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Some aircraft such as the DHC-6 Twin Otter, have their throttles on the overhead panel:

Is there a reason that they are not on a center console between the pilot seats or mounted to the panel like on most airplanes?

It seems like it would be more comfortable for the pilot if he didn't have to reach up to change the power settings.

Danny Beckett
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flyingfisch
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    What I think I would find objectionable from what I see in the image is that the throttles are off-center in favor of the left seat. Seems like it would be quite a reach from the right seat, especially for a short f.o. Great pic, by the way, makes me very much wish I was still flying. – Terry Feb 25 '15 at 23:23
  • The first explanation I thought of for the overhead location, is if the seaplane took on water. I saw such comments elsewhere as well. However, as mentioned in the question, the other standard location for throttles is not the floor where water from the sea would be a problem, but the panel or a console above the floor. So I'm putting this as a comment instead of an answer. – cardiff space man May 16 '17 at 18:10
  • Because the space where the throttle quadrant would be on most aircraft is taken up by the control column. – Vikki Feb 01 '19 at 03:55

3 Answers3

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I think it was for two reasons:

  • It makes for a straight path for the controls to reach the engines, as all of these are fly by cable. Many of these aircraft where also designed for harsh climates, so I imagine it's an advantage to have fewer pulleys and other things which might rust and require maintenance.
  • There is very little space to place the throttles further down, especially with the control column mounted on the DHC6 Twin Otter where it is. If you did want a pedestal, you'd have to separate the control columns, requiring further mechanical components, and you'd have to route the engine cables upwards, both of which would be undesirable.

Twin Otter Cockpit

As you mentioned, there are downsides. Commonly mentioned ones are:

  • It is not particularly comfortable to have you arm raised for an extended period of time, and you lose some sensitivity in it.
  • You hope that the other pilot used his deodorant that morning.

Other somewhat similar aircraft which use this configuration are the PBY Catalina and Grumman Goose. Another one is the Avro York heavy transport aircraft.

tripleee
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Thunderstrike
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Overhead throttles are a pretty common thing in seaplanes (see the picture in Manfred's answer).

This actually came up as an EAA Young Eagles FAQ and in addition to the reasons Manfred gave the Grumman engineer they spoke to gave an explanation I'd not heard before:

…first and foremost, the reason the throttle are overhead is due to a physiological issue related to the g-forces encountered during water landings. At times, forces as high as 3 Gs can be registered on contact with the water, and by having the throttles hanging down from a pivot point above, it's nearly impossible for the hand of the pilot to bend the throttle.
When the downward force is encountered, the pilot's hands will move downward as well, so the force is applied to the throttle in a way that will not damage the linkage, and it will not likely result in an abrupt throttle position change. With a panel mounted throttle, it's likely that a higher-G landing on the water (or on the deck of a carrier) would result in a bent throttle.

Community
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voretaq7
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    This is an interesting explanation, but I'm not quite buying it. 3Gs even for a water landing sounds like a lot. If you have a hard touchdown on the water your hand would move down, and you might risk loosing the grip of the throttle if it caught you off guard. If it would actually be a problem with the strength of the throttle levers, I think it would be a straightforward process to strengthen them...IMHO :) – Thunderstrike Feb 05 '14 at 20:48
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    @Manfred I'm not entirely sure I buy bending the throttle either, but if you catch a wave on a water landing I could definitely see that being 3Gs or more in deceleration forces - It can be a good jolt in a boat, and there you have the benefit of being at 0 feet and a lot fewer knots. I think (no seaplane experience) that the impact of such a landing would tend to knock your hand away from the overhead throttle (as opposed to a traditional push/pull or quadrant where the impact would send your hand forward, advancing the throttle, which may not be what you want) – voretaq7 Feb 05 '14 at 21:39
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    More likely, it would be to prevent inadvertent movement of, or losing one's grip of the throttles in the case of a rough landing. Must be a real issue, because many (but not all) aircraft capable of water landing have overhead throttles. I was looking at a cockpit photo of a Sikorsky S43 (the one once owned by Howard Hughes), and it had overhead throttles. In the case of the twin Otter, I have to wonder if this wasn't held over from the single engine Otter, which is often float equipped. – tj1000 Feb 15 '18 at 09:10
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In the case of a high wing multi engine plane, like the Grumman seaplanes, the distance and a less convoluted path for a steel cable from the throttle control to the engine may have a lot to do with this design choice. However, this is a guess completely unencumbered with facts.....

Skip Miller
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