The topic of low wing vs. high wing aircraft always starts a heated debated amongst pilots. These paragraphs discuss the merits of the high wing aircraft design.
Aircraft Wing Placement
One of the major questions in designing an aircraft is where to mount the wing. The early bi-planes had two wings, one below the fuselage and one above. As designs moved to a single wing, the choice became where to mount the wings? Or which one of the two wings to get rid of? An airplane mounted with the wing above the fuselage is called a high wing aircraft.
The two main civilian aircraft manufacturers, Cessna and Piper, have kept the high wing vs. low wing debate alive. Each airplane builder offers a primary trainer and the Cessna's is high wing and Piper provides a low wing plane. The debate between high wing and low wing probably does not have a winner when discussing flying characteristics. Every pilot has his own opinion. The high wing design has found niches where it is the almost exclusive design.
High Wing Advantages
Flying a high wing airplane provides the best visibility below the aircraft. The downward visibility is definitely a plus for navigating by ground reference, doing ground searches and photography. A high wing airplane is safer in a descent, avoiding the unfortunate possibility of coming down on another aircraft, especially on approach to the airfield or in the traffic pattern.
High wing aircraft are generally easier to get in and out of. The fuselage sits lower to the ground and there is no wing to climb over to enter the cabin. The high wing design is especially useful when there is a necessity to load and unload cargo.
High wing planes are considered safer to land on soft fields or water landings with float equipped planes. Keeping the wing higher off the ground avoids the chances of catching a wingtip in the event of a dip or tilting of the plane.
High Wing Disadvantages
High wing aircraft have poor visibility up and behind the plane. The wing blocks what a pilot can see aft of the front of the wing, especially trying to see above the plane. This may be one reason there are no high wing fighter aircraft.
A major limitation to the high wing design is the placement of landing gear. The gear struts must be attached to the fuselage, resulting in a narrower gear width than a low wing plane with the landing gear coming straight down from the wings. Retractable gear often require pods or nacelles on the fuselage of a high wing plane, increasing the drag from the fuselage.
Since the wing is the main fuel storage area for many aircraft, fueling a high wing aircraft requires climbing up on the wing or some sort of lift.
Cessna has been one of the most successful general aviation companies with their lineup of single-engine high wing airplanes. Cessna's have found a wide range of uses from trainers to bush pilot and float planes.
For commercial / military use the high wing design has proven itself in cargo transport. From the single engine Cessna Grand Caravan, pictured above, to the multi-engine turboprop and jet military transport aircraft like the C-17 Globemaster, high wing has been the way to fly for transporting stuff. A high wing provides a low fuselage with easy entry and a flat cargo floor. High wings keep the engines up off the ground to avoid foreign object damage -- FOD.
Compare high wing aircraft to their low wing counterparts.
The Infrequent Flyer; http://www.theinfrequentflyer.com/airplane-high-wing-vs-low-wing.php
Stoenworks.com: High wing / Low wing; http://stoenworks.com/High%20wing,%20Low%20wing.html
Photo Credits: Wikimedia Commons