A-6 intruder inboard pylon weapon loading

[cat505]

The A-6A SAC shows that the A-6A inboard station can carry 6 Mk82 bombs through the MBR, but the A-6E SAC shows that the A-6 inboard station can only mount 5 Mk82 bombs through the MER. I have not been able to find detailed information on MBR on the Internet. Can someone explain to me the difference between MBR and MER?

[RichB63]

I’m no expert, but, from what I gather, the MBR (Multiple Bomb Rack) debuted in the mid 1960s and its weapons were released through a simple unshackling process. At times the system proved troublesome. A more reliable replacement, the MER (Multiple Ejector Rack) followed a few years later. As its name implies, munitions were forced free of the rack via an electro-pneumatic process. 
 

Outwardly, the MER is distinguishable by its larger aerodynamic nose piece. Surely the individual racks themselves differed in appearance too, at least in detail. The MER has been in service for several decades, so its design and appearance has evolved over time also.

 

I can’t explain the load-out difference for the Intruder…perhaps it had to do with MLG doors clearance differences between laden racks.

 

Edited December 23, 2022 by RichB63

[RichB63]

MBR installed on a Skyhawk 

[Finn]

Here is another one just behind the Mk-79:

 

 

I did see a pic of a A-6A with the MBR loaded so they did carry them, briefly before switching to the MER. 

 

Edit: a close up of one on a F-8 being loaded:

 

 

Jari

 

Edited December 23, 2022 by Finn

[Reddog-03]

Pretty sure its weapons on the forward inboard station of the MER interfering with the main landing gear doors.

[GW8345]

The reason why you can put 6 x Mk 82 on the inboard pylon of A-6 using a MBR is because the shoulder stations on the MBR are angled at 32 degrees where as on a MER they are angled at 45 degrees. There is just enough clearance on the MBR for the bomb to fit where as on the MER the bomb sticks out too far and interferes with the main landing gear door.

 

The MBR was developed by (IIRC) Douglas around 1959 and was in use until the early days of Vietnam. The problem with the MBR is that there was no ejection velocity provided from the rack so all weapons were "gravity released" vice the MER which provided ejection velocity, thus kicking the weapon away and ensure good weapons separation (and lowering the risk of weapon to aircraft collision). MER's uses a gas operated system, the gas pressure is provided by a cartridge actuated device (CAD) which provides the gas pressure to open the hooks and power the ejector foot (that pushes the weapon away from the rack), the MBR's CAD only opened the hooks, there was no provision for an ejector foot in the MBR.

 

hth

GW

Edited December 23, 2022 by GW8345

[cat505]

14 hours ago, RichB63 said:

I’m no expert, but, from what I gather, the MBR (Multiple Bomb Rack) debuted in the mid 1960s and its weapons were released through a simple unshackling process. At times the system proved troublesome. A more reliable replacement, the MER (Multiple Ejector Rack) followed a few years later. As its name implies, munitions were forced free of the rack via an electro-pneumatic process. 
 

Outwardly, the MER is distinguishable by its larger aerodynamic nose piece. Surely the individual racks themselves differed in appearance too, at least in detail. The MER has been in service for several decades, so its design and appearance has evolved over time also.

 

I can’t explain the load-out difference for the Intruder…perhaps it had to do with MLG doors clearance differences between laden racks.

 

Yes, MBR was only in service for a short time before being replaced by MER. MBR caused bomb float and VA-75 lost 3 intruders due to bomb float. 

[cat505]

8 hours ago, GW8345 said:

The reason why you can put 6 x Mk 82 on the inboard pylon of A-6 using a MBR is because the shoulder stations on the MBR are angled at 32 degrees where as on a MER they are angled at 45 degrees. There is just enough clearance on the MBR for the bomb to fit where as on the MER the bomb sticks out too far and interferes with the main landing gear door.

 

The MBR was developed by (IIRC) Douglas around 1959 and was in use until the early days of Vietnam. The problem with the MBR is that there was no ejection velocity provided from the rack so all weapons were "gravity released" vice the MER which provided ejection velocity, thus kicking the weapon away and ensure good weapons separation (and lowering the risk of weapon to aircraft collision). MER's uses a gas operated system, the gas pressure is provided by a cartridge actuated device (CAD) which provides the gas pressure to open the hooks and power the ejector foot (that pushes the weapon away from the rack), the MBR's CAD only opened the hooks, there was no provision for an ejector foot in the MBR.

 

hth

GW

Thank you very much for your information.  I have another question, MER chose 45 degrees instead of 32 degrees. Was it because only 45 degrees could guarantee the safe ejection of bombs?

[Tailspin Turtle]

In the beginning: https://skyhawk.org/article/mcbr-fitch

[GW8345]

11 hours ago, cat505 said:

Thank you very much for your information.  I have another question, MER chose 45 degrees instead of 32 degrees. Was it because only 45 degrees could guarantee the safe ejection of bombs?

IIRC the 45 degree angle was for store/weapon clearance between the centerline stations and the shoulder stations, the increase in angle meant that a larger diameter store/weapon could be carried on the centerline and eliminated clearance issues with weapon's fins contacting each other during release.

[cat505]

15 hours ago, GW8345 said:

IIRC the 45 degree angle was for store/weapon clearance between the centerline stations and the shoulder stations, the increase in angle meant that a larger diameter store/weapon could be carried on the centerline and eliminated clearance issues with weapon's fins contacting each other during release.

Thank you for your information again. During the operation of MER, did the interference with MER and main landing gear doors adversely affect the weapon loading of the A-6 fleet?  

 

By the way, I plan to build an A-6F, but it's hard to find useful information of A-6F? Forgive me for my rude, may I know if you have some information of A-6F?

[GW8345]

10 hours ago, cat505 said:

Thank you for your information again. During the operation of MER, did the interference with MER and main landing gear doors adversely affect the weapon loading of the A-6 fleet?  

 

By the way, I plan to build an A-6F, but it's hard to find useful information of A-6F? Forgive me for my rude, may I know if you have some information of A-6F?

I wouldn't say that not being able to load the inboard forward station of the MER (for station 2 & 4) adversely affected weapons loading. Six Mk 82's could be loaded, you just had to remove main landing gear door in order to do it. It was legal to fly with the door remove, just that it was done very rarely. Every aircraft has loading restrictions, the A-6 (IMO) had the least amount of restrictions when it came to what you could load where.

 

Sorry, I don't have any info specific to the A-6F, to my knowledge it never made it to Navy testing (like being tested at Pax) so manuals (to my knowledge) were never produced.

[habu2]

Five new build A-6Es were diverted to the A-6F development program, only 2 ever flew and the program was cancelled before the last two flew, they went straight to being mothballed. 

[Tailspin Turtle]

14 hours ago, cat505 said:

By the way, I plan to build an A-6F, but it's hard to find useful information of A-6F? Forgive me for my rude, may I know if you have some information of A-6F?

Do you want to build one of the two prototypes that flew or a what-if of the production A-6F (my understanding is that the main difference would be the wing, not counting cockpit and miscellaneous antenna details)?

[RichB63]

If you’re anywhere near New York City, this example can be seen at the USS Intrepid museum.

[Finn]

Also the engine housing was bigger for the different engines:

 

 

compare with a A-6E:

 

 

Jari