Aircraft Clearance / Qualification for Paradropping
Aircraft Clearance / Qualification for Paradropping
I'm looking for some pointers on formal standards for the qualification / clearance of aircraft for parachute operations. The various standards on parachuting (eg FAR 105) do not have much guidance on assessing the suitability of the aircraft for release of parachutists, particularly using static lines.
I have found some reports done on the C-27J and A400M designs, which seem to suggest that paratroopers are assessed in much the same way as stores - flow fields, release paths and so on. (Gives new perspective on the phrase "meatbombs"). But these reports do not seem to have any formal criteria for the assessment, eg assumed body position of jumper, minimum allowable distance between canopy and aircraft during opening.
Is there a formal standard for qualification of aircraft for paradropping?
Thanks
I have found some reports done on the C-27J and A400M designs, which seem to suggest that paratroopers are assessed in much the same way as stores - flow fields, release paths and so on. (Gives new perspective on the phrase "meatbombs"). But these reports do not seem to have any formal criteria for the assessment, eg assumed body position of jumper, minimum allowable distance between canopy and aircraft during opening.
Is there a formal standard for qualification of aircraft for paradropping?
Thanks
I don't recall using any standards when I tested parachute systems.
We did plenty of ground deployments of complete systems to confirm the sequence and snagging points / clearances. Identify, modify or eliminate anything that might damage your parachute system or the system damage your airframe. Try and get the cg and AUM representative, your ballast loads can get quite complex.
When it comes to personell parachute systems you just can not do enough dummy drops first to gain experience at all the corners of the envelop (and beyond, if the programme lets you). This work up should also include any procedures to be taken in the event of malfunctions. Your hung-up dummy paratrooper will damage your aircraft if you let him (guess how I know that)
Basically common sense and some experience are really all that is needed. Above all remember, if it can go wrong it will.
I can also remember standing watching the first drop of a system with its designer stood alongside. He was relieved when it worked, I was disapointed.
We did plenty of ground deployments of complete systems to confirm the sequence and snagging points / clearances. Identify, modify or eliminate anything that might damage your parachute system or the system damage your airframe. Try and get the cg and AUM representative, your ballast loads can get quite complex.
When it comes to personell parachute systems you just can not do enough dummy drops first to gain experience at all the corners of the envelop (and beyond, if the programme lets you). This work up should also include any procedures to be taken in the event of malfunctions. Your hung-up dummy paratrooper will damage your aircraft if you let him (guess how I know that)
Basically common sense and some experience are really all that is needed. Above all remember, if it can go wrong it will.
I can also remember standing watching the first drop of a system with its designer stood alongside. He was relieved when it worked, I was disapointed.
Moderator
A little more detail on the background of your question might make a more appropriate answer possible. Is it civil, or military aircraft being considered?
In the civil world, there is an FAA list of light aircraft which are permitted flight with a door removed, which may be presumed to be for paradropping. In the approval work I do, it is strongly discouraged that I refer to a modification as a "parachuting" modifiction, as Transport Canada has conveyed to me that parachuting is an activity, not a modification. Thus, we end up with a lot of "utility" modifications, and the aircraft operator can use the modified aircraft as he pleases, with its flight, and operational authority.
As for the techniques of the actual departure from the aircraft, those are generally established by the jumpers themselves. That said, however, were I permitted to place operational limitations on the aircraft for parachuting use, I would certainly have a few in mind. During my two seasons of flying jumpers in a Cessna 182 and 185, a few alarming things happened. One thing in common with all, was a lack of briefing between the jump master, and the pilot. In particular, I will never forget an occasion when four hearty jumpers exited the aircraft, but purposefully delayed their jump. The result was these four guys trailing off the wing strut. I suspect that Cessna did not consider this configuration when deciding how much aileron and rudder authority should be available - 'cause there is not enough for that at 55 kts! To make matters worse, with a loud "Yahoo", they were gone, (all together), and I was riding an angry 185 tumbling from huge control deflections, and a sudden reduction in assymetric drag!
Considering how informal some jump operations seem to be, the aircraft don't really seem to be too much a problem. I believe, however, that the aircraft to jumper relationship deserves a lot more attention...
In the civil world, there is an FAA list of light aircraft which are permitted flight with a door removed, which may be presumed to be for paradropping. In the approval work I do, it is strongly discouraged that I refer to a modification as a "parachuting" modifiction, as Transport Canada has conveyed to me that parachuting is an activity, not a modification. Thus, we end up with a lot of "utility" modifications, and the aircraft operator can use the modified aircraft as he pleases, with its flight, and operational authority.
As for the techniques of the actual departure from the aircraft, those are generally established by the jumpers themselves. That said, however, were I permitted to place operational limitations on the aircraft for parachuting use, I would certainly have a few in mind. During my two seasons of flying jumpers in a Cessna 182 and 185, a few alarming things happened. One thing in common with all, was a lack of briefing between the jump master, and the pilot. In particular, I will never forget an occasion when four hearty jumpers exited the aircraft, but purposefully delayed their jump. The result was these four guys trailing off the wing strut. I suspect that Cessna did not consider this configuration when deciding how much aileron and rudder authority should be available - 'cause there is not enough for that at 55 kts! To make matters worse, with a loud "Yahoo", they were gone, (all together), and I was riding an angry 185 tumbling from huge control deflections, and a sudden reduction in assymetric drag!
Considering how informal some jump operations seem to be, the aircraft don't really seem to be too much a problem. I believe, however, that the aircraft to jumper relationship deserves a lot more attention...
A little more detail on the background of your question might make a more appropriate answer possible. Is it civil, or military aircraft being considered?
Two of the fatalities involved another aircraft type, often used for military paradrops, where canopies snagged on an antenna and tore. (The "blamespotting" for these is complicated by the fact that neither victim deployed their reserves, leading some to blame the paratroop training). On review it was found that it was fairly common for canopies to contact the aircraft on deployment, but that there were usually no consequences as the contact zones were relatively smooth.
The third fatality involved a freefaller who contacted the horizontal stabilizer on one of the aircraft I am responsible for. Although the inquiry is not yet complete, I believe that this particular jumper adopted a specific body position on exit, which resulted in his exit path being substantially different to normal. On review what did become clear was that there is a very wide range of possible exit paths - jumper mass can vary considerably, and the body position adopted can cause dramatic variations on trajectory.
I initially contacted our local CAA to inquire how they cleared aircraft for parachuting. They referred me to the national parachuting club safety officer, who in turn suggested that their clearances are mainly based on the opinions of experienced jumpers. They had no formal standards against which they judged the safety.
I also looked through various military standards - including the old AVP 970 documents. the military seemed concerned about 'crossover", where paratroopers are exiting through doors on oth sides of the aircraft, and may collide behind the aircraft under canopy. The A400M people did a lot of simulation work on this issue. However I can find no standard or reference that specifies the acceptable clearance margin (or acceptable contact / required smoothness) between canopy and aircraft. I suspect that it is handled subjectively - a lack of incidents or accidents resulting from contact is taken as proof of acceptability.
I believe, however, that the aircraft to jumper relationship deserves a lot more attention...
Moderator
It sounds like you have already given this a lot more consideration than the segment of the jump industry with whic I was associated. I do recall the intial discussions [training] I had as the jump pilot, during which I asked about jumpers contacting the aircraft (Cessna 185 in that case). I was told that it was considered a goal to attempt to touch the horizontal stabilizer on the way past, and it was very rare to be able to. I asked that no such attempts be made on my flights. One thing I came to understand is that some freefallers like to "fly" upon exit. If the aircraft had a lot of speed on jump run, this was easier for them. I used to slow right down on jump run, usually to 50kts. This probably had the affect of making touching the tail even more difficult, should they attempt it.
There was never a concern about the parachute canopy contacting the airframe. Jumps either involved a freefall, or for student jumpers had the jump master deploying the pilot 'chute by hand as the student exited. The only caution I was given was that if a student decided to not jump, and chose to risk landing back with me, I had to disarm the barometric release system, or I would have a cabin full of parachute, which if it worked its way out the door in flight, would be a serious problem. I suppose word got out about what it was like to land, as everyone always decided the 'chute was the better way down!
I'm sure that there are different level of "professionalism" among jump organizations (I suspect mine was in the "less" category, which was why I stopped flying for them). I certainly saw a cowboy attitude at times, and would worry that if something could be imagined, it would be attempted. That increases the risk of injurious events.
I suspect that the infomation you seek may not so much exit formally, but rather as "tribal knowledge" among jumpers and pilots. You may have to state the aircraft type, and ask if anyone has flown them in jump operations, and has experience, but as it's a twin, it won't be me!
There was never a concern about the parachute canopy contacting the airframe. Jumps either involved a freefall, or for student jumpers had the jump master deploying the pilot 'chute by hand as the student exited. The only caution I was given was that if a student decided to not jump, and chose to risk landing back with me, I had to disarm the barometric release system, or I would have a cabin full of parachute, which if it worked its way out the door in flight, would be a serious problem. I suppose word got out about what it was like to land, as everyone always decided the 'chute was the better way down!
I'm sure that there are different level of "professionalism" among jump organizations (I suspect mine was in the "less" category, which was why I stopped flying for them). I certainly saw a cowboy attitude at times, and would worry that if something could be imagined, it would be attempted. That increases the risk of injurious events.
I suspect that the infomation you seek may not so much exit formally, but rather as "tribal knowledge" among jumpers and pilots. You may have to state the aircraft type, and ask if anyone has flown them in jump operations, and has experience, but as it's a twin, it won't be me!
Hindsight has 20/20 vision ;-)
Ran a small programm this week to test some systems.
From VX275
We conducted several rounds of dummy drops. At the end we were fairly confident, but I have to admit that the first live jumpers still gave me butteflies. I'm a qualified skydiver, but for various reason wasn't a test jumper. I think I would have felt better being a test jumper. All went well, in the sense that there were no emergencies. Buty it wasn't easy just being a spectator..... Somehow felt I was not "putting my money where my mouth was.."
We thought about this long and hard - developed mitigation strategies. Still, the hung-up scenario was scary - for all the theory, we had very little real evidence to go on. Worked OK, but was marginal in that the dummy did swing close to critical control surfaces. At the end of the excercise, the FTE said to me that he'd forgotten what it was like to do a high risk test. Perhaps in comparison to some of the work other members of this forum have done it was very little, but to watch a 75 kg dummy heading towards your fabric control covered control surface ....
From PILOT DAR:
Very true. I'd trained as a sport skydiver, but I found the military crowd very different in technique.
Overall, the concerning issue was that we did have incidents where canopies contacted the aircraft. And, from video evidence, this is not only restricted to the aircraft we were testing - I have seen it on several in-service types. I still have the feeling that this is a very grey area of the aircraft envelope, and will continue to apply caution.
Thanks for the advice, I did appreciate the imput
Ran a small programm this week to test some systems.
From VX275
When it comes to personell parachute systems you just can not do enough dummy drops first to gain experience at all the corners of the envelope
This work up should also include any procedures to be taken in the event of malfunctions. Your hung-up dummy paratrooper will damage your aircraft if you let him
From PILOT DAR:
As for the techniques of the actual departure from the aircraft, those are generally established by the jumpers themselves
Overall, the concerning issue was that we did have incidents where canopies contacted the aircraft. And, from video evidence, this is not only restricted to the aircraft we were testing - I have seen it on several in-service types. I still have the feeling that this is a very grey area of the aircraft envelope, and will continue to apply caution.
Thanks for the advice, I did appreciate the imput
