TO THE LETTER

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Detection of Water in Fuel Drums-
Use of Filters and/or Dipstick


Dear Editor,

Recently, one of our base pilots discovered an accumulation of water in the fuel tank and filter of his Bell 206. The previous day, he had refuelled from a drum near Stewart, B.C. Approximately one litre of water was discovered in the fuel filter-almost enough to cause engine failure. The chief pilot examined the fuel filter and discovered that it would allow the entry of water up to one percent of the fuel flow rate before shutting off the fuel flow. With a fuel flow rate of 25 gallons per minute, the filter would allow 0.25 gallons or one litre of water. That is practically the full capacity of the airframe fuel filter. I have been in the industry for over 30 years and was not aware of this. I am sure that many other pilots are also not aware of this.

Part of the problem is that this particular filter unit is in a casing with no glass sediment bowl; therefore, the pilot cannot perform a visual check of the fuel as it starts to pump. Older filters equipped with a glass sediment bowl were more effective for detecting water visually.

I have noticed over the years that when there is a small quantity of water in a drum, it can be spotted using a flashlight, since water separates from the fuel and can be seen even if the water is clean. However, I once encountered a drum that had enough clear water to cover the bottom of the drum, even when tilted over for inspection. In this case, the water could not be seen. I am now convinced that the only sure-fire way to detect water is to use water-finding paste on a dipstick. I keep a lightweight dipstick made of white plastic, and use it with a bit of water-finding paste on the end to check for water.

Name withheld on request.

Selection of Precautionary Landing Site

Dear Editor,

I am an air traffic controller currently working at the Abbotsford Airport, B.C. I am writing you today with regards to a particular accident synopsis, published in the Aviation Safety Letter (ASL) 4/2007. The article mentions the sequence of events regarding a Cessna 177RG returning to the airport with partially deployed landing gear. The pilot tried unsuccessfully to deploy the gear and ended up landing gear-up on Runway 19. I was working at the Air position that day and remember the event quite well.

What wasn’t mentioned was that the pilot initially insisted on landing in the grassy area adjacent to Runway 19. A fly-by was conducted in accordance with our Manual of Operations and our Unit Operations Manual, and also to buy us some time. I remembered a conversation regarding precautionary landings with a fellow controller who was also an experienced pilot. We had discussed that landing in long or wet grass, or on any other soft surface, involved a risk of digging into the soft ground and the potential of cart-wheeling, or having a wing dig in, resulting in more severe injuries or structural damage. During the fly-by, we confirmed to the pilot that his gear was partially deployed, and that all of the controllers present suggested that the best course of action would be to land on the hard surface.

The airport firefighter responding to the incident also recommended the hard surface because it had rained quite a bit during the previous week. Not only would it be trickier for the aircraft, but the soft ground presented an additional risk that the fire truck might get stuck. After relaying this information back to the pilot, he agreed to land on the runway. All resources were deployed in the staging area; the pilot landed the aircraft on Runway19 and walked away unharmed. Teamwork played an important role in this incident. As a result, I understand that the Airport Manager and other interested parties are discussing the feasibility of making precautionary landings on the hard surface mandatory.

I would like to see an article in the ASL regarding the best choice to be made under different circumstances where a precautionary or forced landing is required. I have witnessed several incidents over the years, and a recurring theme seems to be a desire to minimize damage to the aircraft.

PascalLiebault
Chilliwack, B.C.

Thank you, Mr. Liebault. Your comments do provide for good discussions between pilots, controllers, flight service station (FSS) specialists, and rescue personnel. In this particular event, you and your colleagues were able to assist a pilot in a period of elevated stress, with a most favourable outcome. The publication of your letter should raise the level of awareness on this issue, and encourage pilots to discuss it with their peers, particularly with their instructors. -Ed.


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