Hot and High - Specialized Aircraft

Specialized Aircraft

Several manufacturers of early jet airliners offered variants optimized for hot and high operations. Such aircraft generally offered the largest wings and/or the most powerful engines in the model lineup coupled with a small fuselage to reduce weight. Some such aircraft include:

• The BAC One-Eleven 475 combined the short body of the series 400 with the more powerful engines and improved wings of the series 500. Also featured stronger landing gear for rough field operations.
• The Boeing 707-220, which was a 707-120 airframe fitted with more powerful Pratt & Whitney JT4A engines, civilian versions of the military J75. The 707-220 had extremely high fuel consumption, and only 5 were built, all for Braniff International Airways. The 707-220 was rendered redundant by the release of the turbofan-powered 707-120B, which had even greater power along with much lower fuel consumption.
• The Convair 880. Although Convair only offered one configuration of this aircraft, it had more power and a smaller fuselage than its competitors from Boeing and Douglas. Convair essentially wagered the success of the entire 880 model line on the appeal of an aircraft optimized for hot and high operations. The wager failed; only sixtyfive 880s were sold and Convair's nascent airliner business soon collapsed.
• The Lockheed L-1011-200, which was otherwise an L-1011-100 with more powerful RB.211-524B engines.
• The McDonnell Douglas DC-9-20, which combined the smaller fuselage of the DC-9-10 with the larger wings and more powerful engines of the DC-9-30, and was significantly outsold by both.
• The McDonnell Douglas DC-10-15, which combined the fuselage of the DC-10-10 with the larger engines of the DC-10-30. These were specifically designed for and sold to Aeromexico and Mexicana. Only seven were built.
• The Vickers VC10, which was designed to meet BOAC requirements for a large airliner that could operate medium range flights from short runways in southern Asia and Africa. The resulting high fuel consumption compared to the contemporary Boeing 707 prompted all other major airlines to dismiss the VC10.

The marketing failure of these airplanes demonstrated that airlines were generally unwilling to accept reduced efficiency at cruise and smaller ultimate load-carrying capacity in return for a slight performance gain at particular airports. Rather than accepting these drawbacks, it was easier for airlines to demand the construction of longer runways, operate with smaller loads as conditions dictated, or simply drop the unprofitable destinations.

Furthermore, as the second generation of jet airliners began to appear in the 1970s, some aircraft were designed to eliminate the need for a special "hot and high" variant- for instance, the Airbus A300 can perform a 15/0 takeoff, where the leading edge slats are adjusted to 15 degrees and the flaps kept retracted. This takeoff technique is only used at hot and high airports, for it enables a higher climb limit weight and improves second segment climb performance.

Most jetliner manufacturers have dropped the "hot and high" variants from their model lineups.