Low Altitude Parachute Extraction System (LAPES)
For an insertion with a Low Altitude Parachute Extraction System no special skills are required. This is kind of a cross between LANO and LALO with a twist. LAPES allows cargo loads to be placed directly on the ground in exactly the right place. Some of these places would not allow for aircraft landings. Sometimes the terrain was unsuitable, sometimes it was because of enemy fire. LAPES was better at spotting heavy loads than Heavy Load Air Delivery. Troops can be inside of vehicles and strapped in tight to protect them from the severe shock and vibration from the impact.
LAPES must be done from an aircraft that has a rear opening cargo door/ramp. The landing zone must also be a relatively large, flat area such as a road or open field. First, the equipment, vehicle, or whatever is going to be inserted is very securely strapped down onto a large shock absorbent palette. The palette a parachute attached to it. With the LAPES insertion, low means low. The transport approaches the target zone from an extremely low altitude 0.6 to 3 metres above the ground. At the right moment, the loadmaster pops a large parachute, which drags the cargo pallet across rollers on the cargo bay floor and out the rear doors. The chute drags the palette out of the back of the aircraft where it drops to the ground and skids to a stop with the assistance of the parachute. One or more platforms may be released during a single pass, directly into the hands of the troops on the ground.
LAPES demands perfect stability and controllability from the delivery aircraft. The pilot must give nose down pitch control as the payload rolls out the back. Once the payload is clear of the aircraft - nose down would fly the aircraft into the ground. The pilot must give nose up control inputs to keep the aircraft level and then climb out after delivery. To help the pilots out, the payload is locked in place until there is sufficient drag from the parachutes to pull the payload out very quickly. As the parachutes inflate, the payload remains in place. Then locks release, similar to the way ski bindings release, to allow the payload to make its departure from the aircraft.
Known mishaps are:
- If the palette breaks up then the payload on that palette will receive damage equal to the amount rolled. If the payload is a vehicle with people inside, the people will also receive damage equal to the amount rolled for humans.
Development
The LAPES delivery method was developed during the Vietnam War to solve the problem of quickly placing heavy cargo loads directly on the ground in areas where it would be unsafe to land the aircraft. In Vietnam, C-130s frequently used the technique to land cargoes onto runway areas and reduce the risk of mortar fire. It was also useful for spotting very heavy loads, such as armoured vehicles, directly onto the ground without subjecting them to the risk of parachute failure from a higher altitude.