Astra / Westwind Spring 2004

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• N1 DEECs Approved for Westwind/Astra
• ELT Situation Supports Solid RVSM Date

N1 DEECs Approved for Westwind / Astra

• Mike Healzer

The Supplemental Type Certificate (STC) ST1855CH-D for installation of N1 DEECs on IAI 1124/1124A/1125 model airplanes is now available. It can be accessed at Honeywell’s website www.e-engines.honeywell.com. At the home page, go to Technical Publications/ TFE731 Family/Supplemental Type Certificates (STC’s).

The download includes authorization to use the STC to install N1 DEECs on IAI 1124/1124A Westwind and 1125 Astra airplanes. The installation is accomplished concurrent with Honeywell’s Service Bulletin TFE731-76-3067. FAA-approved airplane flight manual supplements, CAA supplements, and maintenance manual supplements are provided.

Each N1 DEEC weighs 5.5 pounds less than the existing EEC. The N1 DEEC controls thrust through fan speed which reduces transient N1 overshoots. The N1 DEEC is based on digital technology, and automatically monitors and records data necessary for engine trending. The N1 DEEC cannot be mixed with EEC/N2 units on the same airplane.

The engine diagnostic functions of the N1 DEEC are superior to the existing EEC. Periodic downloads of the N1 DEEC are required to prevent a slow flashing light in the cockpit (which indicates the buffer is full in the computer). Reports to JetCare are simply downloaded and e-mailed. If the pilot observes abnormal engine operation, a switch may be activated in the cockpit that will command the N1 DEEC to record the following:

• Four minutes before the event and one minute after in slow scan
• Twenty seconds before the event and ten seconds after in fast scan

Only one pilot-initiated event may be recorded per flight. When the DEEC is downloaded, the anomaly can be traced to the circuit or circuits that caused the problem, greatly improving the troubleshooting process.

The Learjet 55, JetStar II, and Sabreliner are the remaining airplanes to have N1 DEECs approved.

ELT Situation Supports Solid RVSM Date

• Steve Elofson

Just as the 01/01/2004 ELT mandate stood firm, we believe the FAA will not budge on the 01/20/2005 RVSM and 05/29/2005 TAWS mandates. Equipment shortages and mods shop schedules left many last-minute ELT shoppers unprepared for the mandate, but many of them kept flying by installing a 121.5 MHz ELT until a 406 MHz installation date and equipment is available. We believe RVSM and TAWS will make the ELT crunch look like small potatoes and there will be no short-term fixes. While many pilots assume they will simply “file for FL270 if the date sticks,” there will be great demand for the highest non-RVSM altitudes from noncompliant jets and high-flying turboprops. This will result in even lower available altitudes which translate into more fuel consumption and refueling stops for passengers used to nonstop flights. Now is the time to gather the facts and take action toward meeting these mandates. If you have TAWS or RVSM questions, call us for a free copy of “Straight Talk about TAWS” or our recently released “Straight Talk about RVSM: 2nd Edition” or visit DRVSM.com.

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