When will the Boeing 737 MAX fly again?

It is well over a year now since Boeing's latest version of their very successful 737 model was grounded in March 2019. This much-anticipated version of the type brought all sorts of technological improvements that brought it into line with the 787 and 777 models. As we know, the 737 MAX's introduction was marred by two tragic accidents causing the loss of 346 lives. First Lion Air flight 610 out of Jakarta on 29 October 2018 and then Ethiopian Airlines flight 302 on 10 March 2019 out of Addis Ababa. Airlines and aviation authorities around the world were quick to ground the aircraft type. However, the F.A.A. (Federal Aviation Authority (US)) cleared the aircraft as airworthy on the 11th of March 2019. This decision was reversed on the 13th of March as the similarities of the accident causes started to come to light.

So why did Boeing and the F.A.A. drop the ball so badly? There have been many reports about a toxic work environment at Boeing going back many years. It seems that blame can be apportioned to both Boeing and the F.A.A. according to a House report which was released after a year-long investigation in March 2020. The investigation found in evidence which included texts on Boeing employees' phones, that Boeing misled the F.A.A. with regard to the MCAS (Maneuvering Characteristics Augmentation System) which was found to have been the blame for both accidents. For the F.A.A.'s part, the report found that the FAA "failed in its duty" and that its review of the troubled plane was "grossly insufficient." The report also labelled Boeing as having a "culture of concealment". This is quite damning when your industry is 100% about safety.

A Boeing 737 MAX of Lion Air, similar to that which was lost on 29 October 2018.

So what is so different about the MAX that this latest 737 is suddenly struggling with airworthiness certification?

As passenger jets go, the 737 is at the small end of the scale, designed to fly short to medium-haul with relatively few passengers. Small and compact, it was designed when pure jet engines were in use and not the chunkier bypass engines of today. Those first jet engines were long and thin and sat comfortably under the wing with enough ground clearance to spare. Economic and environmental pressures led to the introduction of cleaner and quieter bypass engines which by their nature are chunkier for want of a better word.

The jet in a bypass engine sits in the middle at the core of the engine and is surrounded by an outer shell surrounding the core which carries air pushed through by the larger fan at the front. So full jet thrust from the core then slightly less thrust from the surrounding fan-pushed air. This stops the crackling and roar which happens as a pure jet exhaust is forced out into still air, the surrounding fan air softens that.

An Ethiopian Airlines Boeing 737 MAX much like the one that crashed on 10 March 2019 finally causing the MAX to eventually be grounded.

So back to our 737. As soon as bypass engines were to be added to this aircraft it became evident that ground clearance would be an issue. There was no real option to increase the landing gear length as there was the problem of where it should go during flight.

You may have noticed when you got on your 737 Next Gen or just observed them at the airport, the engine nacelles when viewed from the front are not quite round. There is a bit of flattening of the circle at the bottom. This is for ground clearance.

Boeing-737-NG(Next Gen) Engines have a pronounced flattening at the bottom to preserve ground clearance.

It is easy to see that the Boeing 737 MAX's Leap 1B engines are larger than those of the 737 NG.

The 737 MAX took things to the next level. CFM International, a leading jet engine maker for airliners had designed the Leap 1 engine series and these were to be the engine of choice for the 737 MAX. The Leap 1B produced economic savings, a big drawcard for airlines, as well as noise reduction which enable aircraft to fly friendly to airports where this is important.

The drawback is the larger circumference of the whole engine unit. To accommodate this, Boeing extended the nose landing gear by 8 inches over previous models as well as beefing up the main landing gear and support structures to take the extra weight of the bigger engines.

The change that is important, however, is the position of the new engines. The nose gear extension on its own was not enough to maintain the required 17-inch ground clearance beneath the engines. To do this Boeing moved the engines further forward of the wing's leading edge and higher. Problem solved, but perhaps with some trade-offs that would come and bite later.

A Southwest Airlines Boeing 737 MAX -8 registration N8710M shows off the larger CFM engine.

Boeing realised that in certain phases of flight, the MAX could inadvertently be put into a stall situation. Enter the MCAS (Maneuvering Characteristics Augmentation System). This system was designed to prevent the pilot from being able to put the aircraft into a stall situation, a safety fallback system. It seems that Boeing believed this system would resolve any design-driven compromises and that pilots who were certified on previous 737 models could transition seamlessly onto the new MAX. Boeing was keen to avoid expensive pilot retraining.

So Boeing had a "culture of concealment" and the F.A.A. "failed in its duty". It sounds like a perfect storm for both and let's face it, we're not out of it yet. Boeing for its part is still being investigated by various government agencies on financial and other matters. For the F.A.A.'s part, its chief, Steve Dickson, will testify before the Senate Commerce Committee on Wednesday 17 June 2020 at 10 a.m. ET. According to the committee, Dickson will answer questions about "issues associated with the design, development, certification, and operation" of the Boeing 737 Max. The hearing will also look at ways to reform the certification process.

It is events such as those unfortunate accidents that serve to expose wrongdoing and negligence among those who we trust to protect our safety. Cutting corners or simply being asleep at the wheel because this is all business as usual just doesn't cut it in this industry. How long will it take for Boeing to gain back confidence from the travelling public? Luckily people have short memories. I would hope that what comes out of this is a more vigilant F.A.A., to protect our interests and a more respectable Boeing. With such a long distinguished history in aviation, let's not drop the ball now.

So when will the MAX fly again? Well, Boeing was hoping for January 2020, but this did not eventuate. In fact, Boeing CEO Dennis Muilenburg was let go by the board in December 2019 for trying to rush the MAX back into the air. Boeing continued to produce the MAX and only stopped when they ran out of storage space, including their staff car park. Around March they seemed to be preparing to ramp up again but Boeing has alerted its suppliers to stop production once again. It seems the MAX will definitely miss the Northern Hemisphere summer. It seems like a case of watching this space at the moment.