LAPES history

[CAPFlyer]

I have no special knowledge on this, but it seems that LAPES has been replaced by Combat Offload. Combat Offload involves landing the plane, stopping, releasing the aft clamps (like with an air drop) and then goosing the throttle, letting the cargo just roll off the back of the plane and plop to the ground. Once done, the procedure can be continued into a takeoff or the throttles retarded and the plane moved elsewhere.

Here's a good video on Combat Offload from a C-17 - http://www.youtube.com/watch?feature=pl ... tNI#t=361s

One of one of the LC-130's doing the procedure - http://www.youtube.com/watch?v=TzQ8IxOGpQ4

[Ken]

I believe combat offload is an older concept than LAPES. It isn't really a replacement, however, there is no disputing that a preplanned combat offload minimizes the time the aircraft is in bad guy country as a sitting duck. Unless it were an emergency, a combat offload doesn't transition into a takeoff; those are two distinctly different operations with different checklists and it just isn't done that way. LAPES also was capable of delivering large items and, although I don't have the number handy, such heavy items aren't combat offloaded because they are typically on longer platforms and becuase they would require ballast weight to keep the airplane from dragging the ramp - this weight would likely then need to be drifted aft and re-secured to put the plane back into a flyable CG. In short, they figure if it's safe enough to go across the DZ/LZ at 10' and 140 knots, they allow you to go across between 500-800' and 140 knots and airdrop it more traditionally.

[Aeronut]

Prior to developing ULLA (it looks like LAPES but used totally different equipment) the UK conducted trials with a system called Ground Proximity Extraction (GPE). This was basically ULLA without parachutes.
A Beverley was fitted with an arrestor hook on its rear sill and as it flew over an arrestor cable laid out on the DZ the hook would engage the cable. Instaed of the aircraft coming to a halt the hook broke away from the airframe whilst at the same time as operating a final restraint system on the load which was then withdrawn from the aircarft to land on the DZ.
The idea worked, but the problem was the positioning of the arrestor cable on a DZ, much better to carry extractor parachutes on the aircraft.

[Dan Jones]

The Canadian Forces did one operational LAPES drop in early 1978 for "Operation Morning Light", delivering a small bulldozer to what became known as Cosmos Lake after Kosmos 954, a Russian satellite, came raining down into northern Canada. An air force Twin Otter on skis delivered a camp and crew and a couple of days later a 5000' ice strip had been built and the cleanup operations began.

Dan

[Ken]

The USAF did use GPES which utilized a hook to extract loads. Here are two nicley written articles for those with an interest:

http://www.airpower.au.af.mil/airchroni ... indbo.html

http://www.library.vanderbilt.edu/centr ... e-Sanh.htm

Incidentally, the C-130 currently breaks combat offload into 2 categories: Methods A & B. Method A is stopping the airplane, lowering the cargo ramp to level, releasing the locks on one or more pallets, running the engines to a predetermined torque, releasing brakes, and having the cargo fall to the ground. The airplane "drives out from under" the cargo, if you will. A variation of Method A lowers the ramp to 18" to minimize the fall. Not all cargo can be combat offloaded, obviously glassware, electronics, some types of ammo, etc.

Method B is much slower and consists of easing each pallet onto the tops of 55 gal drums as the aircraft creeps forward. This, of course, eliminates the violent fall off the back of the airplane but is slow, requires patience, and having spare barrels lying around. None of these methods is perfect. Landing on a short strip and then doing 1 or 2 Method A's can really heat up the brakes. And, once you commit to releasing a pallet, don't touch the brakes until it is gone - an unrestrained pallet rolling forward in the cargo compartment could cause some serious injury/damage.

The last time I did a Method A in Iraq, it was simply because the strip didn't have a forklift rated for the pallet weights. The user wanted us to sit there for over an hour while they broke each pallet down by hand so I offered the Method A; I didn't want to take the time, waste the fuel, or shutdown and risk not getting restarted. They got their stuff and were able to break it down at their leisure without the noise and prop blast. Win, win. The funny part of the story is that the users initially were reluctant to allow the CO. Once it was over, however, the lead guy remarked to my loadmaster how great it was and "Why don't we do that all the time?" The services preach "jointness" but the real world disconnects out there on capabilities and procedures are huge.

[Ken]

CAPFlyer's link to the C-17 combat offload was nice and gives a good look at how quickly pallets vacate. Those training loads were probably between 2500-3500 pounds each.

The LC-130 appeared to be doing a hybrid method, sometimes referred to as pallet drifting. See the 0:22 mark in the video below for a Herk doing some drifting at Khe Sanh. You can see that, at the slower speed, the pallets tend to bunch up a tad.

http://youtu.be/rJ1n2K1fY6w

[The Inspector]

On the tragic side of this, I used to work with a guy who was employed by SOUTHERN AIR. He was on a few food drops to areas in Central Africa where the pallets of food and grains in sacks were booted out the back @ around 300 ft on an overhead pass to groups of people so famine stricken that they ran into the path of the freefalling pallets and were crushed by them. He said even years later it deeply affected him, as I bet it would.

[Ken]

Sadly this has happened other times as well. There were similar stories that came from Operation Provide Comfort, the Kurdish relief effort 91-93. Some of the locals thought that loads supported by parachute would be coming down gently, but who knows if those folks had ever seen a paradrop load or even a real parachute before in their life. IIRC the US started picking out DZs and keeping the locations secret until the drops were complete; of course the plane flying outside of town was a giveaway too.

Completely OT, but during Provide Promise over Bosnia, roughly 92-96, a large number of MREs in civilianized wrappers were dropped using TRIADS. These are large cardboard containers that break apart in the windstream and distribute the individual meals randomly, like leaflets. They say that someone can't be injured by a falling MRE, but those things sure feel dense (even before you eat one). Video with good TRIADS footage: http://youtu.be/kCxwprZekpM

Incidentally, once the loads are on the DZ, it's not as if all the danger is over as there are threats of organized crime and the like obtaining more than their share; as similarly portrayed in "Blackhawk Down". I don't intend to get on a soapbox, but I will say that every American should witness stuff like this at some point to help them appreciate the harsh realities of the world we live in and to help realize how well we really have it in the good 'ole USA.

Ken

[Aeronut]

Having brought the idea of GPE to the thread, I had to smile to myself when today whilst clearing out the office I came across three items related to GPE. One was the Boscombe Down report on the GPE trials, this was published in 1964 and reported on trials flown in 1963. The other two items were both from the American manufacturer of the equipment I have a General assembly drawing of the hook and a manual for the arrestor cable system both dated 1964. All this begs the question, who was first with the idea, the UK or the US?

[Aeronut]

Still sorting through the stuff I saved from destruction I've come across a reference to another US document the UK had sight of, it was a report from Edwards AFB on the evaluation of the C-130E stability and control during LAPES deliveries. What made me notice it was the name of the Project Engineer and author of the report, Elbert L Rutan.

[airnutz]

The other two items were both from the American manufacturer of the equipment I have a General assembly drawing of the hook and a manual for the arrestor cable system both dated 1964.

Aeronut...Can you share the name of that American company?

[Aeronut]

Airnutz, the GPE publication and drawing came from the 'All American Engineering Company' of Wilmington Delaware.

[airnutz]

Airnutz, the GPE publication and drawing came from the 'All American Engineering Company' of Wilmington Delaware.

Badabing! Your descriptions had me suspecting All American. They'd been engineers in that business for a long time. As Ken suggested, combat offload is a progression of innovation over time. Nice save on the historic materials Aeronut!!

[airnutz]

The other two items were both from the American manufacturer of the equipment I have a General assembly drawing of the hook and a manual for the arrestor cable system both dated 1964. All this begs the question, who was first with the idea, the UK or the US?

Aeronut...In your materials, is there any mention of personell pallets or skids evaluations?

[Aeronut]

I've not found anything on personnel skids yet but I might in time. I filled my car three times with stuff that otherwise would have gone in the rubbish skip and its taking some time to sort out / condense / store it all.
I have though managed to answer my own question. All American came up with the the GPE/LAPES concept first, the UK adapated its own aircraft and unique airdrop kit to the concept hence whilst LAPES and ULLA look the same they are totally different.
This is a situation I've come across a number of times the US or UK come with an idea but for a number of reasons they have to do it differently to each other. It even happened to me, coming to the end of the trials of a boat airdrop system I was told to expect a visit by the US Navy SEALs with only 30 minutes notice! They arrived so I showed them the equipment, some trials video and explained that the system was a replacement for one the UK had had in service for some time but as the Royal Marines now wanted to drop a larger boat we had a developed a bigger and better system. Their faces when I said that this was a replacement system were a picture, I had just taken the SEALs by surprise. They had just spent years and many many $ unsuccessfully developing a boat drop system and here were the Brits replacing one.
I never did get any commission from that sale