GRAHAM WARWICK / WASHINGTON DC
The US Coast Guard is moving to upgrade airframe-mounted components that Honeywell blames for more than half the partial power-loss mishaps afflicting Eurocopter HH-65 Dolphins. Citing an "alarming increase" in mishaps, the USCG has launched an urgent programme to re-engine the Honeywell LTS101-powered helicopters (Flight International, 10-16 February).
Of the 53 in-flight power-loss incidents reported between 10 October and 29 January, Honeywell says 57% were caused by airframe-mounted elements of the engine control system and only 14% by engine-mounted components. The engine manufacturer accuses the USCG of misrepresenting the problem to justify re-engining the HH-65s with Turbomeca Arriel 2C2s. Under a statement of work agreed last April, Honeywell was to make engine improvements while the USCG tackled the airframe issues. Honeywell has already removed poor-reliability power-turbine governors and main fuel controls from the fleet, and is replacing airflow modulators by attrition under its power-by-the-hour maintenance control with the coastguard.
Honeywell has criticised the USCG for not acting on the airframe issue. The coastguard says it has just received new torque transducers and will install these and upgraded anticipator control boxes in an aircraft for flight testing by Eurocopter early this month. A six-month in-service evaluation on a USCG HH-65 could begin as early as 1 April, with fleet implementation of the upgrades planned to begin between 1 July and 1 November, says the Coast Guard.
Honeywell is about to begin flight testing a full-authority digital engine control (FADEC) system for the LTS101, but is concerned that its HTS900 - a FADEC-equipped version of the uprated LTS101-850 engine - will not be available in time to meet the USCG's desire to re-engine its HH-65s within two years.
Source: Flight International
