High-tension Magneto

Aircraft high-tension magneto is a self-contained unit delivers high voltage to Spark plug, incorporating a coil, points and distributor. Coil having primary and secondary winding, step up the voltage to a spark-generating level, turn it into timed high tension electrical pulses, and sends it to the appropriate spark plug

Magnetos are fixed with manufacturer’s data plate  with either ‘L’ or ‘R’. The L or R does not refer to the position on the engine, but to the magnetos direction of rotation. In one instance, a left-hand rotation magneto was installed in the position where a right-hand rotation was specified. The result was a rough running engine with reduced power and the associated possibility of destructive detonation.

It is important to install serviceable magnetos with the correct part, model and configuration details for the intended engine. The correct magneto configuration should be verified against the approved maintenance data.

Magnetos can be overhauled and refurbished many times but some of the components have inherently limited lives. The plastic gears that turn the distributor are among these and eventually, due to heat and fatigue, will suffer from brittleness and susceptibility to fracture as the plastic degrades. When they snap, shear, or degrade into dust, the magneto stops.

A failed distributor gear can create another problem within the magneto, of electrical arcing, when the mechanism stops turning. This is because the high-tension electricity is still being generated as the magneto continues to operate, and if the electrical energy cannot discharge at the spark plug, it will seek (by arcing and/or burning) another path to earth.

Any event which places a thermal or impact shock on the engine, such as overheating or prop strike, has the potential to also damage the magneto. Oil contamination can enter a magneto through worn or inadequate magneto drive seals or in mist form, from an engine that has crankcase ventilation problems. Once inside a magneto, engine oil accelerates its failure.

Magneto drive rubbers or cushions can become hard and brittle over many hours and years of normal operation. Also, it has been found that abnormal torsional engine vibration (e.g. de-tuned crankshaft dampers) may cause magneto drive rubbers to fragment.

High cycle fatigue cracking can begin from small corrosion pits in the magneto shaft or in the area of the Woodruff key. This shaft can also respond to engine vibration which, under certain conditions, may induce a bending or wave motion response typical of shafts rotating at critical speed, making the shafts vulnerable to any surface defect. Shear failure often soon follows.

Magnetos contain capacitors which are essential to store electric current briefly each time the breaker point opens. Age and/or high temperature may cause the capacitor to change value or break down. The result can include a partial short, which can lower the voltage in the primary coil. Signs of high temperature on the contact spring or severe breaker point erosion are signs of a failing capacitor.

AME APPRENTICESHIP TRAINING – an initiative by DGCA

Through a public notice, DGCA has launched apprenticeship program in collaboration with various airlines, MRO, and Non-Scheduled Operators. Pass out students from AME Institutes, having Papers-l and 2 (or equivalent Modules) would be eligible to apply.
From the merit list of all registered candidates generated on the AME Apprenticeship portal of the Ministry, final selection for apprenticeship would include assessments/interviews by potential employers registered on the portal with pre-announced vacancies.
Selected candidates would be trained academically with a substantial
component of field experience using Standard Training Modules for Fixed Wing,Helicopters and Avionics Streams.
A Certificate of Competence, which is also recognized as a Certificate of Experience of one-year by DGCA and other stakeholders, would be issued by the establishment concerned to every successful Apprentice.
An interactive portal (www.ameapprenticeship.gov.in) for registration, tracking, monitoring, and disseminating information on AME  Apprenticeship is being developed on the Ministry’s website which is expected to be activated shortly. It would serve as a common platform for all stakeholders in AME Apprenticeship training, i.e. students, establishments, academia, training institutes, and regulatory agencies, to register and track and monitor the implementation of such skilling.

FAA AD 2017-16-11 on Lycoming Engines

This AD 2017-16-11  requires an inspection of connecting rods and replacement of affected connecting rod small end bushings.  AD was prompted by several reports of connecting rod failures resulting in uncontained engine failure and in-flight shutdowns (IFSDs).  AD applies to:           (1) All Lycoming Engines reciprocating engines listed in Table 1 of Lycoming Engines MSB No. 632B, dated August 4, 2017, and

(2) all Lycoming Engines reciprocating engines that were overhauled or repaired using any replacement part listed in Table 2 of Lycoming MSB No. 632B, which was shipped from Lycoming Engines during the dates listed in Table 2 of Lycoming  MSB No. 632B.

Reason of this AD is reports of uncontained engine failures and IFSDs due to failed connecting rods on various models of Lycoming Engines reciprocating engines listed in Table 1 of Lycoming MSB No. 632B, that were overhauled or repaired using any replacement part listed in Table 2 of Lycoming Engines MSB No. 632B, which was shipped from Lycoming Engines during the dates listed in Table 2 of Lycoming Engines MSB No. 632B.

This AD requires accomplishing the instructions in MSB  describing procedures for inspecting connecting rods and replacing connecting rod small end bushings to prevent connecting rod failure.  If not complied, could result in uncontained engine failure, total engine power loss, IFSD, and possible loss of the airplane.

Lycoming has determined that a small percentage of the bushings manufactured by a sub-supplier during a specific time period were diametrically undersized, resulting in a tightness of fit below factory accepted tolerances.These non-conforming bushings may have a substantially lower push-in/pull-out force than conforming bushings and may be susceptible to unseating during normal engine operations.

 Required Actions

(1) For all affected engines, within 10 operating hours after the effective date of this AD, inspect all affected connecting rods as specified in MSB.

(2) Replace all connecting rods that fail the inspection required by  this AD with parts eligible for installation.

Issuance of Category A Licence

Another step for compliance of CAR 66, DGCA has now decided to issue Category A licence to eligible person. As per revised Rule 61 of Aircraft Rules 1937, the Category A licence has been made non-type rated. A large number of technical person holding BAMEL/BAMEEC in heavy Aeroplane (HA)  and Jet Engine (JE) are employed in various organization may be considered for issuance of Category A licence. To get Category A licence competent authority has decided some modality to be complied with.

The existing CAR 147 type training organisation will be permitted to conduct Difference Training (difference in syllabus of CAR 66 Cat A licence and syllabus of exiting basic licence/Certificate.Syllabus of difference training will be approve by DGCA HQrs. The schedule of  examination is decided by CEO and likely to be held in October 2017. The application for conduct examination after successful completion of course will be forwarded to RAO by respective organisation along with requisite fees.

Training on CAR-66 & CAR-147 by DGCA

Three days training program   planned by DGCA Hqrs.  on CAR-66 & CAR-147 for benefit of Indian aviation   Industry was held on IAA, NIAMAR, New Delhi from 26 July 2017 to 28 July 2017.  Person nominated  from all the scheduled airlines and MRO’s. participated in training. These  participants are   responsible  and able to train this subject in their organisation after this training. Training is conducted by Senior DGCA officers. 

Mr. K P Srivastava Dy Director General has nicely explained CAR-66 for two day Mr. D K Das  Dy DAW  on CAR-147.  All training is conducted  by Mr. B C Behra  DAW and under guidance of Mr. S Dutta Dy DG.