Glass Panel Retrofitting

Tarheel Pilot

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Tarheel Pilot
I was at the Sebring US Sport Pilot Expo, and there I saw a Cherokee 140 that was retrofitted with a glass panel, and honestly I just don't get it.

I mean a certified glass panel system like the G500 is going to cost about $14k, and that's just for the system. I don't even want to think about the cost of installing it.

Can someone explain why retrofitting an old bird with glass panel make sense? I mean to be (and this is just me), you could build an experimental aircraft that has a glass panel in it with the same amount of money you'd use to buy the Part 23 aircraft, and then retro fit it with the glass panel.

It's confusing to me. :confused:
 
I was at the Sebring US Sport Pilot Expo, and there I saw a Cherokee 140 that was retrofitted with a glass panel, and honestly I just don't get it.

I mean a certified glass panel system like the G500 is going to cost about $14k, and that's just for the system. I don't even want to think about the cost of installing it.

Can someone explain why retrofitting an old bird with glass panel make sense? I mean to be (and this is just me), you could build an experimental aircraft that has a glass panel in it with the same amount of money you'd use to buy the Part 23 aircraft, and then retro fit it with the glass panel.

It's confusing to me. :confused:

You get the panel right now, instead of 2000 work hours later. The aircraft plus glass panel is still way, way cheaper than a new airplane. And you can always yank the glass panel avionics and sell them separately if you have to rid yourself of the aircraft.

And some people love their aircraft s much they go way, way upside down on them. I saw a Cherokee 140 that was totally refurbished with a glass panel. When asked how much he spent, the guy said he stopped counting at $40K.
 
OK, assume you can't build your own airplane, or you don't want to.

You have an airplane you like, but you want some additional capabilities. You can either go buy another airplane with those capabilities, or you can add them yourself.

I've got a 20 year old sports car that I bought for $3500. I've put $6,000 additional into it for maintenance and upgrades and could easily spend another 10K for other upgrades such as a supercharger or a race-ready suspension.

For lots of people, an airplane isn't an investment. It's a cherished part of their life, and reflects the person in very specific ways. They'd no more part with it voluntarily than they would their child.
 
I've got a 20 year old sports car that I bought for $3500. I've put $6,000 additional into it for maintenance and upgrades and could easily spend another 10K for other upgrades such as a supercharger or a race-ready suspension.

You put 6 grand into that Miata! Damn, I'm not racing you unless I've got the sports bike.
 
I was at the Sebring US Sport Pilot Expo, and there I saw a Cherokee 140 that was retrofitted with a glass panel, and honestly I just don't get it.

I mean a certified glass panel system like the G500 is going to cost about $14k, and that's just for the system. I don't even want to think about the cost of installing it.

Can someone explain why retrofitting an old bird with glass panel make sense? I mean to be (and this is just me), you could build an experimental aircraft that has a glass panel in it with the same amount of money you'd use to buy the Part 23 aircraft, and then retro fit it with the glass panel.

It's confusing to me. :confused:

You want to fly an SVT plane because you recognize the huge safety margin and market desirability it buys you. You own a Cherokee 140 that does exactly what you need a plane to do like give primary and instrument instruction. What is the cheapest way to get into the plane you want with SVT?

What it does is modernizes and revitalizes an old but solid airframe very cost effectively. If you question the sense in this type of upgrade, I'm sure there is an office at the Pentagon that can explain it to you because they have been doing it for a long time.
 
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also - if you have questionable instruments and want to replace them all and start from scratch, the cost of installing a basic aspen glass system is about the same as replacing your 6 pack with high quality instruments.

The basic aspen PFD is 6k
 
Can someone explain why retrofitting an old bird with glass panel make sense?

Can you explain to me why aircraft ownership makes sense for someone who flies for recreation? After all, renting a beater from time to time would be far less expensive.

If you can understand why someone would spend a ridiculous amount of money to own and operate their own aircraft in the first place, why are you shocked that they might spend additional dollars on their airplane that don't make economic sense?
 
Can you explain to me why aircraft ownership makes sense for someone who flies for recreation? After all, renting a beater from time to time would be far less expensive.

If you can understand why someone would spend a ridiculous amount of money to own and operate their own aircraft in the first place, why are you shocked that they might spend additional dollars on their airplane that don't make economic sense?

Well I guess in my mind, it'd just make more sense to build an aircraft to the specifications that you want, rather than paying the same amount of money to only get half of what you want.

Like me, I'm going to build an RV-12 so that I can have a full glass panel aircraft with an EFI engine that runs on the same gas I put into my car.

How much would it cost for me to do the same to a Piper Cherokee?
 
You put 6 grand into that Miata! Damn, I'm not racing you unless I've got the sports bike.

That was mostly suspension work and tires and leather seats and... I'm really still waiting to do other things to make it fast fast... I'm debating how far I want to let it go from stock.
 
Well I guess in my mind, it'd just make more sense to build an aircraft to the specifications that you want, rather than paying the same amount of money to only get half of what you want.

Like me, I'm going to build an RV-12 so that I can have a full glass panel aircraft with an EFI engine that runs on the same gas I put into my car.

How much would it cost for me to do the same to a Piper Cherokee?

It never makes sense to build a plane to fly. It takes too long. You build a plane because you want to build a plane. If you want an RV, buy one someone else built, they're available cheaper than building. If you want a specific & uncommon driveline, buy one that doesn't have an engine.

Problem with the RV, you can't make money with it; the Cherokee you can rent out and give instruction in.
 
Well I guess in my mind, it'd just make more sense to build an aircraft to the specifications that you want, rather than paying the same amount of money to only get half of what you want.

Like me, I'm going to build an RV-12 so that I can have a full glass panel aircraft with an EFI engine that runs on the same gas I put into my car.

How much would it cost for me to do the same to a Piper Cherokee?
Well there you go. In your mind, you can't dream of doing anything other than building your own plane.

In my mind, building an aircraft is a non-starter. I don't have the room, I don't have the patience, and I don't know if I have the skill.

So, to answer your original question: Because different people have different desires, requirements, resources, and priorities, that's why.

To answer your current question (How much would it cost to get a comparable Cherokee?), you could easily buy a decent steam-gauge Cherokee with an STC to use mogas for $30K. Put $35K of avionics in it, and you'd have one heck of a panel, and your budget is only as much as the kit cost of the RV-12. Take the money you'd spend on engine and avionics for the RV, and refurb the interior and/or repaint the Cherokee, and for the same price you're flying behind glass in a couple of months instead of the years it would take to build the RV.

Of course, there are a lot of reasons why this isn't a perfectly apples-to-apples comparison. The Cherokee won't have a brand-new engine, for one. On the other hand, the RV-12 is a light sport aircraft. Etc.
 
Back before there was glass or GPS, there was an airline pilot based in the New York area who had a J-3 Cub rigged with a full Cat II ILS system including flight director and radar altimeter. Those pre-solid-state boxes took up the whole front 'pit -- strictly a one-person airplane. Did it make sense? Of course not. But that wan't the point. Sometimes you do things not because they make sense, but just because you can.
 
He didn't even need the FD or RA for CAT II in a Cub, just normal ILS gear.
 
He didn't even need the FD or RA for CAT II in a Cub, just normal ILS gear.

Appendix A to Part 91—Category II Operations: Manual, Instruments, Equipment, and Maintenance

1. Category II Manual
(a) Application for approval. An applicant for approval of a Category II manual or an amendment to an approved Category II manual must submit the proposed manual or amendment to the Flight Standards District Office having jurisdiction of the area in which the applicant is located. If the application requests an evaluation program, it must include the following:
(1) The location of the aircraft and the place where the demonstrations are to be conducted; and
(2) The date the demonstrations are to commence (at least 10 days after filing the application).
(b) Contents. Each Category II manual must contain:
(1) The registration number, make, and model of the aircraft to which it applies;
(2) A maintenance program as specified in section 4 of this appendix; and
(3) The procedures and instructions related to recognition of decision height, use of runway visual range information, approach monitoring, the decision region (the region between the middle marker and the decision height), the maximum permissible deviations of the basic ILS indicator within the decision region, a missed approach, use of airborne low approach equipment, minimum altitude for the use of the autopilot, instrument and equipment failure warning systems, instrument failure, and other procedures, instructions, and limitations that may be found necessary by the Administrator.
2. Required Instruments and Equipment
The instruments and equipment listed in this section must be installed in each aircraft operated in a Category II operation. This section does not require duplication of instruments and equipment required by §91.205 or any other provisions of this chapter.
(a) Group I. (1) Two localizer and glide slope receiving systems. Each system must provide a basic ILS display and each side of the instrument panel must have a basic ILS display. However, a single localizer antenna and a single glide slope antenna may be used.
(2) A communications system that does not affect the operation of at least one of the ILS systems.
(3) A marker beacon receiver that provides distinctive aural and visual indications of the outer and the middle markers.
(4) Two gyroscopic pitch and bank indicating systems.
(5) Two gyroscopic direction indicating systems.
(6) Two airspeed indicators.
(7) Two sensitive altimeters adjustable for barometric pressure, each having a placarded correction for altimeter scale error and for the wheel height of the aircraft. After June 26, 1979, two sensitive altimeters adjustable for barometric pressure, having markings at 20-foot intervals and each having a placarded correction for altimeter scale error and for the wheel height of the aircraft.
(8) Two vertical speed indicators.
(9) A flight control guidance system that consists of either an automatic approach coupler or a flight director system. A flight director system must display computed information as steering command in relation to an ILS localizer and, on the same instrument, either computed information as pitch command in relation to an ILS glide slope or basic ILS glide slope information. An automatic approach coupler must provide at least automatic steering in relation to an ILS localizer. The flight control guidance system may be operated from one of the receiving systems required by subparagraph (1) of this paragraph.
(10) For Category II operations with decision heights below 150 feet either a marker beacon receiver providing aural and visual indications of the inner marker or a radio altimeter.
(b) Group II. (1) Warning systems for immediate detection by the pilot of system faults in items (1), (4), (5), and (9) of Group I and, if installed for use in Category III operations, the radio altimeter and autothrottle system.
(2) Dual controls.
(3) An externally vented static pressure system with an alternate static pressure source.
(4) A windshield wiper or equivalent means of providing adequate cockpit visibility for a safe visual transition by either pilot to touchdown and rollout.
(5) A heat source for each airspeed system pitot tube installed or an equivalent means of preventing malfunctioning due to icing of the pitot system.
3. Instruments and Equipment Approval
(a) General. The instruments and equipment required by section 2 of this appendix must be approved as provided in this section before being used in Category II operations. Before presenting an aircraft for approval of the instruments and equipment, it must be shown that since the beginning of the 12th calendar month before the date of submission—
(1) The ILS localizer and glide slope equipment were bench checked according to the manufacturer's instructions and found to meet those standards specified in RTCA Paper 23–63/DO–117 dated March 14, 1963, “Standard Adjustment Criteria for Airborne Localizer and Glide Slope Receivers,” which may be obtained from the RTCA Secretariat, 1425 K St., NW., Washington, DC 20005.
(2) The altimeters and the static pressure systems were tested and inspected in accordance with appendix E to part 43 of this chapter; and
(3) All other instruments and items of equipment specified in section 2(a) of this appendix that are listed in the proposed maintenance program were bench checked and found to meet the manufacturer's specifications.
(b) Flight control guidance system. All components of the flight control guidance system must be approved as installed by the evaluation program specified in paragraph (e) of this section if they have not been approved for Category III operations under applicable type or supplemental type certification procedures. In addition, subsequent changes to make, model, or design of the components must be approved under this paragraph. Related systems or devices, such as the autothrottle and computed missed approach guidance system, must be approved in the same manner if they are to be used for Category II operations.
(c) Radio altimeter. A radio altimeter must meet the performance criteria of this paragraph for original approval and after each subsequent alteration.
(1) It must display to the flight crew clearly and positively the wheel height of the main landing gear above the terrain.
(2) It must display wheel height above the terrain to an accuracy of plus or minus 5 feet or 5 percent, whichever is greater, under the following conditions:
(i) Pitch angles of zero to plus or minus 5 degrees about the mean approach attitude.
(ii) Roll angles of zero to 20 degrees in either direction.
(iii) Forward velocities from minimum approach speed up to 200 knots.
(iv) Sink rates from zero to 15 feet per second at altitudes from 100 to 200 feet.
(3) Over level ground, it must track the actual altitude of the aircraft without significant lag or oscillation.
(4) With the aircraft at an altitude of 200 feet or less, any abrupt change in terrain representing no more than 10 percent of the aircraft's altitude must not cause the altimeter to unlock, and indicator response to such changes must not exceed 0.1 seconds and, in addition, if the system unlocks for greater changes, it must reacquire the signal in less than 1 second.
(5) Systems that contain a push-to-test feature must test the entire system (with or without an antenna) at a simulated altitude of less than 500 feet.
(6) The system must provide to the flight crew a positive failure warning display any time there is a loss of power or an absence of ground return signals within the designed range of operating altitudes.
(d) Other instruments and equipment. All other instruments and items of equipment required by §2 of this appendix must be capable of performing as necessary for Category II operations. Approval is also required after each subsequent alteration to these instruments and items of equipment.
(e) Evaluation program —(1) Application. Approval by evaluation is requested as a part of the application for approval of the Category II manual.
(2) Demonstrations. Unless otherwise authorized by the Administrator, the evaluation program for each aircraft requires the demonstrations specified in this paragraph. At least 50 ILS approaches must be flown with at least five approaches on each of three different ILS facilities and no more than one half of the total approaches on any one ILS facility. All approaches shall be flown under simulated instrument conditions to a 100-foot decision height and 90 percent of the total approaches made must be successful. A successful approach is one in which—
(i) At the 100-foot decision height, the indicated airspeed and heading are satisfactory for a normal flare and landing (speed must be plus or minus 5 knots of programmed airspeed, but may not be less than computed threshold speed if autothrottles are used);
(ii) The aircraft at the 100-foot decision height, is positioned so that the cockpit is within, and tracking so as to remain within, the lateral confines of the runway extended;
(iii) Deviation from glide slope after leaving the outer marker does not exceed 50 percent of full-scale deflection as displayed on the ILS indicator;
(iv) No unusual roughness or excessive attitude changes occur after leaving the middle marker; and
(v) In the case of an aircraft equipped with an approach coupler, the aircraft is sufficiently in trim when the approach coupler is disconnected at the decision height to allow for the continuation of a normal approach and landing.
(3) Records. During the evaluation program the following information must be maintained by the applicant for the aircraft with respect to each approach and made available to the Adninistrator upon request:
(i) Each deficiency in airborne instruments and equipment that prevented the initiation of an approach.
(ii) The reasons for discontinuing an approach, including the altitude above the runway at which it was discontinued.
(iii) Speed control at the 100-foot decision height if auto throttles are used.
(iv) Trim condition of the aircraft upon disconnecting the auto coupler with respect to continuation to flare and landing.
(v) Position of the aircraft at the middle marker and at the decision height indicated both on a diagram of the basic ILS display and a diagram of the runway extended to the middle marker. Estimated touchdown point must be indicated on the runway diagram.
(vi) Compatibility of flight director with the auto coupler, if applicable.
(vii) Quality of overall system performance.
(4) Evaluation. A final evaluation of the flight control guidance system is made upon successful completion of the demonstrations. If no hazardous tendencies have been displayed or are otherwise known to exist, the system is approved as installed.
4. Maintenance program
(a) Each maintenance program must contain the following:
(1) A list of each instrument and item of equipment specified in §2 of this appendix that is installed in the aircraft and approved for Category II operations, including the make and model of those specified in §2(a).
(2) A schedule that provides for the performance of inspections under subparagraph (5) of this paragraph within 3 calendar months after the date of the previous inspection. The inspection must be performed by a person authorized by part 43 of this chapter, except that each alternate inspection may be replaced by a functional flight check. This functional flight check must be performed by a pilot holding a Category II pilot authorization for the type aircraft checked.
(3) A schedule that provides for the performance of bench checks for each listed instrument and item of equipment that is specified in section 2(a) within 12 calendar months after the date of the previous bench check.
(4) A schedule that provides for the performance of a test and inspection of each static pressure system in accordance with appendix E to part 43 of this chapter within 12 calendar months after the date of the previous test and inspection.
(5) The procedures for the performance of the periodic inspections and functional flight checks to determine the ability of each listed instrument and item of equipment specified in section 2(a) of this appendix to perform as approved for Category II operations including a procedure for recording functional flight checks.
(6) A procedure for assuring that the pilot is informed of all defects in listed instruments and items of equipment.
(7) A procedure for assuring that the condition of each listed instrument and item of equipment upon which maintenance is performed is at least equal to its Category II approval condition before it is returned to service for Category II operations.
(8) A procedure for an entry in the maintenance records required by §43.9 of this chapter that shows the date, airport, and reasons for each discontinued Category II operation because of a malfunction of a listed instrument or item of equipment.
(b) Bench check. A bench check required by this section must comply with this paragraph.
(1) It must be performed by a certificated repair station holding one of the following ratings as appropriate to the equipment checked:
(i) An instrument rating.
(ii) A radio rating.
(2) It must consist of removal of an instrument or item of equipment and performance of the following:
(i) A visual inspection for cleanliness, impending failure, and the need for lubrication, repair, or replacement of parts;
(ii) Correction of items found by that visual inspection; and
(iii) Calibration to at least the manufacturer's specifications unless otherwise specified in the approved Category II manual for the aircraft in which the instrument or item of equipment is installed.
(c) Extensions. After the completion of one maintenance cycle of 12 calendar months, a request to extend the period for checks, tests, and inspections is approved if it is shown that the performance of particular equipment justifies the requested extension.
 
The basic aspen PFD is 6k

Without labor to install it.

A replacement gyro in a standard six-pack is $350. And the shops are awash in yellow-tagged ones in shops where they have a solid string of folks upgrading to glass.

Just pointing out... that you can keep a six-pack running, *darn* cheap right now.
 
Without labor to install it.

A replacement gyro in a standard six-pack is $350. And the shops are awash in yellow-tagged ones in shops where they have a solid string of folks upgrading to glass.

Just pointing out... that you can keep a six-pack running, *darn* cheap right now.

True, however new parts are quite expensive if 'new' is what you are going for.
 
He didn't even need the FD or RA for CAT II in a Cub, just normal ILS gear.
I believe you're thinking of the so-called "Category A" authorization described in 91.193, not regular Cat II, but he chose to put all the Cat II gear in anyway, again, probably just because he could, or maybe because that's what he had in his 707 or whatever and that's what he was used to having. Also, this was a long time ago, and may have been before 91.193 was written.
 
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It isn't always about cheap. An aircraft is an emotional investment.

I can't imagine renting aircraft. They look beaten up, you can't go anywhere, you can't always fly when you want, and you never know who the last guy was or what bone-headed thing he did with the aircraft.
 
Appendix A to Part 91—Category II Operations: Manual, Instruments, Equipment, and Maintenance

1. Category II Manual <snip>
The Administrator may issue a certificate of authorization authorizing deviations from the requirements of §§91.189, 91.191, and 91.205(f) for the operation of small aircraft identified as Category A aircraft in §97.3 of this chapter in Category II operations if the Administrator finds that the proposed operation can be safely conducted under the terms of the certificate. Such authorization does not permit operation of the aircraft carrying persons or property for compensation or hire.
 
I believe you're thinking of the so-called "Category A" authorization described in 91.193, not regular Cat II, but he chose to put all the Cat II gear in anyway, again, probably just because he could, or maybe because that's what he had in his 707 or whatever and that's what he was used to having. Also, this was a long time ago, and may have been before 91.193 was written.

I believe it, I worked on a Supercub that had an HSI, RMI, KNS-80 and the rest of a Silver Crown stack.
 
also - if you have questionable instruments and want to replace them all and start from scratch, the cost of installing a basic aspen glass system is about the same as replacing your 6 pack with high quality instruments.

The basic aspen PFD is 6k

I think the advertised price on an Aspen is $12K installed.:rolleyes: So, unless they make a special version for the experimental crowd that you can install yourself, I would bet you won't get one much under $11K installed. :eek:
I can tell you for a 421 it was $16K installed. ;)
 
I think the advertised price on an Aspen is $12K installed.:rolleyes: So, unless they make a special version for the experimental crowd that you can install yourself, I would bet you won't get one much under $11K installed. :eek:
I can tell you for a 421 it was $16K installed. ;)

It costs 5k to install a basic PFD? I was thinking lower.. but I don't know jack about glass panel installs.
 
It costs 5k to install a basic PFD? I was thinking lower.. but I don't know jack about glass panel installs.

I'm not sure how they break it down, but look at the ads in TAP, the big shops usually list an installed price on major items. And $12K seems to be the advertised deal on Aspen, I figure those are pretty good prices to shop against your local avionics shops. I also figure the final bill will be higher than the advertised price, but after 25 years in the car business, I am a little cynical about price advertising. :dunno:
 
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