Attaching things to Cessna struts

[bugg smasher]

We are looking to attach a camera pod to a wing strut of a Cessna 182, does anyone have experience regarding torsion induced stress to metal parts, in this case the wing and fuselage attach lugs of said strut.

The regulatory aspects of this are another subject altogether, just wondering if any engineering types out there have thoughts on the subject.

[john_tullamarine]

I suggest that your main concern will be with the vibration characteristics... why not do what we all do ? .. and put the camera somewhere more appropriate ?

[compressor stall]

Wander over to Alaska and see all sorts of things on Cessna struts....

[I Am Not The One]

I was even hanging on to a Cessna strut, just before making my first parachute jump! :)

[SNS3Guppy]

does anyone have experience regarding torsion induced stress to metal parts, in this case the wing and fuselage attach lugs of said strut.


Yes, actually...but what are you trying to say when you state "torsion induced stress?"

Your wording suggests stresses a twisting load, but without any further information, it's very little go go on.

If you mount the camera on the strut with any kind of a clamp and expose it to the slipstream, you're going to need to have an approval, and in order to get the approval you're going to require documentation showing it's safe for flight (aerodynamics and function) as well as mechanically sound and properly engineered.

Sounds like you're more interested in just clamping something out there and making do. Without more information and an idea of what you're putting out there, it's hard to be anything but very general on the subject. Also, you really can't separate the safety and the legality; they're tied closely together as both are required in order for the arrangement to be airworthy.

[bugg smasher]

I suggest that your main concern will be with the vibration characteristics... why not do what we all do ? .. and put the camera somewhere more appropriate ?

You are correct, John, vibration is an issue, especially with digital cinecams. More appropriate? No, removing the door and filming from the seat has many restrictive limitations, lots of parts getting in the way. The wing mount pod is an ideal solution. Assuming various engineering issues can be sorted. The Hollywood solution involves gimbal mounts and rotorcraft, very expensive stuff, the documentary film we are looking to produce does not have an unlimited budget.

Sounds like you're more interested in just clamping something out there and making do. Without more information and an idea of what you're putting out there, it's hard to be anything but very general on the subject. Also, you really can't separate the safety and the legality; they're tied closely together as both are required in order for the arrangement to be airworthy.

A working unit in the UK, CAA approved, is already in use.

Wildlife, Documentary, Commercial and Aerial Filming: Last Refuge Ltd. (http://www.lastrefuge.co.uk/data/LRP_aviation_main.html)

We are, however, unsure of the methods by which the UK CAA approved this unit, no info forthcoming from the manufacturer. The FAA here in the US tends to be more skeptical of such devices. I'm sure, Guppy, you're familiar with that mode. Any thoughts on the subject much appreciated.

[SNS3Guppy]

Again, more detailed information is in order. I've seen special camera boxes mounted (and have used them myself), and I've seen camcorders duct taped to struts. I've done a lot of flying with doors off of single engine Cessnas ranging from 182's to Caravans with photographers in and out of the aircraft, as well as hanging from the strut.

I've attached various items to aircraft struts using a variety of means.

What exactly is it that you're trying to accomplish, using what equipment? How large? How well faired? Weight? Position? Intended means of attachment? Type of aircraft? Type of operation? Door on or off? What kind of budget? You needn't reveal confidential information, of course, but any information is a plus.

Details are useful. Your best bet, as always, will be to sit down with a designated engineering or airworthiness representative, and get an approval written up.

[Tinstaafl]

Why not use one of the Cessna models that has its landing light mounted in the wing leading edge? Replace the lights with the camera (presuming the camera fits, of course). There's even a power supply to the location.

[SNS3Guppy]

That's a possibility...but is the camera looking back into the cockpit, out the side of the wing, forward....?

Don't overlook gear mounted cameras, either...far less aerodynamic intrusion, and far less concern about structural integrity.

Unless of course it's retractable gear...:}

[bugg smasher]

We're filming wildlife for a nature documentary.

If you have a look at the link to the UK unit I've supplied, you'll get a good idea of what we're trying to do. BTW, guppy, do you know of a US supplier with something similar?

This unit however, only tilts, it does not pan. Camera control is through a laptop in the cockpit via LANC. We haven't considered gear mounted units for the 182, the main problem there would be prop arc impinging field of view, oil spray from the exhaust, as well as debris on dirt strips kicked up by the nose wheel causing potential damage.

[barit1]

The structural concerns depend somewhat upon where along the length of the strut you mount the camera. At either end there's not too much to worry about - but if it's hung at midspan there are inertial considerations (bending loads, possibly even torsional loads).

And of course you must mount it using a conformal clamp, using care not to mar the strut.

[SNS3Guppy]

I've used hand holds and other mounts through the tie down ring at the top of the strut. You need to ensure that whatever you're mounting out there won't interfere aerodynamically with the operation of the aircraft at all angles of attack and at all configurations. Generally there's a speed limit to consider, as well.

Sometimes it's easier to use a side looking camera from an open doorway looking slightly aft. You can still get very good shots this way, with more camera control.

An older STC is available for certain single Cessna's for a wing mount camera:

Supplemental Type Certificate
STC Number: SA4-662
This certificate issued to:
McBride Clifton G
STC Holder's Address:
620 Rollingwood Drive
Vallejo CA 94590
United States
Description of the Type Design Change: Camera pod.
Issued, 01/01/1961
Responsible Office:
ANM-100L Los Angeles Aircraft Certification Office Tel: (562) 627-5200
TC Number -- Make -- Model:
3A12 -- Cessna Aircraft Company, The -- 172
3A13 -- Cessna Aircraft Company, The -- 182
5A6 -- Cessna Aircraft Company, The -- 180
A-799 -- Cessna Aircraft Company, The -- 170

You can also visit information about the above STC at: HOME (http://www.airbornescientific.com/)

Pictures are available there, as well as a means to contact the STC holder.

This particular STC is different than what you're presently looking for, but it's a starting point, and you may find some direct connections to help build or approve what you're after.

The FLIR (Forward Looking InfraRed) system mounts sold here may also provide you with some alternate options, including the ability to pan in other directions, with some adaption: Paravion Technology, Inc. - FLIR Airborne Infrared Camera / Sensor Mounts (http://www.paravion.com/products/flir/flir.htm)

Depending on what it is that you're using for a camera, you may be able to film through the prop arc, from inside; obviously not a first choice for a high quality shot, but again, it really depends what you're trying to capture.

For your own purposes, one of your biggest enemy will be vibration.

Visit this site for information and safety related material on cameras, mounting, and aerial photography: Aerial Cinematography: Safety (http://www.aerialcinematography.com/sfty.html)

This mount may fit your bill exactly, depending on what it is that you're using for filming. Pan down to see the wing mount camera system: Aerial Filming techniques - aerial camera mounts ; Last Refuge ltd.-page 9 of 9 (http://www.lastrefuge.co.uk/data/aerials/AerialTechniques_page9.html)

Aerial camera wing mount system for Cessna from Last Refuge (http://www.lastrefuge.co.uk/data/aerials/aviation_mount.html)

[bugg smasher]

Many thanks for all the info guppy, much appreciated. The 182 we are using was actually a sensor platform for a law enforcement agency in its previous life, so it has all the appropriate holes already drilled in the fuselage. (Hard to keep it dry sometimes, but that's life I guess.)

The Paravision unit with the vibration-tunable isolation collar may be just what we're looking for, with some minor mods to house our cinecam, I'll be talking to them next week.

You seem very knowledgeable about the subject, any other thoughts you can impart regarding aerial filming?

[SNS3Guppy]

I'm no cinematographer. I can barely take a picture with a disposable camera...but I've flown photographers who have had their work published, and have done it for law enforcement and such work.

A light airplane as a camera platform is easily displaced by turbulence, and consequently without a gyrostabilized platform, the picture taken is only as good as the camera, mount, and obviously the platform...the airplane. Slower flight works best, and any speed adjustments necessary can be processed through the film speed at a later time.

Make sure that when filming, one person is responsible for nothing but the safe handling of the airplane, and the other for shooting. It's too easy to focus on the subject and end up crashing the airplane.

Pick the right aircraft for the right mission; not all are interchangable. A helicopter may be right for some shots, the Cessna for others...a modified lear for others. Use what's appropriate for the mission at hand.

Remember, like any low altitude endeavor, there is no flight which must be made, no shot which must be taken. Always be ready to defer, delay, or say no, or change the way things are being done at any given time in order to be as safe as possible.

[bugg smasher]

Yes indeed. As a low-n-slow kinda guy in a T-34 training environment many many years ago, those lessons are well ingrained. We’re now developing some policies prior to the shoot that include a hard, absolutely no exceptions radio altitude floor, and have been validating our software based terrain warning system through a series of flights recently. As some of the shoot will involve large marine animals at a considerable distance from land, we’re also considering going through an underwater emergency cockpit egress training program, although providers seem to be somewhat scarce in this regard.

In any event, life’s a grand adventure, no amount of training and equipment will cover all the possible permutations, but hey, isn’t that the very definition of aviation?