By Stephen Trimble
With entry-into-service (EIS) far off in the unknown distance in May 2008 - in fact, it would become nearly two-and-a-half years - Boeing felt comfortable revealing one of the 787's hidden and potentially lucrative design secrets.
Tom Crabtree, then a regional director for business strategy at Boeing Commercial Airplanes, casually gave the secret away in a presentation to journalists inside the company's sprawling factory complex in Everett, Washington.
Buried in the blueprints of the all-composite fuselage of the new widebody are the provisions to quickly transform the 787 from an airliner into a pure freighter, Crabtree said.
"We worked with the initial design five years ago during the initial sizing of the airplane," said Crabtree. "We have routed the systems such that the area where the main deck door would go are clear of any reroutings, say, [of] electrical or hydraulic lines."
"Long term, we have designed provisions into the  when the market demands it to allow that aircraft to become a freighter," Crabtree said.
That statement marked the last time Boeing publicly discussed plans for alternative uses of the 787, but did nothing to stop the speculation.
Large aircraft are often launched with a single job envisioned - carrying passengers, for example - but often find second and even third careers serving other markets. Freighters and special mission aircraft for the military are two of the most obvious examples.
Boeing has already planned to make the 787 readily available for the freighter market, and the widebody has already appeared in US Air Force concept studies as a candidate to serve in a variety of roles ranging from next-generation surveillance aircraft to the successor of the Boeing VC-25A - the Boeing 747-200 also known as Air Force One when the US President is on board.
Finding such alternative roles is an established tradition for most new Boeing airliners. The Boeing 707, 737, 747 and 767 have each been adapted for numerous roles. One company - Oregon-based Evergreen - even uses the 747 to dump chemical retardant on wildfires. And the 777 has recently launched a second career as a pure freighter.
On the other hand, there are no guarantees that the 787 will find other roles, and some analysts wonder if the aircraft's design philosophy will prevent its success in other markets.
"One problem is that the 787 is designed with minimal margin tolerances, while older jets were designed before [computer-aided design/computer-aided manufacturing] became an extremely precise tool," says Richard Aboulafia, vice-president of analysis at the Teal Group.
As design methods have become precise, manufacturers have discovered that planning ahead for secondary roles is more critical than ever. Airbus, for example, discovered that the freighter version of the A330-200 required a redesign. The passenger version was built with a slight forward tilt. The slope is almost unnoticeable to passengers, but on a freighter would have forced customers to buy special equipment to slide cargo pallets from the front to the back. For the A330-200F, the nose gear is raised up slightly to make the fuselage level, and a new fairing was added to the enlarged gear doors.
Crabtree's comments in 2008 could still offer reassurance to pricing analysts in the airline market who must predict aircraft valuations over time. If Boeing has already made provisions for the 787 to serve as a freighter, valuation experts may keep price levels stable for a longer period.
Airbus appears to play similar games in public statements about its aircraft. For example, Airbus's latest global market forecast may be sending a subtle signal to pricing analysts about the company's long-term intentions for the new A350 widebody. The A350 is listed in the 2010 forecast as one of five future large freighters, a category listed in the report as also including the 747, 777, MD-11 and A380. Boeing's 787, however, is listed nowhere in Airbus's market forecast, even among the regional and long-range freighters segment that includes the A330 and 767.
Airbus may not want to give Boeing any more ammunition to boost the 787's pricing forecasts. At the same time, it is probably too early for the freighter market to be confident in the 787 as future member of the fleet.
"The 787 freighter concept is extremely premature. Cargo planes in this class tend to be conversions, which are useful for maintaining asset values but typically only kick in after 15-20 years of airline service, at least," Aboulafia says. "The new-build market for cargo planes in this class is quite limited, as Airbus is finding out on its A330F programme."
Boeing's 20-year market forecast shows that it expects the market for a 787-sized freighter to shrink in the future. In 2009, freighters with between a 40-tonne and 80-tonne payload capacity represented 36% of the market, according to Boeing's latest World Air Cargo Forecast 2011. In 2029, the same market is projected to account for 27% of all freighters.
A future military role for the 787 is also not a sure thing, despite Boeing's success with adapting previous models. For one thing, military customers have not expressed great interest in converting widebody airliners into special mission roles.
Several years ago, the USAF purchased a 767-400ER to convert into a replacement for the Northrop Grumman E-8C joint surveillance target attack radar system (JSTARS) and the Boeing E-3 airborne warning and control system (AWACS). However, the USAF cancelled the E-10A multi-sensor command and control aircraft (MC2A) in 2005. Meanwhile, Boeing's 737 narrowbody has become increasingly popular in the special missions market, with the US and Indian navies ordering the P-8 Poseidon.
"There's no need for a larger special mission aircraft. I can only think of one instance of twin-aisle jets being used for [intelligence, surveillance and reconnaissance] or other special mission duties - Japan's four 767-based AWACS," says Aboulafia.
"Single-aisle jets offer superb range and endurance these days, thanks to business jet derivatives of commercial 737s and A320s," adds Aboulafia. "Given that radars and other avionics are getting smaller, special mission size requirements aren't likely to grow at all, particularly with a great reliance on offboard sensors."
In 2008, the USAF also asked Boeing to submit design and cost data for the 787 while researching options for a VC-25A replacement. The USAF request also asked for information about the 777, 747-8 and even the Airbus A380. However, the Obama administration cancelled early studies for the VC-25A replacement programme. Boeing delivered both VC-25As in 1991, and the aircraft now rank among the USAF's most costly aircraft to operate. The 787 seems ill-suited to serve as a VC-25A replacement, if a requirement to recapitalise the fleet is ever relaunched.
"There is no way the 787 would make a respectable Air Force One. It's just too small given the lift requirement," says Aboulafia.
Boeing has already converted the 747 into a tanker for Iran and the 767 into an aerial refueller for Italy and Japan. The USAF has also ordered a new version called the 767-2C as the KC-X tanker. In the KC-X competition, Boeing never seriously considered the 787 as a candidate. Instead, a KC-777 was in development until the USAF issued specifications that favoured a smaller aircraft.
The KC-Y requirement to replace the KC-10 remains in the USAF's long-term plans. Both the 787 and 777 could be possible candidates, but the 787's tight design tolerances could pose problems for the company's engineers to overcome.
"Lots of margin is useful when you've got thousands of gallons of fuel sloshing around, putting weight in different places. While the 787 could be turned into a tanker, it could likely take considerable structural reinforcement," says Aboulafia.