Parachute installation

[Geoff_H]

Does anyone have a parachute installation on the aircraft? If so what is its deployment method? Has anyone ever been in an aircraft where a aircraft parachute has been deployed? What do I do if there is a problem with the attachment position in an aircraft where the CofG is close to everything, or where do you place the connection?

[FlyBoy1960]

Firstly I would reach out make contact with companies like GRS or BRS, both have systems suitable for most aircraft and have installation packages ready to go.

 

Putting in the parachute is one thing but attaching it to the airframe correctly is another completely different exercise that requires advanced engineering. I was only reading the other day about someone that fitted a parachute into a Loele P5151 which is a ultralight version of the famous P 51. He had a Suzuki the engine mounted and it had some sort a gearbox failure requiring him to deploy the parachute. Apparently everything went perfect but because he didn't have the parachute adequately mounted at the proper points of the airframe it simply tore out the pieces of wood that the parachute was anchored to !

 

He did managed to land eventually and walk away but it does tell you and makes you think about it is pointless having a parachute fitted if it is not secured to the airframe correctly. This is why you really do need professional advice and assistance.

 

Also, I was reading that GRS engineer their systems so that the aircraft descends about 20° nosedown. This way when it hits the ground a lot of the impact is absorbed by the nose year and front of the aircraft giving way rather than the aircraft land completely flat. It was a way of lessening the impact loads to the cockpit area by about 70% if I remember correctly. It was all pretty smart engineering so I would recommend you draw on the experience of these companies for your advice.

 

Finally, the only reliable deployment method is ballistic. The other systems like compressed air or nitrogen are just not suitable in our type of aircraft. Ballistic is the only reliable deployment method from what I could remember from the article I was reading. From memory it was in some EAA magazine about five years old out at the aeroclub

[Old Koreelah]

Geoff I haven't had to use mine, but it's there as a last resort.

 

BRS are pretty particular about how and where you mount your 'chute. If you match the correct model to your MTOW, when deployed, your plane comes down at about 1200 fpm. That's not much better than a controlled crash. Therefore, the aircraft should be suspended from a point behind the CoG, so that you arrive at terra firma in a nose down attitude, letting the u/c absorb most of the impact.

 

They wanted pix of my mounting setup before approving my installation. They initially insisted that the harness loop around my mainspar.

Eventually, for aesthetic reasons, I attached the main shackle inside, around my spar bolts and ran the webbing under paper-thin plywood on the outside of the cockpit. To keep the deployed attitude nose down, the harness is attached to a pair of steel cables connected to the rear wing mounting bolts.

 

The whole BRS pack is mounted in a plywood bay in front of my screen- the only place I could fit it and maintain CoG. The Big Red Handle is near my right knee. My preflight includes removing the safety pin, which then plugs into my trim wheel, in case I have to use it as a backup elevator control.

 

A 13kg yank of this handle overcomes the resistance to trigger a pair of primers that launch the rocket.

It comes out thru a "frangible" plastic panel and pulls the harness and canopy clear of the aircraft.

 

After that, you have no control, unless you're some sort of superhero and can restart and try steering with rudder and power.

Edited May 6, 2020 by Old Koreelah

[IBob]

Sport parachuting originally used surplus military canopies, then early round sport designs. The fabric in these had a fair degree of porosity. With the advent of low porosity fabric, then the move to ram-air canopies, the openings became more violent: it was not unusual for sport jumpers to be stunned by an opening and bruised by the harness.

So various systems were tried to slow the openings: one was a heavy webbing strop wound round the lines just below the canopy, another was a loop line from the pilot chute that passed through rings round the canopy periphery that acted as a draw string. These were bulky systems and prone to problems of their own.

The system used now is simple, compact and highly reliable. It is a rectangle of fabric, reinforced with webbing, and with a large grommet set in each corner. 1/4 of the lines pass through each of these grommets, and this slider, as it is called, is pulled up to the canopy skirt during packing. On deployment, the slider is driven down the lines, allowing the skirt of the canopy to progressively open.

This works on both round and ram-air canopies: I had an early low porosity round canopy, and that used a 'spider' which was essentially the same thing with just the webbing and grommets, no fabric.

The tradeoff with a slower opening is that you fall further. My understanding is that opening times are now much longer with high performance sports gear, and certainly so for tandem rigs. But the early versions definitely took the sting out of the opening without greatly extending the opening time.

It would be interesting to see some slider tests on aircraft parachutes, which mostly look to be very simple round or so-called triconical designs.

[Geoff_H]

How does the manufacturer ensure the 20deg nose down. Are they 2 connections to the canopy or 3?

[Geoff_H]

Parachute canopy that is.

[Kyle Communications]

I have fitted a Galaxy Sky chute to a savannah rebuild I am doing. There are 4 straps to each corner of the cabin frame then a pair either side of the cabin that attach to the undercarriage to make sure the cabin frame can never depart the airframe. Mounting the chute can be problematic in some aircraft also how it exits the aircraft. Most ballistic chutes come back to earth between 6 and 7 metres per sec so lets say its a "arrival" but the straps are set to make the aircraft have a nose down attitude. My chute in this aircraft is a 600kg chute..be carefull as eurpoen aircraft usually only have a 450kg chute. My Rans S-21 will have a chute as well but it will be for 750kg

[eightyknots]

I have fitted a Galaxy Sky chute to a savannah rebuild I am doing. There are 4 straps to each corner of the cabin frame then a pair either side of the cabin that attach to the undercarriage to make sure the cabin frame can never depart the airframe. Mounting the chute can be problematic in some aircraft also how it exits the aircraft. Most ballistic chutes come back to earth between 6 and 7 metres per sec so lets say its a "arrival" but the straps are set to make the aircraft have a nose down attitude. My chute in this aircraft is a 600kg chute..be carefull as eurpoen aircraft usually only have a 450kg chute. My Rans S-21 will have a chute as well but it will be for 750kg

 

Do you happen to remember the weight of the Galaxy Sky chute?

[Kyle Communications]

13 kg from memory

[Kyle Communications]

But I had to build a box around it for the rocket blast so all up with mounts and sheets and rivnuts etc probably 15kg

[zodiacpilot]

If it is a 24 registration you must also have permission from the aircraft manufacturer.

[danny_galaga]

Some kit planes have mounting points already. Bushcat does. But I figured I'm riding that baby down if there's a problem ?

[SmithSJ]

On 30/4/2020 at 12:15 AM, Kyle Communications said:

I have fitted a Galaxy Sky chute to a savannah rebuild I am doing. There are 4 straps to each corner of the cabin frame then a pair either side of the cabin that attach to the undercarriage to make sure the cabin frame can never depart the airframe. Mounting the chute can be problematic in some aircraft also how it exits the aircraft. Most ballistic chutes come back to earth between 6 and 7 metres per sec so lets say its a "arrival" but the straps are set to make the aircraft have a nose down attitude. My chute in this aircraft is a 600kg chute..be carefull as eurpoen aircraft usually only have a 450kg chute. My Rans S-21 will have a chute as well but it will be for 750kg

I’m wanting to do an S-21 build with a parachute as well. Did Galaxy provide any installation details for your Savannah or did you have to come up with it on your own?

[Kyle Communications]

Randy is supposed to be doing a option for it. Well thats what they told me. Really its just where to mount the chute for easy extraction for the rocket. The staps for the chute will go to the 4 points of the cabin cage at the wings...usually all chutes are the same so that part is easy. Its where for balance because the chute for 750kg aircraft like mine will be registered as is 21kg so thats 50 lbs or so.