Freewing 90mm F-22 Raptor - Official Thread

Collapse
X
Collapse
First Prev Next Last
 
  • Time
  • Show
Clear All
new posts
  • Airguardian
    Post Stall Svengali

    • Aug 2020
    • 1662
    • Catalonia
    • Send PM

    #3821
    Tip stall is when the airflow detaches from the tip of the wing. On most backwards-sweep designs, tip stall also implies you partially or totally lose aileron control. To make things worse, tip stall will pretty much never occur in a symmetric way, so it causes the plane to yaw and roll out of control. Attempting to roll the plane back level only worsens the condition (due to asymmetric drag from the stalled tips) and instead gotta try to compensate with rudder when possible, or at least a combination of rudder and roll.

    Tip stalls are usually not a big deal on a plane like the F-22 because you don't really lose roll control when the jet stalls, particularly if you have tailerons enabled.
    That's not to say the plane can't depart controlled flight, but in the case of the F-22 that's more due to a lack of lateral stability once the vertical stabs get deprived from clean airflow due to building excessive angle of attack and not having ventral fins to compensate. #stealth

    This said, you will more likely tip stall from planes being nose heavy than tail heavy. Nose heavy planes load more their wings, so you are constantly flying closer (in terms of AoA) to tip stalling. Having a nose heavy CG also makes corkscrewing dynamics much worse, further complicating tipstalls. So no, I don't think you experienced a tip stall on your F-22 because of being tail heavy. You probably just exceed too much AoA and lost directional stability.

    If you had SAFE active, and being that an auto-level stabilization mode, chances are, once you lost speed, and hence, control authority, the plane started rolling and the gyro commanded counter-roll to compensate. In a near stall condition, counter roll will not actually produce a rolling outcome but instead a yawing in the opposite direction, what is used to flat spin these jets without thrust vectoring. Only you probably weren't commanding it consciously, but rather flying in SAFE mode turned out to be not that safe... I still encourage to use gyros in normal 'rate' stabilization mode and totally forget about auto level options (SAFE included) or just keep them for emergency situations in case you lose orientation. Flying with SAFE by default is outright dangerous IMO.

    Comment

    • jasmith41
      EDF-obsessed
      • Sep 2021
      • 316
      • AZ and NE Ohio
      • Send PM

      #3822
      Originally posted by Airguardian
      T
      As always, you're a wealth of information - thank you for all of that as well - very helpful. However, i was flying the eflite viper 90mm that fell out of the sky, and you're exactly correct - it started flailing like a fish out of water (yaw and roll) when it tip stalled... twice... :)

      Comment

      • Airguardian
        Post Stall Svengali

        • Aug 2020
        • 1662
        • Catalonia
        • Send PM

        #3823
        Thanks, I'm pretty invested into this stuff! ^^
        I don't know much of a lot of things, but I know quite a bit about this topic, so there's that ;)

        Here's a new video of a complete flight session at dusk.


        Comment

        • jasmith41
          EDF-obsessed
          • Sep 2021
          • 316
          • AZ and NE Ohio
          • Send PM

          #3824
          Originally posted by Airguardian
          Thanks, I'm pretty invested into this stuff! ^^
          I don't know much of a lot of things, but I know quite a bit about this topic, so there's that ;)

          Here's a new video of a complete flight session at dusk.


          the inverted high-alpha stuff is crazy....

          Comment

          • Airguardian
            Post Stall Svengali

            • Aug 2020
            • 1662
            • Catalonia
            • Send PM

            #3825
            I have some even crazier stuff in the works, wait for it :p

            Comment

            • Airguardian
              Post Stall Svengali

              • Aug 2020
              • 1662
              • Catalonia
              • Send PM

              #3826
              Speaking of...

              Comment

              • Dan McKeag
                Member

                • Sep 2020
                • 22
                • Send PM

                #3827
                b Click image for larger version

Name:	IMG_4105.jpg
Views:	779
Size:	147.8 KB
ID:	345986Click image for larger version

Name:	20220515_102804.jpg
Views:	771
Size:	186.6 KB
ID:	345987Click image for larger version

Name:	20220515_105324_resized.jpg
Views:	738
Size:	79.9 KB
ID:	345988Click image for larger version

Name:	20220515_105345_resized.jpg
Views:	759
Size:	52.4 KB
ID:	345989Click image for larger version

Name:	20220515_105357_resized.jpg
Views:	751
Size:	72.2 KB
ID:	345990
                Here is some fun I had this weekend at Ellsworth AFB with my F22. The F22 Demo pilots and flight crew autographed my plane. What a class act they are. Our club ( Rapid City Propbusters) had a display booth at the show and when I walked up to their promotions tent the crew chief grabbed the plane from me and took it to the flightline. They then delivered it back to our booth a few hours later.

                Comment

                • Aros
                  Lead Adminstrator / Warbirdaholic

                  • May 2013
                  • 8202
                  • Astoria, OR
                  • Send PM

                  #3828
                  How cool is that?!?! Thanks for sharing!
                  My YouTube RC videos:
                  https://www.youtube.com/@toddbreda

                  Comment

                  • Mud Duck
                    Member
                    • Feb 2022
                    • 46
                    • Send PM

                    #3829
                    Ok guys, need some help identifying the proper location for these screws. The illustrations in the instructions leave a lot to be desired. In the attached photo are the three sets of screws which I’ve numbered 1., 2., & 3. I am 95% confident that #3 are the wing screws, but I’m not clear on which ones (1 or 2) go to the horizontal stabs or vertical fins. They all call for 10mm screws and they all measure 10mm and my friend cut up the order of the bag before I could properly identify them with the legend. Thanks for the help!
                    Attached Files

                    Comment

                    • crxmanpat
                      Certified Foam Abuser

                      • Oct 2014
                      • 2464
                      • Crawfordville, FL
                      • Send PM

                      #3830
                      Originally posted by Mud Duck
                      Ok guys, need some help identifying the proper location for these screws. The illustrations in the instructions leave a lot to be desired. In the attached photo are the three sets of screws which I’ve numbered 1., 2., & 3. I am 95% confident that #3 are the wing screws, but I’m not clear on which ones (1 or 2) go to the horizontal stabs or vertical fins. They all call for 10mm screws and they all measure 10mm and my friend cut up the order of the bag before I could properly identify them with the legend. Thanks for the help!
                      1 = Horizontal stab pivot pins

                      2 = Vertical Stabs

                      3 = Wing screws
                      Pat

                      Comment

                      • Evan D
                        I'll fly anything

                        • Jan 2016
                        • 5384
                        • Charlotte
                        • Send PM

                        #3831
                        P3 install vertical tail step 1 KA3x10mm, your #2
                        P3 install horizontal tail step 1 PT3x10mm, your #1
                        P3 install main wing step 2 PWM4x10mm, your #3

                        Comment

                        • xviper
                          Hobby Squawk Regular

                          • Jan 2014
                          • 8747
                          • Calgary, Canada
                          • Send PM

                          #3832
                          Yes, #3 are the wing screws for sure because they are the only 8mm screws in the kit. As for the others, see page 3 of the assembly manual. It tells you what every screw is called and what lengths they are and how many there are. Use that as your guide. I don't have easy access to my plane or I'd tell you exactly where each goes. You've only got 4 types of screws:
                          KA3x10 (4pcs.); PM2x4 (2pcs); PT3x10 (4 pcs); PWM4x8 (4pcs)
                          You've eliminated the wing screws. #1 and #2 in your picture are the only ones that are 10mm long. #1 is a KA and #2 is a PT. The others can be measured and are different from each other. Notice how KA is tapered on the underside of the head. That's a "countersunk" screw (K is for "K"ountersunk - Google will show you what the head looks like), so you know those hold the verticals on. That leaves the PTs and page 3 tells you where those go.

                          Comment

                          • Evan D
                            I'll fly anything

                            • Jan 2016
                            • 5384
                            • Charlotte
                            • Send PM

                            #3833
                            The pointy taper head screws go into a plastic tube to attach the verticals. The pan heads have flat points to bottom onto the metal horizontal pivot shaft.

                            Comment

                            • Mud Duck
                              Member
                              • Feb 2022
                              • 46
                              • Send PM

                              #3834
                              Thanks everyone, that has been cleared up magnificently. 🙏

                              Comment

                              • Airguardian
                                Post Stall Svengali

                                • Aug 2020
                                • 1662
                                • Catalonia
                                • Send PM

                                #3835
                                Originally posted by Dan McKeag
                                Here is some fun I had this weekend at Ellsworth AFB with my F22. The F22 Demo pilots and flight crew autographed my plane. What a class act they are. Our club ( Rapid City Propbusters) had a display booth at the show and when I walked up to their promotions tent the crew chief grabbed the plane from me and took it to the flightline. They then delivered it back to our booth a few hours later.
                                Orsum!


                                Comment

                                • Dan McKeag
                                  Member

                                  • Sep 2020
                                  • 22
                                  • Send PM

                                  #3836
                                  Originally posted by Airguardian

                                  Orsum!

                                  I told the pilots that the model was as maneuverable or more so than their planes and played your latest video for them to prove the point.

                                  Comment

                                  • Airguardian
                                    Post Stall Svengali

                                    • Aug 2020
                                    • 1662
                                    • Catalonia
                                    • Send PM

                                    #3837
                                    Now that's triple Orsum!!!


                                    Thanks!
                                    How did they react? :D

                                    Comment

                                    • Aros
                                      Lead Adminstrator / Warbirdaholic

                                      • May 2013
                                      • 8202
                                      • Astoria, OR
                                      • Send PM

                                      #3838
                                      Cool thing about the hobby...I remember I was loading some jets into my car after some sorties years back and this older gent pulled over and ooooh'd and aaaah'd over them...We got to talking and it turns out he was a 747 captain for over 30 years. Cracked me up, here's this man who has flown this massive aircraft, carrying numerous souls for all those years and he's oogling over my $500 foam jets.

                                      My YouTube RC videos:
                                      https://www.youtube.com/@toddbreda

                                      Comment

                                      • Evan D
                                        I'll fly anything

                                        • Jan 2016
                                        • 5384
                                        • Charlotte
                                        • Send PM

                                        #3839
                                        Having been military and into models for so long I have been part of exhibits and demonstrations during which both the Blue Angels and Thunderbirds and did their routines. At each one where we flew our models at the same demonstration I have to say the models had as much attention as the full scale.

                                        Comment

                                        • davegee
                                          Senior Member

                                          • Nov 2013
                                          • 2648
                                          • Cody, WY
                                          • Send PM

                                          #3840
                                          deleted post, not specifically about F-22

                                          Comment

                                          Working...