5 out of 11 PW engines in IndiGo fleet removed: DGCA

Aviation safety regulator, the Directorate General of Civil Aviation (DGCA) which is probing three recent incidents of commanded In-flight Shut Down (IFSD) involving IndiGo aircraft, has revealed that 11 Pratt & Whitney (P&W) engines in the airline's fleet have been impacted. However, as of the latest update, only five of these engines have been removed.

The incidents, which have raised concerns about the safety of Pratt & Whitney engines, unfolded on various dates, prompting the DGCA to take action. On August 29, an IndiGo A321 neo aircraft with registration VT-IUJ, operating a flight from Madurai to Mumbai, experienced critical issues mid-flight, including high vibration, low oil pressure, and an engine stall. Upon landing in Mumbai, metallic chips were found on the oil chip detector.

On the same day, another A321 neo aircraft with registration VT-IUF, flying from Kolkata to Bangalore, reported identical engine problems, leading to a commanded IFSD. The plane safely returned to Kolkata, where metallic chips were discovered on the oil chip detector.

The third incident occurred on September 3 when an A320 neo aircraft with registration VT-IVI, flying from Amritsar to Delhi, experienced low oil pressure in engine 2. The aircraft returned to Amritsar, where an external oil leak was observed on the affected engine, although there were no reports of vibration or oil chip detection.

Subsequent Boroscopic Inspections (BSI) on the engines involved in these IFSD incidents revealed damage to the Stage 1 blades of the High-Pressure Turbine (HPT) in the engines implicated in the August 29 events. However, no anomalies were detected during the BSI of the engine involved in the September 3 incident in Amritsar.

It's important to note that all three engines involved in these incidents had accumulated more than 3,000 hours since their last shop visit (TSLSV).

In response to the blade damage observed in the 29 August incidents, the DGCA directed IndiGo to conduct BSI on engines installed on A321 aircraft with more than 3,000 hours TSLSV. Three engines were identified and inspected, but no irregularities were found.

An official from the DGCA stated, "DGCA took up the matter with Pratt & Whitney (P&W) on September 1 regarding the three incidents of engine failure in quick succession leading to IFSD, demanding OEM’s urgent intervention of the highest level for suitable mitigation."

As an added precaution, DGCA instructed IndiGo to perform BSI on engines installed on A321 aircraft with more than 2,500 hours TSLSV. Five engines were identified for inspection; again, no abnormalities were detected.

P&W had previously indicated a global recall of 200 engines in July, citing HPT hub issues that could only be detected with an Angular Ultra Sonic Inspection (AUSI) at the shop level. In the first phase, the impacted engines must be removed before 15 September for the AUSI.

"A total of 11 engines of the IndiGo fleet were impacted because of this; however, out of these, six were a part of the current PW Aircraft on Ground (AOG) situation, and only five were operating engines, which were removed before 15 September," clarified the DGCA official.

The official further stated, "On 11 September, PW indicated that the phase 2 recall is being reviewed by PW, which will require removal of up to 600 engines between 2023 and 2026, with most of the removals in Q1 of 2024. With the fleet management action plan, PW will issue an SB (Service Bulletin) in the next 60 days."

The DGCA's proactive measures and continued monitoring of the situation demonstrate its commitment to ensuring air travel safety in India amidst these engine-related concerns. IndiGo and Pratt & Whitney will be closely watched for compliance with safety measures and further developments in this matter.

(With inputs from IANS)