Autopilot Wiring & Setup Problems, Plus Needle Ball & Airspeed Instruments

by Michael J. “Mick” Kaufman
Published in Midwest Flyer – Dec 2016/Jan 2017

There are strange things done in the midnight sun.” This is the first line of the poem, “The Cremation of Sam McGee,” written by Robert W. Service, which makes me think of some of the installations of avionics I have seen in aircraft in recent years. In this issue of Midwest Flyer Magazine, my column will cover some recent avionics installation errors that I have experienced, along with some tips that will help the instrument pilot flying hard IFR without an autopilot and without state-of-the-art avionics.

If you are a regular reader of my column, you know that I refer to the autopilot as “George,” and you may have seen some of my advice and warnings on flying IFR in an airplane that recently came out of the shop, or if you had never flown that particular aircraft before. I am not trying to undermine the mechanics or avionics technicians, but we are all human, just as pilots are, and mistakes can happen.

I recently had a call from a pilot named “Charles,” who was having difficulties with his autopilot. We scheduled a date to fly, and Charles arrived with a beautiful Cessna 206, which had a King KAP-140 autopilot, Garmin 530 Navigator, and a six-pack of instruments. Before we went flying, we sat down and discussed a plan of action with the first sortie being a check out of George and the equipment installation. The next thing we did was ground session, so Charles could learn how to set up and operate his autopilot, followed by a second sortie flight.

During our preflight discussion, I came to the conclusion that Charles was a very accomplished pilot even though we had never flown together before. But “George,” the auto-pilot, had some issues.

After departure from the Eagle River, Wisconsin airport, I had Charles turn on the autopilot during the climb to check out the altitude preselect feature, and then the heading bug with a VOR radial intercept. Everything worked great to this point. George’s next task was to fly the ILS 09 approach to the Rhinelander, Wis. airport. We flew to the Rhinelander VOR, which was one of the initial approach fixes, then outbound for the procedure turn. We used GPS assist from the Garmin 530, and Charles guided George through the procedure turn using the heading bug, as there was no GPSS module installed in the aircraft. As we intercepted the final approach course and switched to the VLOC mode on the 530, all looked well. The autopilot was in the approach mode, the localizer and glide-slope were alive on the CDI, the glide-slope was above us, and the indicator on George said altitude hold on and glide-slope armed. As we approached the final approach fix, with a glide-slope intercept, the CDI needle remained at the top of the display; however the altitude light and the glide-slope armed light went out on the autopilot. The glide-slope light came on, and we proceeded down the glide-slope with a full up glide-slope indicator on the HSI. We realized this was not right, but to further diagnose George’s shortcomings, we decided to do a GPS approach to runway 27 at Rhinelander, which was an LPV approach. After intercepting the inbound course and crossing the intermediate approach fix (IF), the glide-slope needle came alive with the needle showing the slope above us. We had switched our input on the autopilot earlier and re-engaged the approach mode.

The King KFC-225 and KAP-140 require separate inputs for analogue and digital streams. There is normally a message light on the Garmin that tells us to do this, but it did not appear. George now showed all the correct indications – approach mode, altitude hold, glide-slope armed – but as we approached the glide-slope intercept point, nothing happened. The HSI glide-slope indicated we should fly up, and George flew the approach, but never descended. It became obvious that there would be no more training done that day, as George would need to see the doctor. I drew a simple wiring diagram for Charles to take to the avionics shop to explain the problem.

After reading the adventure of “George the autopilot,” what did we learn? It reinforces my comment of never flying IFR in an aircraft that just came out of the shop. In this case, the aircraft was flying like this for some time, and Charles suspected something was wrong.

If you see an abnormality or something that does not seem right, get a flight instructor to help, who is very familiar with your equipment. Accept the fact that these interfaces with different manufacturers’ equipment are difficult for any avionics shop.

Before leaving the autopilot topic, I would like to again give a warning to pilots who have the following equipment combination, as I am not sure whether the situation has been addressed and corrected by the manufacturers:

King KFC-150 Autopilot Garmin 430 or 530 with WAAS Altitude Pre-select Module Electric Trim

I have written about this before, and even notified the FAA that this could be a deadly combination for an unsuspecting pilot. This is a design flaw and not an avionics shop error, which several other instructors in our Beechcraft training program and I have documented in numerous different aircraft so equipped.

While maneuvering at approach airspeed and intercepting the final approach course on an ILS approach when switching to VLOC mode (auto/manual), the autopilot will see the glide-slope needle come alive, disconnect the altitude function on the autopilot, and attempt to climb, thus stalling the aircraft. Should this happen to you, disconnect the autopilot immediately; you can expect the aircraft to be extremely out of trim.

In my last column in Midwest Flyer Magazine, I wrote about flying basic instruments using VOR, ILS and the six-pack. I also made reference to an article published by the National Transportation Safety Board (NTSB) on a study done comparing the six-pack with a glass cockpit. I am still doing some research on my own to make some better conclusions of the study, and reviewing some other studies, as well.

The results of the NTSB study showed an almost double fatal accident rate with glass panels: “Of the 266 total accidents looked at, conventional aircraft had 141 accidents with 23 (16%) of them being fatal. Of the 125 accidents involving glass cockpit aircraft, 39 (31%) of those were fatal.” I will present additional facts in the next issue of Midwest Flyer Magazine.

Emergency Situations Due To Equipment Failure & How To Survive In IMC

If you have followed my column in previous issues, you already know I am a “tech guy” and love to fly new advanced equipment, and evaluate it for a future purchase for my own aircraft. On the flight instructor side, I often shake my head when I see pilots spend thousands of dollars on equipment, which is worthless in my opinion, because there is little benefit and they never get training on how to use it. I have decided to devote the balance of this issue to emergency situations due to equipment failure and how to survive in instrument meteorological conditions (IMC).

As pilots, we can evaluate the equipment in our aircraft and make our equipment more redundant. In years past with steam gauges and no GPS, we practiced partial panel approaches using “Needle Ball & Airspeed.” I have developed my own technique for the procedure sometimes called a “No Gyro Approach,” which I will share at the end of this article, as this may be the last resort for you in some cases.

If you have an instrument six-pack, the most likely component failure is the “vacuum pump.” This may be overcome by installing a “Precise Flight” standby vacuum system, or better yet, a wet vacuum pump as I have on my aircraft, as their failure rate is extremely low. Another option are “standby electric instruments.” If you have an all-electric airplane with a glass panel, you may think you are less likely to have an instrument failure. That is true, but when you do, it is far worse and the odds are against you.

Most glass panel aircraft are equipped with dual electrical systems (batteries and alternators), but don’t take that as total immunity to a total electrical failure. On a flight departing in low IMC, I declared an emergency and with fast thinking on my part and that of ATC, I survived what could have been a fatal accident. I had just departed Palo Alto, California for an IFR flight to Lake Tahoe and contacted San Jose Approach when the glass panel and everything electrical began to flash, and there was smoke in the cockpit. The only backup instrument was a peanut gyro that had its own battery. After declaring an emergency, the San Jose approach controller gave me vectors for intercept, altitudes, ILS frequency and the inbound course. I did not have a chart for the approach readily available, and my #1 job was flying the airplane. There is a lot to be said for prioritizing tasks…“Sully” can attest to that during his successful “Miracle On The Hudson” landing. My instruments continued to flash along with the radios, but held on until I broke out on the approach, and I shut off all electrical equipment and the master. As I touched down on the runway and rolled to a stop, the fire trucks and emergency equipment came up next to me. In conclusion, when the manufacturer changed avionics, a larger alternator was installed to handle the load, but the alternator bracket was not beefed up. I had flown this aircraft for over 30 hours with no problem, but the bracket finally bent under load and caused the alternator terminal to short out on the motor mount causing the arcing and smoke in the cockpit. Fast thinking, some luck on my part and a fast-thinking air traffic controller kept this from being a tragedy. I intentionally omitted the aircraft model for legal and liability reasons, but similar situations can occur at any time in any aircraft.

There are so many emergency situations that can occur, and we cannot prepare for all of them, but knowing your equipment well will make you better prepared.

The following scenario is for training purposes, and you may have equipment in your aircraft, which would dictate an easier procedure. For the purpose of the article, your equipment is the six pack of instruments required for IFR flight (vacuum attitude and heading indicator, electric turn coordinator), a VOR/ILS radio and no GPS. A vacuum pump failure occurs, and you realize you have lost your two gyros (attitude and heading indicator). Your knowledge of the useable systems and how to use them, now comes in handy. You remember from your instrument training that the magnetic compass has lots of errors and decide it is only useable in straight and level flight and easiest to use on headings of east and west. You also remember the turn coordinator and when on the mark you turn at 3 degrees per second. You have to keep cool and remember, “Job #1” is to fly the airplane (heading and altitude); navigation is “Job #2.” Your instructor taught you to fly “by the numbers,” so power settings and airspeed are still there even if pitch is not, and the support of the altimeter and vertical speed indicator, along with gear and flap configuration, are helpful in controlling the aircraft.

I always take some instrument covers with me when flying IFR; I put them in my shirt pocket, so I do not have to hunt for them. It is important to cover failed instruments, as the brain will still scan them even though you told your brain they are not working. Now, we need to find an approach that will lead us to a nearby airport.

I prefer approaches with an inbound course as close as possible to east or west and try to avoid a north approach if at all possible. This is because of magnetic compass errors. There are three popular approaches to consider with the navigation equipment available – VOR, LOC and ILS. Known weather conditions may be an influencing factor to consider in your selection. Don’t try to rush the approach unless fuel or other negative factors exist. Try to fly the full approach unless ATC can give you long vectors or a “No Gyros Approach.” The more distance you have on the inbound course, the better you can tweak your heading and technique to follow your course. Now, it’s time to begin the approach by flying to the initial approach fix (IAF).

You can begin by working on your technique at this point and learn about the wind. From your early instrument training, you should remember to bracket your course and not do an “S-turn” across the radial. You will be tracking to the IAF. The magnetic compass should be used only in straight and level flight, and we should make all of our turns based on standard rate on the turn coordinator based on time.

For an example, let’s say we have an inbound course of 30 degrees to get to a VOR, and we have a negative wind correction factor. Our magnetic compass indicates 30 degrees; we are about 10 miles from the station and have a full left course deviation indicator (CDI). We think about this and decide to try a 30-degree intercept to center the CDI…doing a timed turn for 10 seconds to the left should make that happen. Being brisk on the roll in and roll out of the turn is the way to go and count to determine the 10 seconds instead of using the clock. I count the seconds I need on all turns of 45 degrees or less and use the second hand on the clock or electronic timer for larger turns.

Prior to reaching the IAF, I determine the direction, degrees of turn and the number of seconds to complete it, and proceed outbound for the procedure turn. After the turn is complete, I check the compass to see how I did and start the “5 Ts” – Turn, Time, Twist, Throttle, Talk. It is good procedure to go out as far as possible before making the procedure turn without exceeding the airspace protected for the approach. This will give you more time to tweak your heading while inbound on the approach, as bracketing is very important here to avoid “S-turns” across the course. Prior to reaching the final approach fix (FAF), the rest of the approach must be memorized, as a glance at the approach chart will lose your scan and concentration. Even with everything working and a full panel, I make all of my instrument student pilots memorize the remainder of the approach before reaching the FAF, and I take the chart away from them. If a pilot had learned by the numbers properly and know the numbers for the airplane, flying the vertical portion of this “No Gyros” approach will be easy. It’s all based on power settings and flap and gear configuration, and should not be done any different than when flying with a full panel.

There are more helpful tidbits on doing a partial panel approach than what I covered here. If I would have had a working GPS, flying the course would have been a lot easier and no different than if I had a very accurate heading indicator, which compensated for wind. Learn your systems and practice different scenarios before they occur.

In the next issue of Midwest Flyer Magazine, I will cover some autopilot preflight tests and things you should know about autopilot runaway.

Fly safe and stay warm as winter flying will have begun when you read this column.

EDITOR’S NOTE: Michael J. “Mick” Kaufman is a Certified Instrument Flight Instructor (CFII) and the program manager of flight operations with the “Bonanza/Baron Pilot Training” organization. Kaufman conducts pilot clinics and specialized instruction throughout the U.S. in a variety of aircraft, which are equipped with a variety of avionics, although he is based in Lone Rock (KLNR) and Eagle River (KEGV), Wisconsin. Kaufman was named “FAA’s Safety Team Representative of the Year” for Wisconsin in 2008. Email questions to captmick@me.com or call 817-988-0174.

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