Monday, October 6, 2008

Bush Pilot Tips (2nd of 7) Gravel Strips

By Father Scott Joseph Garrett, Pastor

One fear of the bush pilot is nicking the propeller with rocks. Flying to the villages in the Alaskan Bush, the bush pilot must land and take off on gravel strips. When a propeller gets nicked with a rock a qualified A & P mechanic must file it down to prevent the crack from becoming larger. This is similar to stopping a crack on the windshield of your car. Parts of propellers have been known to break off in flight if the cracks where not properly cared for. A propeller breaking off 2000 feet above the ground is tragic.

The more filing that is done to the propeller, the smaller it gets. Imagine a boat propeller. If the blades of a boat propeller were filled down the propeller blades would be smaller and the boat would not go as fast through the water. Not a big deal. But when the blades of an aircraft propeller become smaller, the speed and power are less, and the aircraft may eventually stall out in midair. A very big deal!

Here are a few tips that I have picked up from numerous different bush pilots in the Bristol Bay area. They are shocking in their simplicity, yet extremely important in there implementation.

One: If there is no wind the bush pilot has the option to land on either end of the gravel strip. Chose the end that will enable you to taxi to the parking area without having to do a 180 in the gravel. Turning around on a gravel strip kicks up rocks that could nick the propeller. In the picture below, set up your approach for the end of the runway at the top right. After landing you should have plenty of time to slow down and turn into the parking spot, which would be on your right if actually landing(shown in the picture below on the left). No 180 necessary. CLICK ON THE PICTURES TO MAKE THEM LARGER.


Two: While taxing on a gravel strip, keep the yoke pulled back as far as possible. The propeller is higher off the ground when the yoke is pulled back and there is less chance that the spinning propeller will suck up rocks.

Three: Make a concrete slab for your home base parking spot. For small aircraft, Dillingham airport does not have a paved parking area. However, thanks to the late Father Jim Kelly, several concrete slabs have been made. Gravel can get sucked up into the propeller when the aircraft is first started up. The concrete slab prevents that from happening. I was lucky enough to rent a space that had one of these concrete slabs. As you can see in the picture, I always park with the propeller over the pad.


Four: Park the airplane into the wind in graveled parking areas. If there is no concrete pad available, parking into the wind helps prevent gravel from flying up into the propeller at start up. As you can see in the picture, the windsock shows little wind so I was not concerned about the direction the nose of the airplane was pointed when I chocked up.


Five: Try not to stop after landing until you have reached the parking area. Each time a bush pilot stops and then starts back up on a gravel runway, there is potential for loose rocks to fly up and crack the propeller.

A propeller for my Cherokee Piper Warrior II is about $2,500. I will be getting my propeller replaced at my next annual inspection in February of 2009. I do not know when the last time my propeller has been replaced. Since I have owned it, my mechanic has been filing it down for three years and says its time for a new one…no complaint from me.

Next Bush Pilot Tip will be about winter flying. Please leave a comment below (click on comment) and if there is anything you would like me to discuss, or have any tips of your own, please let me know. Have a fantastic day and safe flying in the Alaskan Bush!

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