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riggerrob

Best Cessna jump-step?

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After a couple of hang-ups, it is time that we share best-business-practices about the after-market jump-steps installed in piston-pounding Cessna 180 and 200 series airplanes that make up the bulk of our lift capacity.

Can we start by agreeing that the Cessna factory-standard step is a snag-point waiting to happen?

Please post photos of the jump-step on your favorite Cessna jump-plane. DZOs and USPA Group Members please share your wisdom.

Links to Supplementary Type Certificates and modification shops would also be helpful.

It sounds like the FAA is increasingly reluctant to sing-off on 337 Field Modifications.

Now is the time for skydivers to unite in solving a problem before gov't imposes an onerous solution ... like when seat-belts suddenly became fashionable over the winter of 1992-1993.

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I would like to see a one piece step with angled extension going up to just under the door, if that is even possible, with the front edge of the step at the angle having no forward protrusion, so nothing will snag on it.
"Mediocre people don't like high achievers, and high achievers don't like mediocre people." - SIX TIME National Champion coach Nick Saban

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DBCOOPER

Here's the one on my plane.

Looked thru the records to see how it was done. Its a 337 from 1985.



Beautiful co-pilot. B|
"There is only one basic human right, the right to do as you damn well please. And with it comes the only basic human duty, the duty to take the consequences." -P.J. O'Rourke

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Jerry,

You need to get your hand healed up so you not just setting at the computer. I don't know that anyone on the Tech committee is an aircraft mechanic or airframe engineer. There may be but the Tech comm barely has time to talk about parachutes let alone airplanes.

I know at least some folks don't like those that L shaped and attach at the axel as well as clamp to the strut. Creates a rigid triangle with part of the strut that doesn't flex, in theory. But I know there are a lot out there. The other one pictured above that just clamps on and flexes down onto the tire seem less intrusive on the strut design. But I'm not an engineer either.:$

Of course there is always the tire, if the pilot knows where the brakes are.:)

I'm old for my age.
Terry Urban
D-8631
FAA DPRE

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What leads you to believe the FAA is 'increasingly reluctant'?

Actually, it is I think, an individual FSDO- Flight Standards District Office decision, if I am correct, it is done on a district by district basis. Not as an FAA decision as a whole.

Usually when owners go for a 337 mod, such as camera person steps and external handles, they just copy others already approved in their respective districts; and there is no particular problem if it is a proven and safe mod.. Steps for Cessnas have been approved for probably over 50 years.

Wondering why you think there is increasing reluctance. You may be right, maybe things are changing.

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dpreguy

What leads you to believe the FAA is 'increasingly reluctant'? Actually, it is I think, an individual FSDO- Flight Standards District Office decision, if I am correct, it is done on a district by district basis. Not as an FAA decision as a whole.



My research (anecdotal evidence) has indicated that "increasing reluctance" is a good way to describe it, and that yes, it varies greatly with the particular FSDO.

From the USPA February 5th, 2013 newsletter:

FAA Issues Field Approvals

Operators of skydiving aircraft occasionally report that their FAA local Flight Standards District Offices (FSDOs) will not issue field approvals for modifications (such as a jump door) to their aircraft. Some FSDO inspectors have reportedly said that the FAA no longer issues field approvals. USPA decided to investigate these reports. The day after Christmas, staff met with the manager of the Flight Standards maintenance division at FAA Headquarters in Washington, D.C. Good news: The field approval process is alive and well. Comprehensive guidance relating to FAA field approvals is located in Order 8900.1, Volume 4, Chapter 9, Section 1, which can be found under the title Flight Standards Information Management System here.

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The field approval process is alive but barely hanging on by a thread. Inspectors are in fact more and more reluctant to stick their individual necks out to approve data for aircraft modification and have been adding more and more excuses for their inaction. Theyll tell you that there is an existing STC so they cant touch your mod. Theyll say they dont have the expertise or even the time. Neither of these excuses are acctable per their own guidance.

It has been taking some difficult wrangling and sometimes FSDO "shopping" to get jump doors, steps, etc approved in recent years even with literally hundreds of flying examples and copies of previous field approvals.

The inspectors are evaluated by the number of on-site inspections of maintenance facilities, flight schools, repair stations that they do. Field approvals carry no "points" for their performance reviews and are increasingly looked at as a risky waste of their time.

Jon

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Not an a/c engineer but was an airframe repair guy in USAF (cerca 1970's).

Possible Improvements:

1 The inboard end of step could be tapered and extended farther up the a/c gear strut so as to blend in with it up to very near the fuselage just below the door and clamp it there.

2 Possibly a roller system below the step between it and the tire allowing the vertical leg of the step to be removed or shortened to facilitate natural movement of the a/c strut. Upon landing and strut deflection the roller could spin with the tire should they come in contact. Large caveat would be - Will there be enough clamp pressure to hold the step securely without it being tied in with the bolt thru the low end of the existing vertical leg. Possibly application of extreme high strength adhesive to faying surfaces of the clamped areas would help that situation..

3 Would also consider rounding step plate edge to full 180 degree radius and sand and polish it down to very (glass smooth) with 220 or finer sandpaper.

Just my whuffo 2 cents.

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gowlerk

I like ours in Gimli. But it's not perfect.



...............................................................................

That is the smoothest jump-step we have seen so far. The (inboard end) filler block eliminates a couple of snag points.

Wrapping the step down beside the wheel eliminates a couple more snag points.

Some might criticism that step for limiting leg strut flex, but I would need to take a close look at how much rubber is in the upper attachment clamp.

As for the step limiting leg strut flex ... I have seen many with hinges at the inboard and outboard edges, but most of those hinges include snag points.

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"...:$
Of course there is always the tire, if the pilot knows where the brakes are.:)"

...............................................................................

Simple in theory, but students instinctively stand on brake hydraulic fittings.
Which raises the question of "How many times you can stand on a brake line before it fails?????"

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riggerrob

"...:$
Of course there is always the tire, if the pilot knows where the brakes are.:)

"

...............................................................................

Simple in theory, but students instinctively stand on brake hydraulic fittings.
Which raises the question of "How many times you can stand on a brake line before it fails?????"

Yeah yeah, I know. Not enough for the tandems that like to stand facing forward before exit either.
I'm old for my age.
Terry Urban
D-8631
FAA DPRE

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Hi Gary & Terry,

Quote

local Flight Standards District Offices (FSDOs) will not issue field approvals



This is the very reason why I am saying that PIA should grab this problem & run with it.

These FSDO's types do this all of the time because of a personal whim. And, of course, if you always say 'No' it can never come back on you.

I would suggest that PIA/USPA do some work to determine the optimum step design and then go for an STC which would be owned by either/both of the organizations. This would allow everyone in this country to install a well-designed step that has approval.

This is how USPA did it with their obtaining the STC for the swing-up door. Mike Marthaller was the Mountain Conference Director and he took hold of the problem, with the result being that the STC for a swing-up door is now available to anyone.

What else is PIA for?

Jerry Baumchen

PS) Terry, The hand is getting better ( see attached photo ). I cannot make a good fist but the stitches will come out on the 31st.

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Hi,

OK, I have to do a correction as I have been informed that I am incorrect. B|

The paperwork that USPA has/had was for removing the in-flight door and not the swing-up door.

My bad. :o

However, that does not change my argument that these types of problems ( getting field approvals ) should be dealt with on a nationwide basis.

I am wrong but I got some more discussion going; IMO that is a good thing. :)

Jerry Baumchen

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riggerrob

"...:$
Of course there is always the tire, if the pilot knows where the brakes are.:)

"

...............................................................................

Simple in theory, but students instinctively stand on brake hydraulic fittings.
Which raises the question of "How many times you can stand on a brake line before it fails?????"

Yeah yeah, I know. Not enough for the tandems that like to stand facing forward before exit either.
I'm old for my age.
Terry Urban
D-8631
FAA DPRE

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Hi Gary,

The FAA has made a change. The ASIs' guidance for Field Aprrovals is no longer in Order 8900 "Inspectors Handbook". It is now in its own stand alone Order 8300-16. Link below.

I also included some other links. The first one is the Advisory Circular AC 43-210, which is the guidance for submitting a Field Approval.

The last link is to the "Job Aid". This is the one that gives guidelines in determining what needs an STC, Engineering Data or could go thru Field Approval.
This one is the catch all because a look at the first grouping of aircraft type (Normal, Utility, ECT..) shows that changes to aircraft seating configurations and changes to non-pressurized aircraft doors now require Engineering Data. This is a recent change. This means hiring a DER or sending a request to the ACO. If you send something to the ACO you might as well get an STC since that is what they do.

Also, The thing now with Form 337, Field Approvals, is that every one now requires an ICA, or Instructions for Continued Airworthiness. This basically shows how the alteration was installed, how to maintain it and how to replace it if need be, plus any limitations. Out of ALL those previously approved 337s for swing up doors you'll be hard pressed to find one that has an ICA and doesn't just say "installed piano hinge."
I buy a case of beer to the first person who can find a 337 with an ICA before the year 2000.
Inspectors are reluctant to use these previously approved 337s since the Approved Data for them has to be readily available upon request and "installed piano hinge" doesn't cut it. This is a recent change.

The one thing that most FSDOs ARE required to do but don't is help in the whole process.


http://www.faa.gov/about/office_org/headquarters_offices/avs/offices/afs/afs300/media/major_repair_alteration_job-aid.pdf

http://rgl.faa.gov/regulatory_and_guidance_library/rgorders.nsf/786843013bf2d049852569810075c599/b86d2d931ad511a286257cec006dace5/$FILE/8300.16.pdf

http://www.faa.gov/documentLibrary/media/Advisory_Circular/AC43-210.pdf

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riggerrob

***I like ours in Gimli. But it's not perfect.



...............................................................................

That is the smoothest jump-step we have seen so far. The (inboard end) filler block eliminates a couple of snag points.

Wrapping the step down beside the wheel eliminates a couple more snag points.

Some might criticism that step for limiting leg strut flex, but I would need to take a close look at how much rubber is in the upper attachment clamp.

As for the step limiting leg strut flex ... I have seen many with hinges at the inboard and outboard edges, but most of those hinges include snag points.


I had a closer look at it today. The white piece sandwiched in that upper attachment clamp is two pieces of nylon that act as bushings. The whole clamp is allowed to slide on the wheel strut/spring.
Always remember the brave children who died defending your right to bear arms. Freedom is not free.

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The FSDO field approval process is in a slow death. As more and more FSDO people retire and become DER's and DAR's, whom you have to pay, often BIG money to certify something, you will find less and less FSDO people willing to sign off any 337.

It is about the money.
Airline Transport Pilot, Multi-Engine Land, DHC-8
Commercial Multi-Engine Sea, Single Engine Land
Private Glider

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