Twin Commander 500 Shrike

Bob Hoover wowed airshow audiences for years with his aerobatic Shrike routine. Its capable...but watch the ADs.

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It takes a crowbar to separate image from reality with the big Commander twins-the image pitched by Rockwell Intl. in a blaze of promotional glory-and the one left by Bob Hoover in his airshow demo, hanging a Shrike on a prop and deadsticking it out of a loop.

When the image is pried away, what actually remains? Well, something not too far away from the Tough Bird notion of all the hype and promo. Time and again, Commander 500 series owners, in their letters and phone calls to us, talked about reliability and freedom from breakdowns as among the outstanding qualities of the airplane.

But potential buyers might figure its more appropriate to ask: How tough do owners have to be to support an expensive aircraft thrice orphaned by the factory, especially when knowledgeable maintenance shops are not legion? Not only that, but at present a serious storm cloud hovers over all the Twin Commanders: the specter of corrosion in the wing spar, which in 1991 led to an expensive recurrent AD, groundings, a fix priced somewhere up in low Earth orbit, and of course the inevitable lawsuits against the manufacturers.

History
The basic airframe of the Aero Commander was the concept of Ted Smith, long before he came up with the Aerostar. The first model 520 made its bow in 1952, predating the Piper Apache by two years and the Cessna 310 by three. After the 520 came various 560 models. But this article will focus on the straight 500 line and its offshoots.

The first plain-vanilla 500 came out in 1958. Aimed at competing with other light twins like the C-310 and Piper Aztec, it was equipped with relatively puny (for an Aero Commander) 250-HP powerplants. Priced at about $80,000, the first model Commander 500 in those days still represented a sizeable investment-some $8,000 more than a C-310 and about $24,000 more than an Aztec. This economy Commander had carbureted Lycoming engines that represented a move toward simplicity from the expensive, geared 295-HP GO-480s hung on the Commander 560. But the airframe and wing were identical: i.e., massive. By that, were talking about a machine with a wingspan nearly 50 feet long, a fuselage that stretches up to 37 feet (depending on the type of nose), with a vertical tail lofting 14.5 feet above the ground-all in a 6,000-pound (or heavier) gross package. Try to squeeze that in your average T-hangar.

In 1960, Aero Commander made its only switch from Lycoming and outfitted the 500A with 260-HP fuel injected Continental engines. These were supposed to put out an extra 10 horsepower each with fewer cubic inches. But this proved illusory, and experienced Aero Commander pilots agree that the 500A is not nearly as sprightly in the air as the 500, despite book figures to the contrary.

Covering all bets, however, the company also introduced a Lycoming-powered 290-HP 500B using three-bladed props, and raised the already stupendous gross weight by another 750 pounds to 6,750. Although the 500A went out of production in 1963, the 500B continued to 1965, when the 500U was brought out as a successor. Presumably, the U stood for the utility category rating bestowed on the aircraft with this minor model change.

Finally, in 1968 the 500S Shrike made its bow, and remained in production for more than a decade, with the line coming to an end in 1979. So the youngest 500S models out there are at least 10 years old. Rockwell Intl. and Bob Hoover worked their promotional magic to give a boost to Shrike sales, which rose to about 50 in 1973. But popularity (in terms of sales, at least) petered out after that.

Performance
Owners are universally humble about speed figures for the various 500 models. Pilots say they get 150 to 155 knots true out of the small-engine 500s, and anywhere from 160 to 180 knots from the 290-horse birds. When you figure that any big-engined Cessna 310, Baron or Aerostar will get another 20 knots or better without trying, it has to be conceded that blazing speed is not one of the Commanders redeeming qualities.

Range is another poor aspect of the Commanders. With 156 gallons usable, and burning 30-34 GPH, the 290-horse models will yield only 800 nautical without reserves-nothing to write home about. With a full load of fuel, dont count on carrying more than two to three passengers, depending on the equipment load.

Handling
Big and solid and stable are the key words here. And anyone whos seen Bob Hoover do touchdowns alternately on the left and right wheels in the Shrike might expect that control authority can be added to the list. Just for fun, we asked him if he could do the same airshow maneuvers in other twins like a Baron or C-310, or whether the Shrike had some exclusive qualities that permitted him to fly that kind of audacious repertoire in it alone. Although Hoover stopped short of saying he couldnt do the same maneuvers in the other aircraft, he noted that the Shrike was stressed for more Gs (it can pull 4.4 Gs positive thanks to its utility category rating). But wed heard that he really finessed the bird through the dramatic routine with fairly low G loadings, and he conceded that his display is flown within a two-G profile.

But pondering the matter a moment, he volunteered one elusive Shrike quality none of the other aircraft possessed. It shows up-get this-at zero airspeed with full power in the vertical. Where most other aircraft would have a tendency to torque in this position, said Hoover, the Shrike holds true because of the tail dihedral, and its ability to hold aileron effectiveness down to no speed at all.

From the sublime to the prosaic, controllability has more practical everyday benefits: Since the aircraft enjoys such surprisingly low stall speeds for so heavy a machine-59 knots dirty for the Shrike, for example-and has such good low-speed handling-a Vmc of 65 knots-pilots credit the airplane with being a good short-field bird. The biggest ground-handling idiosyncrasy stems from the use of hydraulic nosewheel steering in the aircraft. Pilots must learn to taxi and start the takeoff roll by making judicious taps on the brake pedals to steer the aircraft. Thats because the first portion of travel on the pedals works the nosewheel steering, and the remainder triggers the brakes.

Comfort, loading
Owners like to boast that the Commanders hold seven people on board-five in back. Getting in and out is pleasant, too, since theres (normally) a private door for the pilots in front, one for the passengers in back, and another for the baggage a bit farther rearward. Ease of access to the cabin, in fact, and the resulting high customer acceptance was one of the factors that led Palm Beach Aviation in Florida to operate a fleet of half a dozen Commander 500s around the Caribbean, according to Ed and Kathy Condon.

Drawbacks are a high, resonant noise level in the cabin (pulling back the RPM helps, but does nothing for speed), and a dark, cave-like rear compartment, thanks to the overhanging wing and engine nacelles. Noise is worst in the center seats alongside the prop tips. A positively giant baggage compartment in the rear of the fuselage will swallow golf clubs easily and hold up to 350 pounds structurally, but dont expect to get at it during the flight. A generous CG envelope makes the aircraft almost impossible to load out of tolerances, owners note.

Safety
Our check of accidents over a five year period showed a remarkably low fatal accident tally of only four. And two of those involved bizarre downings at sea in the Caribbean under unusual circumstances. The other two occurred when obstacles were hit during landing approaches. On one, the aircraft hit some trees during an IFR ADF approach; the other occurred in VFR flight.

Among nonfatal accidents, as with so many aircraft types weve tallied over the years, by far the most grief involved landing gear problems. The biggest category for the Commander 500 series was gear collapses, followed by inadvertent gear-up landings and inadvertent retraction while on the rollout or takeoff roll, or during taxi. Although theres a gear handle latch to prevent inadvertent retraction, theres no squat switch to provide an extra measure of security.

Despite the tricky steering and the sheer bulk of the airplane, it pulled off a pretty good record during the five-year period of only two instances of loss of control on takeoff or landing, and one hard landing during a training flight.

We noted only one instance of fuel exhaustion stemming (apparently) from pilot rather than mechanical factors. The fuel system is marvelously simple even though there are normally five fuel tanks (two in each wing, one in the overhead fuselage). The pilot need not worry about switching tanks since the feed is completely automatic.

Theres not so much as a crossfeed system to fuss with should an engine quit. On top of that, theres just one fuel gauge for the pilots attention, and that gives a reading of the total fuel in all five tanks together. It has one idiosyncrasy, however. The gauge peaks at only 135 gallons, and the needle wont budge for almost an hour until the first 21 gallons (of the 156-gallon usable capacity) have been consumed.

There is only one fuel filler access for all five tanks, located on top of the inboard right wing. It pays to check the cap before flight. In one accident listed in FAA files, the fuel cap chain was caught between the neck of the tank and the cap, and fuel siphoned from the tank.

According to one operator, however, the biggest fueling safety hazard is posed by line personnel pumping in turbine fuel instead of avgas, since the piston and turboprop Commanders look so much alike and, in some cases, operate side by side. An earlier study of accident trends in Commander 500-series aircraft by The Aviation Consumer, at the end of the last decade, showed three in-flight airframe failures during a five-year period. Furthermore, an FAA study of structural failure accidents between 1966 and 1975 tagged the Commander twins with the second worst record among 11 classes of twins, second only to the Piper Twin Comanche.

It turns out that the original legendary anvil-like stability of the Commanders was marred by a dangerous instability when loaded near the aft CG limit. No fewer than 22 cases of in-flight structural failures were blamed on extreme pitch sensitivity at aft CG. However, the problem was corrected in 1975 by Airworthiness Directive 75-12-9, which required installation of bob weights in the control system of all 500, A, B, U, S and other models. Buyers should double-check that this AD has been complied with.

Note that some models have only one hydraulic pump, on the left engine. Lose that on departure, and you wont be able to pull up the gear. Since hydraulic pressure alone holds the gear up, lose that and the gear, like Humpty Dumpty, will come tumbling down.

Maintenance
Spar corrosion aside, we received mixed signals from operators on maintenance matters for this class of aircraft. The thrust of owner thinking is that the Commanders are not for the faint of heart or pocketbook, but that a determined, progressive system of care and upkeep by a knowledgeable shop will pay off great dividends in trustworthiness. (Naturally, this philosophy would seem to apply to any sophisticated aircraft, but shops and owners seem to think it pays special dividends with the 500s.) The message is that the aircraft is sturdily engineered to avoid the nasty design glitches that plague other twins.

One experienced shop figured an average annual inspection for a Shrike would run $3,000 to $4,000, barring unusual problems. But one owner moaned about laying out $8,000 annually for maintenance. Some years it can go as high as $10,000 if you need to work on engine mounts or redo all the metal behind the exhaust, wrote one Shrike owner. Parts can be found, he continued, but they will cost you some pretty big bucks. Two wheel rims run more than $4,000. Ted Smith built this plane to military standards, thus it is built like a tank.

Said another Shrike owner, who adores the bird, This is a 20-year-old hydraulic airplane with all the seals and pumps that go with it. Youve got to be conscious of parts. Im constantly on the search for them. Ive had some on order for two to three months. Most owners and repair shops, however, say theyve had no problem getting parts.

A search of Service Difficulty Reports provided by the FAA disclosed no particularly distressful area, with the exception of a rash of Bendix magneto problems (and subsequent mag overhaul problems). Though the aircraft is one giant hydraulic system (gear, brakes, nosewheel steering, flaps), we uncovered only half a dozen reports in the SDRs of problems with lines, pumps or seals during the five year run.

Despite their woefully low 1,400-hour TBO, the big 290-horse Lycomings seem to stand up pretty well. We found only occasional engine grief reported in the SDRs: an engine bearing failure, a failed crankshaft, broken rocker arm boss, couple of cylinders with holes. Bob Hoover told us he figured with all the rough treatment he dealt his Shrike engines-shutting them off when they were red hot-he anticipated they wouldnt last a hundred hours. But his overhaul shop in California (Victor Aviation) told him they could have flown another 500 hours after the prescribed 1,400-hour TBO.

Nevertheless, operators should keep up a healthy war chest for engine overhaul since the big Lycomings will command about $16,000 apiece. However, one operator said they got good results on overhauls from T.W. Smith for $12,000 each. Another gave high marks to Keith Baxter at Aerochrome & Welding in Norwalk, Calif. The Hartzell props seem to stand up well on the Commanders, too. Hoover volunteered that he marvels at how flawlessly they work, despite continuous feathering and unfeathering during his aerobatic routine. Recalling the owners comment earlier about the price of wheel rims, we counted five broken wheels.

Despite all the gear collapses noted in the accident roster, there were surprisingly few SDRs on gear problems. But we did catch several reports of cracked brackets, ribs and assorted flap-attach hardware blamed on presumably too-high flap-lowering speeds by pilots. Perhaps fliers tend to overlook the max flap-lowering speeds (half flaps, 130 knots, full flaps only 118 knots) because of the awesome allowable gear-lowering speed limit of 156 knots. (Baron pilots, listen up.)

ADs
The mid-1990s saw Twin Commanders get socked with a huge raft of ADs after corrosion was reported in the spar caps. The fixes are expensive, and we recommend a thorough check of the records and the aircraft itself for compliance with them. The worst-case scenario is an ugly one, involving disassembly of the wing and replacement of the lower spar caps, a fix that could conceivably cost more than the value of an older airplane.

Modifications
Speaking of onerous spar ADs, there is a mod shop that markets a spar upgrade for Twin Commanders. Check out the Sauders Super Spar from Aviadesign. Also look into Aircenter, long one of the most active Twin Commander shops.

Best models?
The corrosion AD hasnt affected the resale value of the airplane at all. Assuming the potential for problems isnt a factor, which of the 500 series is the best selection for a used-aircraft buy? For relative economy, the straight 500 with 250-horse powerplants gets the vote of a few users like Palm Beach Aviation for short (hour and a half) people hauls where a 150-knot block speed is acceptable. The 260-horse Continental-powered 500A universally appears to draw a thumbs-down rating. Those Continental engines are like having AIDS, sneered one operator.

But aficionados of the big-engine 500s say the straight 500 is a completely different class of airplane. That leaves the choice between the 500B and the Shrike. Gadberry and Towner like the B models because they have more useful load-2,200 to 2,300 pounds.

Class comparison
The Commander 500s are far from bargains on the used-plane market. (We chose the 500S Shrike for the comparison.) Buyers may be surprised to see that a Shrike, on average, is going for a few thousand more than even the perennial favorite 58 Baron.

Although Commander owners talk about their commodious seven-seat cabins, we suspect the average individual pilot will fill the rear only occasionally with family or friends. If lots of passenger seats were the main objective, a Cessna 414, 421 or even a Navajo would fill the bill more satisfactorily. And though they may not have quite the carrying capacity, the big-engine Barons and the C-310 provide quite a bit more speed for a lot less money. Choice of the Commanders, then, would seem largely to satisfy a wish for an uncommon aircraft, and a willingness to trade speed for composure and reliability.

Owner Comments
The 500 Commander is the finest nonpressurized twin ever built. Ted Smith built this plane to military standards; thus, it is built like a tank. With a stall speed of 58 knots dirty and a Vmc of 65 knots, the plane can really get in pretty short. When not at gross and a 100 day, I will take it into a 2,500-foot field without a second thought. The Commander has very long wings-49.5-feet-which means great flying qualities, but dont taxi in close quarters.

-John R. William
Los Angeles, Calif.


My 79 Shrike has been all over the world, all without ever once giving my poor heart cause to skip a beat. Although it likes to putt calmly along the serene airways at a nice 215 MPH indicated, it seems more at home negotiating the soup and slop, going boldly where no plane has gone before. The aircraft has a service ceiling of 19,400 that I use routinely. Aircraft maintenance is easy and straightforward, without any unknowns or hidden surprises. General care and servicing on an on-going basis have given me a very reliable aircraft that has treated me well and protected me from the likes of Murphy and his tricks. The only real drawback is that the Shrike is not a beginners aircraft because of its complexity and cost to operate in a standard configuration.

-Dr. Gregory A. Scher
Chairman
World Warbird Federation
Farmington, Mo.


Ground handling was difficult at first, but after learning to taxi it, I wondered why all twins do not use the Commander system. The more I flew our 500A, the better I liked it, even though it was underpowered with the 260-HP Continentals. We replaced them with Colemill 300 Continentals. (This mod is no longer available, because of insufficient demand-Ed.)

I fell in love with this airplane. Visibility over the nose in climb attitude was better than we have in the Conquest I fly today. One of the problems was high noise level in the rear seats and unacceptable noise in the center pair of seats. We had no serious maintenance problems.

-Thomas B. Mayfield
Athens, Tenn.


I have owned an Aero Commander 500 for the past three years. Since there are so few of these aircraft flying, it is extremely important to have knowledgeable mechanics. Service bulletins on the cables under the seats and on the engine mounts need to be complied with by a competent mechanic.

In addition, the rudder pedals and rudder horn are trouble areas, and although there are no service letters, there have been failures and they should be checked by a mechanic familiar with the aircraft.

The aircraft needs to have the hydraulic system redone about every five years. My generators were replaced with alternators on a Form 337, and this solved all the electrical problems.

The Delco starters need to be updated to Prestolites as the Delcos are difficult to get parts for and have a high failure rate.

I can truthfully say that I have never had an airplane I did not enjoy, but the Commander is the best.

-Alan L. Hoffman
West Palm Beach, Fla.


We like it for its simplicity and ease of loading. We fly all cargo, and the aircraft has about 132 cu. ft. in the cargo area.

We picked it because it has a really rugged, sturdy airframe. We like the B model. Its identical to the S model but has a bit more useful load-2,200 to 2,300 pounds.

It gives us no trouble as long as we keep the components up to specs. Weve owned other airplanes and got spoiled with the good Commander parts supply. Its a lot of airplane for the money.

The factory tells us we have the highest-time aircraft out there-with 17,300 hours on it. With most aircraft after 4,000 to 5,000 hours, they shake, shimmy and creak. With the Commander, it feels the same.

-John Towner
Vice-president
Central Airlines
Kansas City, Mo.


Also With This Article
Click here to view charts for Resale Values, Payload Compared and Prices Compared.
Click here to view the Twin Commander 500 Shrike features guide.

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