SSJ-100 Aircrafts to be Disassembled: Issues at the Joint of Stringers with the Spar Web Doubler

The «Yakovlev» company has released a service bulletin with a precise description of the algorithm of actions for technicians to inspect 14 SSJ-100 aircrafts after identifying defects in the fuselage design.

During the operation of RRJ-95 aircrafts, specialists identified deviations in the typical fuselage design at the joint of stringers 42-44 with the spar web doubler of frame 12 of section F2 from the design documentation.

Urgent Works

Deputy Head of Rosaviatsia, Andrey Dobryakov, instructed air carriers to carry out service work on aircrafts with serial numbers 95104–95117 (14 in total), which may have design deviations. All aircrafts in this batch were produced in 2016.

In the absence of stringer fasteners on already operating aircrafts, it is prescribed to limit their airworthiness until the technical deviations are eliminated. Specifically for these repair works, «Yakovlev» has released a service bulletin with a precise description of the algorithm of actions for technicians.

Exact Location of the Problem

Fastening problems on some SSJ-100s may occur between the passenger door and the cockpit, according to the bulletin. To check the aircraft, it is necessary to conduct a detailed inspection of the skin, as well as frames, spars, and stringers for deformations, folds, cracks, and loosening of riveted or bolted joints.

For this, it is necessary to dismantle the door opening skin, remove the toilet module, and remove the thermal and sound insulation mats. This will give the technician access to the structural elements that he must inspect.

It is necessary to use special tools — a telescopic mirror, a magnifying glass, and a flashlight — to detect possible micro-damages. If deviations in the design are confirmed, the aircrafts must be sent for repair.

Why are Airworthiness Directives Issued

The founder of the flight safety service RunAvia, Andrey Patrakov, explained that airworthiness directives are issued for urgent execution when the risk to flight safety is assessed as high.

Based on the directives, aircrafts can be suspended from flights. This is the restriction of airworthiness.

During the operation of aviation equipment, manufacturing and design defects are sometimes discovered that did not manifest themselves during testing.

Oleg Panteleev, Executive Director of the AviaPort Agency

In this case, an assumption is made that the fasteners are weakened, which could potentially lead to problems, Panteleev clarified. According to him, a similar logic is implemented in recall campaigns in the automotive industry. It is not a fact that a particular aircraft has a defect, but it needs to be checked to ensure safety.

Earlier www1.ru reported that a video of the testing of the new PD-35 aircraft engine has appeared, but there is no aircraft for it yet.