FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1999
1999 - 1273.PDF
on die CDS relating to die engine's electronic control. The power interruption warning is a malfunction that is common to an electronic type of aircraft, says die airline, but the fault sig nals are not being visibly detected soon enough. Crumb says: "The annunciator lights need to be a little bit bigger to gain the attention of the pilot. We've pushed back from the gate a couple of times and just didn't see the fault light because of die way it was displayed. We would then have to return to the gate and do a BIT check." These issues have been characterised as "minor problems" that might normally be asso ciated with "having bought a new car", suggests Crumb, who adds that Boeing has been "very pro-active in seeking a resolution". From an operational perspective, the 737- 700's biggest improvement over the second- generation -3 00/500 is the aircraft's ability to fly higher, further and faster at less cost. It has per mitted Southwest to open new 4-5h-endurance routes including, from January, non-stop ser vices from Las Vegas to Baltimore and Orlando and from Nashville to Los Angeles. CONTINENTAL EXPERIENCE Since receiving its first 737-700 on 30 March lastyear, Continental Airlines has begun amass ing one of the largest 737NG fleets. At die cur rent delivery rate of more than one a week it expects to have 78 in service by year-end. The airline plans eventually to stabilise its 7 3 7 fleet at around 311 by 2003, of which 180 will be the new models, if all options are exercised. By late April, die airline had accepted 22 737- 700s and 17 -800s. The airline will also be one of the first to take die stretched -900s, with the first of 15 due for delivery in 2001. Including the -900s, it plans to receive an additional 64 73 7NGs still on firm order. It also holds options on another 77, but these are interchangeable between all versions. The Next Generation aircraft are replacing the airline's elderly Stage 2 fleet. They will also be flown by Pacific-based affiliate Continental Micronesia. "Air Mike", as the Guam-based operation is better known, will begin operating its first 737-800s in October. The Air Mike -800s will be cleared for 120min extended- range twinjet operations, allowing them to operate die many long over-water sectors that make up the airline's Micronesian network. "We are very pleased widi die aircraft," says Dave Lynn, Continental's 737 fleet manager. Dispatch reliability is up to 99%, he says. The airline has experienced software-related aircraft systems "nuisance warnings" that have afflicted odier operators, but Boeing says it "is adjusting software to filter them out". In general, the faults are flagged because of transitory changes in sys tem status. Boeing is reducing die warning soft ware's sensitivity so that only events which last for more than around 0.75s are registered. "There is nodiing wrong widi the aircraft, just some of the system software," Lynn adds. The only other significant operational • Manufacturers' perspective Production, reliability and certification issues have dominated the 737s debut 3UY NORRIS/LOS ANGELES B ETWEEN THEM, Boeing and CFM International faced die fastest ramp-up in production and delivery of any commer cial airliner widi die 73 7NG. Since deliv ery of die first aircraft to Southwest Airlines in December 1997, some 2 50 examples have been delivered to more than 32 operators. CFMI is to hand over 611 CFM56-7Bs this year alone. The first example, the baseline 737-700 model, was flown in February 1997. US Federal Aviation Administration certification came in December 1997, about two months later than planned, mainly due to the need to incorporate last minute structur al changes to the tailplane. European Joint Aviation Authorities certification was delayed even further after lengthy discussions widi Boeing regarding exit limit certification. JAA approval came in February 1998, after Boeing agreed to revise the 7 3 7NG's overwing exit design, adopting automatic upward-opening exits in place of the manual hatches of the earlier 737s. As a result, some aircraft completed, or being built to the old design, had to be modified. The rapid production rate expansion during 1998 to 24 air craft amondi resulted in major delivery delays, and some of the in-service problems the aircraft experienced during its early months of operation. Despite this, scheduled mechanical relia bility rates reached the 98.9-99% design target within die first six s months, says John Hayhurst, I Boeing 737 programmes' vice- 1 president and general manager. "The aircraft is doing very well in service. We've had a few teething pains and we have had to address what issues have shaken out," he says. Thanks largely to experience gained widi the 737 Classic generations, Boeing avoided most pitfalls that accompanied die introduc tion of the -300, -400 and -500 throughout the 1980s. Airframe and aircraft system-related issues have emerged, however. One of the ear liest being a problem of leaking helium gas, which led to the mandated inspection of fire- detection assemblies and parts of the auxiliary power unit (APU). Some aircraft were also found to be leaking fuel, which led earlier this year to die mandat ed inspections of fuel-hose couplings. In March, the fleet was also inspected for improp erly fitted insulation blankets around the aft strut area of the engine mounts. The US FAA says failure to correct this could have exposed die lower surface of the strut to extreme high temperatures and increased the chances of a fuel-tank explosion and fire. The following month, all power distribution panels were ordered to be inspected. This directive fol lowed an incident in which all electrical power had been lost from an APU-driven generator, following the overheating, melting and subse quent failure of power feeder terminals. Most service issues that could have become serious problems, were defused early, thanks to Boeing's newly developed aircraft reports process. "We have a process in place where the airlines report almost everything," says Hayhurst. "We measure all the of the issues diat come up widi each aircraft in the first 3 0 days of service. It helps us identify any kind of produc tion issues that we need to address." Causing die biggest headaches, however, were problems with the engines and dieir acces sories. In some early incidents, number four bearing failures caused inflight shutdowns • FLIGHT INTERNATIONAL 12 - 19 May 1999 53
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
