Ageing fleets are coming under increasing economic and environmental scrutiny

Max Kingsley-Jones/LONDON

The growth of the world's ageing airliner fleet is starting to stabilise, as this year's additions are countered by older aircraft being retired from service.

A total of 11,230 jet and turboprop airliners are included in this year's census, a decrease on the 1999 total of 11,400 aircraft. The West's ageing fleets, however, have grown slightly - from to 8,200 to 8,400 aircraft.

North America has the most ageing aircraft in the West, with almost 60% of the 5,500 jets and over 40% of the 2,900 turboprops. Europe is next, with 13% of the fleet, while Asia and Latin America share runner-up positions.

Fleet growth is reduced by the increase in retirements - almost 1,000 Western-built jet and turboprop aircraft have been retired over the past four years, with over 200 retirements annually. UK-based consultancy Airclaims recorded 220 Western-built jet and turboprop retirements last year, with 300 in 1998 and 230 in 1997. The high cost of keeping older, inefficient aircraft in good running order and compliant with the increasingly stringent environmental legislation can mean the scrap metal and spares dealers beckon.

The increasing number of widebodies being broken for spares - particularly older Airbus A300s, Boeing 747s and Lockheed L-1011 TriStars - has seen the size of the ageing large aircraft fleet remain static. In the past four years, over 180 747s, L-1011s, McDonnell Douglas DC-10s and A300s have been withdrawn from the world's fleets - 70 last year, 65 in 1998, 30 in 1997 and 20 in 1996.

Meanwhile, Western-built jet airliners in temporary storage has grown to over 960 aircraft. The tally had been stable at around 600-700 aircraft since the mid-1990s, after peaking at over 1,000 in the recession a decade ago.

Since the US Congress passed the Ageing Aircraft Safety Act in 1991, scrutiny of older airliners' structural security has intensified. The act required the FAA to develop regulations to ensure the airworthiness of aircraft approaching 25 years in age. Last year, however, the US agency revealed that the mandate for ageing airliner inspections would be extended to those over 14 years. The aircraft would then be inspected every five years. This would affect 2,800 more airliners.

Meanwhile the recent high profile transatlantic "hushkit" fight has effectively ended the import of non-pure Stage 3 aircraft into Europe. This adds another string to the bow of those seeking enforced obsolescence of older Stage 2 aircraft.

Earlier this year, the FAA issued a ruling requiring operators of certain older types to incorporate repair assessment guidelines (RAG) for work done along the so-called "pressure boundaries" - which include fuselage skins, bulkhead webs and door skins - into their maintenance and inspection programmes.

The RAGs result from the famous April 1988 Aloha Airlines Boeing 737-200 incident. They establish a damage-tolerance-based supplementary inspection programme for repairs carried out, then detect damage which may develop in an already repaired area. Certain Boeing and McDonnell Douglas types are affected, along with Airbus A300s, BAC One-Elevens, Fokker F28s and Lockheed L-1011 TriStars. Compliance is required by a certain number of flight cycles or by 25 May, 2001, which ever is later.

The CIS airlines find themselves in a "catch- 22" situation, as a lack of funding stops them from replacing older aircraft but also makes it hard to keep the ageing fleet airworthy. A major problem looming is the introduction of Stage 3 noise and emission rulings for aircraft that fly to Western Europe, the USA, and parts of Asia.

Ageing airliners - explanatory notes

Airliners defined as ageing by Flight International are turbine-powered aircraft seating as least 15 passengers (or an equivalent freight capacity) and built more than 15 years ago (before 1 January 1986). The 2000 Flight International Ageing Airliner Census covers 57 turbine-powered passenger and cargo types, while designs with few examples have been omitted. Data includes operational aircraft and those in temporary storage.

The fleet data include all non-military operated aircraft and are correct to the beginning of 2000. The utilisation data is the most recent available.

The average age and utilisation figures are for the entire fleets (ie, for all years of manufacture).

Much of the data for the census are derived from records collated by London-based Airclaims within its CASE aviation database and Jet Storage Update publication, while the source for the Russian data was Ireland-based Russian-aviation specialist Paul Duffy.

This information, covering whole fleets, includes information on the airframes that have the highest numbers of cycles (flights completed) and flight hours. The data on stored aircraft, which are available only for Western types, include all years of build, and all variants.

Original design lives are shown, or approved extensions where known. Information on dimensions, weight and accommodation is generic, with the highest value published where there are alternatives. Maximum weight is that at take-off.

Data are taken from various sources, including Flight International records. Input from other sources is welcomed.

To show the age of the fleet (from service entry or year of build), the status of fleet leaders in cycles (flights), hours flown and age - almost always a different aircraft is shown. As a result of high-time aircraft being permanently withdrawn from service (eg, broken up for spares), it is possible for the current high-time aircraft to have lower hours/cycles values than in a previous edition of the census.

Population is by type, collectively for pre-1974 aircraft and by year of build for 1974-1985. Data are scant for many older designs - especially turboprops, CIS types and cargo aircraft. The fact that some types are no longer supported by the manufacturer can affect utilisation data.

Types omitted because of small numbers in service are the Aerospatiale (Sud Aviation) Caravelle (12), Antonov An-8 (10), BAC (Vickers) VC10 (25, but no civil), Canadair CL-44 (six), Handley Page Herald (one stored), Shorts Belfast (two), de Havilland DHC-5 Buffalo (15), IAI Arava (20), Vickers Viscount (only two are believed active) and VFW614 (two).

Conversion factors:

1m = 3.3ft 1kg = 2.2lb


AD Airworthiness Directive BAe British Aerospace CAA UK Civil Aviation Authority FAA US Federal Aviation Administration GE General Electric P&W Pratt & Whitney P&WC Pratt & Whitney Canada RAG Repair Assessment Guidelines R-R Rolls-Royce CFMI CFM International


Aerospatiale/BAe (BAC) Concorde

The first of two Concorde prototypes was flown in March 1969, with the first production aircraft having its first flight in December 1973.

Twenty Concordes were built - four prototype/pre-production and 16 production aircraft - at dual final assembly lines in Toulouse, France and Bristol, UK. Fourteen aircraft were delivered to Air France and British Airways between 1975 and 1980 and 13 are in Service. The remaining six aircraft were used for testing and not delivered.

One of the seven Concordes delivered to Air France has been permanently withdrawn from use as a spares source, while all BA's seven aircraft remain in service. BA achieves a considerably higher utilisation and has the fleet-leading Concordes.

The original design life for the Concorde was set at 24,000 cycles, although the figure was never proved as fatigue testing was suspended in the early 1980s with around 20,000 simulated cycles logged.

BAE Systems is co-ordinating a programme to monitor and calculate airframe life, dubbed Concorde Relife Group, from its Filton, UK, plant. Air France and BA expect to be able to continue Concorde operations until 2014/5.

The aircraft has a calculated design life which is defined as 6,700 reference flights, with one such flight being equivalent to a long sector operated from a take-off at a gross weight of more than 170t (for example, a transatlantic service). A take-off for a shorter flight at, for example, a gross weight of 120t counts as 0.5 reference flights.

Although the high-cycle Concorde has recorded almost 8,000 cycles, its calculated reference flight tally is over 6,000.

As the lead aircraft is approaching the current limit, BA, in conjunction with Aerospatiale Matra and BAe, is working to extend the limit to 8,500 reference flights.

The lead airframe has completed over 6,500 supersonic flights.

The Concorde fleet has suffered control surface delamination incidents over the years resulting in corrective actions having to be employed.

Maximum weight 185,000kg Accommodation 100 (design maximum 144) Wingspan 25.6m length 62.1m height 11.4m Original design life 24,000 cycles (or 6,700 reference flights) 45,000h 12-15 years Average fleet cycles 16,400 Average fleet hours 5,600 Average fleet age 24 years


Airbus A300

A total of 250 of the original B-suffixed A300 variants (the A300B1, B2, B4 and cargo derivatives C4/F4) were completed before production standardised on the -600 models in 1985. Production continues in the latest -600R guise. Around 490 A300s of all variants have been delivered.

After a first flight in October 1972, A300 deliveries began in 1974. Most A300Bs were powered by GE CF6s, with the rest having P&W JT9Ds. The second-generation -600, which entered service in 1984, made its debut in our census in 1998, and 19 examples of that variant qualify. The main difference between the -600 and earlier versions is its two-crew "glass" cockpit, which provides commonality with the A310. Later versions of the -600 have the PW4000 engine.

Early A300B2/B4s have suffered from delamination of the bonded fuselage lap joints apparently as a result of poor preparation of the components before assembly. This has resulted in corrosion caused by moisture penetration.

BAE Systems Aviation Services and DaimlerChrysler Airbus offer cargo conversion programmes for the A300B4, with an increasing number being acquired by express packages operators in Europe and the USA. Many older A300B2/B4s are being broken up for spares.

There are 213 A300s older than 15 years in operation. Japan Air System operates the largest single ageing fleet of A300s (17 aircraft over 15 years).

The A300B2/B4 is included in the FAA RAG programme, with the implementation time set at 36,000 flights for the B2, 30-36,000 for the B4-100 and 25,500-34,000 flights for the B4-200.

Maximum weight (B4) 142,000kg (-600) 165,100kg Accommodation 220-360 Wingspan 44.8m length (B4) 53.6m (-600) 54.1m height 16.5m Original design life 36,000 cycles 60,000h 20 years Average fleet cycles 15,200 Average fleet hours 27,200 Average fleet age 13 years

Airbus A310

Production of the A310 began in 1982, and continues in the latest -300 form (introduced in 1985) in small numbers. This short fuselage, 200-seat derivative of the A300, was flown in April 1982 (-200) and the type entered service a year later.

Two hundred and fifty-five A310s have been delivered, 74 of which are 15 years old or more. FedEx operates the largest A310 fleet, with 41 of its aircraft being at least 15 years old.

Maximum weight (-200) 142,000kg Wingspan 43.9m length 46.7m height 15.8m Original design life 35,000 cycles 60,000h 20 years Average fleet cycles 11,600 Average fleet hours 29,800 Average fleet age 12 years

Boeing 747

Production of the 747 "Classic" (ie, -100/200/300 and SP models), extended to 724 aircraft before production standardised on the advanced, two-crew, 747-400 in 1991. This model remains in production and 1,240 of all variants have been delivered since the first in December 1969. Numerous engine/airframe combinations exist, powered by versions of the GE CF6, P&W JT9D and PW4000 and R-R RB211. Around 480 747s aged 15 years or more remain in operation. With expensive modifications needed for ageing 747s, it is increasingly becoming the most economic solution to dismantle early aircraft for spares. As a result, the ageing fleet has shrunk slightly as older aircraft are retired.

During 1996, a 747-100 operated by TWA passed 100,000 flight hours and this high-time aircraft went on to complete over 111,600h before being retired. The two major structural issues on the type are replacement of the fuselage frames in the Section 41 (cockpit) zone and modification of the engine pylons. Northwest Airlines has the largest ageing 747 fleet, with 27 aircraft aged over 15 years.

The US FAA has issued wiring- and electrical component-related airworthiness directives (ADs) affecting 747s as a result of the continuing investigation into the causes of the TWA 800 crash in July 1996. The FAA has said that its survey of ageing aircraft "revealed no situations that presented immediate safety concerns".

Meanwhile, in December 1998, Boeing advised 747 operators to expand routine inspections to include the pylon structure for all engine types after fatigue-related cracks were found on a Cathay Pacific 747-200 freighter. The 747 is included in the FAA RAG programme, with the implementation time set at 15,000 flights.

Several avionics upgrades have been developed for the classic variants, including a digital cockpit certificated in 1999 by the German civil aviation authority. KLM/Canadian Marconi received a supplemental type certificate (STC) from the US FAA in May for the flightdeck upgrade of the Dutch airline's thirteen 747-200/300 Classics. Honeywell and Boeing have proposed a glass cockpit retrofit for the 747 Classic, which would retain the flight engineer's position but provide a dual rating with the two-crew -400 model.

Maximum weight (-100) 333,000kg (-200) 378,200kg Accommodation (-100) 433 (500 all-economy) Wingspan 59.6m length 70.5m height 19.3m Design life objective 20,000 cycles 60,000h, 20 years Average fleet cycles 10,000 Average fleet hours 46,800 Average fleet age 14 years

Boeing 767

First flown in September 1981, the initial Boeing 767-200 model entered service with United Airlines in August 1982. In all, 132 aircraft qualify for this year's census, all smaller -200 models.

The 767 is one of the types being targeted by the USA's planned broadening of its ageing aircraft programme. United Airlines has the largest ageing fleet, with 19 in service.

The -200 is powered by either P&W JT9D/PW4000 or GE CF6-80 engines. The R-R RB211 is also available on the -300. Some early 767-200s have been upgraded with weight and fuel capacity increases providing transatlantic services.

Airborne Express has acquired a fleet of ex-All Nippon Airways -200s that are being modified for cargo operation. The conversion includes structural modifications, but no cargo door, with the first aircraft having entered service in 1998.

Boeing Airplane Services has developing a full freighter conversion and is seeking launch customers for the project.

The FAA has ordered a Boeing service bulletin for inspection of engine pylons on older 767s to check for cracks. The first 230 aircraft are affected.

Maximum weight (-200) 136,200kg Accommodation (-200) 216 (290 all-economy) Wingspan 47.6m length 48.6m height 15.9m Design life objective 100,000h, 40 years. Cycles not known Average fleet cycles 9,800 Average fleet hours 30,100 Average fleet age nine years

Ilyushin Il-86

The Il-86 was first flown in December 1976, and was the first widebodied airliner produced in the former Soviet Union. The type entered service in 1979. One hundred and four aircraft had been completed and delivered by the time production ceased in 1994. Forty-one examples built before 1986 remain in service. The highest-time aircraft is a 17-year-old example, while the high-cycle machine is 16 years old.

Vnukovo Airlines signed an agreement with IIyushin and the Voronezh production complex in 1998, covering technical support and modernisation for the Russian carrier's Il-86s up to 2005.

Maximum weight 208,200kg Accommodation 234 (380 one class) Wingspan 48.1m length 59.6m height 15.8m Original design life 20,000 cycles, 30,000h, 20 years

Lockheed L-1011 TriStar

Deliveries of the standard body L-1011 TriStar 1 began in 1972, while production of the short-fuselage, long-range TriStar 500 started in 1979. The assembly line closed in 1983 after 249 were delivered. One hundred and seventy three remain in service with non-military operators. All versions of the tri-jet are powered by R-R RB211s.

Lockheed Martin continues to support the type. Corrosion and fatigue cracking affects the airframe. One of the major repairs required to the older aircraft is a modification to the rear spar. There is also a repair assessment programme that enables the design life to be extended.

The TriStar is included in the FAA RAG programme, with the implementation time set at 27,000 flights.

Marshall Aerospace offers a freighter conversion programme and has completed 10 civil conversions. A Lockheed Martin/Rolls-Royce-led consortium, the TriStar Alliance, has been formed to support the tri-jet as part of efforts to enhance the longer-term prospects for the aircraft.

Delta Air Lines, which has the largest fleet (47 aircraft), is also a member of the Alliance. It has an agreement with London-based leasing specialist Intercapital Aviation to sell an initial batch of 13 L-1011-1s, which will be converted to freighters by Lockheed Martin at Greenville, South Carolina. The deal could be extended to include up to 40 ex-Delta TriStars. Lockheed Martin's planned revival of the TriStar conversion will use Marshall Aerospace's STC.

Maximum weight (-100) 211,375kg (-200) 211,600kg (-500) 231,500kg Accommodation 256-400 (-1/100/200) 230-250 (-500) Wingspan (-1/100/200) 47.3m (-500) 50.1m length (-1/100/200) 54.2m (-500) 50.1m height 16.9m Original design life 115,000 cycles, 210,000h, 20 years Average fleet cycles 21,000 Average fleet hours 53,800 Average fleet age 22 years

McDonnell Douglas DC-10

A total of 386 DC-10s was built between 1970 and 1989, when the line switched to the larger MD-11. A further 60 KC-10 tanker/transport versions were delivered to the US Air Force. Three hundred and thirty one DC-10s qualify for this year's census.

This fleet includes versions of the short-haul GE CF6-powered -10/-15 and longer-range -30, plus the P&W JT9D-powered -40.

The first FedEx DC-10 modified by Boeing to MD-10 specification first flew from Long Beach in April 1999 and the Boeing-managed MD-11-based two-crew conversion was certificated by the FAA in May 2000. FedEx, which has the largest ageing fleet of DC-10s (80 aircraft), has orders for around 90 MD-10 conversions.

In April the US FAA notified DC-10 operators that all aircraft would have to undergo a thrust-reverser system safety modifications costing about $172 million. The work includes installing new wiring and an additional thrust reverser locking system, as well as light systems changes to all US-registered aircraft. The FAA's proposed compliance time is five years from a final rule's effective date, but changes to the reverser position indicator light would need to be completed in 18 months. The DC-10 is also included in the FAA RAG programme, with the implementation time set at 30,000 flights.

Maximum weight (-30) 263,320kg Accommodation 270 (380 high density) Wingspan (-30/40) 50.4m length 55.5m height 17.7m Design life and "test-supported life"(DC-10-10) 42,000 cycles 60,000 20 years (DC-10-30/40) 30,000 cycles 60,000h 20 years Average fleet cycles 19,100 Average fleet hours 62,200 Average fleet age 23 years


Boeing 707/720

Boeing built and delivered 856 707s between 1957 and 1991 (including 93 military E-3 and E-6 versions). A further 154 short fuselage 720s were completed. The last civil 707 was handed over in 1979, with production thereafter concentrating on military derivatives.

One hundred and thirty-eight 707/720s remain in operation with civil operators, most of them the longer fuselage -707-300 version operated in the cargo role. Only P&W JT3D-powered versions are in commercial service. The 707 is included in the FAA RAG programme, with the implementation time set at 15,000 flights, and 23,000 for the 720.

Quiet Nacelle has developed a Stage 3 hushkit for the US Air Force-operated 707s/C-135s. Meanwhile Quiet Skies, which was established by Burbank Aeronautical (BAC II), received an STC in November 1998 for its Stage 3 hushkit for the Pratt & Whitney JT3D-3B-powered 707-300.

BAC is restarting its 707 hushkit line following almost a one-year suspension caused by continuing market uncertainty over the impact of European Union regulations on operations of aircraft modified with hushkits for Stage 3 compliance.

The company is also preparing to restart certification work on a 707 winglet modification programme around July, with an STC for this modification is expected around October. The company has also completed work on a "lightweight" Stage 3 modification for the 707-100 series. The package includes flap setting changes and modifications to operating procedures.

Irish 707 leasing specialist Omega has the largest single 707 fleet with eight aircraft. It leads the Seven Q Seven group which has developed a 707 P&W JT8D-200 re-engining programme. Flight-testing is set to begin in earnest later this year, following preliminary tests with an aircraft equipped with one JT8D in place of a JT3D. As well as bringing the 707 within the Stage 3 noise limits, the modification will boost performance significantly.

Maximum weight (300B/C) 161,450kg Accommodation (-300) 141 (219 all economy) Wingspan 44.4m length 46.6m height 12.9m Design life objective 20,000 cycles 60,000h, 20 years Average fleet cycles 13,700 Average fleet hours 35,700 Average fleet age 27 years

Ilyushin Il-62

The first Il-62 flew in January 1963 and 280 aircraft have been produced. The original version of the four-engined design entered service in 1967, powered by Kuznetzov NK-8s. Subsequent variants have been powered by larger Soloviev D-30KUs. Sixty-seven aircraft qualify for the census.

Airframes are subject to a design life extension extended following major airframe overhaul from 30,000h to 40,000h. Further extensions are being studied.

Weight (Il-62M) 165,000kg Accommodation 168 Wingspan 43m length 46.6m height 12.4m Design life 12,000 cycles 30,000h (extended to 40,000h) 20 years

McDonnell Douglas DC-8

In all, 556 DC-8s were produced between 1958 and 1972, of which 250 remain in service with non-military operators. As well as the JT3D-powered -50 and -60 versions, all but one of the 110 Series 70s (-60s re-engined with the CFM56) created remain in service. A Stage 3 hushkit has been developed by Burbank Aeronautical II (BAC II) for the DC-8-62/63, which has been certificated by the FAA.

BAC is preparing to flight test a Stage 3 hushkit for the DC-8-50/61 and hopes to receive its STC around September. The market for the DC-8-50/61 is estimated at around 45 aircraft. BAC says unlike earlier systems, the new hushkit will achieve Stage 3 "without fuel burn penalties or weight restrictions". All the hardware is 75-80% common to the sister programme developed for the 707-300.

The company also plans to fly the DC-8-50 with a version of the winglets developed for the 707.

The DC-8 is included in the FAA RAG programme, with the implementation time set at 30,000 flights.

Maximum weight (-63) 161,000kg Accommodation (-63) 260 Wingspan (-63) 45.2m length 57.1m height 12.9m Original design life 25,000 cycles, 50,000h, 20 years "Test-supported" life 50,000 cycles 100,000h, 20 years Average fleet cycles 25,600 Average fleet hours 68,500 Average fleet age 32 years


Boeing 727

Of 1,831 727s delivered between 1963 and 1984, 1,331 are in service, representing the largest single jet fleet in the census.

FedEx Aviation Services has developed a Stage 3 hushkit for the 727, which was certificated by the FAA in 1989. Dee Howard developed an R-R Tay re-engining programme for the 727-100. UPS' 50 aircraft have been modified.

BFGoodrich markets the old Valsan JT8D-200 re-engining programme as the Super 27 conversion. Over 40 aircraft have been modified. Two companies, Raisbeck Commercial Group and Duganair Technologies, offer modifications which reduce noise levels on the 727-200 below Stage 3 noise levels using aerodynamic modifications, without the need for a hushkit.

BFGoodrich and Raisbeck are studying a plan to tackle Stage 4 noise requirements for the Boeing 727 by combining the Super 27 conversion with Raisbeck's aerodynamic package.

The 727 is included in the FAA RAG programme, with the implementation time set at 45,000 flights.

Maximum weight (-200Adv) 89,450kg Accommodation (-200) 145 (189 high density) Wingspan (-200) 32.9m length 46.7m height 10.4m Design life objective 60,000 cycles, 50,000h, 20 years Average fleet cycles 38,00 Average fleet hours 53,000 Average fleet age 26 years

Boeing 737 (CFMI-powered)

The CFMICFM56-3-powered 737 made its debut in the census last year and 96 examples of the "Classic" model qualify.

Developed from the 737-200 - see entry - the 128-seat 737-300 was the first version of the three-model family and was flown in February 1984. It entered service in December that year. Both larger (-400) and smaller (-500) versions followed, entering service in 1988 and 1990 respectively, before the CFM56-7-powered Next Generation 737 family (-600 to -900 models) was launched in 1994. Production ceased in 2000, after some 1,988 examples had been delivered.

Southwest Airlines operates most of the early 737-300 examples with thirty-three 15-year-old examples in service. All versions of the 737 are included in the FAA RAG programme, with the implementation time set at 60,000 flights.

Maximum weight (-300) 56,500-62,900kg Accommodation ((-300) 128 (149 high-density) Wingspan (-300) 28.9m length 33.4m height 11.1m Design life objective 75,000 cycles, 51,000h, 20 years Average fleet cycles 15,900 (all CFM56-3 models) Average fleet hours 22,300 (all CFM56-3 models) Average fleet age nine years (all CFM56-3 variants)

Boeing 757

The 757-200 twinjet was first flown in February 1982 and entered service a year later. It is available with the R-R RB211-535 and P&W PW2037/PW2040 engines. The stretched -300 model entered service in March 1999.

Eighty-five 757s in service are at least 15 years old, with British Airways operating the single largest ageing fleet (20 aircraft). These aircraft are destined to be converted to freighters in a Boeing-managed programme launched last October for DHL. The first converted aircraft will enter service next year.

Maximum weight (-200) 99,900-115,800kg Accommodation (-200)186 (235 high-density) Wingspan 38.1m length 47.3m (-200) height 13.6m Design life objective 100,000 cycles, 40 years Average fleet cycles 10,100 Average fleet hours 23,300 Average fleet age 8 years

Boeing MD-80

The MD-80, a stretched, P&W JT8D-200-powered McDonnell Douglas DC-9 derivative, was in production between 1979 and 2000, with 1,191 examples being produced. A total of 268 aircraft which were built before 1986 remain. Two sizes have been produced, the basic MD-81/82/83/88 and the short-fuselage MD-87, which entered service in 1987. A small number of MD-80s has been assembled from kits in Shanghai, China.

An FAA AD was issued last February following the crash of an eight-year-old Alaska Arlines' MD-80, requiring operators of MD-80/90s, 717-200s and DC-9s to make urgent examinations of stabiliser jackscrews and gimbal and gimbal nuts used in the pitch-trim actuation system. Preliminary inspections of the wreckage revealed pre-crash damage to the stabiliser jackscrew, which was stripped of thread. The MD-80 is included in the FAA RAG programme, with the implementation time set at 60,000 flights.

Maximum weight (MD-81) 63,500kg Accommodation 155 (114 for MD-87) Wingspan 32.9m length 45.1m height 9m Original design life 30,000h Average fleet cycles 20,000 Average fleet hours 29,800 Average fleet age 12 years

Tupolev Tu-154


The Tu-154 first flew in October 1968 and Aeroflot put the type into service in 1971. Around 920 examples of the tri-jet have been built. Three basic versions have been produced: the original Tu-154, the Tu-154B powered by three Kuznetzov NK-8-2s and the Tu-154M, equipped with Soloviev D-30KUs.

Two hundred and ninety-six examples of the aircraft built before 1986 are in operation. After the Tu-154's service entry, it transpired that structural improvements would be needed to attain the required service life of 30,000h. This has since been extended to 45,000h, when a major overhaul is carried out, which also permits the cycle limit to be extended to 20,000 flights. Production of the Tu-154 at the Aviakor plant in Samara has been running at a trickle and is expected to cease by 2002 when the last 12 aircraft are completed.

Maximum weight 90,000kg Accommodation 167 Wingspan 37.5m length 48m height 11.4m Design life 15,000 cycles (extended to 20,000 cycles), 30,000h (extended to 45,000h), 20 years


British Aerospace (BAC)/Romaero One-Eleven

In all 235 One-Elevens were produced by BAC and its successor British Aerospace, from 1963-82 before assembly was transferred to Rombac (now Romaero) in Romania, where nine aircraft were completed under licence. The last Romanian aircraft was delivered in 1990. One hundred and seven teen aircraft remain, with a large number flying in the executive role.

Two sizes have been produced: the basic 80-seat Series 200, 300, 400 and 475 and the stretched 100/119-seat 500. All versions are powered by two R-R Speys.

A Stage 3 hushkit for the One-Eleven is being developed by US-based specialist Quiet Nacelle in conjunction with European Aviation of the UK.

The One-Eleven is included in the FAA RAG programme, with the implementation time set at 60,000 flights.

Maximum weight (Srs 500) 47,400kg Accommodation (Srs 500) 99 (119 high-density) Wingspan (Srs 500) 28.5m length 32.6m height 7.5m Original design life 55,000 cycles (now 85,000 cycles), 55,000h (now 85,000h), 25 years (now 40) Average fleet cycles 28,200 Average fleet hours 32,100 Average fleet age 30 years

British Aerospace 146

The first BAe 146 was flown in September 1981 (a -100) and the type entered service in May 1983. Powered by four AlliedSignal/Honeywell (formerly Textron Lycoming) ALF502 and LF507 engines, 221 BAe 146s were produced of which 219 were delivered in three fuselage lengths (-100, -200 and -300) of which 40 (all -100s and -200s) were built before 1985. The similar, but more advanced, Avro RJ family replaced the 146 from 1993.

BAe also developed a freighter version, the "QT" (Quiet Trader) which has a large main deck aft cargo door.

BAE Systems has undertaken a major avionics upgrade programme for the aircraft, which involves the installation of an AlliedSignal GNS-XLS satellite-based navigation system. Honeywell's traffic collision avoidance system, the TCAS 2000, is the preferred installation for the worldwide BAe 146 fleet.

Maximum weight (-100) 38,100kg (-200) 42,200kg Accommodation (-100) 82 (-200) 100 Wingspan 26.2m length (-100) 26.2m (-200) 28.6m height 8.5m Original design life 80,000 cycles 60,000h Average fleet cycles 18,800 Average fleet hours 18,800 Average fleet age 12 years

Boeing 737-100/200

The first 737 was flown in April 1967 and service entry followed in February 1968. Production of the initial versions (-100, -200 and -200 Advanced) powered by P&W JT8Ds ceased in 1988 in favour of the second generation family of CFM-powered models (-300/400/500) -- see earlier entry.

Production of the 737-100/200 totalled 1,144 aircraft and the ageing fleet consists of 860 aircraft. The numbers of older aircraft are beginning to diminish as operators retire aircraft and break them for spares.

Two companies, Nordam and AvAero, have developed FAA-approved Stage 3 hushkits for the JT8D-powered 737s.

It emerged earlier this year that design changes to the 737's rudder system, plus operational and maintenance procedure changes, may be ordered by the US FAA in the wake of an Engineering Test and Evaluation Board (ETEB) investigation into potential failure modes that could have contributed to two 737 crashes in 1991 and 1994.

The ETEB's full report is not expected to be submitted until June 2000 and the FAA said that no discoveries were made that require "any immediate action". It added, however, that the board's long-term recommendation is for design changes to address "failures that can result in rudder hardovers". In the short term, the ETEB recommendations are believed to include changes to operations and maintenance that will detect any potential control problems before they happen.

All versions of the 737 are included in the FAA RAG programme, with the implementation time set at 60,000 flights.

Maximum weight (-200) 53,290kg Accommodation (-200) 108 (130 all-economy) Wingspan (-200) 28.3m length 30.5m height 11.3m Design life objective 75,000 cycles, 51,000h, 20 years Average fleet cycles (737-100/200) 42,900 Average fleet hours (737-100/200) 46,900 Average fleet age (737-100/200) 22 years

Fokker F28

Fokker delivered 241 F28s between 1967 and 1987 in four basic versions - the Mks 1000, 2000, 3000 and 4000. All versions are powered by the R-R Spey Mk555. Two fuselage lengths were offered, covering the original short Mk1000 and similarly sized Mk3000 and the stretched Mk2000/4000. The Mk3000 and Mk4000 were equipped with a larger wing offering improved performance.

A Stage 3 hushkit and an R-R Tay 620 re-engining programme have been proposed, but neither has been launched into production. In all, 168 pre-1986 F28s are operational.

The F28's FAA RAG implementation time is 60,000 flights.

Maximum weight (Mk4000) 32,200kg Accommodation (Mk4000) 79 Wingspan (Mk4000) 25.1m, length 29.6m, height 8.5m Original design goal 90,000 cycles 60,000h, 40 years Average fleet cycles 37,300 Average fleet hours 32,200 Average fleet age 22 years

McDonnell Douglas DC-9

Series production of the DC-9 began in 1965 and 976 were delivered through to 1982 when assembly ceased. Five basic models were produced - the series 10, 20, 30, 40 and 50, all powered by the P&W JT8D. Seven hundred and forty four DC-9s are operational.

A DC-9 operated by Northwest Airlines passed the 100,000 cycle mark during 1996 and went on to reach almost 105,000 cycles before being retired. The current high cycle airframe has completed 100,055 cycles. The DC-9 was affected by the FAA AD issued after the Alaska MD-80 crash in January (see MD-80 entry). The FAA also issued DC-9 directives last September on two electrical modifications and a revision on the safe life of structural components. The DC-9's FAA RAG implementation time is 60,000 flights.

ABS Partnership has developed an FAA-approved Stage 3 hushkit for the type. Raisbeck Commercial Group is looking to develop an aerodynamic Stage 3 solution similar to the one it offers for the 727.

Maximum weight (-30) 46,760kg Accommodation (-30) 97 (125 one class) Wingspan 28.5m length 36.3m height 8.5m Original design life 40,000 cycles, 30,000h, 13 years "Test-supported" life 105,000 cycles, 75,000h, 20 years Average fleet cycles 62,000 Average fleet hours 59,400 Average fleet age 29 years

Tupolev Tu-134

After a first flight in July 1963 production of the Tu-134 continued until 1985, with 852 aircraft completed. The aircraft entered service in 1967. Three versions exist: the basic Tu-134, the stretched Tu-134A, powered by two Soloviev D-30 turbofans, and the Tu-134B, similar to the A, with improved engines and revised interior. Around 320 pre-1986 examples remain in service, more than half of which have flown for longer than the design hours. A service life extension to 25,000 cycles and 45,000h has been approved after a major overhaul.

The transfer of Tu-134s from military to civil operators began several years ago and up to 80 aircraft could find their way into the hands of commercial carriers. The two plans to convert military Tu-134s for civil use and to modernise the aircraft with the installation of the Progress D-36 engines have both run into finance problems and need to secure funding to progress further. Meanwhile, work by the design bureaus TsAGI, GosNII GA and SibNII is helping service lives to continue to be extended.

Maximum weight (Tu-134A) 47,000kg Accommodation 80 Wingspan 29m length 37m height 9.1m Original design life 20,000 cycles (extended to 25,000 cycles), 30,000h (extended to 45,000h), 20 years

Yakovlev Yak-40

The Yak-40 was flown in October 1966 and entered service in 1968. About 1,000 aircraft were built before production ceased in 1985. Powered by Ivchenko AI-25 turbofans, the tri-jet and was envisaged as the Soviet Li-2-replacement regional jet airliner designed to fly from grass airfields.

Large numbers remain in service with CIS airlines, although some are being purchased for corporate use. Five hundred and one pre-1986 examples are in service, with about 40% believed to be in storage. The civil fleet is increasing as aircraft are transferred from Russian flight schools as they are closed, and from research bodies.

Maximum weight 13,700kg Accommodation 33 Wingspan 25m length 20.3m height 6.5m Original design life 25,000 cycles (extended to 30,000 cycles), 30,000h (extended to 35,000h), 25 years

Yakovlev Yak-42

The Yak-42 had its maiden flight in March 1975 and the first delivery to Aeroflot was in 1980. The tri-jet was withdrawn in 1982 after an accident and re-introduced into service in 1984. Over 170 Yak-42s, powered by Lotarev D-36 turbofans, are believed to have been delivered and 34 aircraft in service are aged 15 years or older.

The aircraft remains in production as an updated version, dubbed the Yak-142, equipped with an AlliedSignal avionics suite and electronic flight instrument system.

The Yak -42 fleet leader finished 1999 with a total of 19,999 flight hours. This aircraft and the second highest time aircraft began a very heavy check earlier this year, and both airframes completed the inspection with few problems.

The Yakovlev design bureau is barely ticking over and the overhaul centres responsible for the two jet models have drawn up proposals to take over the design and modification authority for the types. This would be similar to the issuing of an STC in the West, but is not a standard practice in the CIS.

Maximum weight 54,000kg Accommodation 120 Wingspan 34.9m length, 36.4m, height 9.8m Original design life 30,000 cycles 30,000h


Ilyushin Il-76M/T

The Il-76 was originally conceived for the military role, but older aircraft with low hours and cycles are being converted to civil use. The first example of the high-winged, four-engined freighter was flown in March 1971 and entered service in 1972. More than 1,000 aircraft have been produced. The original versions were powered by MKB (Soloviev) D-30s, while a Aviadvigatel PS-90 powered MF was flown in August 1995. A civil version, the TF, is being produced for East Line.

There are 103 pre-1986 Il-76s in commercial service, a smaller number than previously recorded. The fleet reduction is principally due to the fall in market demand following the 1998 roubIe crisis. As a result, many of the Ukraine air force aircraft that were leased out to airlines have been returned to "uniform".

Rybinsk Motors, the manufacturer of the D-30 engine, has introduced a Stage 3 modification, but with a price of over $2 million an engine will struggle to find customers. Plans to retrofit the Il-76 with either the PS-90A or the CFM56-5 also require funding.

Maximum weight 170,000kg Maximum payload 40,000kg Wingspan 50.5m length 46.6m height 14.8m Design life 10,000 cycles, 30,000h, 20 years


Ilyushin Il-18

First flown in July 1957, over 700 examples of the Russian four-turboprop airliner were produced before production ceased in 1983. The Il-18 was powered by four Ivchenko AI-20M turboprops. Three civil versions were produced: the -18V, the more powerful -18E and the heavier, longer-range -18. Forty-eight examples remain in service, with one late production Il-22 military command post converted to Il-18 standard in 1999 for a Ukraine based airline. A 5,000h service life extension is possible following major overhaul.

Maximum weight (-18D) 64,000kg Accommodation 122 Wingspan 37.4m length 35.9m height 10.2m Original design life 25,000 cycles 30,000h


Lockheed L-188 Electra

The short/medium range Electra turboprop was first flown in December 1957 and entered service in January 1959. Powered by four Allison 501 turboprops, the aircraft remained in production until 1962, during which time 170 aircraft had been built. Fifty-four aircraft remain in existence, of which 30 are active operating mainly as freighters. Zantop International has the largest fleet, with 10 aircraft.

Lockheed Martin continues to provide technical support for the aircraft through its Marrietta plant. Operators report that the aircraft is ageing well, with any structural problems being detected by inspection rather than failure. The aircraft is the only turboprop affected by the FAA's ageing aircraft programme.

Maximum weight 52,660kg Accommodation 98 Wingspan 30.2m length 31.8m height 9.8m Original design life none set Average fleet age 41 years


Aerospatiale (Nord) 262

Aerospatiale's predecessor Nord flew the first example of the 262, then designated the MH-260, in July 1960 and in modified form in December 1962. The twin turboprop entered service in 1965, with 111 were produced through to 1976. A re-engined version, the Mohawk 298, featured P&WC PT6A engines in place of the original Turbom‚ca Bastan VIIs. Nineteen examples remain in service,

Maximum weight 10,800kg Accommodation 26-29 Wingspan 22.6m length 19.3m height 6.2m Original design life n/a Average fleet age 33 years

Antonov An-24/30

The twin turboprop An-24 was flown in April 1960 and entered service in 1963 with Aeroflot. There are five models, including B, RT, RV and T variants, all powered by two Ivchenko AI-24s -- some with an auxiliary turbojet for improved performance and engine starting.

Some CIS military An-24s are being transferred for civil operation, but these are mainly outside Russia.

An airborne survey derivative, the An-30, is increasingly being used as a freighter and occasionally in the passenger role as survey work is falling off. Sixty-seven aircraft are included within the An-24 totals. A 5,000h service life extension is possible following major overhaul.

Maximum weight 21,000kg Accommodation 50 Wingspan 29.2m length 23.5m height 8.3m Design life 35,000 cycles, 50,000h, 25 years

ATR 42

The ATR 42 had its first flight in August 1984, and entered service in December 1985. Powered by the P&WC PW100 this 48-seat twin turboprop makes its debut in the census this year. Production continues of the model in current -500 form, along with the larger 64-72 seat ATR 72 model, which entered service in 1989.

A total of 355 ATR 42s has been delivered, of which four are 15 years old.

Maximum weight 18,600kg Accommodation 42-50 Wingspan 24.6m length 22.7m height 7.6m Original design life 70,000 cycles Average fleet age nine years

BAe (Avro/HS)/Hindustan Aeronautics (HAL) 748

In all, 293 748s were produced between 1962 and 1989 by British Aerospace (and predecessors Hawker Siddeley and Avro) and a further 89 aircraft were manufactured under licence by HAL in India. The Andover military version, equipped with a rear cargo door was developed for the Royal Air Force, with 31 delivered.

All 748s are powered by two R-R Darts. One hundred and forty-two 748s in service are pre-1986 examples.

Most of the Andovers have been sold to civil operators as freighters and are included in the figures.

Maximum weight (Srs 2A) 21,100kg Accommodation 58 Wingspan 30m length 20.4m height 7.6m Original design life 30,000 cycles, 30,000h Average fleet age 27 years

Bombardier (de Havilland) Dash 8

The initial version of the Dash 8, the 37-seat -100, was first flown in June 1983, and entered service in October 1984. Two stretched versions have been developed, the 50-seat -300 and 70-seat Q400, as well as an updated version of the -100, dubbed the -200. All variants are powered by versions of the P&WC PW100.

Of the 540 Dash 8s delivered to date, 23 are over 15 years old. Piedmont Airlines has the largest ageing Dash 8 fleet.

Maximum weight (Srs 100) 14,970kg Accommodation 37 Wingspan 25.9m length 22.3m height 7.5m Original design life 60,000 cycles 80,000h Average fleet age eight years


The 19-26-seat C212 Aviocar was developed for the military/utility and regional airliner roles. The aircraft had its first flight in 1971 and deliveries of the military variant began in 1974. One hundred and sixteen aircraft qualify for this year's survey.

Production has been undertaken by CASA in Spain and IPTN in Indonesia. Production for the military market continues.

Maximum weight 7,300kg Accommodation 26 Wingspan 9.0m length 15.2m height 6.7m Original design life 25,000 cycles Average fleet age 17 years

Convair CV-580

The CV-580 is a conversion carried out by Pacific Airmotive of Burbank of the piston-powered Convair 340/440, but with two Allison 501-D13 turboprops. It has a larger fin for single-engined stability, modified systems and new instrument panel.

A total of 164 aircraft was converted and 123 remain in operation. Kelowna Flightcraft has developed a stretched version - the -5800.

Maximum weight 26,370kg Wingspan 32.1m length 24.1m height 8.6m Original design life never established

Convair CV-600 and 640

These are turboprop conversions of the Convair 240 and 340/440, respectively, powered by two R-R Dart 10 Mk524s. A total of 38 CV-600s and 27 CV-640s was created, with 25 examples remaining.

Maximum weight (640) 24,950kg Accommodation (640) 56 Wingspan (640) 32.1m length 24.8m height 8.6m Original design life never established.

De Havilland (Bombardier) Dash 7

The first Dash 7 was flown in March 1975 and the aircraft entered service in February 1978. Powered by four P&WC PT6A-50s, the 50-seat regional turboprop offers short take-off and landing performance.

Production ceased in 1988 after 113 aircraft had been completed, of which eight-four are at least 15 years old.

Maximum weight 19,960kg Accommodation 50 Wingspan 28.4m length 24.6m height 7.9m Original design life 60,000 cycles (crack-free). Extended to 80,000 cycles. Further extensions possible through continued engineering evaluations. Average fleet age 19 years

Embraer EMB-120 Brasilia

The first EMB-120 Brasilia was flown in July 1983 and the type entered service in August 1985. Powered by two PWC PW115 or PW118 turboprops, the baseline EMB-120 was joined by the increased gross weight -120ER Advanced model from 1994, offering extended range. QC and cargo versions are also available.

The 30-seat turboprop made its debut in the census last year. Eight aircraft qualify this year and over 350 aircraft have been delivered.

Maximum weight (-120) 11,990kg Accommodation 30 Wingspan 19.8m length 20.1m height 6.4m Original design life 60,000 cycles, 40,000h, 22 years Average fleet age nine years

Fairchild FH-227

Fairchild (then known as Fairchild Hiller) developed a stretched 52-seat derivative of the R-R Dart-powered Fokker F27 (see entry) for the US market. The first FH-227 was delivered in 1966 and 78 aircraft were built before production ceased in 1968. Several dimensionally similar versions were developed, including a cargo variant. The fleet totals 27 aircraft, with product support for the FH-227, and the Fairchild F-27, being provided by Hagerstown, Maryland-based Maryland Air Industries.

Maximum weight (FH-227B/D) 29,640kg Accommodation 52 Wingspan 29m length 25.5m height 8.4m Original design life not known Average fleet age 33 years

Fokker F27/Fairchild F-27

The F27 twin turboprop was flown in November 1955 and civil production continued until 1986. Several versions of the R-R Dart-powered twin turboprop were developed, including mixed passenger/cargo and freighter variants and a stretched version (the Mk500), all powered by two R-R Darts. Production of the F27 was undertaken in the USA under licence by Fairchild with US-produced versions dubbed the F-27. Hagerstown, Maryland-based Maryland Air Industries provides support for the US-built F-27 models.

The US-developed stretched derivative, the FH-227, is described separately.

Some 580 F27s were completed by Fokker and a further 129 F-27s by Fairchild in the USA, for a total of 709. Production of an advanced derivative - the Fokker 50 - began in 1985 but it is also out of production. A total of 306 F27/F-27s 15 years old or greater remain in service with civil operators.

Maximum weight 20,410kg Accommodation (Mk 500) 52 (60 maximum) Wingspan 29m length (Mk 500) 25.1m height (Mk 500) 8.7m Original design goal 60,000 cycles/60,000h extended to 90,000 cycles/90,000h Average fleet age 30 years

Grumman Gulfstream I

Grumman originally conceived the G-159 Gulfstream I as a business aircraft, flying the first example of the twin turboprop in August 1958. The aircraft entered service in 1959, and some 197 of the R-R Dart-powered aircraft were produced between 1958 and 1963.

A number of aircraft were converted to 24-seat passenger aircraft or freighters after delivery. 105 aircraft remain in civil operation. A stretched conversion, dubbed the GI-C, can accommodate 37 passengers, but only five aircraft were modified before the programme was ended.

Maximum weight 16,300kg Accommodation 24 or 37 Wingspan 23.9m length 23m height 7m Original design life n/a Average fleet age 37 years


This 60-seat regional airliner was developed by Japan's Nihon Aircraft Manufacturing (NAMC) in the early 1960s to satisfy a requirement of Japan's domestic airlines. Powered by two R-R Dart turboprops, the first example was flown in August 1962 and 182 aircraft were produced through to 1973.

Variants included all passenger passenger/cargo combi and all-cargo models. Ninety-two examples remain in commercial operation, some employed in the cargo role.

Maximum weight 25,000kg Accommodation 60 Wingspan 32m length 26.3m height 9m Original design life not known Average fleet age 31 years

Saab 340

Saab launched the 340 as a joint venture with Fairchild (initially designated SF340), and it was first flown in January 1983. Deliveries of the initial Saab 340A model began in June 1984, and Saab took full control of the programme a year later. An improved version, the Saab 340B, was introduced in 1989 and production of the type ceased in 1999 after 455 had been delivered.

The Saab 340 joined the census last year, and 42 aircraft now qualify. Saab says the in-service life of the aircraft is 38 years, based on cycles, or 21 years based on flying hours. A programme is under way to extend the hours limit from 45,000h to 60,000h as a first step, based on the in-service experience. The manufacturer aims to achieve the extension during 2000, enabling the in-service life of the aircraft, based on flight hours, to increase to 28 years. Saab will continue to work on further life extensions.

Maximum weight 13,160kg Accommodation 35 Wingspan 21.4m length 19.7m height 7m Original design life 90,000 cycles, 45,000h (extension to 60,000h being undertaken), 38 years (cycles)/21 years (hours) Average fleet age nine years

Shorts 330/360

Originally called the SD3-30, the 330 is a 30-seat utility development of the Shorts SD3 Skyvan powered by two P&WC PT6As. Including the military Sherpa, 139 aircraft were produced between 1974 and 1992.

Most were produced between 1976 and 1985 and the design was superseded by the slightly larger Shorts 360 from 1982. This features a conventional tailplane and fin in place of its predecessor's twin-tail design.

The first mid-life audit of the type, required at 50,000 cycles or 28,800h, was carried out in 1987 by Gill Airways. The work needs two months of downtime and costs around £150,000 ($245,000).

There are 94 examples with civil operators of the 330/360 which are at least 15 years old.

Maximum weight (330) 10,160kg (360) 12,290kg Accommodation (330) 30 (360) 36 Wingspan 22.8m length (330) 17.7m (360) 21.6m height (330) 4.95m (360) 7.3m Original design life 30,000 cycles (extendible to 57,600 cycles), 30,000h (extendible to 40,000 on 330 Sherpa) Average fleet age 17 years (330) 15 years (360)


Antonov An-28

Developed from the An-14, the twin-engined utility turboprop was first flown in 1969. However, series production was allocated to PZL Mielec which did not complete the first production An -28 until 1985, powered by PZL TVD-10B engines. Although certification was not issued until 1991, a few precertification models were issued to airlines and a 1985-built aircraft is included in this census.

Maximum weight 6,500kg Accommodation 17 pax/2,000kg Wingspan 22.1m length 13.1m height 4.9m Design life n/a

Ayres Let L-410 Turbolet

The 19-seat L-410 had its first flight in April 1969 and entered service the following year. US manufacturer Ayres purchased Let in August 1998. An improved UVP version entered production in 1977 and production passed 1,000 in 1990, by which time the UVP-E was the standard production version. Over 480 aircraft are at least 15 years old.

Maximum weight 5,700kg Accommodation 19 Wingspan 20m length 14.4m height 5.8m Original design life 20,000 cycles 20,000h Average fleet age 15 years

BAe/Handley Page Jetstream/J31

Handley Page was the initial producer of the Jetstream, equipped with the Turboméca Astazou engine, which entered service in the late 1960s. Forty-four aircraft were produced through to 1970 when Handley Page was declared bankrupt. The programme was bought by Prestwick Scotland-based Scottish Aviation (which became part of BAe), with the aircraft being relaunched, powered by the AlliedSignal TPE331 and redesignated the Jetstream 31 (or J31). The first J31 was flown in 1980 and 385 aircraft were assembled at Prestwick before production ceased in 1993. An enhanced version, the Super 31 (or J32), was introduced in 1988. Eighty Jetstreams (including 66 J31s) qualify for the census.

A BAE scheme to extend J31 life to 45,000 cycles has been approved and the company while a J32 life extension to 65,000 cycles was approved last year.

BAE has developed a $100,000 upgrade package to improve the hot and high plus short-field performance of the J32, dubbed the J32EP (enhanced performance), which makes use of alternative flap settings and drag reduction fillets on the wing/engine nacelle joint. Detroit-based Murray Aviation is working on a cargo conversion.

Maximum weight 6,400kg Accommodation 18-19 Wingspan 15.9m length 14.4m height 5.3m Original design life 30,000 cycles (extendible to 45,000 cycles on J31 - 65,000 cycles extension for J32 being available) Average fleet age 31 years (HP Jetstream) 14 years (J31/32)

Beech (Raytheon) 99

The 15-seat Beech 99 was an airliner evolution of the Beech Queen Air general aviation aircraft. It was first flown in 1966 and deliveries started in 1968. Production of the P&WC PT6A-powered twin turboprop ceased in 1986 after 239 aircraft had been built.

The aircraft's original life had a spar limit of 10,000h, which was later increased to 20,000h with the installation of a spar reinforcement kit. This can be extended by 20,000h to 40,000h, with another spar kit.

Ameriflight, the largest operator of the type, has funded research into a "super spar" to extend life further. Three of Ameriflight's aircraft have accumulated more than 40,000h.

Maximum weight 4,940kg Accommodation 15-17 Wingspan 14m length 13.6m height 4.4m Original design life 10,000h (extended to 46,000h) Average fleet age 25 years

De Havilland (Bombardier) DHC-6 Twin Otter

Twin Otter production began in 1965 and continued until 1988, with 844 aircraft built. The P&WC PT6A-powered aircraft was conceived for short take-off and landing operations, and the first aircraft was flown in May 1965. The fleet leaders are on their second set of wings, while many -200s and -300s have been relifed to 49,000h and 33,000h, respectively. Inspections every five years for corrosion are mandatory.

Five hundred and sixty-one aircraft in service are at least 15 years old, with Sun Express Airlines having the largest fleet.

Maximum weight 5,670kg Accommodation 20 Wingspan 19.8m length 15.8m height 5.9m Original design life 50,000 cycles 25,000h Average fleet age 25 years

Embraer EMB-110 Bandeirante

Brazil's Embraer flew the first Bandeirante in October 1968 and unpressurised twin turboprop entered service in 1973. Deliveries of the civil commuter version did not begin until 1978. Production ceased in 1991 after 500 aircraft had been built.

The UK CAA set the most stringent lifetime limitation for the lower wing-to-fuselage attachment fittings in the front centre-section spar of 11,420 or 17,569 landings. It also prescribed inspections of the front-spar lower cap at 20,000h to allow continuation to 30,000h and then to 45,000h with an approved reinforcing kit in the nacelle region. The Australian CAA was the most demanding for wing-to-fuselage attachment fittings in the forward spar cap at 15,400 or 23,600 cycles.

Two hundred and fifty six aircraft qualify for the survey, and US-based AirNow has the largest ageing fleet, with 11 in service.

Maximum weight 5,600kg Accommodation 19-21 Wingspan 15.3m length 14.2m height 4.7m Original design life 21,000 cycles 30,000h Average fleet age 20 years

Fairchild Dornier 228

Dornier, now part of Fairchild Dornier, produced the twin turboprop 228 in two versions - the basic 15-seat -100 and the stretched 19-seat -200. The first 228 was flown in 1981 and 270 examples of the unpressurised high-wing design have been built to date. Versions of the 228 include military/utility and regional airliner.

Maximum weight 5,700kg Accommodation 15-19 Wingspan 17.0m length (-100) 15.0m (-200) 16.6m height 4.9m Original design life 62,500 cycles, 42,800h Average fleet age 13 years

Fairchild (Swearingen) Metro

The Metro was developed from the Merlin business twin turboprop by Swearingen, with the first example flying in August 1969 and entering service in 1970. A corporate version, the Merlin IV, was also developed.

Six hundred and six examples of the 19-20-seat aircraft have been built, of which 280 are over 15 years old, with Ameriflight having the largest fleet. The Metro 23 is the most recent version to be developed.

Maximum weight 5,670kg Accommodation 20 Wingspan 14.1m length 18.1m height 5.1m Original design life 35,000h Average fleet age 14 years

GAF Nomad

The Nomad was developed by Australia's Government Aircraft Factories for utility and commuter roles. The first example flew in July 1971 and production ceased in 1984 after 172 aircraft had been built. Two versions of the twin turboprop short take-off and landing capable aircraft were produced, seating 13 and 17 passengers. Thirty-three aircraft remain in civil operations.

Maximum weight 3,855kg Accommodation 13-19 Wingspan 16.5m length 14.4m height 5.5m Original design life n/a Average fleet age 21 years

Raytheon Beech 1900 Airliner

Developed from the Super King Air business twin turboprop, the 19-seat Beech 1900C Airliner was first flown in September 1982 and entered service in early 1984. A total of 250 1900Cs was built through to 1992 before production switched entirely to the current version, dubbed the 1900D, which has a taller cabin.

Forty-eight aircraft are over 15 years old, with Gulfstream International Airlines having the largest fleet.

Maximum weight 7,530kg Accommodation 19 Wingspan 16.6m length 17.6m height 4.4m Original design life tail structure has a life limit of 45,000h Average fleet age seven years

Shorts Skyvan

Developed as a piston-powered aircraft, the Skyvan had its maiden flight in January 1963. A turboprop version was developed, initially with the Turboméca Astazou engine, but later with the AlliedSignal TPE331. The first TPE331-powered Skyvan was flown in 1967 and production continued until 1986, with 149 aircraft being produced. 63 aircraft are over 15 years old.

Maximum weight 5,670kg Accommodation 19 Wingspan 12.2m length 19.8m height 4.6m Original design life 20,000 cycles Average fleet age 26 years


Antonov An-12


The An-12, which was developed from the An-10 high wing transport, had its first flight in March 1957 and entered service with the Soviet air force. The aircraft has a rear loading ramp and is powered by four Ivchenko AI-20K turboprops. The civil An-12 fleet is fairly static in size, with some 181 aircraft in operation, but the commercial fleet may increase through conversions of the military version.

A 5,000h service life extension is possible following major overhaul.

Maximum weight 61,000kg Maximum payload 20,000kg Wingspan 38m length 33.1m height 10.5m Design life 25,000 cycles 30,000h

Antonov An-26/32

The pressurised An-26 twin turboprop entered service in 1970. Developed from the An-24, the aircraft has a redesigned rear fuselage, more powerful Ivchenko AI-24VTs and an RU-19A-300 auxiliary power unit that can provide additional power for take-off/cruise. The An-32 is an improved version offering better hot and high take-off performance. This was introduced in the early 1980s.

More An-26s are moving across to the civil sector as airlines acquire the surplus military aircraft particularly since modifications have permitted an increase in payload from 4.5t to 6.3t. In all, 261 pre-1986 examples are in service. A 5,000h service life extension is possible following major overhaul.

Maximum weight 50,700kg Maximum payload 6,300kg Design life 16,000 cycles 30,000h

Lockheed L-100 Commercial Hercules

Developed from the military C-130, the L-100 Commercial Hercules which entered production in 1964. A total of 115 aircraft was built through to 1993, although most were completed before 1985. Three versions were developed - the basic L-100 and two stretched variants, the L-100-20 and L-100-30. All versions are powered by four Allison 501 turboprops.

Fifty aircraft older than 15 years are in service. Some military C-130s have been transferred to civil operators, but these are not included in the figures.

Maximum weight 70,300kg Maximum payload (-30) 23,200kg Wingspan (-30) 40.3m length 34.4m height 11.7m Original design life not set Average fleet age 22 years

Source: Flight International