The McDonnell Douglas DC-10 was one of several "tri-engine" jet-powered airliners developed into the 1970s. The aircraft marked the first airliner product following the merger of aviation concerns McDonnell and Douglas. Design work began in February of 1968 in respond to a long-range wide body airliner requirement from American Airlines. The design would compete with the range provided by Boeing's 747 line with smaller payload capabilities though what began as a twin-jet airframe - later evolved to include a third powerplant to meet performance requirements. A prototype DC-10 achieved first flight on August 28th, 1970 (at Long Beach, California) and the line was formally introduced on August 5th, 1971 through American Airlines (United States) as the initial launch customer. The type went on to see service with Biman Bangladesh Airlines (Bangladesh), FedEx Express (United States), Kelowna Flightcraft Air Charter (Canada) , Transportes Aereos Bolivianos (Bolivia) and Turkish Airlines (Turkey) (among others). Production spanned from 1968 to 1988 to which 446 airframes were completed - 60 of these earmarked for the United States Air Force (USAF) in its modified KC-10 "Extender" aerial refueling aircraft. Deliveries of all marks spanned from 1971 into 1989 with peak year being 1973 with 57 aircraft delivered. McDonnell Douglas now exists as a subsidiary of powerhouse Boeing.
The MD-10 was developed as a long-ranged, wide-body airliner. Its fuselage could accommodate typical three-class seating or cargo pallets as required by the customer. Its outward design was conventional for the period with a tubular fuselage, low-mounted, swept-back wings and a single-vertical tail fin. The most unique aspect of the configuration was its three engine arrangement - two in underslung nacelles at each wing leading edge and the third over the fuselage spine at the base of the vertical tail fin. The cockpit flightdeck was at the extreme forward end of the aircraft and aft of a short nose cone assembly. Horizontal planes partnered with the tail fin at the rear and sported slight dihedral. The undercarriage was wholly retractable and featured a pair of four-wheeled main landing gear legs at center and a two-wheeled nose leg at front.
The DC-10 was produced across four major "body" versions beginning with the DC-10-10 and followed by the DC-10-15, the DC-10-30 and the DC-10-40. All early versions utilized a cockpit crew of three and, depending on the internal class configuration, could support seating for nearly 400 persons while freighters could house up to 22 pallets in the hold. Overall length was 170.5 feet with a height of 58 feet. The -10 and -15 models sported wingspans of 155.3 feet while -30 and -40 forms were given wider wingspans of 165.3 feet. Weights varied expectedly across the four production types with the -10 and -15 versions fielded at 240,170lbs when empty while the -30 and -40 marks tipped the scales at 266,200lbs and 270,200lbs respectively. Maximum Take-Off Weights (MTOWs) were equally different across all four versions - 430,000lbs, 455,000lbs, 572,000lbs and 555,000lbs respectively.
Each body was given various engine types: -10 models issued the General Electric CF6-6D turbofan engine of 40,000lb thrust each (3x). -15 models carried the GE CF6-50C2F turbofan engines of 46,500lb thrust each. -30 mounts were outfitted with the GE CF6-50C turbofans of 51,000lb thrust each and the -40 was completed with the Pratt & Whitney JT9D-59A turbofan of 53,000lb thrust each. All marks could reach cruising speeds of 610 miles per hour with typical speeds ranging closer to 560mph. Range was listed at 3,800 miles for the -10, 4,350 miles for the -15, 6,600 miles for the -30 and 5,750 miles for the -40.
Beyond the four major body forms, DC-10s were produced in several variants. Part of the original release were the DC-10-10, DC-10-10CF and DC-10-15. The -10 was the early base passenger variant of which 122 examples were produced. The -10CF was a passenger/cargo conversion model though only nine were produced. The -15 represented seven "hot and high" variants with special performing engines. The long-range forms began with the DC-10-30 (bypassing the proposed DC-10-20). Its conversion (passenger/cargo hauler) form was the DC-10-30CF. The DC-10-30ER was an "extended range" model with different engines for the longer-range role. The DC-10-30AF/F was the dedicated cargo hauler of the group. Military KC-10 Extenders were born from the DC-10-30 line (DC-10-30CF) and delivered from 1981 to 1988 across 60 examples. The USAF selection of the DC-10 occurred in December of 1977 through the Advanced Tanker Cargo Aircraft (ATCA) program. The KFC-10 was of similar form and function, destined for the Royal Netherlands Air Force though based on conversions of civilian DC-10-30CF models and not new-build airframes. The RNAF took delivery of their aircraft in 1995. The DC-10-40 was the first DC-10 to be outfitted with Pratt & Whitney engines (previous forms all used GE engines). The DC-10-50 and DC-10 "Twin" were ultimately abandoned endeavors.
Operational service of the DC-10 line was not without issue. Its type was centered across some 50+ situations which went on to stain the aircraft's reputation time. Despite this, the aircraft managed a useful service life only recently retired in December of 2013 with Bangladesh. Comparatively, the DC-10's service life was not much worse than other competing types seeing issues in heavy aviation operation. Some notable events included American Airlines Flight 96 and its "near-crash" incident while Turkish Airlines Flight 981 crashed and killed all 346 onboard. American Airlines Flight 191 resulted in the loss of 271 lives when its Number One engine detached on take-off, severing hydraulic lines in the wing. United Airlines Flight 232's tail engine unit failed due to a detached fan disk, again severing hydraulic control. This aircraft managed a partially-controlled landing under duress (pilots were forced to work the remaining engines to stabilize the aircraft) with 111 killed at a Sioux City, Iowa airport in July of 1989. It was a DC-10's piece found on the runway that ended the flight of an Air France Concorde in 2000, the Concorde crashing shortly after take-off with all lives lost.
Modifications eventually met the series and modernization kept it flying in a more safe manner. The MD-10 mark represented upgraded DC-10s with seating for just two personnel with more advanced instrument panels (based on the MD-11 line). The MD-11 was a further tri-engine development of the MD-10 and introduced in 1990 with FinnAir. 200 of this model were produced and remain in service.