Used Turboprop Review: Merlin IV—The Agony and the Ecstasy

Jan 18, 2015 - 9:30 PM

I pushed the power levers forward. Both engines came to life and I was quickly jammed back into my seat. In a blink we were at 120 knots—jet speed. I heaved the control yoke toward me, climbed out of Milwaukee into the starless black night and headed out over the wintry waters of Lake Michigan.

Once airborne, the stub-winged turboprop accelerated quickly—a couple more blinks and we were at 250 knots. The engines whined, the props were loud, and the sounds bounced through the gutted, empty cabin behind me. A good part of the instrument panel was placarded. The autopilot was gone, the nose-wheel steering didn’t work, and we had lost a landing light. I counted down the minutes until we reached the opposite shore. It was exhilarating.

My ride that night—a Fairchild/Swearingen Metroliner—was the darling of commuter airlines in the 1970s and 1980s. Well past its prime and denuded  of its interior, this one now flew freight. If Procrustes designed an airplane cabin, this would be the result. With its low 4.8-foot ceiling, narrow 5.2-foot cross section and 33.1-foot length, some people called it “the flying pencil.” Others named it “the lawn dart,” because flying folklore had it that that’s essentially what you had if you lost an engine on takeoff with any kind of a load. Perched on its gear, it sits high off the ground with a menacing rake that oozes speed and taunts you at the same time, almost like a Lamborghini super-car. Why buy a minivan when you can have this?

In This Story

M7 Aerospace Merlin IVC

This 8-passenger Turboprop from M7 Aerospace has a range of 1,170 nm.

An airline pilot friend who flew Metroliners in the 1970s told me that some passengers would take one look at the airplane and refuse to board. His ­company actually experimented with hiring short flight attendants on the theory that they could move around better in the cabin.

Developed from the ­Swearingen Merlin corporate turboprop twin of the 1960s, the Metroliner differed mainly by having a slightly longer wingspan and fuselage. Fairchild—the defense contractor and builder of legendary aircraft, including the A-10 “Warthog” ground-attack aircraft that became the darling of the first Gulf War—initially made just the Metroliner’s wings.

Famed aircraft designer Ed Swearingen, the mastermind behind the SJ30 light jet, developed the ­Merlin in the 1960s. More than 440 of them were sold between 1967 and 1991. Some 117 of those were Merlin IVs, aircraft that essentially shared the Metroliner’s wing and fuselage, but were configured with executive seating, usually for nine to 14. The Merlin stood out among turboprops of the era for its speed, range and load-carring capability—performance that holds up well, even to this day. The aircraft boasts maximum range of 1,750 nautical miles (1,170 with seats full), a cruise speed of 280 knots and a 490-cubic-foot cabin with 181 cubic feet of baggage space.

All this capability comes with a price—exacted in the main on mechanics and pilots. Hang around a maintenance hangar where they work on these airplanes even for a little bit and you’ll hear all kinds of language Mother never taught you.

For a turboprop, the Merlin is complex, with a cockpit that makes the space Shuttle’s seem almost simple: a dizzying array of switches, circuit breakers, control knobs and gauges jammed into a decidedly small space. In pilot speak, this an “unforgiving” airplane—fast with a high workload. There’s even a ­provision for “rocket-assisted take off” in the tail cone—designed for use at high-elevation runways on hot days. And the TPE331 engines (now manufactured and supported by Honeywell) have an alcohol/water injection system to boost takeoff power. (Water lets you add power by lowering the exhaust and turbine temperatures without over-temping the engines.)

You can fly the airplane single pilot, but unless your captain is at the top of his or her game and has a ton of experience in it, that’s probably a bad idea. At least, so it appears in the database of the National Transportation Safety Board, where you’ll find some 300 records ­relating to incidents and accidents with all models of the aircraft. However, the Merlin IV seems to have a good safety record in corporate operations, according to the Flight Safety Foundation’s Aviation Safety Network; its reports show that only one of the hull-loss accidents occurred during a business or private flight. That was in 1975 when a pilot attempted a visual approach in fog. (This is why they give out Darwin Awards.)

While Swearingen was a brilliant designer, his company was struggling by 1971. It owed Fairchild a pile of money that it couldn’t pay, so Fairchild basically took the place over, getting a 90 percent stake and rechristening it the Swearingen Aircraft Corporation.

Prior to that, Swearingen had developed a stretched Merlin called the Metroliner for commuter airline operations, but had trouble bringing it to market. Now with Fairchild’s backing, this was no longer a problem. Between 1971 and 1997, the company built 605. Many are still flying as “freight dogs,” commuter airliners or military reconnaissance platforms—often in remote places such as Africa, the Australian outback, and the coldest parts of Canada. Head out to North Dakota’s Bakken oil boom and you’ll still see Metroliners hauling freight and roughnecks.

There are a couple of reasons for this. Mainly, given the airplane’s capabilities, it’s dirt cheap to buy. According to the aircraft pricing service Vref, a 1983 Merlin IVC retails for $880,000; vintages a decade older can be had for as little as $280,000.

Secondly, these airplanes were constructed to airliner standards and are therefore ridiculously overbuilt. The fuselage has a life limit of 25,000 hours and even the 30-year-old ones on the market rarely exceed 12,000 hours, total time. Look hard enough and you can find Merlins that have less than 7,000 hours—or even 5,000 hours. The fuselage is so strong and tight that it maintains a sea-level cabin all the way to 16,000 feet. Of the 1,053 Merlins and Metroliners produced, an estimated 75 percent are still flying.

Last but not least, there are the engines. Operated with the proper finesse, they reward with good fuel economy and plenty of power. Honeywell does a good job supporting them with a worldwide service network and is continually finding ways to lower the cost of parts or extend overhaul intervals. And Honeywell’s MSP hourly engine maintenance program—which costs an estimated $60 to $100 per hour depending on engine condition at enrollment—softens the blow of any unscheduled engine service. Yes, a King Air is easier to fly and is less complicated to maintain. But you don’t really want the minivan. You want the Lamborghini.


Mark Huber (mhuber@bjtonline.com) is a private pilot with experience in more than 50 aircraft models.