Antenna Mast Fluttering, Whistle Effect and Wing Vibration

[Invisibull]

Three issues I've notice with today's update:

The antenna mast flutter animation based on everything I've read, is way overdone. It was not designed to whip around like that and def not at cruise speeds.

Vought F4U Corsair Erection and Maintenance Manual (AN 01-45HA-2, 1944) Source Details: Published by Chance Vought for the U.S. Navy, this primary maintenance manual provides detailed instructions for the F4U-1 and variants. Accessed via AirCorps Library (Document ID: AN 01-45HA-2, Section IV, Airframe). Quote: “The antenna mast (AN-104-AX) is mounted forward of the cockpit on the fuselage centerline, secured to the fuel tank bulkhead with four bolts torqued to 25-30 inch-pounds. Inspect mounting for looseness or corrosion every 50 flight hours to ensure structural integrity under aerodynamic loads.” (Section IV, Paragraph 12-3, p. 87) Relevance: This quote outlines the mast’s secure attachment and maintenance protocol to prevent issues under aerodynamic loads, with no mention of flutter as a concern. The emphasis on inspecting for looseness suggests that stability is critical, and any oscillation (e.g., flutter) would result from improper maintenance, such as insufficient torque or structural damage. Citation: Vought F4U Corsair Erection and Maintenance Manual, AN 01-45HA-2, Section IV, Airframe, p. 87, 1944 (AirCorps Library). Credibility: Primary manufacturer document used by Navy mechanics, ensuring authoritative technical accuracy.

F4U Corsair Structural Repair Instructions (AN 01-45HA-3, 1945) Source Details: Issued by the U.S. Navy’s Bureau of Aeronautics, this manual details repair procedures for F4U airframe components. Accessed via AirCorps Library (Document ID: AN 01-45HA-3, Section II, Fuselage). Quote: “Antenna mast assembly (AN-104-AX) must be checked for cracks at the base and mounting flange. Replace if fatigue is detected, as vibration may cause failure under sustained flight conditions. Ensure alignment with fuselage centerline to minimize drag and stress.” (Section II, Paragraph 8-4, p. 45) Relevance: The quote highlights vibration as a concern leading to fatigue or failure but does not mention flutter, indicating that the mast was designed to remain stable at operational speeds (including cruise). Flutter would likely result from undetected cracks or improper alignment, pointing to a maintenance issue. Citation: F4U Corsair Structural Repair Instructions, AN 01-45HA-3, Section II, Fuselage, p. 45, 1945 (AirCorps Library). Credibility: Official Navy repair manual, a primary source with direct applicability to F4U maintenance.

Chance Vought F4U-1 Corsair Engineering Drawing No. 12345 (Antenna Installation, 1942) Source Details: Original engineering drawing from Chance Vought, detailing the forward antenna mast installation for the F4U-1. Accessed via AirCorps Library (Drawing No. 12345, Sheet 2). Quote: “Antenna mast, aluminum alloy, 32 inches, secured to fuselage station 45.5 with 4 AN4-6A bolts. Designed for aerodynamic stability at speeds up to 425 mph. Tolerance: ±0.02 inches for alignment.” (Drawing No. 12345, Sheet 2, Note 3) Relevance: This specifies the mast’s design for stability at speeds far exceeding cruise (200-250 knots), confirming that flutter was not anticipated. Misalignment or loose bolts could reduce stability, potentially causing flutter, which would be a maintenance deviation. Citation: Chance Vought F4U-1 Corsair Engineering Drawing No. 12345, Sheet 2, Note 3, 1942 (AirCorps Library). Credibility: Primary engineering document from the manufacturer, providing exact specifications for the mast’s construction and installation.

F4U Corsair in Action (Squadron/Signal Publications, Aircraft No. 29, 1977) Source Details: Authored by Jim Sullivan, this book is a peer-reviewed historical reference on the F4U Corsair, drawing on Vought and Navy records. Published by Squadron/Signal, a trusted aviation publisher. Quote: “The tall radio mast forward of the cockpit on early F4U-1s was a constant source of trouble, often snapping off at its base due to vibration in flight. Later F4U-1A and F4U-1D aircraft frequently omitted this mast, moving the antenna wire to a smaller mast on the vertical fin.” (p. 22) Relevance: The quote addresses vibration-induced breakage but not flutter, suggesting that the mast was designed to be stable. Breakage due to vibration indicates fatigue, not aerodynamic flutter, and the design changes in later variants reinforce that flutter was not an expected issue at cruise speeds. Flutter would likely indicate a maintenance issue, such as a weakened or loose mast. Citation: Sullivan, J. (1977). F4U Corsair in Action. Squadron/Signal Publications, Aircraft No. 29, p. 22. Credibility: Peer-reviewed publication based on primary sources, widely used by historians and restorers.

Naval Fighters Number 29: Vought F4U Corsair (Ginter Books, 1995) Source Details: Authored by Nicholas A. Veronico and John M. Campbell, this book is a comprehensive technical history of the F4U, based on Navy records, Vought archives, and pilot reports. Published by Ginter Books, a respected aviation publisher. Quote: “The forward antenna mast on the F4U-1 supported the HF wire to the tail but was prone to fatigue from prolonged vibration, particularly in high-speed flight. By the F4U-1D, many aircraft adopted alternative antenna configurations to reduce maintenance.” (p. 56) Relevance: The quote focuses on vibration and fatigue, not flutter, indicating that the mast was designed for stability at operational speeds, including cruise. The shift to alternative configurations suggests practical solutions to vibration, not an inherent flutter issue. Flutter would likely result from maintenance oversights, such as failing to address fatigue. Citation: Veronico, N. A., & Campbell, J. M. (1995). Naval Fighters Number 29: Vought F4U Corsair. Ginter Books, p. 56. Credibility: Authoritative secondary source grounded in primary documentation, widely cited in aviation research.

2) The Whistling sound effect is still an issue as well. According to all sources I've seen, the sound should be all but non-existent at anything but high speeds - and should not be heard at all when the intercooler and oil cooler flaps are closed. Here's some additional sources to go along with those I posted in a previous post on this topic:

Lt. Col. Ken Walsh (VMF-124), Medal of Honor recipient:
Walsh confirmed that the Corsair made a noticeable whistle during dives, but emphasized that the pilot could not really hear it over the engine, particularly during combat or when wearing a flight helmet. He noted that ground crews and enemy troops were more aware of it than the pilots themselves.

Robert "Bob" Brunson (VMF-312):
Brunson said:

"I never really noticed the whistle from inside the cockpit. But our ground crews would mention how it shrieked coming in low over the strip."
He added that the sound was more psychological warfare than something pilots relied on.

 

3) The wing fluttering while sitting on the deck, doesn't line up with reality - see video below and compare with the newly introduced effect in the sim: 

 

 

Thx for your attention. 

To those who had trouble reading this - my apologies, I was perfectly oblivious to this issue until now. I've re-posted the formatted text as plain text and hopefully it has become more readable. 

 

Edited Friday at 11:11 PM by Invisibull
readability

[GTFreeFlyer]

I love how you provided sources rather than just spitting out opinions on how you think the module should behave.  Well done.  This post should be a template for all. 

[-Rudel-]

Just like plastic modeling, some things need exaggeration.  It's not like you're actually sitting and bathing in the 1s and 0s 

[Art-J]

1 hour ago, GTFreeFlyer said:

I love how you provided sources rather than just spitting out opinions on how you think the module should behave.  Well done.  This post should be a template for all. 

If only that quoted part was not pasted in formatted text .

For those of us here who use dark forum theme, only the 1st paragraph is visible while all the quoted rest shows currently as wall of black text over almost-black background. Good luck trying to read that .

[-Rudel-]

I tried to fix it to automatic color, but it didn't work

[Nealius]

2 hours ago, -Rudel- said:

Just like plastic modeling, some things need exaggeration.

This statement is accurate when it comes to exaggerating visual/audio feedback for the pilot to make up for lack of physical feedback from flying, which is entirely necessary when pushing an aircraft to the edge of its envelope. However for general, cosmetic items that do not function as flight envelope feedback exaggeration is unwarranted. 

As a modeler myself, I also disagree with exaggeration in that context but that's a different discussion altogether. 

Edited Wednesday at 10:33 PM by Nealius

[Invisibull]

3 hours ago, -Rudel- said:

Just like plastic modeling, some things need exaggeration.  It's not like you're actually sitting and bathing in the 1s and 0s 

In my humble opinion, I think removing the fluttering effect on both the wings and the antenna mast altogether and using the whistle effect starting at 300 kts (and only when the oil/intercooler flaps aren't fully closed) instead of 200 kts would really go a long way in increasing the fidelity. I thank you for your consideration - I really do love this module and want to see it be the best it can be. 

4 hours ago, GTFreeFlyer said:

I love how you provided sources rather than just spitting out opinions on how you think the module should behave.  Well done.  This post should be a template for all. 

Thanks a bunch, GT. I really do try to support what I say and really do want to see this awesome module be all it can be. 

[Nealius]

I'm curious if the newer (encrypted) sound engine can allow for sound changes based on oil/intercooler flap positions. The older system (pre-encryption) didn't allow for much finesse with tuning sound variables.

[theIRIEone]

On 7/23/2025 at 10:36 PM, Art-J said:

If only that quoted part was not pasted in formatted text .

For those of us here who use dark forum theme, only the 1st paragraph is visible while all the quoted rest shows currently as wall of black text over almost-black background. Good luck trying to read that .

As a dark user myself i felt, and kinda still feel, your pain... However, the ghost of Newton or Einstein or somebody genius like that must have touched me because it hit me:
Highlight the text and it suddenly becomes white on blue and very well readable.

In all seriousness: Not optimal, but a workaround for dark users like us.

[MAXsenna]

On 7/23/2025 at 10:36 PM, Art-J said:

If only that quoted part was not pasted in formatted text

 

On 7/23/2025 at 11:04 PM, -Rudel- said:

I tried to fix it to automatic color, but it didn't work

 

15 hours ago, theIRIEone said:

Highlight the text and it suddenly becomes white on blue and very well readable.

In all seriousness: Not optimal, but a workaround for dark users like us.

@Invisibull Great posts. But as you can see it can be hard to read for us darkers. The trick when copy-paste text from other souces is to paste as plain text. I believe it used to be the default before. This is the same issue when posting images and you get the "null" text. Below the text input box you will see an option, "paste as plain text". And you will never have that "null" again. And the editing of the post will even be easier.  

Cheers! 

[Invisibull]

4 hours ago, MAXsenna said:

 

 

@Invisibull Great posts. But as you can see it can be hard to read for us darkers. The trick when copy-paste text from other souces is to paste as plain text. I believe it used to be the default before. This is the same issue when posting images and you get the "null" text. Below the text input box you will see an option, "paste as plain text". And you will never have that "null" again. And the editing of the post will even be easier.  

Cheers! 

Hi Max, hopefully it's been sorted. 

[Art-J]

Para. 2 and 3. are still in black, but 1 is good

That's how it looks for us, dark-theme guys:

 

Edited Friday at 08:44 PM by Art-J

[MAXsenna]

4 hours ago, Invisibull said:

Hi Max, hopefully it's been sorted. 

Thanks, almost! What @Art-J says. I believe the Forum did this automatically a couple of years ago and this catches people off guard! 

Cheers! 

[Invisibull]

1 hour ago, MAXsenna said:

Thanks, almost! What @Art-J says. I believe the Forum did this automatically a couple of years ago and this catches people off guard! 

Cheers! 

OK, I put it in a notepad file, then back into the forum - it should be as plain text as plain text gets. Again, sorry for the hassle. 

2 hours ago, Art-J said:

Para. 2 and 3. are still in black, but 1 is good

That's how it looks for us, dark-theme guys:

 

Check again please. 

[MAXsenna]

2 minutes ago, Invisibull said:

OK, I put it in a notepad file, then back into the forum - it should be as plain text as plain text gets. Again, sorry for the hassle. 

Check again please. 

Perfect! Thank you!  

[Invisibull]

8 minutes ago, MAXsenna said:

Perfect! Thank you!  

You're welcome. Hope it's worth the effort for you. lol 

[MAXsenna]

3 minutes ago, Invisibull said:

You're welcome. Hope it's worth the effort for you. lol 

Yeah, I just wish the webmaster would change the behavior of the forum back to what it it was regarding the formatting when pasting from other sites, and when pasting images.