Interstate S-1A Cadet

Interstate Cadet VCQAs announced in earlier posts, I have been lucky enough to acquire a 1941 Interstate S-1A Cadet aircraft. This particular example  – serial number 9 – originally rolled off the Interstate Aircraft and Engineering Company production line in Segundo, California, in January 1941. It has recently been restored to better than new condition in the States, with an 0-235 115 hp engine replacing the original Continental A-65 hp, toe brakes replacing the original and much disliked heel brakes, raising the MTOW to 1,650 pounds (750 kgs) from the original 1,200 pounds (544 kgs) and a host of other improvements, including an improved tail wheel.

As far as I know, this is the first Interstate Cadet in Australia, registered VH-VCQ, replacing its original USA registration N28317. Around 320 S-1’s were built by Interstate during 1940-1942, then later some more by Callair, who acquired the Interstate manufacturing rights. The aircraft was also built as a military variant – the Interstate L-6, which had a bigger glasshouse to facilitate its observation role. The Interstate Aircraft manufacturing rights were eventually purchased from Callair in the 1970’s by Arctic Aircraft in Alaska. They have developed the S-1 into the Arctic Tern by adding a 160 hp engine and many other upgrades and improvements.

A small piece of trivia – interesting mainly to me – is that Interstate originally sold the S-1 manufacturing rights to the Harlow Aircraft Company, who then sold them on to Callair. I’m hunting through the family tree to find out which (probably none) of my relatives were involved in this venture.

The Interstate Cadet was one of several similar aircraft types made at the time by competing manufacturers – Piper, Stinson, Aeronca and Taylorcraft to name a few. However, although the Interstate was much bigger and more rugged than these other aircraft, it was also much more expensive – in fact, almost three times the cost of a J-3 Cub. So Piper went on to make literally thousands of Cubs, while Interstate disappeared by the mid-1940’s.

A final historical footnote – an Interstate Cadet, flying on a Sunday morning training flight, was the first US aircraft to be shot at when Japanese forces attacked Pearl Harbour – not, as incorrectly portrayed in the film ‘Tora Tora Tora’ a Stearman Kaydet biplane.  Thankfully, the instructor – Cornelia Fort (yes, a woman! and only 23 years old too) – was able to evade the fighters and get back on the ground safely. This very aircraft is now apparently owned by Kent Pietsch – he of the ‘Jelly Belly’ comedy aerobatic display, seen all over the world, including at our own Avalon Airshow. However, the provenance of some of these older aircraft can be difficult to confirm and at least one other person lays claim to ownership of the Pearl harbour Interstate.

I’ll be posting some more about flying the Interstate and some links to videos of the aircraft in due course. Meanwhile, here are a few YouTube links to whet your appetite:

Me introducing the Interstate Cadet:
oug’s Super Cadet:
Dick O’Reilly’s Christmas Crosswind Flight:


12 thoughts on “Interstate S-1A Cadet

  1. Always something interesting, Peter! And the dulcet tones of Mike… Hi to both of you and I look forward to first flight.. Pauline

  2. Absolutely beautiful Peter. I love old cars, but this raises the bar ! I also can’t believe it’s yellow.
    BTW, if it’s really cold and you drop the oil, don’t let anybody see you, and just blame it on a Jabiru failure.

  3. Pingback: Oshkosh 2014 | Foxbat Pilot

  4. Pingback: Spring fly-in: Antique Aeroplane Association | Foxbat Pilot

  5. Pingback: Antique Aeroplane spring fly-in at Swan Hill | Foxbat Pilot

  6. Pingback: Fly with Kent Pietsch in his Interstate Cadet | Foxbat Pilot

  7. Peter, I have N28319 S1A and am restoring it right now. I’ve upgraded the radios, added S-mode transponder with encoding altimeter and ADS-B, added a metal prop, replaced the original struts (compliments of Tim Talen), converted the tailwheel to a Scott 3200 and added a metal prop but am keeping everything else original and within CG. Before grounding this fall due to fabric, it was a “hands off” long distance cruiser (it has 2 ea. 6.5 gallon wing and the 15 gallon main tank), it just porpoised gently in stall (35-50ft elevation loss) with no wing drop, and it was real easy on fuel. I bought it in Carson City, Nevada and after flying it home to Alaska in 2009, I’ve cruised all over. In 2015, I had a wing tank vapor lock and had a forced off-airport landing in the tree tops with little damage, so after inspection, installing skis and a ferry permit, I flew her home for repairs and continued to fly it until this last fall. Interstate Cadet’s are TOUGH. After the rebuild, I hope we can tune it be as docile to fly after we put her back together so I can focus on using the most valuable flight instrument, my eyes.

    • Hi Ronald – thanks for the information. Sadly, I had to part ownership with my Interstate a couple of years ago, although its new custodian keeps it in my hangar. It’s flown regularly and although not a truly original Interstate (I think very few are) it looks and flies great. Thanks again for your news.

  8. Beautiful plane. I would like to get some info on the O-235 installation. Was it done by STC or Airworthiness changed to Experimental. I have also seen some with the Continental O-200 but can’t find any info on that either. My first plane was a Stinson L-5. It was a hoot to fly.
    Any help on the engines would be greatly appreciated.

    • Hi Keith – sadly I no longer own this aircraft. It’s still in Australia but with a new custodian. I bought it originally from a man called Doug Trager in Idaho, who I believe arranged for all the conversion work to be done by local engineers, including someone at Aircraft Refactory(?) who specialise(d) in restoring Interstates. I’m sorry but I don’t have their contact details any more but I think if you contact either Antique Airfield or Refactory in USA they would be able to help. There is also an Interstate Cadet Club in USA but again, sorry, I don’t have contact details any more.

      • Thanks so much for the leads! I’ll check them all out. I noticed on the N-number registration (old) that it was listed as Experimental/ Exhibition so figured it was a specialty engine mod but hoping it might have developed into an STC.

Leave a Reply

Your email address will not be published. Required fields are marked *