I am a 24 year veteran of the US Army - all of that time I was in Airborne units on jump status. I am both Static Line and HALO Jumpmaster qualified.
I also have a civilian Freefall Jumpmaster status and license. Over 300 static line jumps and 3000 HALO jumps counting all my civilian freefall
jumps. I have a few HAHO jumps as well but that is a very specialized thing and not normally performed by other than very unique special operations
units in very specific circumstances.
The C130 is an aircraft capable of delivering a payload of up to 80 paratroopers in combat. In training the US military limits that number to 64 for
safety and comfort of the jumpers.
I don't know what your interpretation of "low altitude" is but the C130 is capable of conducting both static line and HALO operations. Static line
jumps are conducted at between 800' and 1250' agl for training and as low as 500' agl for combat. HALO can be conducted anywhere from 3500' agl which
is sort of a minumum (in case of a malfunction) and up to 36,000' agl at the unclassified level.
The difference between the two:
Static line parachuting is intended for delivering a large number of troops over a large area in a rather imprecise pattern - sort of saturating the
battle space like on D-Day or Operation Market Garden. There is usually no traffic pattern as the location for a drop like that is general in nature
and the aircraft are very vulnerable at that low altitude. However in training if the winds were high they might abort a pass or two.
If you are seeing 15 people they can drop that on a DZ about 1000 yards long using both doors. Using the ramp about 1500 yards. Static line chutes
are not very steerable at all even the fancy new ones. You can basically maneuver enough (and not always then) to avoid obstacles on the DZ.
Usually this is not done in an urban area for that reason. If you research the 2/508th 82nd ABN and their disaster at Ste. MereEglise in WWII you
will see that they dropped in the town proper and most of the men got killed in the air and while hanging from buildings. A disaster.
HALO sometimes does do a racetrack which allows the pilot and the jumpmaster to confirm the exit point (which may be miles away from the DZ) to be
calculated/confirmed correctly based on winds at altitude and at ground level. It is done to allow the aircraft to fly above most radar systems and
allow the teams to infiltrate silently with chutes that are very steerable - a good 15 man team that stacks correctly in the air can land within 20'
of one another on a building or in a small clearing and be ready for combat in 5 seconds or so of landing.
I don't know if there is a sports arena in the area but we have a sport parachuting team that jumps in the American flag during the national anthem at
events. That is very few people only 2-3 jumpers and usually done from a contcract small aircraft - a Cessna or something. It is a PR thing. It
would be very costly to float a C130 for a small 15 man operation BTW. Doesn’t make sense.
Usually a helicopter rooftop insertion or a helicopter fast rope combo is used in urban areas because it a rotary platform has more maneuverability
and can abort more quickly if there is determined opposition.
Hope that gives you some insight - knowing the actual altitude or approximate would help.
ETA: Just reread the OP and since it is near an airport (airports are ideal DZ's btw - hard to miss for inexperienced people) and they are doing 30
passes they could be doing jumpmaster training. Allowing each one to spot the terrain features and estimate the winds while they get individually
graded on their technique. At the end they all jump for proficiency. Just a possibility.
edit on 18/2/2013 by Golf66 because: (no reason given)