totter

I've built quite a number of jump doors for C206, King Airs, Caravans & Twin Otters and each one is different. Even between the same aircraft type they can be different. You have to remember, these are not kits that you buy from the aircraft manufacture. Jump doors are all hand made and hand fitted. The best working combination that I have found is a one piece door of 1/8" Lexan with the gap in the track being the same as the thickness of the door. This seems to give a nice seal, keep vibration down and helps keep the door from binding. You always want to open the door from the center. If you try to open it from the forward side ore aft side the door will get cocked and bind up. The best doors I have ever seen, though, are the ones that were built by Graham Meise fro Freefall Express. All the doors have a "Tool Hanger" Support attach to them so that it takes very little effort to open and is difficult to slam.

That's correct. The thing that make this instance different from a wheeled Twin is the floats. You just added more lifting surface to the aircraft that is affected by the airflow.

There are two sets of floats that are certified for install on the Twin Otter, Whip Air 13000 & CAP Floats. The CAP floats were designed as part of the Original Certification of the aircraft, i.e. -100s short nose. You can install the CAP floats on a 300 series, but you need to install the short nose because that's how they were certified. The Whip Air 13000 were STCd to be installed on either long or short nose. The Whips also have a higher floatation rating, so the extra weight out front will not make the bows dig under water. A Twin Otter on floats does not use water rudders. It uses differential thrust. The Whip install adds an 18" stall bar on the outer part of the RH wing, so that both wings stall evenly. On the Rudder Servo tab the conecting rod length was changed to assist with yaw and the aircraft retains the Sea Fins on the horizontal.

In the States it is all part of the 337 Major Alteration process that every operator has to go through to install the jump mods. There should be a seperate Form 337 just for the seatbelt install. For an aircraft like the Caravan, you show where the belts will be placed (Stations), how many belts there will be, how they will be installed, how they will be inspected and how they will be replaced. You work up "Sample" weight and balances to show compliance. If the FAA Inspector agrees with your work, they approve the 337 and your good to go. One thing to keep in mind, When did they have the 21 jumpers on board? Was it the first load after fueling or the 3rd? The Grand Caravans that I used to work on, PT6A, we would put 15 on after fueling, 17 max on the next load and 19 max for the 3rd load after fueling. We did run the numbers and you could put 21 on board for the 3rd load after fueling. We did not do it though. That extra 2 people just killed the climb performance it was not worth it. We also did not do it because of comfort. If 19 in a Caravan is comfort. We would let one person sit on the rear cargo deck, but only after the forward part of the aircraft was full and that person would be one of the smallest on the load. Hypothetically speaking, you could install 10 seatbelts in a 182 if you could show on paper that the aircraft would remain in W&B limits.

Harbour Air a good company. I'm 500 miles north of you and we operate 6 Turbine Otters, with the -34's on them. We also have 4 Beavers w/ 985s. I never had to work on the PW 1340s. All the plans were converted before I got here. We did maintain one DHC-3 with the PZL on it. What a maintenance pig that was. Our Beavers, to my suprise, are pretty much trouble free, KNOCK ON WOOD. Our pilots don't beat the crap out of them, so that helps. There is an operator up in Juneau that has a couple -3s with Garretts on them. All fairly new engines. We are waiting to see how they fair. Garretts in salt water. Just the thought makes me shutter. We do have an operator here that has a 208 with the Garrett on it with Wipline floats. That thing hauls ass when it's flying. The big statement is "When it's flying". On the ground and in the water it's still LOUD. It also takes 3 times the distance to get off the water compared to the Otter. It comes up on step fairly quickly, but eats up about 3/4 of a mile to get airborne. Thats empty. I had a good chance to look at it when it was parked on our ramp. On thing I did not like was that there is no inertial seperator. You injest a bird or FOD on take off, make sure your helmet is on. Also, being on saltwater you have that big magnesim nose case just waiting to get corroded.

If you are able to jump, bring warm clothes. The high in Anchorage today is 38 F.

Under a standard TBO, 3600 hours for a Pratt & 3000 hours for a Garrett, the Hot Section Inspection requirement is 1/2 the TBO. 1800 for the Pratt & 1500 for the Garrett. No start or cycle requirements. For operators that have received a TBO extension the Hot Section Inspection requirements are closer together. It depends on their approval. So, for an operator that gets an extension to 10,000 hours, they may be doing a HSI, Hot Section Inspection, every 800 hours. The company that I work for, Part 135, has an On Condition Program for our -34s & -135s. We have no TBO. We can run the engines for as long as we want, changing Life Limited components of course. To do so, though, we have to do borescope inspection of the Hot Section, which is the same as splitting the engine, every 400 hours. An A&P can due a Hot Section on a Garrett. If they have the money they can buy all the tools the need. I would make sure that that A&P has lots of experience on Garretts before I let them dig into it. There is no requirement under Part 91 to comply with Hot Section Inspections. It is a manufactures requirement. Under Part 91 (i.e. Skydiving, General Aviation) you do have to comply with all life limts. TBO is not a life limit.

Basically thats correct. The Garret has two shafts. One runs inside the other. One is for the Power Turbine, that drives the prop. The other is for the Compressor Turbine, which of course drives the Compressor. When the engine is shut down the outer shaft begins to cool down. The inner shaft stays hot. This causes the inner shaft to "Bow" and it will rub on the outer shaft. By pulling the prop through after shut down the pilot is running cooling air through the engine so that both shafts cool down equally or close to it. I do agree with everyone. Give me a Pratt any day. Even a R-985 radial is more reliable then a Garrett.

In the US, let's say for High Altitude jumps, the DZ would need to file a waver with the FAA (the local FSDO). This is basically to receive permission to operate in Class A airspace for jump ops and also to seek relief from the IFR requirements. Diverdriver can probably give you the fine details on this.

That is good to hear. There is a mandatory replacement time, for hydraulic hoses and fluid hoses, required by the Limitations Section of the Maintenance Manual.

Transport Canada's Regs are more stringent then the FAA's here in the states. In the US basically any licensed A&P can work on any aircraft from a 152 to 747 after receiving their license. In Canada, as a mechanic, you can not work on a specific aircraft or engine or propeller until you have received a ratings indorsment from Transport Canada. What that means is that someone who is approved to work on a Radial engine cannot work on a turbine engine until they have received an endorsement to do so. As far as modification approvals go the FAA has caught up with Canada. There are many alterations that do require engineering data and an STC today. Before was not the case. Floats do not use the original gear legs. You can install floats on anything from a Cessna 150 to a 208 Caravan. There are many modifications that need to be done to the airframe to does so, though. 1) Engine mount needs to be strengthened. 2) Fire wall needs to be strengthened and fittings attached for the forward struts of the floats. 3) A V brace is added to the top of the firewall that runs upward through the dash to the forward carry-thru spar. 4) The Landing Gear is remove, fronts nose wheel strut and both main landing gear legs. Two fittings are attached to the original main gear attachements usng the same hardware. 5) Cables for the water rudder steering are installed. 6) A ventral fin is installed. In the case of the Caravan two sea-fins are installed on the horizontal. The float installation is actual more rigid than Land gear. That's why must manufactures put a limit on the height of the waves you can land in.

I have seen the attach bolts fail due to shear caused by a hard landing. As far as the story from Lou that I was referring to, I really can't say that "Broke" ment total failure or that something was found at inspection that caused it to be rejected.

I can not give you a definite answer to that. This was an event that was told to me by a long time & highly respected skydiver. I was never witness to the event. If you think about the design of the gear it is plausable. The gear is designed to support the weight of the aircraft and take the load of landing, were the weight of the aircraft is multiplied. It's not really design to go the other way under stress. If you ever watch a Cessna bounce on landing you see the gear flex up, as the weight of the aircraft pushes down. Once the gear rebounds and the plane is airborne again the gear does not go past its starting point in the opposite direction. It stops at its origin starting point. I do see your point, though. I've never seen one fail due to this. There are no STCs, at least in the US, to do this modification. All step installs would have been done under a Form 337 Field Approval, Major Alteration. Being that the first install was done years ago, before engineering data was required, and the fact that you can use a previously approved Form 337 as Acceptable Data for doing the same modification to another aircraft, I doubt that engineering data will ever be required. Today, if you wished to do this to an aircraft and it was the first of its kind, you would have to get supporting engineering data, and apply for an STC. They changed the requirement about 3 years ago.

An MEL for a PART 91 aircraft has no time limitations on how long the deferred item can remain inoperative. The A, B, C, D categories do not apply. I forget what the exact web site is, but if you were to go to www.faa.gov, type in "MMEL" in the search box, it will give you a link to all the Master Minimum Equipment Lists that the FAA has. You would then select from the MMEL drop down menu, Part 91, Small Aircraft. If you had a 182 you would select Single Engine Aircraft, if you had a Twin Otter you would select DHC-6. You would then just print out that MMEL. You would then send a letter to the FAA, the local FSDO, asking them permission to use the MMEL as written. The FAA will then send a letter back giving approval to do so. You then take the MMEL, as written, along with the Authorization Letter from the FAA, and include some type of discrepancy sheet, place them in a binder and then place it in the aircraft. The only thing that takes some doing, on the operators part, are the procedures for the (M) & (O) items. Each operator must come up with their own. For those that don't understand what (M) & (O) are: They are the procedures for deferring a specific item. (M) means tha only a mechanic can defer that item because it involves a maintenance step. (O) means an operations procedure. An alternate means of operating the aircraft with the deferred item must be established. All others can be deferred by the pilot or mechanic. After this you are good to go. There are no more approvals needed.

How many operators actually have or use an MEL? Even though it is not difficult to obtain an MEL for Part 91,(i.e. jump aircraft operations) you still need to receive approval from the local airworthiness authority to use it. Of those who have an MEL for the aircraft, how many use it properly? If there is no MEL for the aircraft or there is inoperative equipment that is not properly deferred then the aircraft is not airworthy. All installed equipment must be working. If something is not working and is not required for VFR jump operations then it should be removed from the aircraft. If there are any operators that do wish to obtain an MEL I would be more than happy to answer an questions you may have and lend a hand.

I always found that having an open relationship with the local FSDO is the best way to go. It shows them that you are trying to be pro-active in your maintenance. It also allows for time to make corrective actions to anything that they might find before the season gets in full swing and down time is tight. They will find something, that's their job. This also gives you the opportunity to self-disclose anything that may have been missed. It means, for those who do not know, that you let the FAA know that "Hey, I missed this check or inspection, I know I missed it, I am letting you know and here is what I am going to do to make sure it does not happen again." Their reaction depends on what you missed, but by admitting to the mistake before they find it goes a long way.

Rookie120 & Kallend both have valied points. With the maintenance records, unless you know what you are looking at, there is noo way to tell if the are bogus or legit. As far as aircraft apperance, bingo. A good looking aircraft is one that can be fairly assumed to be well maintained. So lets start there. Using terms and visuals that all jumpers can reckonize. Walk up to the aircraft when its not flying. First take a look at the seatbelts. Are any frayed or the color so faded that it does not match. These are no good. Does it buckle easily and release easily. If it does not its no good. Can you read the data tag that every seatbelt half is supposed to have. If you can not read the TSO number on the tag, C22(?), or the tag is missing the seatbelt is no good. If you can not eaisly adjust it, its no good. On aircraft with a roll-up jump door. Are there screws missing. Are any of the lexan panels cracked or chipped. In the cockpit, are there missing instruments from the panel. There should be no holes in the instrument panel. If there are put a cover on them. Are placards falling off or unreadable. Placards are the labels that give info to the pilot. This is no good. Take a walk around the aircraft. Do you notice screws missing, corrosion, heavy oil stains on the belly, cowlings or nacelles. Are there broken antennas. Are the tires bald. All these are signs that maybe not enough is being done to the aircraft.

The covers where the struts connect to the wings are made of fiberglass. Just being old can make them dry and brittle. Also, they are just that, covers. Or you may here them referred to as fairings. They have nothing to do with the way the struts are connected to the wings. As for the elevators, I would assume from experience that the cracks you refer to are on the trailing, rear, edge of the elevators or out by the tips. Wear and tear do age is the most likely cause. Some newer Cessnas, 1970 & after, have fiberglass tips on the elevators. Same thing as the strut fairings. Stop drilling a crack is an acceptable repair. The ones on the elevator, though, should have a patch repair. _________________________________________________ QuoteSo does th extra engine also warrant concern over extra weight and flying stresses upon the airframe? So does th extra engine also warrant concern over extra weight and flying stresses upon the airframe? The upgrade in engines are fairly new, in respect to the age of most 182s used for jumping. If there are any stress related issue due to the engines they may not be known for some time. It takes time for them to manifest themselves. As far as the extra weight is concerned this should be factored into the new empty weight of the aircraft if and when a Weight & Balance was done at the engine install. The Max Gross weight remains the same, the usefull load, or how much the aircraft can carry, will be lower.

Runaway, have you ever considered the stress on the Landing Gear of a 182. Not from landings, but from jumpers standing on the step that is attached to th RH Main. I remember sitting on the deck of the DZ, oh '97ish, having a beer with Lou Sanborne. He mentioned something to me that has always stuck in the back of my mind. The Landing gear on a Cessna is made of Spring Steel. It is designed to flex upwards on landing as the weigh of the aircraft pushes down. Now take 4 185-200 lbs skydivers and have them stand on that step in flight. Which way is the direction of the load now. He told me about when a RH Landing gear broke do to this stress. It was something I had never thought about. It is something I don't forget when I do an inspection. Expect the unexpected and you will never be suprised.

Thanks Chris for your input. You are absolutely correct when you state that we need to educate people on this matter. I know there are people out there that have questions. I've been reading them on the various Incident posts. I just feel that here is a better place to deal with them then just cluttering up a post with unrelated questions. I may not have all the answers, but when I do I will state them as fact when possible and if I am using past experiences as speculation then I will explain it as such.

If the average jumper were to ask me this question then I would answer: If the Beech 18 did not have a puddle of oil under it, then there is no oil in the engine. Radials leak oil, expecially from the exhaust if the have been sitting for awhile. Where as if there was a puddle of oil under the Westwind Beech I would state that something is wrong because turbines are not suppost to leak. If you would like I can go more indepth.

This response is based on requirements in the US. The may not translate to the UK. There are three different ways that a Caravan can be inspected. 1)100 Hour & Annual Every 100 hours of operation the aircraft is inspected and then every 12 months. Each time the complete aircraft is inpected. 2)Progressive Inspection as per the maintenance manual. I never used the progressive inspection, so I can not comment. 3)Phase Card Inspection Program. This program is broken down into 12 Inspections. Every 200 hours you performed one of these inspections. Every 100 hours you would perform a "Mini" Inspection. The Mini was basically checking brakes, tires, prop and filters. It is difficult to say what is checked at each inspection because it varied from inspection to inspection. But at each 200 hour the prop was always inspected, the engine was always inspected and filters changed and the flight controls were always inspected. There are also special inspections for the Main Landing Gear, Wing Struts and Spar. Hope this answered something for you.

Using the tail number for the aircraft will only get you the Registration information for that aircraft, (i.e. who owns it, serial number, etc.). Some aircraft operators will have maintenance info in the aircraft in some form or another. I have seen operators that will make copies of the log book entries and have them in the aircraft. For aircraft that I was responsable for we had a spread sheet that showed when the last inspection was completed, when the next was due, what the current AD status was. It was signed by an A&P with the mechanics number. We also kept copies of all the 337s, (Major Alterations & repairs) in the aircraft. We started doing this at the suggestion of our FAA Inspector. It made it easy for them when they did ramp inspections, expecially when the aircraft was away from the home DZ, at a boogie or demo, when the log books were not availlable. It also let the pilot know the current status of the aircraft. Check with your pilot. Maybe your DZO does this in some form or another. If not a hint will not hurt.

For those that do have questions concerning maintenance on aircraft I will be more than happy to answer them. Grimmie, the previous was my last reply to you. I know that will upset you greatly.

You are correct. Many do not know. That is why I posted this thread. To help make them more aware, answer questions. You are also correct that many people don't give a shit. The old saying, "Why would anyone jump out of a perfectly good airplane?". But there are a few that do, and that number seems to be growing following the recent events. Can you please show me where I made the remark that I want to debate MX schedules? I also thought that these forms were to discuss topics like this to make the average person more knowlodgeable about the sport and what goes on around it. I've never seen anyone slam diverdriver for giving his pilot's perspective.