July 2012
This month, we’ve compiled some of the most useful tips from Q&As published in Piper Flyer over the last year. The questions and answers you’ll see here are abridged; refer to the original publication for complete information, including photos, drawings and company resources. —Eds.
SEPTEMBER 2011
Q: Dear Steve,
I just replaced the starter on my PA-28… again! The starter teeth didn’t disengage from the ring gear after the engine started. What’s the solution?
—Tired of Buying Starters
A: Dear Tired,
If all you burned up was the starter, you dodged a bullet. Bendix-type starters stick on Lycoming engines. There’s two reasons.
The first is lack of proper lubrication of the screw-shaft the Bendix assembly rotates on. Either your technician didn’t put a shot of silicone spray on the shaft at the last annual, or rain, dirt and airborne schmutz contaminated the front end of the shaft at the front bushing.
On my aircraft, I prevent contamination of the front end of the shaft and the bushing area by covering it with a bit of heavy-duty aluminum foil tape.
The second reason starters fail is because the starter solenoid fails to open after the start button or key is released.
You can purchase and install a “starter engaged” light that will give you a visual indication of a stuck starter. Or, you can call Texas Skyways and buy the company’s STC for this installation. Another alternative is to buy a new starter.
OCTOBER 2011
Q: Dear Steve,
Last week, the prop on my 1958 Tri-Pacer started rotating when I turned on the master switch during my preflight. My mechanic explained that the starter contactor had failed shut and told me that changing it is easy.
I think I did everything right but when I turned on the master switch, the prop started rotating again. My mechanic told me that I had screwed up the installation. Is he right?
—Prop Turning
A: Dear Prop,
Your mechanic is right. If the nuts that are tight against the metal can of the contactor are not prevented from turning while the nuts holding the wires are tightened, the contactor will fail.
Piper issued Service Letter 1116 on Dec. 12, 2008 that addresses this issue. It’s applicable on Piper aircraft from PA-18A Super Cubs through the latest PA-46R-350T Matrix, and includes turboprop aircraft such as the PA-42-1000 Cheyenne.
The letter spells out the procedures required to prevent contactor failures during installation. The large and small inner nuts—the ones against the barrel—must not be removed and must be prevented from turning during wire installation.
Don’t get discouraged. The fact that Piper printed and distributed this Service Letter proves you’re not the first person who improperly installed a contactor.
JANUARY 2012
Q: Steve,
I have an early model 1973 Cherokee Six 260. I’ve heard that if the selector leaks internally, I’ll lose fuel. How does this happen?
—Gas Be Gone
A: Dear Gas,
Piper Service Bulletins 376, 444, 571A, and 1198A have been generated to address fuel selector issues over the years. SB 444 spells out the details of replacing certain valves with improved valves.
FAA Airworthiness Directive 76-18-04 describes a simple test to determine if your fuel valve is leaking internally. Fill the fuel tanks; sump the selector valve quick drain three times to eliminate the possibility of air in the system; and start the engine and run it at 1,000 rpm with the electric fuel pump on.
With the engine running, turn the fuel selector to the “off” position and note the time. If the valve is not leaking, the engine will die before seven minutes passes. If it continues to run past the seven-minute limit, the valve is leaking internally.
AD 77-12-01 applies to Airborne Model 1H10, 1H16-1, 1H26-2, 1H26-3 or 1H26-4 model fuel selector valves. This leak test consists of turning the fuel selector handle to the “off” position; emptying the fuel in the selector by opening the selector sump drain; then closing the drain after fuel stops flowing. Wait at least three minutes, then again open the fuel selector sump drain and collect the contents.
If the fuel collected exceeds one-half fluid ounce this indicates the valve is leaking internally. If removing, cleaning and re-testing does not stop the leakage, the valve must be replaced.
Tim Henderson of Aero Accessories, Inc. in Gibsonville, N.C. said that the O-rings are most likely responsible for any internal leakage. These O-rings are widely available at aviation parts houses. One facility that overhauls fuel valves is Parker Hannifin in Naples, Fla.
FEBRUARY 2012
Q: Hi Steve,
I accidently whacked the windshield of my Pacer with the broom handle, and now I have a big crack radiating out from that hole. My mechanic told me that it’s okay
to sew up the crack with safety wire.
Is he kidding?
—Cracked
A: Dear Cracked,
He is correct. In Section 4, “Windshields, Enclosures and Windows” of Advisory Circular (AC) 43.13-1B, repairs are described. This AC says that when acrylic windshields or side windows are damaged, they are usually replaced “unless the damage is minor and a repair would not be in the field of vision.”
Under “Minor repairs” it says that if safety is not impaired, the crack may be repaired by drilling a hole at the end of the crack with a 1/8 inch or #30 drill. Next, drill a series of holes with a #40 drill. The recommendation for these holes is that they be spaced ½ inch from the edges of the crack, and also spaced ½ inch apart for the length of the crack. Brass safety wire is threaded through the holes to “sew” the crack together. Cover the repair with clear silicone sealant.
AC 43.13-1B, which is titled “Aircraft Inspection Repair and Alterations; Acceptable methods, techniques and practices,” not only outlines the safety wiring sewing minor repair, it also outlines a simple permanent repair.
The simple permanent repair goes like this: Stop drill the end of the crack with the 1/8 inch or #30 drill. Then use a hypodermic syringe and needle to fill the crack with a polymerizable two-part cement. The hole is plugged by soaking the end of a 1/8-inch acrylic rod in the cement and then inserting it into the hole. Let the repair dry for about 30 minutes and then trim off the end of the rod.
After the repair is dry, clarity can be restored by polishing.
APRIL 2012
Q: Dear Steve,
I just can’t seem to keep my feet under control while landing my Archer III in crosswinds. I have locked up the left brake—and scraped off hundreds of dollars’ worth of tire rubber—three times now. Do you have any suggestions?
—Gotta ‘nother flat one
A: Dear Flat One,
I think you have two problems. The first is a fear of losing control during crosswind landings. High speed on final causes you to touch down much farther down the runway than you should, which translates into heavy braking.
The rule of thumb for airspeed on final during normal conditions is 1.3 Vso. The bottom of the white arc on your Archer III airspeed indicator is 45 knots IAS. Applying the rule of thumb yields an over-the-fence target speed of 59 knots IAS.
It’s suggested that half the gust factor of a crosswind be added to the normal approach speed to arrive at a safe gusty wind approach speed. For instance, if the crosswind is 14 knots with gusts to 26, the gust factor is 12; add 6 to the 59 knots, and fly the approach at 65 knots.
According to the Information Manual, the demonstrated crosswind component for the Archer III you’re flying is 17 knots.
The Information Manual cites 66 knots IAS as the correct final approach speed (with flaps 40 degrees). Sixty-six knots turns out to be 1.3 times 50 knots, which is the speed at the bottom of the green arc on the airspeed indicator.
The other contributing factor could be confusion about which crosswind landing technique to use. The two most common are the crab/kick-out method and the sideslip to landing method. If you’re unsure of which method to use, or the one you’re using isn’t working, hire an instructor and practice.
Know your FAR/AIM and check with your mechanic before starting any work
Steve Ells has been an A&P/IA for 38 years and is a commercial pilot with Instrument and Multi-Engine ratings. Ells also loves utility and bush-style airplanes and operations. He served as Associate Editor for AOPA Pilot until 2008. Ells is the owner of Ells Aviation and the proud owner of a 1960 Piper Comanche. He lives in Paso Robles, Calif. with his wife Audrey. Send questions or comments to editor@www.piperflyer.com.
