Portable Altitude Test Chamber

[varigging 0]

Where might one purchase a Portable Altitude Test Chamber to properly test Astra AAD's? I believe the requirement is that these devices (the 1200J, not the new style) must be tested on every repack. (I.E. During every repack of the parachute, a functional test is recommended on the ASTRA, using the Cutter-Test-Probe and the Portable Altitude Test Chamber.) Does anyone have a line on one of these test chamber units and their approximate cost? I am going to contact FXC, but figured I would check here first.

William
Virginia Rigging Services

William Linne
Virginia Rigging Services

[JeffD 0]

Make one. Use some physics, a vaccumme bell, and a control valve. determine the change in pressure related to altitude and create a valve that would simulate that. probably cost as much as the vaccumme bell costs and a vaccumme pump.

[chutingstar 1]

William,

If you come up with one (built or bought), let me know. I recently had to send an ASTRA back to FXC for the testing since I don't own a test chamber nor know of one close by...would be interested in purchasing or building one at a reasonable price.

Mike

ChutingStar.com

[PhreeZone 15]

We have one that was home built it at the DZ. We have a vacumn pump hooked up to container that holds the AAD, an Altimeter and some room to spare. The container have a variable control inlet valve that we use to control decent rate. The lid of the container is inch thick plexiglass, it bends in when the vacumn is applied and ran up to about 7500 feet to dial in the decent rate.

The parts are all cheap, but I'm not sure what the test chamber was originally used as before it was converted to a test chamber.

Yesterday is history
And tomorrow is a mystery

Parachutemanuals.com

[VectorBoy 0]

Alti master has a couple that they take to boogies to test and tune customers altis. Take a look at their unit its fast acting and simple.

[GroundZero 0]

when I bought mine, it was about $3500... direct from FXC.

If You need to use it, either pm or e-mail me.

it is not for sale as it tests far more than just FXC AD's.

Chris

(I'm in Tennessee, for shipping , very close)

[Aviatrr 0]

Quote

when I bought mine, it was about $3500... direct from FXC.

Holy shit! That's ridiculous! It's a simple airtight chamber with a vacuum pump! Can you post a pic of it? If there's really some interest, I can probably make a few of 'em fairly cheap.

Mike

[councilman24 36]

There are two types of chambers being discussed above. One is automated, calibrated, uses aircraft quality instruments, and is several thousand dollars. The other is something that holds vacuum, a valve, and a pump. It's suitable for function testing 12000's astras, altimeters, audibles, etc.

Unless you do a lot of FXC 12000 testing and need a certified chamber it's not worth considering buying a fancy one. My simple function chamber uses a vacuum desicator and a small electric pump. A hand pump from the local auto repair store works fine. An 11" diam. vacuum desicator is available from www.vwrsp.com for $135. Part # 24987-048. Smaller ones are available cheaper. The same thing can be made with plexiglass plate, cylinder, a router, an 0-ring, and a valve. But probably easier to order it.

Don't remember details off the top of my head of FXC 12000 testing but at some point they have to go in one of the fancy, calibrated, test chambers. It's been years since I've delt with them. You can function test them with the simple device but last I knew they needed to go back to FXC every two years for calibration.

Any way, for about $180 dollars for the desicator and hand pump and no work your in business.

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

[riggerrob 561]

Before he gave US$3000 to FXC, my boss compared the cost of home-made, versus a factory-built test chamber. He concluded that new, aircraft quality instruments (3-needle altimeter and rate of climb), pump, valves and plumbing would cost almost US$3000, so he bought a genuine FXC test chamber.
I have used several home-made test chambers to test FXCs and altimeters and all of them were a pain to use. The biggest problem was getting a consistent seal between the top edge of the drum and the Plexiglas lid. Like many home-made devices, you needed as much insight as the builder to operate it.
I much prefer factory-built test chambers. The only advantage I can see to home-made test chambers is that you can use the entire 45 gallon drum and stuff the entire rig inside.
Even with a large home-made test chamber, I cannot see the point to going through the whole hassle without recently-overhauled, aircraft quality instruments.

[markbaur 0]

The "calibrated" portable test chamber shown in FXC's ads appears to have an aircraft altimeter and an aircraft vertical speed indicator (VSI). The altimeter can be calibrated by an FAA-approved avionics shop to an accuracy of +75 feet, which combines with allowable firing range of + 300 feet. Most aircraft altimeters depend on aircraft vibration to help with needle movement, and I suppose the vibration of a vacuum pump might substitute.

The VSI is more problematic. One of the tests requires a descent rate of 175 fps, something in excess of 10,000 feet per minute, but the mechanical VSIs I know of have a maximum indication of only 6000 fpm. If the $5500 FXC test chamber has an aircraft VSI with a maximum reading of 6000 fpm, it cannot be used to test FXCs. Further, IIRC, there are no FAA accuracy standards for aircraft VSIs, so accuracy is not guaranteed.

I use a Stratomaster ALT-1 in my chamber. The ALT-1 is a digital altimeter/VSI intended for uncertified applications (experimentals and ultralights), but it goes periodically to an avionics shop for a ride in an altitude chamber to check the accuracy. The VSI maxes out at 9990 fpm, or 166 fps, just shy of the 175 fps required by the freefall speed test, but I think that's as close as any field equipment can get.

Mark

[varigging 0]

What are riggers charging to perform this test? I am just trying to calculate how long it will take to recoup the $3500 investment. There seem to be very few of these units (1200j) in my area that require this test. But I don't mind making the investment to open this service up to them, even if that means a 15 year amortization rate.
I am all for making a system that will work well. But, I would think that this test system has to be pretty darn accurate. I have not performed this test before, so am not real clear on the exact procedure. But I would think that the measurement would need to be closer to +/- a couple of feet, and not +/- a couple of hundred feet.
From what I am seeing in the posts here, the home units aren't really calibrated to an exact measurement. Isn't this required from the manufacturer in regards to the test?

William Linne
Virginia Rigging Services

[Hooknswoop 19]

If I could find an aircraft altimeter that is accurate, my test chamber would be operational.

From FXC:

MAINTENANCE

The FXC Model 12000 is a delicate instrument. To maintain its reliability the user must not:

* Drag it through sand
* Submerge it in any kind of liquid
* Alter, misuse, tamper with or strike the device
* The FXC Model 12000 must not be fired without a load.

If the user has any doubts as to the operational reliability of his FXC Model 12000, return it to FXC Corporation for a functional test. This is free of charge if under warranty.

FXC Corporation will perform a complete functional test (free of charge, if under warranty). Should any repair or replacement parts be necessary, FXC will advise the customer of costs involved before repairing the unit.

If a FXC Model 12000 is ever submerged in any kind of liquid, it must immediately be returned to FXC for complete disassembly and recalibration.

WARRANTY

Warranty is one (1) year from the date of manufacture for parts and labor. Warranty after servicing is one hundred twenty (120) days for parts and labor.

PERIODIC INSPECTION & TESTING

The FXC Model 12000 must be functionally tested in an altitude chamber ever 120 days. A physical inspection of the following items is also required:

* Free and easy movement of the Safety Lockout Knob
* Free and easy movement of the Altitude Control Knob and Altitude Indicator
* Power Cable fraying at the end fitting and torn and/or abraded cable coating near the Power Cable Housing
* Condition of Altitude Control Housing at all terminals and for kinks and/or excessive bending
* Condition of Power Housing

The FXC Model 12000 Revision ‘A’ thru Revision ‘G’ requires annual factory servicing, while Revision ‘J’ and later require factory servicing every two (2) years.
INSPECTION CRITERIA
FXC MODEL 12000
P/N 811-00042

INSPECTION INSTRUCTIONS

Using an FXC Altitude Test Chamber, PN 711-07146 or equivalent, set up and test per instructions provided. Assure that the test set altimeter is set at 29.92 in. Hg. The following functional tests must be accomplished:

Test 1. 65 fps - Must Fire
Test chamber rate of descent: 3900 fpm.
Altitude control setting: 1000 ft.
The unit MUST fire at 1000 ft. +/- 300 ft.

Test 2. 40 fps - No Fire
Test chamber rate of descent: 2400 fpm.
Altitude control setting: 1000 ft.
The unit MUST NOT fire at any time.

Test 3. Freefall Verification Test (175 fps)
Test chamber rate of descent: 175 fps.
Altitude control setting: 1000 ft.
The unit should fire at 1000 ft. +/- 300 ft.

If an FXC Model 12000 fails any of these tests, it should be sent directly to FXC Corporation or to an FXC authorized repair station for calibration.












PUBLISHED 24 MARCH 2003

Derek

[riggerrob 561]

If you consider the time to remove an FXC 12000, chamber test it, re-install it in the rig and complete the paperwork, you need to charge for at least a half-hour's labour = $20 to 30.

As for amortizing the cost of the official FXC test chamber, you need a lot of AADs to justify it. For example, my boss owns a dozen student rigs equipped with FXC 12000 AADs and he looked at the 15-year picture before deciding to purchase an official test chamber.
Most smaller DZs just skip the 120 day inspection because they cannot justify the cost of shipping their FXCs away for testing.

[mjosparky 3]

Quote

Before he gave US$3000 to FXC, my boss compared the cost of home-made, versus a factory-built test chamber. He concluded that new, aircraft quality instruments (3-needle altimeter and rate of climb), pump, valves and plumbing would cost almost US$3000, so he bought a genuine FXC test chamber.
I have used several home-made test chambers to test FXCs and altimeters and all of them were a pain to use. The biggest problem was getting a consistent seal between the top edge of the drum and the Plexiglas lid. Like many home-made devices, you needed as much insight as the builder to operate it.
I much prefer factory-built test chambers. The only advantage I can see to home-made test chambers is that you can use the entire 45 gallon drum and stuff the entire rig inside.
Even with a large home-made test chamber, I cannot see the point to going through the whole hassle without recently-overhauled, aircraft quality instruments.

If you have fxc 12000 in service on gear, they must be tested in a fxc chamber. With the FAA's new stance on AAD's you must follow the manufactures requirements. I have never seen a homemade chamber that has a rate of decent reading much less one that is adjustable.

My idea of a fair fight is clubbing baby seals

[PhreeZone 15]

I found it was pretty easy to do the math to figure out descent rate and as long as the vacumn chamber had an adjustable intake valve it was fairly easy to control the rate -/+ 10 fps.

I'm just glad that we got rig of the FXC's outof the studet gear so I don't have to mess with them any more.

Yesterday is history
And tomorrow is a mystery

Parachutemanuals.com

[webracer 0]

I have a unit I'd sell. It is a Scott automatic parachute opener tester, a bit smaller chamber than the FXC unit, but much more professional. Microprocessor controlled and programmable. Inside super-durable military style case, almost new. I have checked alitmeters and such in it. Just bought it because it was forsale. It has all the parts incase you wanted to make your own chamber. I'd be asking about $500 + shipping.
It is in top shape and hardly used.
Troy
[email protected]

Troy

I am now free to exercise my downward mobility.

[teason 0]

I'm looking for a manual for an older FXC tester PN#711-07135

It's the older version of the more modern 711-07135.

If anyone out there has one please PM me.

Thanks

Tim

I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet.

[masterrig 1]

I have an FXC-Test Chamber I'll to you. It's in excellent condition. PM me if, you are interested.


Chuck

[masterrig 1]

Quote

I have an FXC-Test Chamber I'll sell to you at far less than the 'new' price. It's in excellent condition. PM me if, you are interested.


Chuck

[riggerrob 561]

We have both an (ancient) FXC 8000 and an (8-year old) FXC 12000 test chamber.
Since we no longer use FXCs, both chambers are for sale.

[masterrig 1]

Quote

We have both an (ancient) FXC 8000 and an (8-year old) FXC 12000 test chamber.
Since we no longer use FXCs, both chambers are for sale.

____________________________________

No fair, Rob! I'm trying to sell mine!


Chuck