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When is Old Too Old?

by Jeremy Cox 1. August 2009 00:00
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Is it now time for us to accelerate the natural attrition of "old" business jets as the older members of the ageing fleet are laid to rest?

The oldest pyramid at 4,639 years is the Step Pyramid of Djoser built in the desert twelve miles south of Cairo near Saqqara, Egypt. The oldest standing structure, a temple in Malta is 6,000 years old. The oldest archaeological remains of a structure found in Japan, dates back to 500,000 years ago. The Grand Canyon is somewhere around 2,000,000,000,000 years old.

The oldest machine that is still functioning is reputed to be either a waterwheel in Spain, at about 1,300 years, or a clock in England that is 620 years old, or so. The oldest aircraft that is still flown today is a 1909 Bleriot (The Shuttleworth Collection in England, and Old Reinbeck Aerodrome here in the USA.) The oldest turbo-propeller aircraft still in operation are a handful of early 1950's Vickers Viscount aircraft. The oldest business jet aircraft that are still in operation includes: several 1964 Rockwell Sabreliner 40 aircraft (including serial number 001), two 1965 Learjet 23 aircraft, a handful of 1965 and 1966 Hawker 1A aircraft, a slew of 1965 and up Dassault Falcon 20 aircraft, a 1967 Lockheed Jetstar TFE731 converted aircraft, and several 1968 'dash-eight's' Jetstar aircraft. Since I myself am a 1965 model that has considerably more time on me than any of the aforementioned business jets, I am not suggesting that any of these aircraft are physically and technically 'over the hill'; no my argument is purely spawned from today's market and economic realities.

The 1977 crash of the Zambia Airways leased B707 was the first major commercial aircraft accident that was caused by age and metal fatigue. The horizontal stabilizer spars were fatigue cracked, and after inspection, more than fifteen percent of the 'then' in-service fleet were found to have the same problems that brought down the Zambia aircraft. Eleven years later when the Aloha airlines accident took place in 1988, where unnoticed corrosion caused an explosive decompression of a Boeing 737 while in-flight, immediately converting the subject aircraft into an 'open-top' vehicle, had rocked the aviation industry. Mainly thanks to the over-built strength that was inherent in the design of the B737 which allowed the damaged aircraft to make a safe landing, the Federal Aviation Administration (FAA) immediately leapt into action and created an 'Ageing Aircraft' Task Force to review the technical issues that were the result of aircraft ageing in service.

Apart from issues with the embrittlement of conductors and the breakdown of insulation in electrical wiring; crack formation and growth within some metal structures caused by stress and/or corrosion, the FAA found that the majority of ageing issues found in older aircraft were more likely to be serious in areas that had been structurally modified or repaired. Technically speaking, there is still no physical 'across the board', industry-wide hourly or calendar limit that is either required or implemented. In simple terms, there is little to no "too old" in aircraft design. Obviously then this becomes an issue of economics only, whereby the useful age of an aircraft is reached, when economic gain is either lost or significantly reduced.

Having worked for a time at Marshalls of Cambridge in England, I immediately learnt about a fundamental distinction between Commercial and Military Aviation that sets each segment diametrically opposite to each other, namely that it costs money when a commercial aircraft is down and parked, while conversely it costs money when a military aircraft is up and flying.

While the fact that the United States Air Force is still flying many 43 year-old Boeing B-52 Stratofortress aircraft, the average age of their fleet is approximately 26 years old. Notwithstanding the obscure African airlines that continue to fly their unsuspecting public around in fifty plus year-old turbo-props, the World's passenger airlines are operating aircraft that are younger than 25 years old. The target of the airlines is to have a fleet that is younger than 15 years old which today means that they are now unwilling to operate anything built before 1985. When one adds to the issue of calendar age, by introducing the factor of flight-hours, a truer picture emerges.

The airlines target at least 3,000 hours per annum for their business model, hence that the target retirement/scrap age of most commercial passenger airliners starts around 60,000 hours and pushes as high as 90,000 hours. The business jet fleet truly falls under the 'boutique' category of aviation because it is rare for any business jet to fly more than 400 hours per annum. 30,000 hour business jet aircraft are highly unusual, especially in a field where 14,000 hours is considered 'high-time', and a fleet snapshot returns an average of 4,115 hours total-time-in-service for the majority of the active fleet.

Currently there are 29,858 business aircraft in existence all-around the World. 4,850 of which are advertised as available for sale. A normal healthy used business aircraft marketplace sees that there are ten-percent of the entire fleet up for sale at all times. Unfortunately if I borrow a term from the stock market, I can best describe today's used business aircraft market as being a 'Bear Market.' This is bourne out by the fact that since the late summer of 2008, the market value of most of the aircraft that are for sale, has dropped between 40% to 60%, while the number of available aircraft has gone up by more than 50% to sixteen-percent of the entire fleet being up for sale today.

Since 1958 there has been 3,667 turbo-prop and jet business aircraft that has crashed, been scrapped, stored, or written-off for whatever reason. This 'attrition number' accounts for almost 11% of all turbine powered business aircraft built (34,301 historically in total.) To force the return of a normal-stable and healthy marketplace ahead of any economic miracles taking place, at least 1,800 aircraft must be immediately removed from the marketplace. I don't foresee this taking place anytime soon. There are 10,382 turbine powered business aircraft in existence that were manufactured prior to 1985. If it were possible to see half of these aircraft removed from service, the used aircraft marketplace would be much healthier for it.

I do envision that a new business sector with our industry shall become prominent and then see immense growth over the next decade. This is the sector that transcends the normal aircraft salvage businesses of today, and focuses more on disposal and recycling of rare materials, rather than filling barns with spare wings, controls, cowlings, engines, etc.

The USA is the World's leader in aircraft manufacturing. This country could also become the leading aircraft recycler as well, just like Bangladesh is the leading ship recycler, and Africa is the leading computer recycler. This is 'food for thought'; eh?

See you all next month.

Do you have additional experience with this topic? Tips, Tricks, or Advice? Please discuss it with us!


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