Nite Hawk Embryo

[sandfac]

Rainy weekend here in NYC, and working on Nite Hawk #3 after #2 was lost to the corn post-DT at the Flying Aces contest in Geneseo last year. Building mostly with 7# 1/16" balsa, and trying accommodations for removable landing gear, wing, and tail. Hard to make it both strong and light enough for a model of this scale, but will see how it works out with 0.015 music wire, 0-80 nylon screws, and super-thin stripped FAI rubber. Carving a 7.5" x 9" prop for propulsion.

[g_kandylakis]

Hi Oliver,

could you please write the rules for Embryo Endurance? It is a well established class in FAC competition but not quite known to most (non-FAC) European guys...

Thanks,

George

[sandfac]

Hi George, I'll post the FAC rules for the category below: Embryo Endurance is a non-scale category that features planes that must ROG, usually in the 18-20" span range. These planes were my entry into the competition side of the hobby years ago, and continue to be a fun, relatively low-time-investment way to get some long outdoor flights.

A. Design considerations:
1. Wing Area (WA) is measured off of the flat plan.
2. MONOPLANES not to exceed 50 sq. inches WA.
3. BIPLANES not to exceed 70 sq. inches of WA, with 45 sq. inches WA maximum for the larger wing.
4. Stab area not to exceed 50% of the WA.
5. Any part of any wing that sits on top of or passes (physically or projected) through the fuselage is considered wing area.
6. Fuselage volume to enclose a space 1.25 x 1.50 x 3.00 inches or larger.
7. The wing and tail must be built up and covered on both sides ("double covered") with Japanese tissue or equivalent.
B. Wing span: No limits, but refer to wing area rules above.
C. Landing gear:
1. Landing gear legs must be conventional configuration.
Example: two wheels on a single landing gear leg are prohibited.
2. Wheels must be 3/4 inches or larger in diameter, and must rotate freely on their axles.
D. Launch technique: unassisted ROG from a three-point stance.
E. Bonus points: Cumulative; added just once to the total flight points. Maximum bonus points—9
PTS. CRITERIA
1 3-dimensional exhaust pipes
3 3-dimensional wheel pants
5 Open cockpit with windscreen and headrest—OR
5 Full bubble canopy containing head rest and (at a minimum) a pilot's head silhouette—OR
5 Raised cabin with no less than a 30-degree windshield slant, referenced from the bottom of the wing (low wing on bipes).
F. Flight scoring: Total of three flights
G. Official flight: Official flight: 20 sec. minimum, 120 sec. MAX
H. Total Score: Flight score + bonus points.
I. Embryo Endurance may NOT be combined with any other events.

[sandfac]

My first model in this category was the Prairie Bird, which is still available from Peck Polymers in the US, and which I built stock and modified a few times before trying Josh Finn's Maxout design. This was a great flyer, as well as the Big Cat, previously offered by Volare Products, and from these 2 designs and an admiration for George Perryman's swept-back wings I put together the Nite Hawk plans.

Hopefully Nite Hawk #3 will be a good flyer, and a friend suggested making 2 more designs for a trio: nightjar? Niteshade? Maybe one of these will be a future name for a biplane version.

There is significant similarity in Embryos to the Bostonian plans -- I think that some (or all?) Bostonians qualify for Embryo, but not necessarily the other way around.

[OZPAF]

Hello Oliver - greetings from a wet and miserable Moss Vale. Although I'm predominately a RC glider flyer - I like FF - rubber and CLG's.

Embryo's look interesting as do Bostonians.

Good luck with your Nighthawk. Is that a Wing pop off DT system that you are adding?

Happy flying.
John

[g_kandylakis]

Hi Oliver,

Thanks for the rules...
So, no minimum weight restrictions? Interesting.

And the bonus points mostly make sense when you can achieve max points in flight? For an extra push?

George

[MKelly]

Hi George, as Oliver says Embryos are great fun and typically fly extremely well. Like Bostonians many designers put a lot of character into their Embryos, making them fun and whimsical similar to Ebenezers. The bonus points for exhaust, wheel pants and cabin/cockpit are intended to encourage that spirit.

In contests stateside it's very common for multiple flyers to achieve three two-minute max flights generating a fly-off to determine the winner. Bonus points are applied on top of the flight score of the three official flights, so if a builder decided not to include features earning the bonus points (and others did) that model would have a lower total score and wouldn't be eligible for the flyoff.

I've built six models for Embryo, four of them flew away. Most took less than a week from start to first flight, even when built from plans rather than kits. It's really a great event, and as Oliver said an excellent way to get a newcomer successfully building and flying stick and tissue models.

Mike

[g_kandylakis]

Hi Mike, thanks...

A nice coincidence. Tom Hallman posted this on his youtube channel today.

[Jmk89]

If you are thinking of building one, the plan of Nite Hawkis available in the Plans Gallery

[g_kandylakis]

Quite right Jeremy, thanks!

https://hpa.aeromodelling.gr/plans/details.php?image_id=1880

I 'll give it a look. Not for now of course, already up to my neck...

George

[calgoddard]

Oliver -

Your Nite Hawk Embryo is very well designed for the FAC Embryo event.

I built a MAXOUT Embryo (picture attached). I made it to a fly-off against Wally Farrell in a WESTFAC contest. It was one flight, with the winner being the last one down. I locked down the DT on my MAXOUT Embryo and my model climbed higher than Wally's Embryo. Unfortunately my timer lost sight of my model in the fly-off and I lost to Wally because his model landed in sight at least 30 seconds after my model flew OOS. Hours of searching did not lead to a recovery of my MAXOUT Embryo.

From your design, the GO DEVIL Embryo designed by Herb Kothe, and the Embryomatic Embryo design by Don DeLoach, I learned that a fuselage length like that of your Nite Hawk is a better choice than the super long fuselagae of the MAXOUT Embryo.

[MEETOO]

My first model in this category was the Prairie Bird, which is still available from Peck Polymers in the US, and which I built stock and modified a few times before trying Josh Finn's Maxout design. This was a great flyer, as well as the Big Cat, previously offered by Volare Products, and from these 2 designs and an admiration for George Perryman's swept-back wings I put together the Nite Hawk plans.

Hopefully Nite Hawk #3 will be a good flyer, and a friend suggested making 2 more designs for a trio: nightjar? Niteshade? Maybe one of these will be a future name for a biplane version.

There is significant similarity in Embryos to the Bostonian plans -- I think that some (or all?) Bostonians qualify for Embryo, but not necessarily the other way around.

When Florent Baecke designed the Scimitar kitted by Lee Campbell he borrowed my Sig Minimaxer plan from me and got several embryos designed from that original Sig Mini Maxer kit plan . George Perryman had sent me to the local hobby shop in Smyrna,Ga. Did you know the wing tip for the Lockheed C-5A was designed by George Perryman way back in the day?

[sandfac]

MT,

Thank you for the piece of trivia! I did not know that about George Perryman, so cool to know about this throughline of aircraft design. I much admire FB's designs too, and would like to build an Embryo Streak at some point.

[sandfac]

Cal,

Thanks for sharing about your Maxout. I originally built a few Maxout IV's, an earlier iteration of the long-fuselage one you built, and they were certainly an inspiration for the Nite Hawk. It sounds like you got quite a climb from yours, I got plans from Josh a few years ago for a later Maxout design and would like to try out one of those as well. Seems very rigid with the X-braced wing.

[calgoddard]

Oliver -

I am not sure the X-braced wing of the MAXOUT Embryo is necessary for a small model like an Embryo. There is no kit for building the MAXOUT Embryo so it has to be scratch-built using the plan from J & H Aerospace. It is a great deal of work to cut all the ribs so that they can criss-cross and also accept the spars. See the attached picture of the bones of my MAXOUT Embryo. I think a conventional arrangement of ribs like that of your Nite Hawk is sufficient to resist warping. If the builder has concerns regarding warping, the tissue can be pre-shrunk before using it to cover the wing.