Revisiting the Super Hornet's canted pilons issue

[José Herculano]

Boeing is in no visible hurry to develop a more elegant solution to the
weapons separation issues that lead to the 4º cant / toe-out of the Super
Hornet's wing pilons. I'm not hearing too much complain from the Navy
either. The reasons that have me worried about this current solution are:

1: It increases drag, impacting range and performance;
2: It increases the aircraft's head-on radar signature;
3: It generates great lateral stress loads on the weapons and the wing
itself.

It may be that I am ignorant on the above points and those are non-issues;
it may be that I am out of the loop, and Boeing is really working hard on a
solution.

Any pointers you'd like to contribute, for or against my impressions?
_____________
José Herculano

[Thomas Schoene]

José Herculano wrote:
> Boeing is in no visible hurry to develop a more elegant solution to
> the weapons separation issues that lead to the 4º cant / toe-out of
> the Super Hornet's wing pilons. I'm not hearing too much complain
> from the Navy either. The reasons that have me worried about this
> current solution are:
> 1: It increases drag, impacting range and performance;
> 2: It increases the aircraft's head-on radar signature;
> 3: It generates great lateral stress loads on the weapons and the wing
> itself.

I thought the point of the toe-out was that it actually aligns the weapons
with the local airflow, meaning that it does not increase drag or stress
loading. Am I wrong?

--
Tom Schoene Replace "invalid" with "net" to e-mail
"Our country, right or wrong. When right, to be kept right, when
wrong to be put right." - Senator Carl Schurz, 1872

[Doug \Woody\ and Erin Beal]

On 5/4/05 6:09 AM, in article
et, "Thomas Schoene"
> wrote:

> José Herculano wrote:
>> Boeing is in no visible hurry to develop a more elegant solution to
>> the weapons separation issues that lead to the 4º cant / toe-out of
>> the Super Hornet's wing pilons. I'm not hearing too much complain
>> from the Navy either. The reasons that have me worried about this
>> current solution are:
>> 1: It increases drag, impacting range and performance;
>> 2: It increases the aircraft's head-on radar signature;
>> 3: It generates great lateral stress loads on the weapons and the wing
>> itself.
>
> I thought the point of the toe-out was that it actually aligns the weapons
> with the local airflow, meaning that it does not increase drag or stress
> loading. Am I wrong?

Not a Super Hornet guy, but I do remember seeing this one first hand at
Tullahoma, TN when the solution was being developed.

In the original design during stores separation wind tunnel testing before
any full scale production, the engineers discovered that the bombs had big
dispersion errors when dropped off of the non-canted pylons (IIRC on the
order of about 1,000 foot error for a medium altitude drop). Essentially,
dumb bombs were not predictable because of aerodynamic interaction with the
airframe immediately after release.

Several solutions were proposed (not all inclusive):

1. Stronger CADS/ejector feet to push the stores off the aircraft harder.
2. Longer pylons.
3. Strake/wing redesign.
4. Pylon canting.

The first three were rejected for cost (short term, of course, and I don't
know the numbers).

Number 4 was the only viable solution for an aircraft that was already well
on its way from a design standpoint.

At this point, the Navy has no real "elegant" solution left. They're stuck
with the cheap solution for now.

--Woody

[Kyle]

From a brief I saw the canting of the pylons does surprisingly little to the
range of the aircraft. If the numbers presented were true, it was less than
30 NM on a round-trip strike. The Navy at the time didn't see the need to
fix the pylons for such a small number.

-Former SH pilot


"Doug "Woody" and Erin Beal" > wrote in message
...
> On 5/4/05 6:09 AM, in article
> et, "Thomas Schoene"
> > wrote:
>
>> José Herculano wrote:
>>> Boeing is in no visible hurry to develop a more elegant solution to
>>> the weapons separation issues that lead to the 4º cant / toe-out of
>>> the Super Hornet's wing pilons. I'm not hearing too much complain
>>> from the Navy either. The reasons that have me worried about this
>>> current solution are:
>>> 1: It increases drag, impacting range and performance;
>>> 2: It increases the aircraft's head-on radar signature;
>>> 3: It generates great lateral stress loads on the weapons and the wing
>>> itself.
>>
>> I thought the point of the toe-out was that it actually aligns the
>> weapons
>> with the local airflow, meaning that it does not increase drag or stress
>> loading. Am I wrong?
>
> Not a Super Hornet guy, but I do remember seeing this one first hand at
> Tullahoma, TN when the solution was being developed.
>
> In the original design during stores separation wind tunnel testing before
> any full scale production, the engineers discovered that the bombs had big
> dispersion errors when dropped off of the non-canted pylons (IIRC on the
> order of about 1,000 foot error for a medium altitude drop). Essentially,
> dumb bombs were not predictable because of aerodynamic interaction with
> the
> airframe immediately after release.
>
> Several solutions were proposed (not all inclusive):
>
> 1. Stronger CADS/ejector feet to push the stores off the aircraft harder.
> 2. Longer pylons.
> 3. Strake/wing redesign.
> 4. Pylon canting.
>
> The first three were rejected for cost (short term, of course, and I don't
> know the numbers).
>
> Number 4 was the only viable solution for an aircraft that was already
> well
> on its way from a design standpoint.
>
> At this point, the Navy has no real "elegant" solution left. They're
> stuck
> with the cheap solution for now.
>
> --Woody
>