Weapons question for military air people...

[seawasp]

When a missile or rocket is loaded onto an aircraft, I presume the launch rail/holder must have some kind of coupler to not only hold the weapon, but to activate it (set off the drive and, if it's a smart weapon, tell it "look there" or something to that effect).

When such weapons are loaded onto an aircraft, (A) would the act of connecting it trigger some sequence of recognition by the aircraft ("Hey, I've just got a new missile!")? (B) How long does an aircraft remain loaded? That is, is it standard practice for them to sit around with their missiles onboard, or are those only loaded prior to taking off on a flight where using them is considered normal? (C) Is there an event in which the missiles get "checked" when the aircraft prepares for takeoff (that is, is the missile control "pinged" by the aircraft systems to make sure it's active?)

Comments

I'm just guessing...

[mike giroux (from livejournal.com)]

...but I'd think the answers to all 3 would be "that's classified" :)

I'd guess (with absolutely no personal knowledge) that a) is "sort of, yes", depending on how modern the aircraft is. Older aircraft might not have as much "software knowledge" of weapon loadouts, I'd guess.

b) I don't even have a guess about.

c) would seem like a reasonable checklist precaution - I don't think the pilots want to hop out at 45,000 feet and wiggle the connectors if the connection is bad.

I'm looking forward to seeing what the actual answers turn out to be (if they're not classified).

[gridlore.livejournal.com]

A. Modern combat aircraft do recognize what is loaded on each pylon. The pilot or Weapons Officer has a munitions read-out that gives the location and status on all weapons systems.

B. Weapons are only loaded when needed. Sitting fully loaded is a huge risk. The only exception I know if in US service is the wing-tip Sidewinders on the F-16C Falcon. The plane is designed to be most effective with those missile in place, so they're left on most of the time.

C. Along with physically checking the ordinance, the pilot or WO will do a function check for all weapons before taking off. This involves having the plane make sure that the weapon is "seen" and has a good connection to the cockpit. There is a specific test mode for this to prevent accidents.

D. If this is for a book, please put me in it and kill me horribly.

My uncle was a Naval Aviator and I have a good number of friends in the community.

[dsrtao]

http://en.wikipedia.org/wiki/MIL-STD-1760

Isn't Wikipedia great?

This is a specialized data bus design that is allowed to have endpoints drop off unexpectedly, unlike the main avionics bus MIL-STD-1553 (which needs to be properly terminated at all times).

So that's (A).

(B) varies from situation to situation. A carrier maintaining an air patrol but not in wartime will bring up replacement aircraft and arm them on deck before the last set come in. In wartime, they would maintain several sets of aircraft ready to go. The current coastal patrol flights are probably loaded within an hour or two of scheduled launch time. Bombers don't sit around loaded anymore.

(C) Both visually and electronically, yes.

[mouser.livejournal.com]

This. Beginning to end.

What they said, yeah.

[scott-sanford.livejournal.com]

The previous posters have already covered most of what I'd say without checking in with my USAF friends or shaking the internet to see what falls out. From memory, though:

A) Yes - and if it doesn't a bunch of non-flying technical work happens. This is for smart missiles and such, of course; a Vietnam-era rocket pod carried rather less elaborate electronics.

B) It depends, as said. Often the 'missiles' on a fighter are dummies, training units that don't actually fly away and go boom. (Mixing up dummies and live rounds is an embarrassing error that happens rarely - but more often than any air force wants to admit, since having the wrong thing loaded has no good results either way. Real effort is made to avoid this.) Another exception is the gun rounds; almost all fighter planes have a multi-barrel cannon, often in 20mm, and the plane is designed to handle well with the weight of the ammunition aboard.

C) As dsrtao said. The onboard electronics are supposed to tell the pilot "Yeah, I've got (1, 2, 3, 4) FOUR missiles aboard!" but nobody in their right mind is going to trust a computer on this, so an important part of the not-screwing-up protocol is for somebody to actually LOOK at the plane and see if what's bolted on underneath matches the paperwork.

[dalesql.livejournal.com]

Pretty much what other's have said. Weapons tend not to be loaded on aircraft until it's time for a specific mission. (That mission may be "Stand by to launch on five minutes notice for air to air combat."

On aircraft carriers, bringing live weapons down into the hanger deck on an aircraft is absolutely verboten!!!! USN has lost much treasure and blood from accidents with ordinance and pyrotechnics that have ended up in hanger decks. See the accident reports on all three major carrier fires during operations off vietnam.

If the aircraft is powered up, the weapons control system is more or less continuously communicating with the various weapons on the stations. Even if it is a dumb iron bomb, there is communication to the fuse to report that it is still there. Plus options,including if the pilot needs to jettison the ordinance, to tell the thing to go safe and fall to the ground without detonating. More advanced ordinance can be programmed with targeting info up to moment of release, plus running various diagnostics on the weapon.

There is still the manual safety pin cable on pretty much everything. This is a physical pin that is attached to the aircraft via a short cable that gets pulled when the weapon is dropped or launched. This is so that if the aircraft goes nose first into the ground fifty feet past the end of the runway, the weapons will not detonate from the crash. They will, eventually, explode if they are sitting in a big puddle of burning jet fuel. That's why the first place they trained us to spray with water in aircraft firefighting was the ordinance. Keep the weapons from cooking off and blowing up the pilot and rescue crews.

There are also a lot of other considerations. Military aircraft, especially naval aircraft landing on a carrier, can take off with substantially larger weight than they can safely land with. So if a carrier strike aircraft is loaded to the gills with fuel and weapons has a mechanical failure that forces it to abort the mission and return to carrier. It will have to jettison some or all of it's weapons, and probably also dump fuel to bring it's weight down to safe landing condition. So if the aircraft is flying a CAP, it will likely not be fully loaded with weapons. Since the navy paid a lot of money for those weapons, they prefer not to have them dumped into the ocean.

Another consideration is that preparing weapons for aircraft is also a fairly time consuming task. A task that has an ever-present risk of horrible explosive accident. If the weapon comes back, it has to be deprepped, various maintainance and recertification tasks have to be performed to make it safe for storage and ready to be used again. So preparing live weapons is not something done on a whim. There are so-called blue bombs for this purpose. Blue bombs are ordinance shapes that have the weight, shape, and other characteristics of the actual weapon, but no explosives or propellents. These can be as simple as a iron bomb filled with sand to a missile shape that has all the sensors and stuff that the real missile has. All inert weapons in the USN are painted blue, and no live weapons are ever painted blue.