Major improvements in expected reliability are claimed by Honeywell Aerospace for its new-technology Model 131-9 auxiliary power unit, for which the company recently notched its 1,000th delivery. "So far they are delivering more than three times our targeted mean times between chargeable removals," said Todd Inskeep, marketing director of Honeywell's Commercial APU division. More than 800 of the new APUs have already been installed, and have accumulated more than two million hours of operation. Two versions are in production-the 131-9(A), used in the Airbus A319, A320 and A321, and the 131-9(B) for the next-generation Boeing 737 series aircraft.