t for the AME’s attention to detail and the short amount of time between the installation of the avionics and the annual inspection, the consequences of this incident could have been drastic.

Moral of the story: it is of the utmost importance to carefully tighten all screws, nuts, bolts, etc., and if a part (screw, nut, or other) accidentally falls while work is being carried out, it is essential to find the part to prevent it from causing damage elsewhere.

Name withheld upon request.


Engine failure
Dear Editor,

After a four-hour wildlife survey mission in a C-337 Skymaster, I was on final approach to land when, to my utter surprise, the front engine suddenly quit even though the fuel gauges were showing plenty of fuel in the tanks. After making a safe landing, I taxied off the runway, shut down the rear engine, and scratched my head, wondering what had just happened.

After having the fuel tanks filled, it was discovered that the main tank for the front engine had run dry. How could this have happened to me? I am the type who always goes the extra mile to ensure I manage my fuel carefully. This is the type of thing that only happens to careless pilots, right? Well, let’s take a closer look at some of the factors at play here.

Although I had over 100 hr of experience flying the Skymaster, I had not flown it within the previous six months, and my comfort level was not at its best. It was also my first wildlife survey mission. I was new to the area where we were flying, and I had never before flown with the three crew members on board that day.

Secondly, there was no fuel dipstick available for the aircraft to verify the amount of fuel in the tanks during a pre-flight inspection. I was told that, because of the shape of the fuel tanks on the Skymaster, it was impossible to get a reliable indication of the fuel quantity from a dipstick. Therefore, the company did not use one.

The three-hour wildlife survey actually took closer to four hours. I had not been the last person to fuel the aircraft, and therefore, I was unsure of the total fuel on board. I felt the amount of fuel my employer said I had on board was accurate and sufficient for the four-hour mission. I was also relying too much on the fuel gauges to provide an accurate fuel quantity indication. Accordingly, I was not as concerned about the mission’s duration as I should have been.

After landing, it was determined that a ground wire for the electrical fuel gauges was broken, and this made the gauges read substantially higher than they should have. Also, it was noticed that one of the fuel tanks had blue fuel dye streaks streaming back from the fuel cap. It is unknown how much fuel had evaporated during the mission.

My employer had dispatched the aircraft to the operating base without full auxiliary tanks. I was warned that they were not full, but I didn’t know they were completely empty, especially when the gauges were showing 3/8 fuel in these tanks. I was told to return the aircraft with full tanks. All the fuel at the operating base was going to be purchased by the client. Sending an aircraft out without full tanks and returning it with full fuel would probably mean that my employer would come out ahead. However, as it would turn out, this practice was a factor that contributed to my engine failure.

Ultimately, as the aircraft’s pilot-in-command (PIC), I accept full responsibility for my engine failure and I consider myself very lucky that I did not become another statistic. I learned from my mistake. I learned to never assume anything, and you can never be too careful when it comes to fuel management.

Name withheld upon request.


Lost satellite reception
Dear Editor,

Portable GPS units are wonderful, and they sure make flying and navigating much easier. In fact, numerous general aviation aircraft are now equipped with both panel-mounted and portable GPS units, some even including satellite weather depiction and radio.

I have a top-of-the-line portable GPS unit of a well-known brand mounted on my yoke, and I use it all the time. Like all portable units, it is a VFR-only GPS, but it is wide area augmentation system (WAAS) enabled, has a color moving map and integrated horizontal situation indicator (HSI), and I consider it to be a very useful tool to maintain situational awareness when navigating. It cannot legally be used to fly IFR, but sure can be used as back-up navigational gear in case of electrical failure, as well as to provide you with the big picture of where you are situated in relation to the other NAVAIDs that you are using to legally fly IFR.

Over a year ago, I was flying IFR in actual instrument meteorological conditions (IMC), preparing to shoot an ILS approach at my home base. In such circumstances, I always use the GPS as back-up for situational awareness, load the approach in the active flight plan, and use the vectors /OBS configuration to project an extended runway centreline track inbound to the approach runway. Of course, I use my ADF and localizer/glide path from my navigation (NAV) radios to legally fly the approach, but the moving map will visually show my progression when intercepting the localizer. That day, I started setting up my NAV/COM radios for the approach about 10 mi. out and was happily watching my progression towards the airport on the moving map, when all of a sudden I got the message: "LOST SATELLITE RECEPTION." I kept flying the approach with my NAV radios, and thought to myself, "what bad timing for losing GPS reception." Since I had never lost reception in hundreds of hours of flying with that faithful unit, I wanted to believe the problem was not caused by the portable unit itself, but rather had something to do with the satellites.

A few months later, I was flying VFR, practicing instrument approaches at my home base. After completing one localizer approach to one runway, I started setting up for another localizer approach to an intersecting runway; then all of a sudden: "LOST SATELLITE RECEPTION." I thought it was an interesting coincidence that I lost satellite reception doing exactly the same type of approach, at the same location, as the first time it happened in actual IMC. As a test, I quickly changed one digit on the NAV radio frequency used for the localizer, and the GPS immediately came back to life. The offending frequency in my case was109.5, and it produced some interference with the GPS.

I called the GPS manufacturer to inquire as to whether they had similar problems reported by other users. Theysaid yes, and that the frequency I mentioned was one of several frequencies that may affect the unit from time to time. They told me to try and change the location of the remote satellite antenna placed on the glareshield to eliminate the problem. I proceeded on a trial and error basis, flying VFR, and finally found a location on the glareshield, far from the other radios, thatwould not produce any interference on that frequency. The manufacturer also made a point of reminding me clearly that these portable GPS units, although wonderful in providing easy and accurate navigation, are strictly made for VFR use, and this is why they make you agree with this warning by pressing "Enter" when you turn them on.

I have since decided to install a panel-mounted IFR-approved GPS. Of course, these TSO-approved GPS units are not affected by frequency interference and can be used to shoot approaches in IMC, but only when they have the required receiver autonomous integrity monitoring (RAIM). Again, this is to ensure that the satellite reception is acceptable for accurate navigation.

The lesson learned here is that frequency interference does affect portable GPS units; they are wonderful and you can use them for VFR, or as a prudent back-up aid to navigation for IFR, but always be ready to resume navigation with conventional navigation gears at the worst anticipated time.

Franz Reinhardt
Ottawa, Ont.



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