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Is Retractable Undercarriage Worth it?

April 5, 2019

It’s always a thrill when we move the landing gear selector to the ‘Up’ position and a whole lot of stuff obediently starts happening to make the gear travel upward, with the accompanying noises, flashing lights and the final thump against the up-locks. And then even more rewarding, the plane accelerates and its controls become lighter and crisper. We revel in the efficiency of having the gear neatly tucked away.

 

 

 

Forty years ago, in the heyday of general aviation, most light aircraft manufacturers had high performance aircraft in their line-up. Now, however, there are almost no new retractable planes sold. Yet, without exception, retractables outperformed their fixed gear equivalent and it was accepted that a plane with fixed gear was aerodynamically handicapped.

To compare the same models; a good example is Piper’s Cherokee Archer 180 and the Cherokee Arrow 180. The Arrow is about 12 knots faster in cruise than the fixed gear Archer. Moving the goalposts a little, a Cessna 210 is roughly 20 knots faster than the 206, and the Cessna 182RG is around 15 Knots faster than the fixed gear version.

The retractables usually came with slightly larger engines and constant speed propellers that made it difficult to assess precisely how much difference the retractable gear really made over their fixed gear siblings. By way of example, flying from Bloemfontein to Cape-Town will save you about 25 minutes in flying time between the Cessna 210 and the 206. Both aircraft have the same fuel consumption per hour, although the 206 is spending 25 minutes longer in the air, but it has a greater payload, shorter take-off roll and better climb performance than the sleek 210. Spending an extra 25 minutes after a bumpy three hour flight in the hot summer months over the Karoo, dodging thunderstorms, could just be 25 minutes too long.

It is also important to note that a Cessna 210 with its gear hanging out is by no means just a 206, neither is a Cherokee Arrow with its gear hanging out a Cherokee Archer. Retracts tend to fly like bricks once their gear is out in the breeze.

So, what to choose? Here are a few facts to consider when comparing a retractable and fixed gear piston single:

 

Costs

The purchase price of a retract within the same model range will be higher than the fixed gear equivalent, although more recent high performance models available today, such as the Cirrus, have an eye-watering price premium compared to older retract models with basically the same cruise performance, such as an F33 or V35 Bonanza.

 

Higher Insurance

There may be as much as a 50% increase in insurance premiums over a fixed gear equivalent. For pilots with lots of retract time the insurance bill could be less, but the premium never goes away.

 

Complex Aircraft

Flying a retract means operating an aircraft with more complex systems. Landing gear operating speeds and emergency procedures in the event of an undercarriage failure add a lot to the workload of a pilot, especially less experienced pilots.

 

Failure

There is a chance that due to mechanical, electrical or hydraulic failure, the gear will not extend, putting you in a higher risk (and stress) bracket.

Drag

Cessna’s simple steel leaf spring has made an excellent landing gear. Even without a fairing, the thin steel leg, though heavy, produces relatively little drag and a faired tubular one even less. A good wheel spat, fully enclosing the brakes, and making a clean intersection with a thin leg, does away with at least half of a wheel and tyre’s drag, provided that most of the tyre is inside it. However, wheel spats and fairings are prone to frequent maintenance due to the shock of landing, vibrations during taxi, landing and takeoff. This gets even worse on rough unpaved landing strips, to the extent that wheel spats have to be removed before landing there. The Piper Cherokee’s oleo struts are comparatively difficult to streamline. In terms of frontal area, the oleo struts’ drag is as much as nine times that of a Cessna’s aerofoil-shaped fairing.

 

Maintenance

Retractable landing gear systems require additional maintenance, apart from scheduled inspections and lubrication. Some manufacturers require hydraulic systems to be overhauled every five years, landing gear retract gearbox overhauls at 2000 hour intervals, actuators to be overhauled at 400 hour intervals, and so on. Further to this, there are micro switches, electrical wiring snags, excessive play on door hinges and undercarriage pivot points that can be costly to repair. Some of the older retract systems have parts that have become obsolete, making replacement of worn parts a real challenge. You can expect to pay around 20% more on maintenance costs for a retractable gear.

Be aware of the costs of ownership of the different types. On one hand, my old Cessna 210B costs upwards of R250,000 to carry out the 5-year power-pack overhaul, hydraulic system O-ring replacement, one or two expensive, hard to come by micro switches, solenoids, worn braces and electrical wiring snags. But to see the old lady open its gear doors, tuck its legs away and close them with a thud in such an elegant fashion, with an average ground speed of 150 knots, for an initial purchase price of just R450,000 makes it all worthwhile. On the other hand, our Bonanza V35 gave us 170 knots on average out of not-so-good unpaved strips, with no additional costs apart from the normal manufacturer’s inspection and lubrication requirements.

During the 1980’s there weren’t any fixed gear aircraft that had the same or better cruise performance than the retractable gear aircraft. But today you have a choice – you can buy a new or still young Cirrus with fixed gear that outperforms all the older retracts. But they come with a high price premium. Or you could refurbish a Cessna 210 or older Bonanza with a new engine, propeller, glass cockpit, new paint, windows and almost better than new interior, and still have a lot of change left before buying a new high performance fixed gear single. But that change may be then be eaten over time by the higher maintenance and insurance premiums.

My advice would be to consider what you would like to spend, what are your typical application requirements, and then buy whatever aircraft type best suits your pocket and mission requirements.

 

 

 

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