Page 34 - AAA JULY - SEPTEMBER 2019 Online Magazine

In July, the DGCA instructed both IndiGo and
Go Air, that all new A320/321 neo inductions
after August 2019 must be installed with mod-
ified MGB and new modified 3rd stage LPT
blades. In addition to this, the aviation agency
has asked that no engines from MROs shall
be accepted unless they have been fitted with
modified MGBs and new modified 3rd stage
LPT blades (except those which are at final
stages in shop or in transit). Finally the agency
has put a restriction on acceptance of lease
engines without modified LPT and MGB.

Pratt & Whitney has been directed by the DGCA
to increase the availability of spare engines
to Indian operators to prevent grounding of Steps Implemented by India’s Directorate General
aircraft due to removal of engines. “It is true of Civil Aviation (DGCA) for early detection of
that there have been cases of Air Turn Back, In associated problems and removal of engines to
Flight Shut down or Engine vibrations beyond prevent impending PW1100G-JM engine failure:
the prescribed limits, but with strong mitiga-
tion measures in place and strict adherence
to Standard Operating Procedures (SOPs) by • Reduced periodicity of boroscopic inspection (BSI) on
the airlines, the problem is being contained. Combustion chambers from 1500/750 /375/150 Hrs/ 30 Cycles
Whenever, there is a problem with the engine, to 1000/500 /375 Hrs and replacement of engine when recom-
mendation of the manufacturer for further operation of the engine
the aircraft is being grounded and the engine below 375 hours.
replaced,” the DGCA says.
• Replacing the engine, whenever cases of metallic chips in oil
While issues related to Combustion Chamber due to wear of No.3 Bearing Seal is detected under Oil Debris
Distress, No.3 Bearing Seal failures and High Monitoring (ODM) mechanism.
Pressure Compressor (HPC) Rear Knife Edge
seal failures have been addressed by Pratt • Logging all the cases detecting odours/ smoke in cabin during
peration for necessary investigation and rectification. In all odour
& Whitney through mitigation measures, the / smoke cases, engine inspected in detail and to be used only
DGCA says that the engine maker is in the pro- after rectification of the defect.
cess of implementing mitigation actions with
regards to Gear Box failure, Low Pressure • Record, monitor and inspect engines if Vibration > 3CU (man-
Turbine (LPT) failure and engine vibration. The ufacturer’s guideline of 5CU). Conduct BSI in repeat cases. This
aviation agency also states that issues related may result in removal of engines before vibration level is aggra-
to MGB, LPT and vibration are being addressed vated.
by Pratt & Whitney by undertaking the required
modifications on related parts. • Restricting operation of A320neo aircraft with P&W engines on
Port Blair Sector.
With regards to Gear Box failure, the DGCA • Extended Diversion Time Operation (EDTO) for Airbus Neo
states that Pratt & Whitney is tackling these aircraft has not been allowed by DGCA even though the In- Flight
issues in two stages - Immediate and Long- shut downrates of aircraft engine combination is well below
Term. With regards to the former, Pratt & acceptable limit.
Whitney has implemented a new software
update (FCS 5.0). This software update has Issues related to Low Pressure Turbine (LPT) failure are being
been completed on all the aircraft operated by addressed with the incorporation of new and more durable LPT
Indian operators. stage 3 blades. These new blades are now being fitted on new
The FCS 5.0 software update will signifi- production engines and retrofitted on older engines, during MRO
cantly reduce the potential for gear fracture during shop visit. have received. A total of 47 engines (IndiGo-40,
by minimizing the time spent at excitation Go Air-7) have already been fitted with new LPT blades. A rede-
speeds. To mitigate long term issues related signed piston seal in HPC will also be implemented to deal with
to Gear Box failure, Pratt & Whitney has devel- issues related to high transient vibration.
oped a more robust gear design to circumvent
excitation. This design is being incorporated With engine failure related to MGB expected to be contained after
at MROs from July 2019 and 20 engines with the recent software updates, the DGCA says that, engine failures
modified gears have already been received by related to LPT blade damage are being addressed by providing
Indigo (14) and Go Air (6). new LPT 3rd Stage blades.

34 | July/August/September 2019 WWW .GBP .COM.SG/ AAA