Boeing wants to continue moving forward with certification of the top versions of the 737 MAX while addressing the latest problems, and has now applied for a new exemption from the FAA, the US aviation agency responsible for certifying all aircraft manufactured in the country.
The order was placed in November last year and has now been announced by AviationWeek, in light of the events on the 737 MAX 9, which had a fuselage panel torn off midflight and is currently suspended.
This exemption, requested by Boeing, introduces a “new” problem on the 737 MAX: the engines' antiicing system can overheat to the point that the edge of the fairing (called the inlet) can break off and be sucked into the engine itself. with catastrophic consequences.
The engine's antiicing system acts precisely on the leading edge, which directs the air to the first fan (engine blade system), where it is compressed and then burned in the turbine.
737 MAX engine intake in silver color | Photo: CFM International
If ice forms in this area in addition to the weight of the aircraft, the air enters the engine turbulently and eventually pieces of ice may break off and enter the interior of the aircraft, causing various problems such as compressor stalling or air loss.
Likewise, if part of the fairing is sucked in, the same consequences can occur. A similar accident occurred in the recent past with a Southwest Airlines Boeing 737700, in which one passenger died.
In the November order, Boeing says there are already hundreds of 737 MAXs in service since 2017 (Models 8 and 9), with a total of 6.5 million flight hours, with no reported cases of parts failing due to overheating Fairing triggered antiice system, and that the likelihood of this happening is “very low”.
And in order not to stop deliveries, a solution is being developed during the manufacture of the aircraft and is therefore requesting a timelimited exception until March 31, 2026, when the solution will be ready and implemented not only on the 737 MAX 7 delivered, but already certified in all other models including the MAX 8 and 9 as well as the MAX 10, which is already further advanced in the certification part.
FAA officials consulted by AviationWeek have stated that the technical group is leaning toward denying Boeing this exemption, either because of similar recurring requests (in 2017, the 767 received a corrective exemption valid until 2027, that is, only if the (that aircraft is already out of production as it is only a corrective action and not a preventive measure) as well as for all of the company's failures related to the MAX 8, the 787 Dreamliner and the 777X.
These problems ultimately tarnish the image of the FAA itself, which in many cases is not responsible for Boeing's mistakes but, as a regulator, is naturally and rightly blamed for failing to adequately monitor. This demand comes from both the White House and Congress, from passengers, government opponents and even from foreign air carriers, which normally ratify the certification process carried out by the agency.
So far, the FAA has not provided a response to Boeing, which had already requested a temporary exemption to adapt the software on the MAX 7 and 10, which, if not accepted, will abandon the two stateoftheart aircraft (the smallest and the largest). of the MAX series) for several years with differences in operation and piloting compared to the already operational Models 8 and 9.