September 2014- Q: Hi Steve,
I have a 1968 Arrow 180 and I am trying to determine the proper routing for the fuel hose between the electric fuel pump and the mechanical fuel pump. My current routing brings the hose under the engine mount tube where it makes a tight bend (radius) up to a 45-degree fitting on the mechanical pump.
The current placement makes it impossible to remove the lower oil filter screen without damaging the firesleeve. I would like to compare mine to other PA-28R-180 installations as I suspect the hose should route over the engine mount tube and then straight into the mechanical pump. Attached are pictures of my installation.
—Steve
A: Hi Steve,
This isn’t an unusual situation especially since the service and parts manuals from that era reveal almost nothing about hose routings. As long as the routing change doesn’t interfere with any moving parts, isn’t routed too close to exhaust pipes, and is secured to prevent abrasion and provide support, it’s my opinion that you are free to route the hose as required.
According to the preventive maintenance tasks listed in the FARs (Part 43, Appendix A, paragraph (c) 22), you as the pilot may replace prefabricated fuel lines. Since that is approved, it’s assumed that it’s also legal to unscrew the end fitting on your existing fuel line, reroute it, and reattach it to the fuel pump.
However, even though it’s legal, the line end—called a B-nut—must be torqued to the proper value during reinstallation. My advice is this: if you haven’t done a preventive maintenance task before, get your certified A&P mechanic to show you how the first time.
Savvy mechanics know to always take photos of an engine installation prior to disassembly or engine removal. These photos will usually be the only reliable guide to proper reinstallation.
Happy flying,
Steve
Q: Dear Steve,
Do you know if there is an STC for the replacement of the factory oil temp, oil pressure and fuel pressure cluster gauges in my PA-28? I have had no success while researching STCs.
At one time there was a company that rebuilt the existing factory gauges, but I have not been able to locate it. I would prefer a replacement for the originals, but need to find a resolution to the problem one way or another.
—Bill
A: Hi Bill,
You have a couple options. You can remove your existing instruments and send them to Air-Parts of Lock Haven for overhaul. In addition to overhaul and repair of instruments, Air-Parts of Lock Haven offers many other repair and overhaul services for various GA aircraft parts.
Another option you may want to explore would be installing a set of new modular instruments. I spoke with Bob at Mitchell Aircraft Products, and he told me that Mitchell will supply the paperwork required to submit to the local FAA Flight Standards District Office (FSDO) for a field approval of the installation of a set of Mitchell instruments.
Mitchell instruments are quality analog-type instruments and do have FAA PMA approvals for installation—but not for all airplane models. These high quality instruments can be configured to create a very good-looking display.
According to Ken, a Piper Flyer member who has installed Mitchell’s modular instruments, the finished instrument cluster is only slightly larger than the original Piper cluster which translates into very little metal cutting to complete the installation. A rough estimate of cost is around $1,000 for all six gauges, the required senders and the modular mount.
Although Ken and his mechanic were able to get their local FSDO to grant a field approval for this installation, it may not be so easy at your FSDO. Bob at Mitchell Aircraft Products told me there are three FSDOs that won’t grant field approvals; so if the Mitchell option is one you’re looking at, you and your mechanic need to contact your local FSDO to see if it’s willing to grant a field approval before you make the decision to go forward.
I recommend that you also look at other options that are already approved to replace what are known as the “primary” engine instruments, which are the oil pressure and oil temperature gauges and fuel quantity gauges. I replaced the original primary instruments in my Comanche by converting to three 2 1/4 inch round instruments from AeroSpace Logic when I completely redid my instrument panel.
This option would require you to cut new holes or enlarge the existing holes in your panel to accommodate the new gauges. You would also have to make some changes both forward of the firewall and under the panel to facilitate the installation.
List price for the three Aerospace Logic gauge kits (left and right fuel quantity gauge; fuel pressure/ammeter gauge; oil pressure/oil temperature gauge) is $2,242.
Lastly, if you’re in the mood to install a state-of-the-art engine management system, you have three options. All of these have displays that can be mounted in the panel space presently occupied by old analog instruments such as the tachometer, manifold pressure gauge and the small primary gauges.
In addition to replacing the gauges presently in your airplane, all of these systems provide normal alerting functions for low oil pressure, high CHT and low fuel states, for example. The more sophisticated ones can also be configured to warn of everything from increased carbon monoxide levels to landing gear unsafe conditions. Think of these units like a silent copilot who monitors everything and taps you on the shoulder when anything is abnormal.
Another important feature of engine management systems is data logging. This allows owners to study how their operation procedures affect parameters such as temperatures and fuel flows, for example. The data can be invaluable if a warranty claim is filed due to the premature failure of an engine or related components.
Three companies make these systems.
JP Instruments (also known as JPI) has been in the engine monitor business the longest. In addition to a series of small engine monitors, JPI also sells what it calls an Engine Management System under part numbers 900 Primary and 930 Primary.
Both JPI systems provide a clear display of all engine information that includes rpm, manifold pressure, percent of power, all EGT, all CHT, fuel pressure, oil pressure and temperature, left and right fuel quantity, volts and amps, fuel flow, outside air temperature and ground speed when interfaced with a GPS unit.
The 900 Primary and 930 Primary are FAA approved to replace the original equipment primary instruments. The JPI instrument kits include almost every part needed to complete the installation.
Ultra Electronics is another company that produces a sophisticated full-featured primary replacement engine management system. Its AuRACLE display simulates the look of analog gauges; to pilots used to needles on faces, this provides a familiar-looking picture. AuRACLE CRM2100 and CRM2101 systems require a panel cutout of 5.7 inches by 3.9 inches. This cutout can be located at the original location of the tachometer and manifold pressure gauges.
Electronics International produces what it calls a Glass Panel Engine Monitor, and it does so in two configurations. Both the MVP-50P, and the newest of these all-information displays—the CGR-30—are FAA approved for installation and replacement of primary instruments in almost every single and twin engine Piper airplane ever built, from the early 50 hp J-3 Cub up through the PA-60-700P pressurized Aerostar twin.
The MVP-50P is similar to the other what’s offered by Ultra Electronics and JPI, as its display is big; it measures 5.5 inches wide and 5.1 inches high.
The CGR-30P is unique since it provides all the same engine management and warning options as the MVP-50P but is mounted in a normal 3 1/8 inch instrument cutout. This eliminates the requirement to reconfigure the instrument panel (i.e., cut metal) in order to install a true state-of-the-art engine management and warning system. Just remove the original tachometer and slide the CGR-30P in the same space.
The least expensive options will be to work with your local FSDO to install a set of Mitchell primary replacement instruments, or to repair the existing parts with Air-Parts of Lock Haven. Digital gauges are an obvious upgrade, and ultra-sophisticated engine management systems are the top-of-the-line option. Your budget will help you decide.
Happy flying,
Steve
Know your FAR/AIM and check with your mechanic before starting any work.
Steve Ells has been an A&P/IA for 39 years and is a commercial pilot with instrument and multi-engine ratings. Ells also loves utility and bush-style airplanes and operations. He’s a former tech rep and editor for Cessna Pilots Association and served as associate editor for AOPA Pilot until 2008. Ells is the owner of Ells Aviation (EllsAviation.com) and the proud owner of a 1960 Piper Comanche. He lives in Paso Robles, Calif. with his wife Audrey. Send questions and comments to editor@www.piperflyer.com.
RESOURCES
Instrument overhaul
Air-Parts of Lock Haven
airpartsoflockhaven.com
Modular replacement instruments
Mitchell Aircraft Products, Inc.
mitchellproducts.com
Primary instrument replacement
AeroSpace Logic
aerospacelogic.com
Engine management systems
Ultra Electronics
ultra-auracle.com/auracle
Electronics International
buy-ei.com
JP Instruments
jpinstruments.com
