Photo Report – A Different Angle To The Seneca Cockpit

By me
All photos me too, copyrighted

Not even a full hour had passed from when I came home from my last exam (for this session that is) to when I was back on the road again, heading to Lučko by the straightest path possible :). After spending a good part of the last two months with my head in the books – and passing through all possible forms of stir crazy along the way – I was in desperate need of fresh air, planes and photography; so undaunted by the fact that there wouldn’t be anything interesting left to photograph, I set out for the field, if anything to at least try and find some new angle on the 150’s pitot tube or the Diamond Star’s left winglet :D.

However, before it came to those desperate measures, I had a stroke of good luck. 9A-DMO, ECOS’ Piper Seneca III, was undergoing minor servicing at the time, so I decided to make myself helpful by avoiding manual labor – I’m notoriously accident prone whenever I’m near tools – instead plonking myself in the cockpit and seeing what I could do with my camera in there. I’ve always wanted to catch a good, artsy cockpit shot (reminiscent of the many fine shots of Airliners.net such as this one), so, combining leisure with some badly-needed physical activity, I set about twisting and crawling around the Seneca’s relatively small cockpit…

Up close and personal with the fun controls :). Below the usual throttle, prop and mixture levers you have the Alternate Air controls. Should the main air intake on either engine become blocked for whatever reason (often due to ice), operating the Alternate Air will open an alternate intake within the engine cowling which will - hopefully - be unaffected by whatever blocked the primary one

A closer view. In addition to being color coded, the levers are each of different shape, to allow the pilot to identify which is which without looking at them

DMO's avionics are a bit dated - but from a photographer's perspective that makes them all the more exciting! This antiquated King KNS 80 unit is one such marvelous gem...

But before we move on, the above photo is just screaming for a long additional explanation – if anything on account of the rarity of the “NAV SYSTEM” :D. In essence, this is not a simple instrument, but an integrated navigation system that was, before the GPS came along, by far one of the most sophisticated navigation units you could get for a small aircraft. What it does is combine VOR, ILS and DME data to provide the aircraft with (among other things) Area Navigation (RNAV) capability. Now, unlike classic radio navigation that relies on flying between radio stations (VOR, NDB), RNAV allows the aircraft to fly between “waypoints”, points whose location is not bound to the physical location of a ground radio station. Today in the fun fun world of GPS, these waypoints are predetermined and defined in navigation computers by their geographic coordinates; in the olden days however, they were defined by their radial and distance from a VOR/DME station (the “rho/theta” system) or by their distance from two DMEs (“rho/rho”), which was more accurate.

This is where the KNS 80 came in. When a pilot wanted to fly to a waypoint, or along a series of waypoints – back then they could also be defined at will (within certain areas) and when linked together were known as “Random RNAV routes” – he/she would input the waypoint’s distance and radial from a VOR/DME station, along with the station’s frequency. In flight, the unit would then continually measure the aircraft’s distance and radial from that station, compare it to that of the waypoint and calculate and numerically display the aircraft’s distance and time from, and the track to, the waypoint – and, if traveling between two waypoints, the aircraft’s displacement from the shortest line between them.

Despite being a very capable device – and one of the first truly modern GA navigation systems – the “NAV system” as a whole quickly fell out of use with the appearance of the first cheap GPS units, which had provided capability and flexibility at an entirely different level. Very, very rare today – this specific unit is the first one I’ve ever seen, despite it staring me in the face for quite awhile now 🙂 – I think it isn’t even approved for any form of serious (IFR) navigation anymore…

A view of the whole avionics stack - equally interesting as from the other side :D. This specific King suite also includes two communication radios (under the NAV system), a second NAV radio at the top of the other stack (the first being integrated into the NAV system), ADF and a rather old weather radar display

And that’s pretty much it :). Some photos didn’t come out well, but this was just an photography exercise in tight spaces that produced some usable results in the end… 😀

One thought on “Photo Report – A Different Angle To The Seneca Cockpit

  1. Pingback: Rare Aircraft – 2+2: The Four Seat UTVA 75 | Achtung, Skyhawk!

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