Ilyushin Il-62 - Operational History

Operational History

After the introduction of the Il-62M, Aeroflot (the largest operator of the plane) gradually upgraded its old Il-62s with the D-30 KU Soloviev powerplant, which, coupled with engine housing and other modifications, greatly reduced the chance of contiguous powerplant damage. By mid 1973, the airline was operating some 60 Il-62s, and by 1989 this had increased to 165 (Il-62 and Il-62M) (Thiel, 2001). The Il-62M had a dispatch rate with Aeroflot of 97% with some examples logging as many as 17 flight hrs/day, and it was described as the most reliable type in the fleet at that time (Gordon et al., 2004). It set several international records in its class, mostly exemplifying a range capability far in excess of the conservative Aeroflot calculations applied in Soviet times. Some of these records were set by an all-woman crew of five captained by Iraida ("Inna") Vertiprahova. With 10 tonnes of freight, the Il-62M had a maximum range of 10,300 km compared to 9,412 km for the VC10 carrying the same weight. With a 23 tonne payload, the Il-62M range was 8000 km, compared to 6,920 km for a Boeing 707 with maximum payload. Because of its capacity, the plane has been used for emergency evacuation flights, one of the most notable being the landing of an Aeroflot-registered Il-62 at Santiago Airport, Chile on the night of Sep 10th 1973 (the day before the military coup by Augusto Pinochet) in order to evacuate 147 Cuban embassy personnel.

The Il-62 was said to be well regarded by pilots and passengers alike, especially for its strong directional stability in high turbulence (although landings are sometimes bouncy), smooth cruising ability and very quiet interior in cruise mode due partly to engine placement (Gordon et al., 2004). Although the original IL-62 was rated for a service life of 23 years and was criticised for heavy fuel consumption, upgraded M versions are sometimes rated for 50 years and have greatly improved operational economics. One of the drawbacks of the original Il-62 design was the lack of a cargo bay roller transfer system, which necessitated manual loading of pre-packaged baggage and cargo thus making preparation of the aircraft rather slow (a cargo/baggage conveyance system is standard on the Il-62M). Conversely, there is relatively easy access to all serviceable mechanical components including the engines (Thiel, 2001) whilst the plane's thrust reversal capabilities allows reverse taxiing without the need for tow-vehicles. Powerplant overhaul intervals varied between specifications and maintenance procedures and between the thrust reverse-capable outer engines and the inner ones. Czech Airlines operated an early Il-62 on a proving basis up to 3000 hrs between overhauls, which was well beyond the recommended (and their usual) intervals which were nearer 2000 hrs (Gordon et al., 2004) although Interflug were able to designate up to 5000 hrs with their service facilities. Subsequent upgrades to some Il-62Ms provided for 6000 hr overhaul intervals (with total engine life of 18,000-20,000 hrs). Later examples of the Il-62M remain in regular commercial service (as at 2012), and the type also sees continuing use as a VIP/head of state transport.

Although the plane's safety record does not equal that of new generation airliners, there were no fatal accidents involving an Il-62 between 1989 and 2009 during which time the highest number of planes were in service (Thiel, 2001). With successive Il-62M upgrades and improved avionics, including triplex intertial navigation systems and enhanced flight controls to cope with the worst visibility (IMP, 1997), the plane gained a reputation as a very safe airliner whose record compares favorably with similar airliners, most of which are no longer in civilian use. Its total hull loss rate (7.7%) is lower than those of the Boeing 707 (16.4%) and DC-8 (14.9%), and near that of the VC10/Super VC10 (= 7.8% excluding the three examples destroyed by terrorists) although the VC10 was only in civilian service for 16 years versus 45 for the Il-62 (as at 2012), and only 40 of 54 airframes were airliners (the remainder going to the RAF). Several Il-62/M accidents over the first decades of operation mainly involved runway overruns or aborted takeoffs. The braking system employed the reverse thrust of the outer engines only, and if for some reason one or other failed to engage, the aircraft could become difficult to steer for an unprepared pilot. In seven takeoff or landing accidents there were no fatalities, a testament to the high level of structural integrity (and in two cases with landing-related fatalities these were due to the aircraft colliding with structures near the runway ). The Il-62/M fuselage features a strengthened hull with 'ski' keel originally designed to allow for an undercarriage-up emergency landing (in practice the undercarriage and landing gear proved extremely reliable). However, the trade-off for the reinforced airframe is the relatively high fuel consumption and some airlines such as Interflug modified their planes to reduce fuel consumption (Thiel, 2001).