Glossary

Aviation and Alaska Terminology

Alaska Airstrip Types

bush strip – A remote airstrip, typically unimproved and not connected to the road system. A bush strip may be difficult to spot from the air, consisting only of wheel tracks visible on a natural feature such as alpine tundra or a braided river bar.

cub strip – A short, challenging airstrip, typically in a remote location. Cub strips may be rough, narrow, or one-way. They require a highly skilled pilot and the ruggedness and STOL performance typical of a bush-modified Piper Super Cub.

natural feature – Naturally occurring landforms and vegetation. In our context, a natural feature is a naturally occurring landform (with or without vegetation) that has been or could be used as an airstrip or landing site. Some natural feature types may lack visible evidence of previous landings because of surface integrity. Visible wheel tracks may be ephemeral due to flooding, ecological succession, weathering, or erosion. 

one-way strip – An airstrip or natural feature where a go-around is not possible or prudent after reaching the abort point.

sheep strip – An airstrip or landable natural feature (often a cub strip) that provides access for Dall Sheep hunting. Sheep strips are typically located in mountainous terrain and can be very hazardous.

General Aviation

abort – The premature termination of a flight procedure.

abort point A point during the approach or takeoff phase beyond which a termination of the procedure may yield undesirable and/or catastrophic results. 

abort point, landing approach – The point beyond which discontinuing the approach (going around) is not safe or possible and the airstrip is considered one-way.

abort point, takeoff  – The point beyond which aborting the takeoff is considered to be unsafe. In bush operations, continuing the takeoff run beyond the abort point is often necessary to get airborne – especially in a heavily loaded airplane. 

bush mods – Airplane modifications to enhance safety, durability, utility, and STOL performance for private and commercial off-airport/bush flying operations. Popular bush mods include shoulder harnesses, tundra tires, heavy-duty nose wheel fork, high-pressure double-puck brakes, heavy-duty extended landing gear, landing gear long step, bush shocks (main gear suspension), landing gear safety cables, two-bolt tailwheel, fat tailwheel tire, 1.5″ tail spring or tailwheel suspension system, climb prop, PSTOL flaps, leading-edge wing cuffs, vortex generators, over-spar wing tie-downs, spar lifting eyes, extended baggage, cargo pod, gross weight increase, long-range fuel, all-metal gascolator, and engine power upgrades. 

bush pilot – A pilot who operates (flying, navigating, landing and taking off) small airplanes in remote and often uninhabited areas. 

bush plane – Airplanes used for bush flying operations in remote, undeveloped areas that lack ground transportation options. Preferred configurations are high-wing with conventional landing gear (tailwheel) often outfitted with bush and STOL modifications. Preferred Alaska bush planes include the Piper Super Cub (PA-18), Cessna Skywagon (C-185 and C-180), DeHavilland Beaver (DHC-2), DeHavilland Otter (DHC-3), and Helio Courier. Nose wheel airplanes typically used for less hazardous airstrip surface conditions include the Cessna Stationaire (C-206), Cessna Stationaire 7 (C-207), Cherokee Six (PA-32), and Cessna Caravan (C-208).

field repair – Improvised, makeshift repairs, often urgent in nature, accomplished at inconvenient or remote locations without available resources such as infrastructure, communication, parts, tools, and sometimes without the aid of a certified mechanic. Field repairs are often temporary with the goal of getting the plane out of the bush or ferrying it to a location where permanent repairs can be made.

decision point A point in space and time when a final decision must be made. 

decision point, landing approach – A point during the landing approach when the final decision to either land or to abort must be made. The decision point precedes the abort point allowing time for a go-no-go decision to be made. 

STOL – Acronym for “short takeoff and landing” used to describe the performance characteristics of a small airplane. 

tundra tires – Oversized airplane tires commonly used on bush planes that enable landings on rough terrain; also for exhibition. Tundra tires such as Alaskan Bushwheels, are sometimes under-inflated to improve cushioning, floatation, and minimize bounce. Taildraggers run the largest sizes (29”, 31”, and 35”) and often have corresponding fat “baby Bushwheel” tailwheel tires.

Natural Environment

alluvial fan – A low, outspread mass of loose materials such as silt, sand, gravel, rocks, and mud shaped like an open fan, deposited by a stream. It is steepest near its apex which points upstream and slopes gently and convexly outward (downstream) with a gradual decrease in gradient

ash flow – (aka pyroclastic flow) A superheated mixture of volcanic gases and ash, traveling down the flank of a volcano or along the surface of the ground forming a sheet; produced by the explosive disintegration of viscous lava in a volcanic crater, or by the explosive emission of gas-charged ash from a fissure. The solid materials contained in a typical ash flow are generally unsorted and ordinarily include volcanic dust, pumice, scoria, and blocks in addition to ash.

beach terrace – A landform that consists of a wave-built terrace of well-sorted sand and gravel of marine (sea) or lacustrine (lake) origin.

braided river – A river (or stream) with multiple channels that interweave as a result of repeated divisions and convergence of flow around bars, resembling the strands of a complex braid. Braiding is generally confined to broad, shallow rivers and streams whose overall courses are not intricate or overly winding that have non-cohesive bank material and high bed load. 

estuary – (a) A seaward end or the tidal mouth of a river valley where fresh water comes into contact with seawater and where tidal effects are evident. (b) A portion of an ocean or an arm of the sea affected by fresh water. 

glacial outwash – Stratified and sorted sediments of sand, gravel, and silt washed out from a glacier by melt-water streams and deposited downstream of the end moraine or the margin of a glacier. The coarser material is deposited nearer to the ice. 

muskeg – A sphagnum bog, sometimes with grassy tussocks (hummocks), growing in wet, poorly drained boreal regions often occuring in but not exclusive to areas of permafrost.

stream terrace – Flat-topped landforms in a stream valley that flank and are parallel to the stream channel, originally formed by a previous stream level, and representing remnants of an abandoned flood plain, stream bed, or valley floor. 

tidal flat – An extensive, nearly horizontal, barren or sparsely vegetated tract of land that is alternately covered and uncovered by the tide, and consists of unconsolidated sediment (mostly clays, silts and/or sands and organic materials). 

tundra – A treeless zone with low temperatures and a short growing season. Alpine tundra is found at high elevations. Arctic tundra is found north of the permafrost line, generally north of the arctic circle. 

water course – A natural channel through which water flows. Watercourses, aka water channels, may be dry.