View Full Version : Helicopter Jump
A question for the old and bold…
The Dalton computer section of AP3456 in Chapter 9 briefly mentions older versions of the sliding card having graduations from 20-120 for ‘helicopter jump’ use in the Wessex 1. Was this simply an extension of the card to allow for the slower speeds of helios and/or parachutes? Can anyone expand?
John Eacott
21st Apr 2022, 10:54
'Jump' in this case refers to flying between hover ('Dip') positions when on ASW sorties. I don't recall the Whiz Wheel exactly, and it is squirreled away somewhere along with other rabbits, but 20-120 would be a reasonable range of speeds to cover the Wessex HAS1.
We had Dalton computers with helicopter speeds on one side of the card and FW speeds on the other. 20 -120 is a little shy on the top end as you can have much higher groundspeeds with a tailwind - ISTR ours went up to around 160 Kts.
I might still have one in the loft so I'll check.;
'Jump' in this case refers to flying between hover ('Dip') positions when on ASW sorties. I don't recall the Whiz Wheel exactly, and it is squirreled away somewhere along with other rabbits, but 20-120 would be a reasonable range of speeds to cover the Wessex HAS1.
Ah! That makes more sense than actually jumping out what with downwash issues etc.
Doors Off
21st Apr 2022, 12:36
Ah! That makes more sense than actually jumping out what with downwash issues etc.
I was going to recommend turning the engines off, to ensure the blades weren’t rotating, before you try to jump a helicopter.
Ah! That makes more sense than actually jumping out what with downwash issues etc. I've dropped free-fall parachutists from 10,000' and divers from 30' from helicopters - no problems with downwash in either scenario but the forward speed of the former is 40-60 kts and the latter a slow hover taxi.
MENELAUS
21st Apr 2022, 22:52
The gentlemen from Hereford regularly jumped out of the Wessex. By day/ night and at all sorts of altitudes.
Even tried to undo the crewman’s dispatcher harness ( he had been giving them a lot of lip ) and take him with them on one occasion.
Trim Stab
22nd Apr 2022, 13:59
The downwash felt by the parachutist is a function of mass of the aircraft divided by wingspan or rotorspan - it is not really much different whether fixed wing or helicopter. Even if helicopter is stationary it is not reallly any different from a moving helicopter, as the parachutist is initially moving at same horizontal speed of helicopter. I’ve jumped from C130, Chinook and C17 and the latter was by far the most violent, the Chinook the least.
The Oberon
23rd Apr 2022, 06:14
It used to be a good day out, as part of the NEAF Parachute Rescue Team, to jump out from a Whirlwind into Limassol bay and then be picked up by the MCU.
teeteringhead
23rd Apr 2022, 10:16
Dropped a mate from a Huey once. He was a sport free-fall parachutist (as well). At 10,000 he got onto the right skid, eased his way forward, banged on my door and - with a feigned look of horror - fell off backwards with his arms windmilling.
One of the scariest things I've seen while flying..........
One of the scariest things I've seen while flying.......... yes, the AAC display team have done that to me as well from a Lynx!
Dropping a mixed team of military skydivers from a Wessex overhead Nicosia at 10,000', one pulled his smoke and then they didn't immediately jump - instant IMC in the Wessex cockpit.
ShyTorque
23rd Apr 2022, 12:24
The Puma SOP was to fly at below 55 kts with the U/C retracted (which annoyingly set off the flashing red warning light).
The airframe fit was a clear floor with the seatbelts clipped to a steel cable running through the floor tie down rings.
The more energetic meat bombs used to like to run right from the rear of the cabin and dive out of the cabin door headfirst so they overtook the pilot, waving as they went.
John Eacott
28th Apr 2022, 23:52
I found the old Dalton in my tin trunk, but it doesn't have the Wessex low-speed option, so not much help I'm afraid!
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https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/768x1024/unadjustednonraw_thumb_124a4_69e0b0bd301f39d05758b9ee3e402ef 809d1dfd8.jpg
On the thread drift to parachuting from helicopters, on many jumps from my machines the jumpers actually wanted minimum airspeed for the 'thrill' of tumbling until they built up enough airspeed to control themselves!
Then there were the thoroughly briefed four participating in the Senior's Games over Melbourne, who pushed off from the left skid (two of them) leaving the other two still on the right skid. The pilot elected to go with the roll rather than risk a must bump (Bell 206) and did a complete 360; the remaining two departed somewhere and managed to avoid the rotor blades by sheer joss. Subsequent jumps had all departing on the left, stepping off two at a time. Valuable lesson learned the hard (and expensive) way :ugh: