Official Freewing Twin 70mm SR-71 Blackbird with Gyro EDF Jet Thread

[Evan D]

And once fixed is there a next weakest link?

[GliderGuy]

Good info…thanks. Luckily I have less-convenient access to a concrete surface and also a smooth-surface asphalt surface. Just need to get the spare parts opened for order. Will nix the gravel surfaces….heads up to all.

FedEx confirms delivery of the Panther Jet mains today. I’ll be evaluating the anti-torsion arms on them.

-GG

[f4u ausie]

There (Always) is......

[f4u ausie]

Next weakest.. that is

[GliderGuy]

Possibly, but FW/MRC quality shows that for the birds I have purchased and have flown way beyond any reasonable design limits..all do a great job of holding up to tons of flights.

If a milled upgrade isn’t offered as a fix, then this may be the only weak point in this beautiful SR-71. I’m not seeing anything else (30 flights only).

-GG

[GliderGuy]

The 70 mm FW F9F Panther Jet mains have the same anti-torsion arm. Thanks Evan! I will be removing the arms and installing them on the SR-71 ASAP.

SKU FJ22111084

Available option until the SR-71 spares open for ordering if you are in a “gotta have” situation like I
am.

Update: Installed the Panther Jet’s anti-torsion arms on the SR-71. Perfect fit! I am in business again.

-GG

Photo of the Panther Jet’s main gear.

[Evan D]

You’re very welcome

[EDF-Jetpilot]

The 70 mm FW F9F Panther Jet mains have the same anti-torsion arm. Thanks Evan! I will be removing the arms and installing them on the SR-71 ASAP.

SKU FJ22111084

Available option until the SR-71 spares open for ordering if you are in a “gotta have” situation like I
am.

Update: Installed the Panther Jet’s anti-torsion arms on the SR-71. Perfect fit! I am in business again.

-GG

Photo of the Panther Jet’s main gear.

Great, I wish you luck! From the looks of it, it's exactly the same cast aluminum as the SR-71, just not painted black, not promising... but I don't want to dash your hopes and wish you good luck and a long life.

[GliderGuy]

Thanks! But I’m not going down without a fight! This has been an interesting journey. Appreciate all the guidance and comments. Now we know more than we did a few weeks ago.

All three are beefed up…starting with a good wash/scrub with isopropyl alcohol:

1) Voids are filled with JB Weld epoxy
2) The entire length of each 1/2 is wrapped in 0.6 mm steel aircraft grade safety wire embedded into a layer of JB Weld before the epoxy cured
3) An outer covering layer of JB Weld is painted over the entirety of each 1/2.

I’m also going to fly ONLY on smooth concrete or smooth asphalt…,no gravel. No more 40F flights…warmer air temperature flights to enhance the metal’s flexibility.

I hope all this will make them last. Spares will be kept on hand once they can be ordered because 100s of flights is gonna stress my attempts to beef them up. Dremel removal of the black paint down to bare aluminum before 1, 2, 3 above will be a first step, if they are painted black.

-GG

[EDF-Jetpilot]

Thanks! But I’m not going down without a fight! This has been an interesting journey. Appreciate all the guidance and comments. Now we know more than we did a few weeks ago.

All three are beefed up…starting with a good wash/scrub with isopropyl alcohol:

1) Voids are filled with JB Weld epoxy
2) The entire length of each 1/2 is wrapped in 0.6 mm steel aircraft grade safety wire embedded into a layer of JB Weld before the epoxy cured
3) An outer covering layer of JB Weld is painted over the entirety of each 1/2.

I’m also going to fly ONLY on smooth concrete or smooth asphalt…,no gravel. No more 40F flights…warmer air temperature flights to enhance the metal’s flexibility.

I hope all this will make them last. Spares will be kept on hand once they can be ordered because 100s of flights is gonna stress my attempts to beef them up. Dremel removal of the black paint down to bare aluminum before 1, 2, 3 above will be a first step, if they are painted black.

-GG

OK... good! You seem to be a real model building genius.

[Glideman]

Anybody have the factory gyro settings for SR71 Blackbird Freewing gyro ?

[GliderGuy]

One YouTube video comment is, “Don’t stall it! The nose won’t come down…it over rotates, and it won’t recover.”

Basically a high alpha lock situation.

Has anyone witnessed this happening (crash)? Or….is this the pilot’s “assumption”?

As in full scale birds during FAA certification flights, they use spin chutes to get the nose down when experimenting with aft CG stall conditions to get out of the high alpha lock.

Worth a try if you get into an unrecoverable high alpha lock situation…pop the chute out. It might just save your bird.

-GG

[Aros]

Oh my, yes, the Blackbird is notorious for a vertical nose high attitude if slowed/flared too much on approach. I flew the LX version hundreds of times and I can't count how many times it happened to me on approach. Luckily it rarely caused damage but looks hilarious on video. I just had it happen to my E-flite version a couple weeks back. We got a good laugh at the field. Wobble, wobble, wobble and then nose to the sky, slam the elevator stick full down and she plops down, lol.

With the Blackbird she needs to come in with speed and the nose AoA just barely over horizon. She wants to be flown to the ground, and not like an F-16 in High Alpha either.

[EDF-Jetpilot]

Oh my, yes, the Blackbird is notorious for a vertical nose high attitude if slowed/flared too much on approach. I flew the LX version hundreds of times and I can't count how many times it happened to me on approach. Luckily it rarely caused damage but looks hilarious on video. I just had it happen to my E-flite version a couple weeks back. We got a good laugh at the field. Wobble, wobble, wobble and then nose to the sky, slam the elevator stick full down and she plops down, lol.

With the Blackbird she needs to come in with speed and the nose AoA just barely over horizon. She wants to be flown to the ground, and not like an F-16 in High Alpha either.

He can land the SR-71 with high alpha... but I doubt it always works that well.

https://www.youtube.com/watch?v=t5gIJomxkAE

[Aros]

Yep, it can be done but it's definitely a high wire act.

[MeyerVW]

I was excited to see this bird until, I heard 3 min of flight time. What are you getting for time and what battery, and how do you fly it? Thanks.

[Aros]

I haven't maidened mine yet. Sounds like between 3-4 minutes is the average depending on flying style and battery. Actually right in line with most EDFs.

[GliderGuy]

I was excited to see this bird until, I heard 3 min of flight time. What are you getting for time and what battery, and how do you fly it? Thanks.

Admiral 6S 6000 and getting 3:30 and landing with reserve enough for a go-around and ending with a bit over 3.8V post-flight voltage. Most of my flying is done with a click or two more than 50% throttle stick position and a little 100% hot rodding.

With a total 50% throttle position after take-off, getting a 4 min flight should be possible. It all depends on how much reserve, how low you want to drive the post-flight cell voltage down, your battery condition and capacity, etc.

Pretty much in line with most of my EDF jets.

-GG

PS I try to end with 3.8V so I have a shorter charge time at the field. I get more flights this way.

[DCORSAIR]

I was excited to see this bird until, I heard 3 min of flight time. What are you getting for time and what battery, and how do you fly it? Thanks.

Well it depends on what battery you use and what throttle setting you like to fly it at, I can only get 2:30 flying time out of mine, about 3:00 minutes total counting taxiing out and taxiing back, I throttle back to just over 1/2-3/4 after takeoff and do some cruising around with a couple of full throttle high speed passes. I'm using the red/silver HRB 5000mah 100C batts in mine which are almost brand new and they are a little warm when I return and the cells are around 3.77, 3.80.

I love the jet and it flies really well right out of the box and is a joy to fly but it eats batteries which I do believe in my opinion is the worst I've seen from any of my EDF jets. I just can't fly this SR-71 slow so maybe I could do better but that's boring, full throttle passes are the only way to fly an SR-71..............

[Aros]

Full throttle or no throttle!!