Diseño del blog
Redundancy On and Off the Ground
Marcelo Gerin Giacomeli • Aug 23, 2023
Redundancy On and Off the Ground
As some might know most of the modern and commercial aircrafts do have a set of redundant systems and components.
Two engines, two or more hydraulic systems, segregated hydraulic tubes and electrical wires, redundant sensors, etc.
The main reason for that is to provide a safe and alternative mean to keep the machine flying until an emergency landing procedure is performed in case of a system/component fail.
Additionally, a backup system or component can also save the mission because the aircraft can "safely" be dispatched if the Master MEL (subject for another post) allows that.
But although redundant systems and components serve as backup, most of them work concomitantly.
And based on that basic premise, why similar and usual activities performed on the ground should also have redundancies?
The answer is simple: to avoid the repetition of a maintenance error.
The probability of two different people make the same mistake is lower unless the procedure is wrong and lead to that.
Other than that, it is advisable mapping the activities that are susceptible to repeated errors and applying some best practices to prevent simultaneous failures in redundant systems and/or components.
One of the most applied best practices is avoiding the same person performing maintenance tasks and routine checks on aircraft’s redundant systems and components.
Additionally, I would suggest a step back. Whenever writing any technical publication or working instruction, you might also have a robust and dual check process, including but not limited to check-lists. The checkers and approvers must have most attention and understand the work scope on its essence.
Procedures and illustrations can be a big barrier against maintenance and operation mistakes.
Think about that!
Regards from Brazil!
Picture: https://www.mdpi.com/2226-4310/10/1/55
On May 2, 2024, a Hawaiian Airlines Airbus A321Neo that had just arrived from Kahului to San Francisco International Airport suffered damage to its left front door. The passengers had all disembarked before the jet bridge collapsed. No injuries were reported. The aircraft was taken out of service. Source: FlightMode Image: A Fly Guy's Cabin Crew Lounge
On April 26, 2024, a Delta Airlines Boeing 767-300 performing flight from JFK New York to Los Angeles encountered an issue and promptly decided to return to JFK due to reports of vibrations. The aircraft landed safely. An after-flight inspection revealed that the right-hand overwing emergency slide was missing. The crew, who responded swiftly and effectively, stated that they had received an indication about the emergency slide and that they had heard a sound from that side of the aircraft during the climb out. The location of where the overwing slide could be is still unknown. Source: Aviation Herald Images: JACDEC
On April 26, 2024, an Ethiopian Boeing 787-8 performing a flight from Addis Ababa, Ethiopia, to Goma, DR Congo, became disabled after landing due to a hydraulic leak that caused the aircraft to lose nose-wheel steering. The aircraft was towed off the runway, and clean-up crews cleaned up the hydraulic fluid. Fortunately, no injuries were reported. Source: AvHerald Images: Mafuta Kasongo & Flightradar24
On April 21, 2024, an American Airlines Airbus A321 was involved in an incident at Charlotte Douglas International Airport. The aircraft, which was under tow and had no passengers on board, experienced substantial damage when the tug lost control and struck the underside of the fuselage behind the nose gear. No injuries were reported. Source: FlightMode Images: twitter/goodbadugly_ap
On April 24, 2024, an ANA All Nippon Airways Boeing 787-8 performing a flight from Tokyo Haneda to Sapporo Chitose, Japan, experienced a hydraulic fluid leak upon landing, causing its number two Rolls Royce Trent 1000 engine to emit smoke. The aircraft stopped on the runway and shut both engines down. Emergency services responded, and no injuries were reported. The runway was closed until the aircraft was towed off. What caused the hydraulic leak is still unknown. Source: JACDEC, FL360aero, Aviation Herald Images: JACDEC, FL360aero, Aviation Herald
On April 22, 2024, an Aeroflot Airbus A330-300 performing a flight from Yekaterinburg, Russia, to Phuket, Thailand, suffered a severe loss of hydraulic fluid while landing at Phuket International Airport. The aircraft stopped and blocked the runway for over an hour until a tug towed it away. A team cleaned up the hydraulic fluid from the runway, and operations then restarted on the runway. No injuries were reported. What caused the loss of hydraulic fluid is still unknown. Source: FlightMode Images: AOT Phuket
On April 21, 2024, a Safair Boeing 737-800, under the skilled command of its crew, performed a flight from Johannesburg to Cape Town. Despite the unexpected loss of its left-outboard main wheel on departure, the crew demonstrated their professionalism by leveling off at FL220 and burning off fuel before performing a low approach at Johannesburg. The aircraft then finally landed on runway 21R, sustaining damage to its left main landing gear. However, due to the crew's swift and decisive actions, no injuries were reported. Source: AvHerald Images: Twitter/MDN News
On April 17, 2024, an Air Algerie Boeing 737-800 performing a flight from Algiers, Algeria, to Lyon, France, decided to return to Algiers after reaching cruising altitude FL340 because of a cracked outer window pane. The aircraft landed without any incident, and no injuries were reported. Another aircraft was used to take the passengers to Lyon with a 7-hour delay. The cracked window pane aircraft was repaired and returned to service 19 hours later. Source: AvHerald Images: JACDEC
On April 15, 2024, a Virgin Atlantic Airbus A350-1000 received minor damage at New York JFK Airport when a vehicle from the Gategourment catering service struck the number 1 engine nacelle of the Rolls Royce Trent XWB aircraft which was parked at the time. The aircraft had no passengers and was subsequently taken out of service. No injuries were reported. Source: Aviation Safety Network Image: JACDEC