The Great, Constantly Changing Picture Gallery, Troisième partie: la vengeance!

[MIDNJAC]

Weapon release clearance when carrying 6 pylons.

It took me many hours of searching, but I did actually find the original MacAir source document (circa 1993 or 1995) that recommended the cant. IIRC (its been a couple years since I read it), it was specific to mid board Mk-83 release with a HARM on the adjacent (outboard) station. What I have heard is that this configuration ended up not causing the wind tunnel predicted release issues. Classic

 

[sevenhelmet]

It took me many hours of searching, but I did actually find the original MacAir source document (circa 1993 or 1995) that recommended the cant. IIRC (its been a couple years since I read it), it was specific to mid board Mk-83 release with a HARM on the adjacent (outboard) station. What I have heard is that this configuration ended up not causing the wind tunnel predicted release issues. Classic

Can confirm. It was a corner case that ended up not being the problem they thought it would be.

Engineers are always quick to point out that the flow field IVO the pylons is already a couple of degrees off-axis, so the canted pylons aren’t as canted to the wind as they appear.

Uh huh. We can still tell the difference.

 

[ea6bflyr]

Can confirm. It was a corner case that ended up not being the problem they thought it would be.

Engineers are always quick to point out that the flow field IVO the pylons is already a couple of degrees off-axis, so the canted pylons aren’t as canted to the wind as they appear.

Uh huh. We can still tell the difference.

I believe the canted pylons were driven by the larger squared intakes on the Super Hornets.

 

[number9]

I believe the canted pylons were driven by the larger squared intakes on the Super Hornets.

Can you please explain to me (like you would a child, or a golden retriever) me why a square intake has better performance than a round intake? I would have thought air prefers a curve to a right angle...

 

[sevenhelmet]

Can you please explain to me (like you would a child, or a golden retriever) me why a square intake has better performance than a round intake? I would have thought air prefers a curve to a right angle...

It's not about performance. Without going into too much detail, the sharp angles are there to help reduce radar detectability as compared to a rounded surface.

 

[number9]

It's not about performance. Without going into too much detail, the sharp angles are there to help reduce radar detectability as compared to a rounded surface.

No worries, thank you!

 

[sevenhelmet]

I believe the canted pylons were driven by the larger squared intakes on the Super Hornets.

I have not heard that before.

As previously stated, the canted pylons were driven by how engineering modeled weapons separation characteristics. Canting the pylons outward was one of several solutions that were proposed during development of the Rhino in order to ensure safe weapons separation for all loadouts. Actual testing later (I have been told) showed that the weapons separation concerns probably did not warrant the design change.

It's possible that the engine intake shape could have been a contributing factor that led to the above design change, but if so, it wasn't mentioned in the briefs and discussions we had on the subject when I was in active in the F/A-18 community.

 

[MIDNJAC]

I have not heard that before.

As previously stated, the canted pylons were driven by how engineering modeled weapons separation characteristics. Canting the pylons outward was one of several solutions that were proposed during development of the Rhino in order to ensure safe weapons separation for all loadouts. Actual testing later (I have been told) showed that the weapons separation concerns probably did not warrant the design change.

It's possible that the engine intake shape could have been a contributing factor that led to the above design change, but if so, it wasn't mentioned in the briefs and discussions we had on the subject when I was in active in the F/A-18 community.

Yeah haven't heard this one either. Now that you mention it, I had forgotten about the other 2-3 engineering solutions they came up with to solve the problem. I can't remember what they were now, but I remember them sounding really dumb. Now I have to dig that doc up, it's saved somewhere on my work computer.

 

[Llarry]

California Air National Guard 144th Fighter Wing F-15C. As can be seen from the serial number, procured with FY1984 funds. Presumably yanked and banked for almost 40 years. The 144th is scheduled to get the new F-15EXs in the future. It's time for this old Eagle to retire.

 

[TacticalTater]

California Air National Guard 144th Fighter Wing F-15C. As can be seen from the serial number, procured with FY1984 funds. Presumably yanked and banked for almost 40 years. The 144th is scheduled to get the new F-15EXs in the future. It's time for this old Eagle to retire.

View attachment 41111

84.... hell that's a new jet for "C" squadrons

 

[sevenhelmet]

Yeah haven't heard this one either. Now that you mention it, I had forgotten about the other 2-3 engineering solutions they came up with to solve the problem. I can't remember what they were now, but I remember them sounding really dumb. Now I have to dig that doc up, it's saved somewhere on my work computer.

I was thinking about that too. The one crazy proposal I remember was the “trapeze” setup for the BRU, so it would swing the store down and away from the pylon for weapon release, to ensure safe separation from adjacent stores. I’m sure nothing would have gone wrong with that setup!

 

[zipmartin]

As previously stated, the canted pylons were driven by how engineering modeled weapons separation characteristics......

This happened back in 1981: