Comments by "Nicholas Conder" (@nicholasconder4703) on "Ed Nash's Military Matters" channel.

It should be remembered that Wallis was involved with the development of the Wellington as well. My father flew on them in 1941 as a navigator, and told me a few fun facts about the airplane. First, if you stood at the front of a Wellington and looked back to the tail gunner's position, you would be able to see the tail of the aircraft "corkscrewing" while in flight. Second, if you had to reduce weight due to battle damage and were losing altitude, the structural members on the fuselage were marked to indicate which ones could be safely removed and thrown out of the aircraft.
10
@stevejohnson4774 Barry has a point. The issue lies in weights and balances. Adding two Merlins to the airframe would have increased the weight in front of the centre of lift, a change in the centre of mass requiring a redesign of the wings, changing the fuselage, or some other change to facilitate using the larger and heavier engines. It would be like the Boeing 737 Max-8 problem all over again, without computer assistance to compensate for the change in aerodynamic performance of the aircraft.
3
@stevejohnson4774 The issue is not whether the Whirlwind could accept the Merlin, but how much weight would be added forward of the wings by switching to the Merlin, how this might negatively affect the flight characteristics of the aircraft, and how much redesign would be needed to counteract any negative flight characteristics. It's a question of weights and balances, or more specifically, how far forward the centre of mass was shifted in relation to the centre of lift, and what (if any) instability was thus incurred. As I previously stated, this is a similar issue to adding the new engines to the 737 Max-8 - by adding heavier engines Boeing altered the centre of mass, making the plane inherently unstable. In the case of the Halifax, the bomber had somewhat differing flight characteristics depending on if you used Merlins or Hercules radials. From what I have heard, the flight characteristics of the Liberator actually improved when the changed out the plexiglas nose for a bow turret. This is the point I am making. It is not whether the Merlin could be used or not, but whether the addition of the Merlins would negatively impact the handling characteristics of an airplane that was originally designed to take Peregrines, not Merlins. And it is interesting that the quote you give says nothing about aircraft handling or performance, just fixing an undercarriage retraction issue. Which leaves one scratching their heads wondering if there was a marked improvement, or the plane suddenly developed major issues that couldn't be easily fixed. Perhaps we will never know.
2
@TheHarryMann The point I was trying to make is that changing the engines COULD have negatively affected the flight characteristics, and I used the Max-8 issue as a recent example of how this happens. We don't know if using Merlins would have worked without negatively affecting the aircraft's performance because there is very little test data. And as I said elsewhere, changing engines sometimes had a positive impact as well. The Handley-Page Halifax comes to mind.
2
@allangibson2408 Which was a stupid thing to do. Who cares if the customers noticed? But that does raise a new question - would increasing the size of the elevator have meant more testing and going through the whole certification process? I suspect that a change like that would have added time to the development process (plus certification time), and that is why they didn't do it because they wanted to get the Max-8 out as soon as possible.
2
@allangibson2408 That was more or less my point. Boeing wanted to avoid the whole recertification process, which would have added another year or two to the roll-out of the 737-Max8. So rather than do the right thing, which would have been to redesign the plane and go through certification, they tried a rather ill-conceived quick fix (ill-conceived because there was no back-up sensor or easy way to disable the system if it malfunctioned).
2
It shouldn't be forgotten that the Vickers Wellington also used Barnes Wallis' geodetic frame as well.
2
@benholroyd5221 No, very structurally sound. Just slightly flexible.
2
To ne, the ME-309 looks like the German response to the Bell P-39 Airacobra.
1