May 2014- Last month, I discussed the history and maintenance of the PA-23 Apache. But as a longtime owner, I have some insights about flying and owning an Apache, too. This month I’ll focus on specific flying tips and the practical aspects of ownership of Piper’s original twin.
The PA-23 Apache has been around for over 50 years and during this time thousands of pilots experienced the Apache as their first twin and/or became multi-engine rated in this aircraft.
The Apache got a bad reputation, though—mostly due to accidents as a result of training aircraft that were not well maintained and in many cases flown by inexperienced instructors or students who did not fully understand the aircraft and tried to do the impossible. (A single engine go-around close to the ground is not a maneuver to be attempted in an Apache.)
A different mindset
When flying this aircraft, you should be thinking about what you will do if an engine fails on takeoff. Are you going to stop on the remaining runway, or fly on one engine?
Since there is only one hydraulic pump on the left engine, and hand pumping the gear up takes many strokes, it is best to retract the landing gear once the aircraft is solidly flying at sufficient speed to maintain flight on one engine.
Delaying gear retraction after takeoff and experiencing a left engine failure with the landing gear down can produce disastrous landing results with high sink rates. This aircraft will descend rapidly and will not fly far on one engine with the landing gear down—and if the flaps are also extended, the result will most likely be described as a crash. Flaps are never used for takeoff for this reason.
Safety
The Apache is a wonderful plane when it’s used as it was intended, but—like any aircraft—its limitations need to be absolutely respected. This aircraft should not be compared to a single engine aircraft, nor should it be flown as a single; it is a twin, and although the performance on one engine is poor, it is not so different than other low powered normally aspirated twins when loaded to maximum allowed weight.
The Apache and twin engine aircraft in general are about utility, not just the obvious safety factor of an additional engine. With a single engine aircraft, when the engine is not producing useful power, you are operating a glider. Even if a twin aircraft is descending with partial power (one engine inoperative), there are many options not available to a single engine aircraft with no power.
If maintained properly, and if the pilot is somewhat proficient on engine-out operations, twin engine aircraft—including the Apache—can offer a much safer experience than a single.
Although some Apaches were delivered from the factory with a single generator and a single vacuum pump, most Apaches had dual generators and dual vacuum pumps. This adds greatly to the safety of the aircraft especially in IFR operations, flights over water, or at night.
The feel of an Apache
The Apache flies like a large commercial aircraft with a solid and positive feel. In normal operations little or no rudder input is ever required and the elevator control is easily trimmed for any condition.
When the flaps and landing gear are operated there are pitch changes, but action is not extreme and is easily countered.
The rudder and elevator trim control located in the ceiling is awkward but similar to the Tri-Pacer and Cherokee—and although marked, some trial and error may be necessary to find the correct direction to move the trim.
The position of the flap and landing gear handles are different than some General Aviation aircraft, and it is something you have to be careful with and get used to.
The entry door
There is only one entry door on Apaches (and Aztecs), and it’s on the right side. Early advertisements for the Apache show the removal of the door so large items could be loaded in the aircraft, but this is not normally done. There is a large baggage door on the right side just aft of the flap.
One problem with the door is that its design can cause it to open inadvertently. The door on these aircraft is round at the top and curves around the top of the fuselage causing the natural airflow to lift the door into the open position.
When the door is open—especially at cruise speed—the door will open quite far and cause disturbed air over the right elevator and rudder making for reduced elevator control. Flaps extended seem to only aggravate the situation.
The aircraft is controllable with the door open but it can be a serious problem depending on when it happens and whether or not the pilot knows how to operate the aircraft with the door open.
Occasionally the door will open during takeoff right at rotation. If sufficient runway remains it is best to stop and then deal with the problem rather than take the problem into the air especially if you cannot easily return to land (for example, in IFR weather).
Dealing with an open door in-flight requires some talent and a different landing technique with very little flare. I have experienced this emergency more than once and have learned that maintaining 100 mph; putting the gear down early on approach; using no flaps for landing; and selecting an adequate runway to stop on, taking into account the extra landing speed are all necessary to make the best of a difficult situation.
It also helps to hold the door closed as much as possible but I have not been able to close the door in-flight. If you are an Apache pilot and have successfully closed the door while in flight, I would like to hear from you!
Later models of Aztecs have a redesigned door and latching mechanism but the majority of the Apache and Aztec line have problems with the door. Checking, lubricating and adjusting the door and latching mechanism as well as making sure the pilot (not a passenger) secures the door can prevent a problem from occurring.
Make certain that the door is properly secured before flying the aircraft, but should the door open in flight, always remember the cardinal rule: FLY THE AIRPLANE, then talk.
Performance
As an owner of a 160 hp Apache, I appreciate the utility of this aircraft and whenever I have considered making a change, I could not find an aircraft in a similar price range that does what this aircraft will do. Most flights I make are with one or two passengers and with much less fuel than full (108 gallon) fuel tanks.
I have based my aircraft at a 2,000 foot runway with trees at both ends, and this aircraft is safe to operate even at night at an airfield such as this. The accelerate-stop distance is something on the order of 1,700 feet due in part to the low Vmc speed of 72 mph (63 knots).
The climb performance on two engines is impressive as I regularly see more than 1,000 fpm ascents at climb power of 2,500 rpm and 25 inches of manifold pressure at moderate weights. This is not for a short time, but easily up to 5,000 feet or higher.
An actual climb rate of 1,000 feet per mile is no problem and has been confirmed by departure control many times. It’s not uncommon for me to hear “Radar contact; passing 5,000 feet, five miles from XX airport”—the airport I just departed from—in my headset.
Cruise performance is not stellar, but is acceptable considering what the aircraft does. Flying at 70 percent power I see an actual speed of 138 knots at 5,000 feet and the GPS proves this out over several flight legs and altitudes of 5,000 to 7,000 feet.
Another important fact about this aircraft is its altitude capability, and the utility that this offers is something that many single engine aircraft cannot duplicate. The aircraft easily climbs to 16,000 feet when not fully loaded and can take advantage of strong tailwinds; I have seen ground speeds approaching 200 knots several times at this flight level, making the climb and oxygen well worth it.
Economy and limitations
The Apache is a good time-builder and can be operated economically at 2,100 rpm and 21 inches of manifold pressure for a fuel burn of approximately 11 gph at 95 knots. Normal cruise—75 percent power—will produce 138 knots true airspeed using 18 gph.
Auto fuel (without alcohol) is a possibility with the Petersen STC and will further reduce fuel costs for Apache operators.
Flying this aircraft with all five seats filled (in 160 hp models) is a much different matter than when the Apache is lightly loaded. While safe to do so, it requires some careful planning and good flying techniques. The weight and balance must be calculated and checked to be within limits before anyone gets into the aircraft. Exceeding CG limits or weight is a serious matter.
It is not possible to fill the fuel tanks (108 gallons) and fill the cabin with people and be within limit. While the aircraft may fly, this plane—and all aircraft—can be very dangerous if overloaded or out of center of gravity limits, as wild things tend to happen quickly from which there may be no recovery.
A couple of limiting features of the earlier model Apaches (those below serial number 1870) were the maximum gear and flap speeds of 125 and 100 mph. The limits for later aircraft were increased (with additional strengthening) to 150 mph (gear) and 125 mph (flaps).
I had the misfortune of finding cracked spars on both flaps during an annual inspection shortly after I purchased my aircraft, probably as a result of previous pilots exceeding flap limit speeds. With a recommended final approach speed of 90 mph, it can be easy to exceed the 100 mph limit and damage the flaps which can cost $4,000 to repair.
Planning, planning and more planning
The aircraft takes a while to slow down, so some planning must be made prior to entering the downwind; reducing power incrementally rather than going to idle power will avoid shock cooling the engines.
An Apache is easy to fly, and even on one engine it is easy to fly when trimmed up, but expect some planning to make things work. Single engine climb performance at high gross weights is very minimal (240 fpm at gross weight at low altitudes) but can be obtained if the aircraft is loaded properly and flown using the proper technique, including maintaining speed (95 mph) accurately.
Practically speaking, this aircraft can be safely operated at weights at or near gross but to make it safe some savvy must be used. I once made a trip into Montrose, Colo. (5,700 MSL) and departed at 5 p.m. in July at full gross weight and the aircraft performed satisfactorily with a slow climb to 14,500 feet.
The mechanical condition of the aircraft is very important. A few low cylinders, a poorly functioning ignition system, inaccurate tachs or an airspeed indicator out of calibration can make the difference between a climb and a descent.
Unless there is a good reason to operate at low altitudes such as strong headwinds or weather, pick a cruising altitude that will allow a single engine drift down to a landing on an airport should it become necessary. Even if the aircraft is flown above the single engine ceiling, a moderate descent rate can buy you many miles of drift down to allow for a safe on-airport landing.
Practical aspects of ownership
As a longtime Apache owner, as well as an IA mechanic and ATP pilot, I have spent a considerable amount of money and time on maintenance even while being able to do a lot of the work myself.
Over the 24 years that I have owned an Apache I have spent more than two times the original cost of the aircraft just in material and parts to maintain the aircraft in good condition. This figure is not taking into consideration the cost of paint, avionics, windows and interior.
This is a Part 91 aircraft and overhauls are not required in most cases, but it’s a good idea to plan for the inevitable. An Apache is an old aircraft and you can expect that parts will need to be overhauled.
For example, the hydraulic power pack needs to be overhauled if the landing gear takes upward of one minute to retract, with the norm being around 20 seconds. The timely operation of the landing gear is important and while having the power pack or hydraulic components overhauled is expensive, it must be done. The proper and timely operation of the landing gear is critical to the safe operation of this aircraft.
Rubber fuel bladders also require replacement from time to time as fuel leaks will run down behind the engine exhaust area and are a safety issue that must be addressed.
Propellers—even the newest style “No-AD” props—need to be opened up and inspected on a regular basis. A five- to six-year inspection interval for propellers is appropriate even if it is not required by AD.
Heaters also need regular maintenance and certainly, you could say, “I will just not operate the heater,” but in reality, this is not a reasonable option especially if your window needs defrosting and you can’t see to land the aircraft.
It is imperative that you become involved in the maintenance of your aircraft or the expense of owning can be prohibitive. Purchase a maintenance manual and parts manual as they have a wealth of information—and they are required prior to attempting any maintenance.
Also important to the success of owning and operating an Apache is to become friendly with a mechanic that knows the aircraft well. A Piper Apache is not much different than other aircraft, but there are tricks and techniques that make life easier and prevent needless damage to the aircraft.
I recently had to replace the right propeller and throttle control cables as cleaning and lubricating didn’t correct the problem of stiff controls—and you should not operate any aircraft that you don’t have full control of. It was a time-consuming job taking in excess of 12 hours to remove and replace the cables and another example of what you can expect of an old aircraft.
As I reported in Part 1, there are hundreds of screws and dzus fasteners as well as bolts and nuts that attach panels, cowlings and sheet metal parts that must be removed in preparation for an annual inspection. And then these parts must be reinstalled after the inspection.
All of the parts need to be marked or noted as to the proper position, orientation and length of the screws, bolts, etc. and kept in separate containers simplifying the reinstallation process.
When there is a malfunction or evidence of a problem such as a leak, seep, or mag drop, address the situation right away; do not wait until the annual to correct a problem as usually the problem gets worse and can cost much more to repair. Deferring maintenance can quickly become a safety of flight issue.
If your budget does not allow a comfortable margin for maintenance then don’t plan on owning or operating this aircraft; over time, the odds are that it will require some expensive repairs or maintenance.
Buying an Apache
If you are planning to buy an Apache, keep in mind that deferred maintenance in the past can be an indication of maintenance expenses in the future. Check the aircraft logs and get a thorough pre-buy inspection prior to buying an Apache—or any aircraft.
While the list of ADs is quite lengthy on the PA-23 models, most have been complied with by now; however, some ADs may linger with the option of replacing a part to eliminate the reoccurring inspection. Replacement parts are an issue for all old planes and the parts you may need to terminate an inspection required by an AD may not be available in future years.
If you plan on flying your Apache much, buy an Apache that is up-to-date on maintenance as serviceable parts are getting more difficult to obtain for the Apache and downtime for maintenance can be measured in weeks, not days.
Check with insurance companies before you make any purchase as many insurance companies have declined to insure this or other older piston twin engine aircraft without regard to how much experience the pilot has.
I have been able to purchase liability and ground coverage insurance from only one company in the past five years at a reasonable annual rate ($1,000). Other quotes were excessive or coverage was not available. Tell the truth on the insurance application as incorrect information may void your insurance and you may be wasting your money for a policy on which you will never be able to collect.
Willing to work at it
Don’t let all of the caveats scare you away completely. Owning and operating an Apache can be a pleasant experience if you are willing to spend the time and money keeping the aircraft in good condition.
A partnership arrangement may be worthwhile if you choose your partners carefully and you all agree to share not only in the expense of maintenance but also the time needed to do the physical work. This is not an aircraft you can go out and fly, roll into the hangar and walk away from week after week.
If you are considering purchasing an Apache, fly in one, and then take the time to discuss ownership aspects with the owner. Pay very little attention to pilots who have only flown the plane a few hours 20 years ago, or those helpful individuals willing to give advice who have never actually flown an Apache.
The 160 hp models perform noticeably better than the 150 hp models especially on one engine. The later 160 hp models offer some worthwhile improvements such as the center stack radio rack, improved heating system, and fifth seat with higher gross weight and they are priced in the same range as the earlier 150 hp model.
While both the 160 and 150 hp Apaches can burn low cost auto fuel when STC approved (high octane for the 160 model), most auto fuels in the United States have alcohol added and this is strictly prohibited (and unsafe) for aircraft use. The 235 Apache was never approved for auto fuel, as it would not pass required tests for the STC.
A well-equipped Apache in good condition with modern avionics can be had for $50,000 to $60,000. Despite the maintenance concerns, that can be a real bargain for what it offers compared to a single engine aircraft in the same price range as the Apache offers utility, economy and safety.
Michael Berry, a former aircraft repair shop owner, is a multi-engine rated ATP (757/727). In addition, he’s a turbo jet flight engineer, an A&P/IA mechanic, airplane owner and 121 air carrier captain. Berry has 15,000-plus pilot hours. Send questions or comments to editor@www.piperflyer.com.
RESOURCES
Auto fuel STC
Petersen Aviation, Inc.
autofuelstc.com
Maintenance manuals
ATP
Phone (415) 330-9500
Email sales@atp.com
