-
Location
-
North America
-
Latin America
-
Asia Pacific
- |
- Sales & Service Partners
- |
- Contact Us
- |
-
Select Shopping Cart Account
Choose the account number for your parts ordering shopping cart. Your current cart will be saved when switching accounts.
Account# Account Name City Zip/Post Code My Account
-
Support & Resources
Support & Resources
-
Location
-
North America
-
Latin America
-
Asia Pacific
- |
- Sales & Service Partners
- |
- Contact Us
- |
You are browsing the product catalog for
Your browser is not supported.
For the best experience, please access this site using the latest version of the following browsers:
By closing this window you acknowledge that your experience on this website may be degraded.
Engine Insights
April 18, 2019
Occasional reports from operators and Service Centers citing premature erosion or igniter plug failure indicate a possible misunderstanding of the term Continuous Ignition. To be clear, Continuous Ignition means the ignition system has no defined maximum duty cycle; therefore, it may be operated continuously when necessary to assure safe aircraft operation.
However, igniter plug life is limited by erosion; and the rate of erosion is directly proportional to the number of cycles or the number of times the plug “sparks.”
Therefore, in order to avoid excessive plug erosion, Continuous Ignition should only be used as dictated by the appropriate Flight or Crew Manual. For example, some Aircraft Flight Manuals recommend the use of ignition for all takeoffs and landings, regardless of flight conditions. In addition to this repetitious and predictable use, ignition should also be used:
- During operation in icing conditions.
- Following operations in icing conditions, until accumulated ice has dissipated.
- In heavy rain or turbulence, particularly at reduced power settings.
- At high angles of attack, especially at high altitudes.
The following should provide some insight into ignition system use under normal and unusual circumstances. To put ignition utilization into the proper perspective, a typical operator’s annual use of the engine ignition system can be broken down as outlined below:
Use During - Average Duration in Seconds / Flight
Engine Start - 20
Takeoff - 180
Landing - 300
Total - 500
Assumptions:
- Average flight duration = 2 hours
- Average annual flight time = 500 hours
- Ignition utilized during all takeoffs and landings
Therefore: 250 flights x 500 seconds / flight = 34.7 hours per year
Furthermore, the ignition unit (exciter) normally produces a spark rate of 2 sparks per second. However, during the first 15 – 20 seconds of system operation, the ignition unit provides a burst rate of 4 sparks per second to enhance starting and relight. While not startling information by itself, these estimations provide a baseline for analysis of overall annual ignition system utilization and igniter life expectancy.
During certification testing, the TFE731 engine met or exceeded all FAA requirements for water and ice, as well as bird ingestion without the use of Continuous Ignition. However, as added protection against inadvertent power loss during critical phases of flight under extreme conditions –
such as takeoffs, departures, approaches and landings where excessive amounts of water, snow, ice, or birds might be encountered – a Continuous Ignition system has been provided and should be turned ON.
As soon as the aircraft is clear of such conditions, the ignition system should be turned OFF after checking that residual ice is no longer present and won’t shed into the engine inlets.
Note: Guidance from the AFM and other OEM documentation takes precedence over this recommendation.
These and other TFE731 Pilot Tips are broad in scope and general in nature. Always consult the Aircraft Flight Manual for specific limitations, procedures and recommendations.
Sign up to receive exclusive marketing e-communications including updates about our product offerings, special offers, news, and events.
Copyright © 2024 Honeywell International Inc.
Maximum File Size
Maximum Files Exceeded
Due to inactivity you will be logged out in 000 seconds.
![warning image](/content/dam/aerobt/en/images/icons/modal-icons/AeroBT-timer.png)
Maximum File Size
Maximum Files Exceeded
Your documents are ready for you. Please click here to open.
![warning image](/content/dam/aerobt/en/images/icons/modal-icons/AeroBT-exclamation.png)
Maximum File Size
Maximum Files Exceeded
There is an issue with invoices zip file download. Please go back and try again later. Thanks!
![warning image](/content/dam/aerobt/en/images/icons/modal-icons/AeroBT-exclamation.png)
Maximum File Size
Maximum Files Exceeded
Your orders excel is ready for download. Please click here to download.
![warning image](/content/dam/aerobt/en/images/icons/modal-icons/AeroBT-exclamation.png)
Maximum File Size
Maximum Files Exceeded
There is an issue with orders excel file download. Please go back and try again later. Thanks!
![warning image](/content/dam/aerobt/en/images/icons/modal-icons/AeroBT-exclamation.png)