For an old airliner, the Boeing 757-200 operated by Honeywell as a flying testbed is enjoying a remarkable second career. Delivered new to Eastern Airlines in February 1983, it was the fifth 757 to be produced.

Initially registered as N504EA in its Eastern days, it then had stints in storage and with UK charter operator MyTravel Airways. It was obtained by Honeywell in 2005. After extensive modifications, it returned to service in 2008, now bearing the registration N757HW.

Joe Duval, who leads Honeywell’s flight-test department, says the aircraft is "the only 757 in the world with three engines". That is a slight bending of the truth. Unless the aircraft's universal test pylon - located on the upper fuselage on the right-hand side of the aircraft forward of the wing - is occupied, it very much remains a twinjet. Still, the testbed makes for a unique sight lined up with the 777s and Airbus A330s at Singapore's Changi airport.

FlightGlobal was lucky enough to join a test flight from Changi. Although the 757 bristles with new systems and avionics, we wondered if any vestiges of its former Eastern career remained. Lead test pilot Jason McMahon pointed out a modest button labelled T/O CHK, above and to the right of the old-school mechanical altimeter. Pressed immediately before departure, the Take-Off Configuration Check button will alert the crew if there is something amiss with flaps, control surfaces, and other systems. McMahon says Eastern had the only 757s equipped with this feature.

The cockpit is a curious mix of mechanical instruments – altimeter, attitude indicator, airspeed indicator – and digital screens – namely an advanced radar display. Mounted at eye level between the two pilots is an iPad electronic flightbag. In a commercial airliner, data available on the iPad, such as a strategic weather picture and a moving map, would probably be shown on multifunction displays – if not on paper, depending on the age of the jet. Since N757HW is classified as an experimental aircraft, the crew has more liberal options for the use of such devices.


Usually based in the USA, the 757 is in the Asia-Pacific for a month, mainly to coincide with the region’s monsoon season – "chasing storms" as McMahon puts it. Among other missions, the aircraft is gathering data for Honeywell’s Intuvue 3D weather hazard and avoidance system. This involves flights over the Andaman and South China Seas, preferably during inclement weather. Later this year, the aircraft will also perform radar calibration flights in Europe and the USA.

While the aircraft's RDR-4000 radar is a mature technology, Honeywell has a long-term project to keep refining how the software that powers Intuvue interprets weather. To do this, cameras in the cockpit record data appearing on aircraft displays, while a powerful sensor on the jet’s right-side pylon detects air and water molecules. The objective is to ensure the radar is calibrated to show the real picture in front of the aircraft.

The main cabin of the 757 is spartan: crew amenities are limited to a big box of instant noodles and cartons of bottled water located in the rear of the fuselage. Apart from a few rows of passenger seats, the cabin is dominated by 16 equipment bays, which can provide displays for engineers, or be used to house other equipment.

When an engine is being tested, there will typically be five engineers on board, while avionics tests usually involve two or three personnel. For the sake of efficiency, it is preferable to conduct work on more than one system during flights.


Despite the stripped-back cabin, there is one area where the aircraft reigns supreme in passenger comfort, however: onboard wi-fi. The aircraft’s JetWave high-speed communications system enabled a dozen journalists to conduct crystal-clear WhatsApp video calls or live stream from the flight. Indeed, Honeywell dubs the jet the “Connected Aircraft”.

Still, the aircraft retains a distinctly old-school feel. In the rear of the cabin is a modest piece of aviation history: an original trailing static cone reel from the early days of the 757 programme. Honeywell acquired it from Boeing at the same time as it bought the twinjet. It is used to reel out a trailing cone to measure static air pressure during test flights.

The aircraft's current tour of the Asia-Pacific region involves stops in Australia, Hong Kong, Indonesia and Vietnam. But a constant challenge for Duval and McMahon is coping with local authorities that are not used to dealing with experimental aircraft.

McMahon says that a flight in the USA that would be relatively simple from a regulatory perspective can be quite challenging in other jurisdictions. Indeed, Changi controllers delayed the Singapore flight for nearly 1h owing to paperwork issues. A cause of particular consternation among the region's air traffic controllers is the idea that a jet can leave from a given airport and then return to the same site.

"We’re also a big plane," says McMahon. "This can make it hard for them to squeeze us into a slot."