I have a question about Fokker E.I and E.III.

[kodam]

Hello. My English is not good, so I wrote this using Google Translate. Please take this into consideration when reading.

 

This isn't a game-related question, but I don't know where to ask it, so I'm posting it here.

 

Anthony Fokker developed the M.5, the prototype of the Fokker Eindecker. The prototype with a shorter wing span was called the M.5K (A.III), and the prototype with a longer wing span was called the M.5L (A.II). From what I've read, the M.5K was slightly faster, but the M.5L was adopted by the German because of its better handling and maneuverability.

 

However, the aircraft that Anthony Fokker mounted the machine gun synchronization gear on was the M.5K.

 

What I'm curious about is why Fokker installed a machine gun synchronization gear on the M.5K, even though the M.5L had superior performance. Of course, there were changes in the E.II and E.III to make the wings longer and the fuselage longer, but wouldn't it have been better to just use the M.5L? Why did the German military not require the M.5L to be equipped with a machine gun?

 

My guess is that Fokker installed a machine gun on the M.5K instead of the M.5L for the purpose of selling the M.5K, which was not adopted by the German military. In that case, Fokker will sell both prototypes to Germany. What do you guys think?

 

Another question is that I read that the Fokker E-series had a small window inside the cockpit that allowed a view of the outside. The cockpit photos of the Fokker E.III and the IL-2 Flying Circus, Rise of Flight from Fokker E.III, have square windows with handles on both sides of the cockpit. The pilot could open and close this window to view the outside.

 

What I'm curious about is that I've heard that there another windows or doors on the cockpit bottom that allow a view of the outside, so that the pilot can see the outside between his legs. However, I haven't found any detailed photos of this. I've also checked the cockpit bottom in the game, but I can't get a sense of how it opens. Is it true that the floor is open? Where can I find detailed information about this?

 

 

Edited May 14 by kodam

[FrankieZZw313145]

Because M.5L probably didn't really have superior performance and it was lighter. Plus there was only one M.5K with a machine gun so it didn't matter. The E1 was closer to the M.5K, so that is presumably what the Inspektion der Fliegertruppen wanted. The window sounds like a good idea, I have never seen a photo of one though.

[LufberyJAA]

Hello! These are great questions about some fascinating early war aircraft.

 

I have been intrigued by the Fokker E.III for a while and enjoy flying it in the game.

 

I don't have answers, but suggest you go to: www.theaerodrome.com and post your questions in the forum at that site. There are many true experts on WWI aviation who participate in the forum.

 

Warm regards,

-Drew

 

[kodam]

Oh, thank you for recommending a good site. I will post on that site. 😄

 

[kodam]

6 hours ago, FrankieZZw313145 said:

Because M.5L probably didn't really have superior performance and it was lighter. Plus there was only one M.5K with a machine gun so it didn't matter. The E1 was closer to the M.5K, so that is presumably what the Inspektion der Fliegertruppen wanted. The window sounds like a good idea, I have never seen a photo of one though.

Thanks for the reply. That's an interesting story. So, I guess the story that M.5L's performance was better isn't completely true. Then I wonder why Germany only adopted A.II(M.5L) and not A.III(M.5K). Do you know the details?

[kodam]

I got the answer to my second question from the site LufberyJAA told me about.

According to photos from The Vintage Aviator Collection's Facebook page, the E.III's bottom appears to have small doors that open and close on hinges. 

 

You can see the picture at the link below.

https://www.facebook.com/photo/?fbid=905055884758984&set=a.529481345649775

 

Now I just need to figure out why the M.5K was equipped with a machine gun. 🤔

 

[AndyJWest]

Given the small size and the location of the doors, and the fact that any view is going to be obstructed by the pilots arms and legs and the stick, I have to doubt that it is intended to be looked through. More likely there to make access for maintenance easier, I'd have thought. 

 

The caption saying they "offer the pilot a view of the ground for landing" makes no sense at all to me, unless the E.III had vertical landing capabilities since lost to history. Under what circumstances would looking through it be in any way useful as a landing aid?

[kodam]

26 minutes ago, AndyJWest said:

Given the small size and the location of the doors, and the fact that any view is going to be obstructed by the pilots arms and legs and the stick, I have to doubt that it is intended to be looked through. More likely there to make access for maintenance easier, I'd have thought. 

 

The caption saying they "offer the pilot a view of the ground for landing" makes no sense at all to me, unless the E.III had vertical landing capabilities since lost to history. Under what circumstances would looking through it be in any way useful as a landing aid?

 

From what I've read, the Fokker Eindecker had very limited visibility below the fuselage due to the wings on either side of the cockpit. So when the M.5L prototype was adopted as the A.II, the wing root area was not covered with canvas so that the ground could be observed. However, this method was aerodynamically unstable, so a different method was used in the E-series.

 

Initially, small accordion-style doors or panels were built into the sides of the cockpit, and the pilot could open these when necessary to obtain a view below the fuselage. Later on in the E.III it was changed to a rectangular panel or door which the pilot opened and closed by sliding it with a handle. And they added panels to the cockpit bottom to provide visibility underneath the fuselage.

 

I'm not sure how effective these devices were in checking the ground, but given the continued efforts to secure visibility under the aircraft from A.II to E.III, I suspect that it was a constant issue by pilots.

Edited May 15 by kodam

[AndyJWest]

The view downwards in the E.III is certainly poor, but I'm unconvinced the doors would actually do anything useful. The field of view offered looks too obstructed, and too narrow. Were they perhaps tried in prototypes only?

[kodam]

17 minutes ago, AndyJWest said:

The view downwards in the E.III is certainly poor, but I'm unconvinced the doors would actually do anything useful. The field of view offered looks too obstructed, and too narrow. Were they perhaps tried in prototypes only?

 

I think all E-series were equipped with it.

 

[Avimimus]

On 5/14/2025 at 3:52 AM, kodam said:

Anthony Fokker developed the M.5, the prototype of the Fokker Eindecker. The prototype with a shorter wing span was called the M.5K (A.III), and the prototype with a longer wing span was called the M.5L (A.II). From what I've read, the M.5K was slightly faster, but the M.5L was adopted by the German because of its better handling and maneuverability.

 

However, the aircraft that Anthony Fokker mounted the machine gun synchronization gear on was the M.5K.

 

What I'm curious about is why Fokker installed a machine gun synchronization gear on the M.5K, even though the M.5L had superior performance. Of course, there were changes in the E.II and E.III to make the wings longer and the fuselage longer, but wouldn't it have been better to just use the M.5L? Why did the German military not require the M.5L to be equipped with a machine gun?

 

These aircraft are very marginal in performance (speed, climb, manoeuvrability). I wouldn't be surprised if the increased weight of an armed version of the M.5L would have rendered an such a derivative quite a bit slower.

 

It is also worth noting that it appears the main benefits of the longer wings were expected to be range and easy of handling (not manoeuvrability per se), and that manoeuvrability was impressive in comparison to aircraft like the Fokker Spin (in other words - compared to designs from 1912)... so may have been very marginal by even 1916 standards.

 

It is also worth noting that the E.I/E.II/E.III designations were applied retroactively... so there were actually subvariants of the E.I and there was a gradual roll-out of improvements on the production lines as refinements were approved or engine availability increased... so it is probably best to see all of these types as iterative redesigns starting from the Morane Saulnier G and ending with the Fokker E.III ...a gradual evolution as improvements are made and combined.

 

Note: I stop at the E.III because the E.IV was essentially a complete redesign from the ground-up.

[kodam]

10 hours ago, Avimimus said:

 

These aircraft are very marginal in performance (speed, climb, manoeuvrability). I wouldn't be surprised if the increased weight of an armed version of the M.5L would have rendered an such a derivative quite a bit slower.

 

It is also worth noting that it appears the main benefits of the longer wings were expected to be range and easy of handling (not manoeuvrability per se), and that manoeuvrability was impressive in comparison to aircraft like the Fokker Spin (in other words - compared to designs from 1912)... so may have been very marginal by even 1916 standards.

 

It is also worth noting that the E.I/E.II/E.III designations were applied retroactively... so there were actually subvariants of the E.I and there was a gradual roll-out of improvements on the production lines as refinements were approved or engine availability increased... so it is probably best to see all of these types as iterative redesigns starting from the Morane Saulnier G and ending with the Fokker E.III ...a gradual evolution as improvements are made and combined.

 

Note: I stop at the E.III because the E.IV was essentially a complete redesign from the ground-up.

 

Thanks for the reply!!

Another opinion is that the performance difference between the M.5L and M.5K is minimal. And it is also interesting that the M.5L is heavier, so mounting a machine gun would further reduce its performance. Then, it is possible that Germany adopted the M.5L, which is easier to control than the performance, and the Fokker chose the M.5K due to weight issues.

 

However, if the performance difference between the M.5L and the M.5K is so small, shouldn't there be much difference in performance when equipped with a machine gun?

 

Since it's difficult to get information on this subject, I keep having questions. T_T

 

Perhaps the A.II, which was an M.5L, was supplied to the German military as soon as it was produced, so is it possible that they installed a machine gun synchronization gear on the relatively spare M.5K?

 

Edited May 15 by kodam

[Avimimus]

5 minutes ago, kodam said:

However, if the performance difference between the M.5L and the M.5K is so small, shouldn't there be much difference in performance when equipped with a machine gun?

 

Since it's difficult to get information on this subject, I keep having questions. T_T

 

Perhaps the A.II, which was an M.5L, was supplied to the German military as soon as it was produced, so is it possible that they installed a machine gun synchronization gear on the relatively spare M.5K?

 

 

It is quite possible that the M.5K remained with Fokker and thus could be used for testing.

 

However, I also suspect that performance was so marginal that there could have been a significant difference when the weight of a machine gun was added.

 

It is also worth noting that the A-type Fokkers were meant for unarmed observation - so there the longer endurance and slower cruise associated with the larger wing was desirable... but the E-type were meant to catch other aircraft which required every bit of available speed and climb.

 

P.S. Overall it is very interesting to see how the first fighter aircraft were converted two-seaters or based on single seat observation aircraft that had been derived from pre-war racers. Both tended to fail - the two-seater derived aircraft were a bit too heavy to run down enemy aircraft and tended to be too stable - the single-seat racer types were generally too lightly built to safely manoeuvre or be up-engined.

[kodam]

3 hours ago, Avimimus said:

 

It is quite possible that the M.5K remained with Fokker and thus could be used for testing.

 

However, I also suspect that performance was so marginal that there could have been a significant difference when the weight of a machine gun was added.

 

It is also worth noting that the A-type Fokkers were meant for unarmed observation - so there the longer endurance and slower cruise associated with the larger wing was desirable... but the E-type were meant to catch other aircraft which required every bit of available speed and climb.

 

P.S. Overall it is very interesting to see how the first fighter aircraft were converted two-seaters or based on single seat observation aircraft that had been derived from pre-war racers. Both tended to fail - the two-seater derived aircraft were a bit too heavy to run down enemy aircraft and tended to be too stable - the single-seat racer types were generally too lightly built to safely manoeuvre or be up-engined.

 

It makes sense. 

Thank you so much for your detailed opinion. Now my doubts have been somewhat resolved.

 

Salute~! 🫡