Aircraft Maintenance for Jump Aircraft; (Your Thoughts)

[DBCOOPER 1]

I know a DZO who in the spring calls the local FSDO and request a inspection of his aircraft and logs. He doesn't want to have any issues being ramped during the season. I cringe at the thought of asking the feds to come out but its a good way to foster a relationship with them, and give me a little comfort that at least they looked at it.

Replying to: Re: Stall On Jump Run Emergency Procedure? by billvon

If the plane is unrecoverable then exiting is a very very good idea.

[totter 2]

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.

[kallend 1,623]

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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.

In many cases placards are required by type certificate, STC or AD. While missing placards will not by themselves cause an accident, they are another indicator that the plane is not properly maintained.

...

The only sure way to survive a canopy collision is not to have one.

[grimmie 173]

I made a nice 4 way afternoon leap today. All of the jumpers had their helmets belted in to their chest straps. I suggested they don their buckets in case the spinny things stopped at a critical time. They looked at me like I was crazy. I don't think they care, nor ever think about MX.

[Rookie120 0]

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What he said. Going over ADs in particular can take hours and hours, and determining which ones are relevant to your particular plane often requires knowing things like the serial number of the propellor hub or what kind of oil pump the engine has installed , etc. (to list just two examples that applied to my Mooney).

Some nights I can more time on the computer doing research than actual work. It is a pain in the ass but thats what has to be done sometimes. I could not imagine what it would be like trying to dig up information before computers came along. Digging through boxes of records would have sucked.

If you find yourself in a fair fight, your tactics suck!

[Rookie120 0]

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In many cases placards are required by type certificate, STC or AD. While missing placards will not by themselves cause an accident, they are another indicator that the plane is not properly maintained.

Another great point John. If in the spring I get on an otter and the fuel flow gauge has an INOP placard on it I dont care. I understand things can be placed on MEL. But when August rolls around and the same placard is on the plane I have red flags flying at that point.

If you find yourself in a fair fight, your tactics suck!

[totter 2]

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I understand things can be placed on MEL.

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.

[Tuna-Salad 0]

After seeing how they are flown on the way down after releasing jumpers I would hope the airframe gets inspected more often than average Joe's cessna 182.

Millions of my potential children died on your daughters' face last night.

[Rookie120 0]

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How many operators actually have or use an MEL?

I would hope a DZ would have something in place for MEL. I really dont know.

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Of those who have an MEL for the aircraft, how many use it properly?

Thats what I was saying before. When you see an INOP placard in april then august rolls around and it's still there there is something fishy going on. I have never seen an MEL that lasted that long.

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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.

How hard is it to obtain an MEL if you dont already have a program in place? How do you get a MEL program goin in the first place?

If you find yourself in a fair fight, your tactics suck!

[Rookie120 0]

***After seeing how they are flown on the way down after releasing jumpers I would hope the airframe gets inspected more often than average Joe's cessna 182.
***


As long as the pilot doesnt roll the thing of overspeed on the way down I dont see why that would be required.

If you find yourself in a fair fight, your tactics suck!

[totter 2]

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I have never seen an MEL that lasted that long.

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.

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How hard is it to obtain an MEL if you dont already have a program in place? How do you get a MEL program goin in the first place?

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.

[Rookie120 0]

Thanks for that. I have never had to put an MEL or anything except at my airline and they have the programs in place so I never has to deal with the FSDO for that.

If you find yourself in a fair fight, your tactics suck!

[hackish 8]

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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.
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.

Did the landing gear break because of stress from jumpers or inadequate inspection and stress cracks from normal wear that were undiscovered? I would hope the failure mode of that design would be flattened gear, not gear pieces snapping off while the plane skids to a stop on it's belly...

I am unaware of a spring steel that is only designed to flex in one direction. As long as you stay within the elastic zone of the material I don't think it is going to matter which way you push on the gear. Also, with the STC to add a step was the engineering to validate that the gear structure was able to take the loads of its intended use.

I'm not saying I know everything or that you're full of it but what you say conflicts with my basic knowledge of metals.

-Michael

[davelepka 4]

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As long as you stay within the elastic zone of the material I don't think it is going to matter which way you push on the gear.

The gear leg itself, yes. How about the attachment hardware, or the attachment point itself? That is not designed to flex in any direction, and certainly not designed to carry a downward load.

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the STC to add a step was the engineering to validate that the gear structure was able to take the loads of its intended use.

When was this STC approved? How many years ago? There was a time when jumpers exited one at a time, and didn't think it was possible to touch each other in freefall, let alone do it so well that they all needed to stand on the step at the same time.

Even that aside, the issue of the aging of the fleet itself could be a factor as well. Did they really expect that these steps would be supporting jumpers 20 or 30 years later?

[totter 2]

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Did the landing gear break because of stress from jumpers or inadequate inspection and stress cracks from normal wear that were undiscovered?

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.

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Also, with the STC to add a step was the engineering to validate that the gear structure was able to take the loads of its intended use.

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.

[totter 2]

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How about the attachment hardware, or the attachment point itself?

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.

[hackish 8]

I assume our requirements must be much stricter than yours. In Canada it has to go through transport Canada. AFAIK someone comes out and inspects the mods and an engineering type has signed off on the STC. I would have to check into that. I am aware of several step designs that did not pass their scrutiny.

As for downward stress can you tell us if there is a significant difference between the hardware used to attach the normal landing gear and if you were to put floats on the AC? I do know that floats can be very heavy but I don't know if they can even be attached to a cessna.

-Michael

[girthrockwel 0]

I was at the DZ today learning how to pack and they had the King Air taken apart replacing some hoses I think. They said they were part of a 2 or 4 yr maintenance schedule, can't remember which. Made me feel good too see them taking care of that kind of thing.

[totter 2]

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I assume our requirements must be much stricter than yours.

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.

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As for downward stress can you tell us if there is a significant difference between the hardware used to attach the normal landing gear and if you were to put floats on the AC? I do know that floats can be very heavy but I don't know if they can even be attached to a cessna.

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.

[totter 2]

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I was at the DZ today learning how to pack and they had the King Air taken apart replacing some hoses I think. They said they were part of a 2 or 4 yr maintenance schedule, can't remember which. Made me feel good too see them taking care of that kind of thing.

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.