I'm referring to this Wendover Productions video - The Economics That Made Boeing Build The 737 Max.

The creator asserts that designing a new long range narrow body plane would be more expensive than modifying an existing design, which is uncontroversial enough.

But he also makes the claim (timestamp 6:13) that there was pressure from American Airlines to provide a re-engined 737 over a new model, because existing American Airline pilots are already trained to use the 737.

Pilots are generally trained to operate just one type of aircraft. Some fly the a380, some fly the 777, some fly the a320, and some fly the 737, but they don't fly the 737-700 or the 737-800 or the 737-900, they fly the 737 airplane as a whole.

Pilots are trained to the aircraft, not the specific aircraft variant.

In general, pilots can and do switch between variants of aircraft even in any given day and are not required to do any substantial training to be certified on different aircraft variants.

Crucially, the FAA has never required that 737 pilots complete any simulator training before flying new 737 variants.

That's because a 50 year-old 737 more or less flies like a 1 year-old 737.

American [Airlines] wanted a refreshed 737 over a new plane since they already had thousands of trained and certified 737 pilots.

They had no pilots for a hypothetical new narrow-body Boeing and the cost of training their pilots to a new plane would be massive.

Is this characterisation correct, or is there some nuance missing here?

The thing that I'm finding a little hard to understand, is that these different variants of aircraft must have different handling characteristics, or different things to consider (ie. things unique to doing a longer flight), it does seem a bit crazy that no training would be required.

It also seems that the economic incentives are a bit backward - this kind of dynamic would stiffle aircraft innovation as a whole.

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    $\begingroup$ The question is about pilot training, but the other big issue is certification. With a 50-year old basic design, there is a huge economic incentive to make design changes that can be certified using "grandfather rights" instead of having to re-certify to current regulations. When that tail is wagging the design engineering dog, you can end up where the 737 Max has ended up. $\endgroup$
    – alephzero
    Aug 27, 2019 at 12:22
  • $\begingroup$ … Of course you can argue that the 50 year safety record of the 737 family is better data about safety than any new-aircraft certification program, but the rules have to be the same for everybody - though arguably the entire concept of "grandfather rights" is in practice a not-so-subtle form of national protectionism, given that the F in "FAA" standards for "Federal" and Airbus doesn't (yet) have any 50-year-old aircraft designs. $\endgroup$
    – alephzero
    Aug 27, 2019 at 12:27
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    $\begingroup$ Related: How are evolution and variants of aircraft considered by certification authorities? $\endgroup$ Aug 27, 2019 at 14:37
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    $\begingroup$ This question brought to you by the letters M C A and S. $\endgroup$ Aug 27, 2019 at 21:06

3 Answers 3


It appears to depend on how much changed. You do have to have some training between models. The selling point was that an airline with 737 pilots could fly the MAX variant with minimal retraining

"The airplane is configured to be very common with the [737 NG]," Wilson, who is now retired, said, "and so a pilot can walk into here and will find everything he can just like he can in the [737 NG]."

"FAA-approved this for two-and-a-half hours of computer-based training for the transition between the two aircraft," Wilson continued. "All the overhead panel switches are the same. The only minor difference is, because of the change in the display, is to move some of the center console items here on the forward console."

And from the Wall Street Journal

To make the plane as inexpensive as possible for airlines to adopt, Boeing was intent on persuading regulators that pilots of earlier 737s should be allowed to start flying the MAX without simulator training. That training would have been required if there were substantial safety differences between the models, boosting the plane’s cost to airlines since training cuts into time flying paying passengers. “Our marching orders are no training impact on this airplane. Period,” Richard Reed, a former Federal Aviation Administration engineer, recalled a senior Boeing official telling him during a meeting in the early years of the MAX’s development.

The company had promised its biggest customer for the MAX, Southwest Airlines Co. , that it would pay it $1 million per plane ordered if pilots needed to do additional simulator training, according to Rick Ludtke, a Boeing engineer who worked on the jet’s cockpit systems, and another person who had been involved in the airplane’s development.

And later

Boeing officials were focused on making the MAX fly as similarly as possible to earlier 737s. The fewer differences, the less likely the FAA would require pilots to undergo retraining.

Mr. Ludtke, the former Boeing cockpit engineer, said company managers put pressure on engineers to avoid tweaks in designs that could result in pilots needing to learn new maneuvers in a simulator.

Wasn't there a difference?

The issue was that the MAX had a system (MCAS) that could push the nose down to make it behave more like previous 737s. Having read several articles on it, the root problem was

  1. The initial specs said it was a minor change with the same course of action to correct as a runaway stabilizer (i.e. it was something 737 pilots already knew)

    The company reasoned that pilots had trained for years to deal with a problem known as a runaway stabilizer that also can force the nose of the plane to dip. The correct response to an MCAS misfire was identical. Pilots didn’t need to know why it was happening.

  2. Boeing made MCAS 4x more powerful without really notifying anyone. It could also operate at slower speeds.
  3. Boeing apparently wrote its manuals based on the original MCAS spec. Assuming it was still a minor system, it was buried or omitted

    Southwest Airlines, the jet’s first and biggest customer, followed Boeing’s lead and deleted MCAS from the manuals and emergency procedures it devised for its pilots. Other carriers didn’t mention it, either.

  4. As predicted, the previous crew of the aircraft that would be Lion Air 610 had issues with MCAS, but correctly diagnosed a runaway stabilizer and shut off MCAS in the process

    The puzzled cockpit crew checked a quick reference handbook, running through other emergency steps before successfully regaining control of the plane by executing the checklist for a runaway stabilizer. That turned off MCAS and the crew flew manually for the rest of the trip.

Lion Air 610 would not be so lucky. They only figured it out moments before the plane slammed into the ground. Apparently it wasn't as obvious to pilots as Boeing thought.

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    $\begingroup$ The MCAS was not, actually, the problem but rather the solution. The problem was that the MAX needed bigger engines, which had to be mounted further towards the nose of the aircraft (to still fit under the wings). This new position would cause "issues" with the stability of the aircraft - notably, the nose would rise unexpectedly. The MCAS had to be added to actively counter that issue. There was just the minor detail that some pilots "who were not initially informed about existence of the new MCAS system" were a bit...surprised. $\endgroup$
    – Klaws
    Aug 27, 2019 at 13:30
  • $\begingroup$ There was also another less public info regarding the recovery plan requiring the pilots to make the correct decision in 4 seconds. When they tested the revised MCAS system (2019), the pilots made the correct assertion in 4 seconds and recovered the plane, but this is not a good margin of safety and so that's why the entire concept of requiring perfect pilot response is being revised. The Lion Air pilots turned off the MCAS and then turned it back on minutes later, dooming their flight. $\endgroup$
    – Nelson
    Aug 28, 2019 at 0:39
  • $\begingroup$ @Nelson I believed they turn off motorized trim not the MCAS as such, because manual trim was just too physically expensive $\endgroup$
    – curiousguy
    Aug 28, 2019 at 19:51

Firstly, some terminology: A class rating allows a pilot to fly a certain class of aircraft (Fixed wing, Heli, gyro-copters etc.). Whereas a type rating allows a pilot to fly a certain type of aircraft (A320, 737, etc.). I believe this is the same all over the world as it is ICAO.

I can't answer for the FAA rules as I have no real experience with those. But at least, here in Australia, CASA (our civil regulator) lumps together all 737s from the 737-300 to the 737Max into one type rating.

They do however have a requirement for differences training, which was the "iPad video the transitioning pilots had to watch" - as far as I know there is no real prescription for what this training consists of.

Another interesting side effect of this legislation is that a pilot can fly an ATR42 and ATR72 on the same type rating, despite one being almost 2x the size of the other in some configurations!

SEE https://www.legislation.gov.au/Details/F2018L00660

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    $\begingroup$ Other examples...757 and 767, A40-300/200 and 600, A350 / A330. $\endgroup$
    – Anilv
    Aug 27, 2019 at 1:49
  • $\begingroup$ Wow, I had never seen that! Really goes to demonstrate the importance of proper regulation and type certification when introducing an airliner on the same type rating! $\endgroup$
    – Noah
    Aug 27, 2019 at 1:52

Where the regulator allows a common type rating but requires differences training among different models within a type, a major priority of the OEM is to limit the training to videos or CBT (computer based training). They will pull out all the stops to avoid a requirement for dedicated simulator time, as this has a significant cost impact for an airline and screws up the commonality benefit to a degree and can really hurt sales (this is specifically what Boeing was trying to avoid in the MAX).

On the CRJ regional jet program there were some interesting aspects to this. The CRJ200 has a hard leading edge (no slats) and lands VERY differently, technique wise, than their slatted 700/900 relatives, but Bombardier was able to avoid dedicated sim time, and just requires a video (which really may not be enough; hard landings have been a problem with pilots transitioning from 200 to 700/900 - you go to idle much sooner on the 200, crossing the threshold at 50 ft, and if you do that on a 7/9, down you come).

The 700 and 900 have FADEC engines, and could have used push button start, as the Embraers using the same engines do, but to minimize differences requirements between FADEC and non-FADEC you start the engines with the thrust levers the same as the manually controlled engines of the 200. It's mostly about trying to keep the cockpit environment, QRH procedures, and checklists and flows as similar as possible.

When Bombardier introduced the CRJ1000 however, the differences got to be too much for Transport Canada and dedicated sim time (one session) became a requirement for a 200/700/900 pilot to qualify on the 1000. A lot of it was related to the length. The sim session includes making a 180 turn during taxi to show that you know how much real estate it needs. And when you land it, the fuselage being so long the nosewheel comes down quite a bit later than the mains (it's actually like two landings - you land the mains, then the nose in seemingly two separate actions, like a lot of heavies). Plus various system differences that made the gap between the 1000 and 200 a little more than TC could take.

It was a little strange because the break really should have been between 200 and 7/9/1000, because that's were the differences were most significant, both system and operating wise, but because the 1000 was the tail end charlie in the family, that's where TC made the cutoff, and it did have some impact on CRJ1000 sales (besides scope clause issues in the US)


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