Instrument Panel Overlay

LoPresti Cowl

Mitchell Gauges

Philips Landing Light Bulbs

Wingtip Landing Lights

I am interested in the panel overlay you installed. Could you comment on what you did, why you did it and the problems you encountered along the way?

It's a (.060"?) aluminum sheet that I bought from a fellow AYA member named Fred Kokaska. Fred gets the wild hair every once in a while and makes a run of them. He sends them cut-to-shape on the outline, and already cut for the standard instruments and screw holes. I think I paid him $135 for it 4 years ago.

It replaces the factory Royalite overlay, and installs the same way (it's captured between the back structural panel and the instrument mounting screws.) It requires a lot of customization of the panel to fit your airplane to account for intercom, headset plugs, alt static, etc, and definitely requires removal of all instruments.

I went a bit overboard on mine, dimpling the screw holes and using black oxide countersunk screws, and I countersunk the holes in the back panel to relieve it for the dimpled panel. I also had to spend a lot of time customizing the panel for my equipment, like alt static, headset plugs, intercom, autopilot switches, etc.

All in all, I have about 50 man-hours in it. The only thing I shoulda done is had it powdercoated instead of painting it. That would have saved 5 hours or so and the coating would have been more scratch and chip resistant.

Did the additional thickness of the overlay create any problems in mounting the instruments? I can't tell from the photograph if the instruments are recessed or if they are flush with the overlay.

No problems at all, they're pretty flush. The aluminum is not much more thicker (maybe thinner) than the Royalite overlay it replaced.

Was the original [underside] panel in such a condition that re-painting it would not have provided the same results?

The original structural panel is not suitable for a finish. It's ugly and has a ton of additional holes for various equipment that was factory, optional from the factory, or no longer installed. Peel off the Royalite on yours and you'll see what I mean; it would take much more work to clean that up than to simply put an overlay on it.

How do I get one of those aluminum overlays?

By contacting Fred Kokaska directly. Following is an email Fred sent to the Grumman Gang list in September 2001. Note that Fred is not a retailer, he's a guy like you and me trying to help out others:

Well, as I had promised many who asked me about the availability of the aluminum overlays at Blue Ash, there is indeed a new batch. I was expecting to have them upon return home but, like most good intentions, something totally unexpected goes wrong. The first clue was the weight of the package that contained the pilot's side panels. Just seemed heavy for the number of panels. Got out the ole micrometer and sure enough, the right side panels were made from .040 material and the left side panels were made from .050 thick material. The original plastic overlays are about .040 thick and produce a flush mate with the outer front surface of most instruments. The .050 would cause the instrument to be slightly sub mounted (.010) behind the overlay. The original aluminum overlay design was done with .032 material but we changed to .040 as .040 allows enough material thickness to allow 100 degree countersink flathead 6/32 screws to be used to support the instruments. The mounting holes do not come countersunk but there is enough material there if you chose to do so. Anyhow, after much hassle with the shop that produced them (first the denial phase, then the drawings must be wrong, (nope), then the "evil employee who no longer works here pulled the wrong stock" and finally "I guess we will re-run the job with the right material".)

After all the dust settled, the new batch (.040) arrived and are ready to ship.

Same old deal.

$125 if you catch me at a fly-in with some, or for $25 additional, ($150 total) I have a place that wraps them, insures the shipment, and UPSs them to your door step. Make sure to include a good "UPS" address.

Glad to respond on any install questions.

Fred Kokaska
13843 Recuerdo Dr.
Del Mar, Ca 92014
Home 858-755-8702
Work 858-332-5951

http://home.san.rr.com/n6dg

 

Concerning the LoPresti cowl mod: What actual difference - if any - could you detect in aircraft performance after installation?

Honestly, I can't say. I don't have engine instrumentation to give me the straight scoop on if it made any difference on the engine temps. Further, I did not do a direct back-to-back speed comparisons.

One thing I can say with confidence, though: after the install I had a consistent 100 RPM gain across the board in speed at the same throttle. I can fly the airplane over redline below 8000 feet, and at full throttle I can maintain redline up to 10-11000 feet burning less than 9 gph. I true out at 140 KTAS up to 8-9000 feet burning 10 gph, and if I let if run over redline (2800-2850) I'll true out at 145-147 KTAS. I tend to not like doing that though...<grin>.

If this from the cowl exclusively, I can't say for sure. Coincidental, though...?

I would think the cooler temp of the induction air would be beneficial

I think that's where the lion's share of any speed comes from...

None. If that NACA duct gets plugged, you better reach for the carb heat. Same as the original.

Mitchell Aircraft Products, Inc.
9703 South Route 12
Richmond, IL 60071

- Bob will MAIL Package (with STC).
- Gauges are 1.5 inch square.
- Module Frame has a ? inch flange for mounting.
- Lighting on SEPARATE circuit from gauges.
- Gauges are 75 mA each (ammeter is "0" draw).
- Approx. $500. for package of 4 gauges, including senders.

Further Info from The Grumman Gang mailing list, 07/19/03:

From: N976MSTiger*at*aol.com
Sent: Saturday, July 19, 2003 9:55 PM
Subject: MITCHELL GAGES

Anna asked where Mitchell gages could be obtained. My supplier went out of business but, Mitchell Aircraft Products, Inc at 910 Sherwood Drive, Suite 20, Lake Bluff, IL 60044, phone (847)615 2887, is still alive and selling.

My gauges were installed under stc 00811CH and consist of the following:

FM-211-682 Gauge Mount Assembly
D1-211-6106 75 Amp Ammeter
D1-211-6066 120_300F Oil Temp Gauge
D1-211-6090 0-100 PSI Oil Pressure Gauge
D1-211-6061 0-15 Fuel Pressure Gauge

The gauges are pre mounted and supplied with sensors for oil pressure and fuel pressure to be mounted outside the cabin and an stc covering AA-1, 1A, 1B, !C, AA-5, AA5A, and AA5B. Hope that answers your Question.

I don't know the price.

You're mistaken. I'd like to pipe in here on this, as I have done significant research on this issue before I bought my UPSAT (nee Apollo) GX-60. Here's the facts as I understand it:

- To shoot a GPS Approach in the GNS-430, you must have a current database in the unit.

- To shoot an approach in the GX-60 (or other UPSAT IFR approach (A1)-certified units) you must verify that the APPROACH you're about to fly is current in the existing database. This is easily done by comparing the plate's approach revision date with the revision of the IFR GPS database.

How can this be? Isn't this controlled by the TSO? You bet. It can be because Apollo was either very clever or stumbled into it by accident. In their approval for TSO certification of the unit:

- Garmin used wording in the flight manual saying the "database must be current", and
- Apollo used wording in the flight manual saying the "approach about to be flown must be current"

A subtle but significant difference. The flight manual is submitted as an integral part of the TSO approval process and is approved by the FAA.

Can I provide the documentation for this? Well, it's not really my responsibility to prove that Garmin screwed up. I certainly cannot provide a letter from Jane Garvey telling me it's OK. Further, I did this research 3 or so years ago. However, the FAA-approved GX-60 flight manual (http://www.upsat.com/dwnlds/gxdoc/gx60op.pdf) states (page 149):

"It is very important that the pilot verify that the approach data is current prior to use". Note no requirement to verify that the DATABASE is current prior to use.

What's the FAA-approved GNS-430 operations manual say? Well, I don't have a paper copy of their manual, but I invite anyone with the motivation to review the PDF file on their web site (http://www.garmin.com/manuals/gns430.pdf)

In fact, doesn't the GNS-430 DISABLE the approach functions unless the database is current? I've heard varying reports either way, but this sound almost Microsoft-like in its heavy handedness, if true. The GX-60 certainly does not do this.

Alternatively, can I find any FAA regulation that states, without any wiggling room, that TSO c129 A1 requires that "the database must be current"? Here ya go, have at it: http://www.faa.gov/avr/air/air100/129saved.doc The only thing I found in a cursory search was (a)(3)(x), which basically says an updateable navigation database with all the waypoints must be present.

Interestingly, AC 20-138 (http://ntl.bts.gov/data/ac20-138.pdf) was issued by AIR-130. It appears to be a "real-word" interpretation of TSO c129 and follows the general outline of the TSO. Paragraph 8.b.9 has a statement that says "Instrument approaches must be conducted using a current data base." However, there is no mention of this is the regulatory TSO. Of course, as it plainly states in the opening paragraph, "Like all advisory material, this advisory circular is not mandatory and does not constitute a requirement. As such, the terms "shall" and "must" used in this advisory circular pertain to an applicant who chooses to follow the method presented." Therefore, we go back to the TSO, where no mention of a requirement for a current database exists.

The manufacturer of the device has instructed me that this practice is acceptable (and encouraged), and this was a major selling point on my equipment decision. Everyone that inquires about it to UPSAT is told the same, and I gotta wonder, if not true, how come the FAA hasn't said something about it. A person from the local FSDO has told me the same on a casual (off the record) inquiry, and to the best of my research I agree with it. Frankly, even if it was not true I'm certainly not losing any sleep over it; it's not an unsafe practice.

At about this point, the only thing that can happen is if a bunch of Garmin owners become crybabies to their local FSDOs and the FSDO decides to adjust themselves and destroy it for EVERYONE. Seen it done, just about any times the local fox is invited into the chicken coop feathers fly.

As I've told others that have challenged me on it: Prove me wrong. Otherwise it's just spilt milk from disappointed competitors. Next time do your homework.

> Are we being told that last year's UPS database is OK for shooting today's approach? Let's hope not!

Why not? If you're flying on a 12/99 database, and the approach plate says that the last time the approach was changed was 09/96, why is it unsafe to use a 2-yr-old database to shoot this particular GPS approach? Are you afraid that the database card is degrading or something? As far as I know, they don't turn to curds because of an expiration date.

If your argument is that the old database might be wrong (which is one of the specious arguments I've gotten) then how can you be sure that the current database card is not wrong as well? Using that logic, EVERY database has potential errors waiting to smite the pilot so brazen as to use it to fly into an airport.

As I said, prove me wrong.

>>> I'm leaning towards buying a low-time Cheetah, if I can find one,
>>> adding the 180 HP engine, along with an avionics upgrade and
>>> hopefuly get a very good aircraft for less than I would pay for a
>>> fairly new, low-time Tiger.

Not a good idea.

First, while the cost difference between a Cheetah and a Tiger may seem immense enough to make it worth it, once you figure in the costs involved with the conversion you'll find it will cost you significantly more in the long run. In reality, the price differences between comparable Cheetahs and Tigers tend to stick around $10-15K; an engine conversion will easily exceed that.

Secondly, I'm only aware of one STC to install a Tiger engine in a Cheetah, and it requires that EVERYTHING be converted. This includes the engine and its associated attachments, the air intake (which is pretty much unavailable), the carburetor and intake system, the exhaust, the propeller, and the lower cowl complete (which is pretty much unavailable). In effect, everything forward of the firewall will need to be purchased, with a limited market for resale of your existing components.

Finally, and the really big deal-killer, the Cheetah airframe has a 200-pound lower gross weight than the Tiger airframe (2200 pounds versus 2400 pounds, respectively). This is primarily due to thinner-wall center spars on the Cheetah (why they did that, we have no clue). No engine conversion STC will be able to give you the Tiger's 2400 pound gross weight. Additionally, the Cheetah powerplant typically weighs about 50 or so pounds less than the Tiger engine, therefore not only will you not be able to have the Tiger's 200-pound extra gross weight, you'll *lose* 50 pounds usable because of the increase in powerplant weight.

And then when it's all said and done, you still have "a Cheetah" so its intrinsic value to a potential buyer does not rise to the value of a comparable Tiger.

The only time that a conversion such as this make any sense is to an existing Cheetah owner that has sunk considerable money into their airplane and refuses to sell it. Even then we try to talk them into selling it and buying a Tiger. In the end it just makes more sense. I strongly encourage you that if you goal is to have a Tiger, then buy one rather than converting a seemingly less-expensive Cheetah. You'll be much happier.

If you insist, here's the STC holder for the engine conversion. Feel free to give him a call for his opinion. Even better, join the Grumman Gang mailing list and ask current owners for yourself.

STCNumber SA1186NW (Click To Print Record)
Manufacturer TIGER AIRCRAFT (previously under American General)
MakeModel AA-5, AA-5A
TCNumber A16EA
Description Installation of a Lycoming O-360-A4K engine, a McCauley 1A170FFA/7563 or a Sensenich76EM8S10-0-60 thru -65 propeller and associated systems.
Status Amended 4/29/91
ACO NM-S
STCHolder Maynard C Crosby
P.O. Box 2361
Everett WASHINGTON 98204 UNITED STATES

However, can I make a suggestion? If the price of a Tiger is a bit daunting (and believe me, *I* don't understand why they're so high) then maybe a straight-up Cheetah is in order? How many times do you need to fill all four seats? The Cheetah makes a DAMN FINE two-seater airplane. Even better, there's a cost-effective STC to install the high-compression pistons in the O-320, and with the resulting 160hp the Cheetah isn't that much slower than a Tiger, while drinking 2+ less gph. If you don't need all four seats, but want an excellent 2 or 3 seater with tons of baggage room, a 160hp Cheetah's a good bird.

Also, look for a 1975 Traveler. The '75 got the Cheetah nose, gear, and wing speed mods, but keeps the Traveler's smaller tail feathers and name. It's a slightly faster Cheetah at a lower Traveler price.