Boy, if you don't know when you see an accelerated stall, and need a flight data recorder to figure it out, I sure as heck don't want to be in the riding in the back of your plane.

what's your aviation background? Have you done any type of crash investigation studies? Have you heard eye witness theories on why aircraft went down that sound logical just to be proven by the NTSB to be totally wrong? I never said it wasn't an accelerated stall. If I had to bet on it, because of the position it happened, I'd say it was, but it also could have been a servo failure or a number of other things. My experience tells me to be very humble with theories, because at the end of the day you just don't know unless you can prove it.
We'll all be students of aviation for life, & anyone who thinks otherwise is who you should be afraid of being in your cocpit!

Bunch a [link=http://www.youtube.com/watch?v=5tR3voTMGDY]Maverick's[/link] and [link=http://www.youtube.com/watch?v=1fhKnfZqZvI&feature=related]Aces.[/link]


[sm=tired.gif]

When you exceed the critical angle of attack, a wing can and will depart (stall) at any airpeed and/or attitude.

DING DING DING DING DING!

We have a winner folks!

Beave

They may have all crashed in Cyprus but not necessarily (nor likely) for the same pilot induced reason. If you read the build threads, the "vices" have been widely discussed on the Viper and, as is usually the case, 'work arounds' have been made by the owners. If your comment was based on the tail/rudder and wing connection issues which have caused MANY crashes, you have justification and if SM hasn't corrected them, shame on SM. I have NEVER heard anyone fault the Viper's flight characteristics.

George

Very few jets die of old age, most crash. It's just a matter of time. I have only had one that lasted years & still lives. That is an Avonds F15.
I have just ordered another from Avonds. It is the old style kit. Lovely flyer.

Does anyone know what the words "PROBABLE CAUSE" mean? Even the NTSB uses it in all of their reports. Sure it could have a servo, linkage, bird strike, alien attack, sun spots.....We have a dirty, heavy airplane doing a loop that suddenly rolls and rotates to the ground at the point in the maneuver where the wing loading and angle of attack is probably peaking and pilot's attention is being distracted by a gear problem. Do you think he may have been pulling a little extra at that point to try and secure what he though was a gear problem? HELLO!!!!

George

P.S. And to the pilot's credit, he was probably burning smoke in order to off-load weight for what he though might be a gear failure on landing. I bet under the same circumstances, a lot of us would have done everything the same way and maybe with the same outcome.

For me it looks like one of the flap servos got striped doing the loop causing the plane getting into an spiral.

Something similar happened to me once with my CARF Lightning, I put the flaps and then the plane started to make a roll,
I remove the flaps and I could retrieve, when I landed one of the control horns was loose from the surface, but this was a matter of seconds.

This was my case.

Did you have a flap elevator mixing on during the loop? this would explain the flap movement in different parts of the shooting.

Just one question. WHY the pilot not landed when he had the gear problems???
Instead he opted for continue flying and doing his stuff, then disaster striked .
IMO , and I won't any comments as to the cause , I would have landed immediately,
and checked everything. That's what I've learned in my years of rc. If I see something
wrong, just land, and check.


ENT

Wellll @ 0:46 looks like flaps back up again. My opinion fail-safe gear down . Rc lock out top of the loop with only left aileron Input?? reading from (Ntsb report)

P.S then again after looking at 2:42 and the f-16 crash almost looks the same [X(].

[youtube]http://www.youtube.com/watch?v=ZL7upK2kUqQ[/youtube]

Jan,

Can the pilot himself make some comments here, we like to hear from the black box.

Allan

I have been privately emailed more info regarding the crash from an on-site source who is very knowledgeable regarding the matter (and does not want to get involved here in the forum because of all of the rock-throwing). It's my privilege to pass along the following:

1) The pilot is not an RCU member
2) He has MANY years in RC jets
3) A post-mortem has revealed that there was indeed a radio issue, specifically regarding uncommanded and asymmetric movement on the the flap channel.

Guys, it's natural and inevitable to critique others' performances and actions and there is often a lot to be learned from doing so. We WANT to believe that an expensive jet crashed simply because some guy can't fly very well and/or he screwed up, and that is partly because we don't want to be reminded that there are a lot of non-thumb variables which can waste $10,000 in an instant.

The trick to watching a vid like the one at the top of this thread is to do so while remembering that the "facts" are not always what we percieve them to be and that there is always more info than first meets the eye. Always.

Is it common to control flaps with two separate channels?

How were the flaps setup??

I have not been privately email by anyone that was on-site, or anywhere else for that matter. My source tells me that the email HH received was full of crap. The dual flap channel radio malfunction instigated by a stripped metal servo gear causing RF interference is not true.

No disrespect intended to you HH, as I know you present the email in good faith HH, but it is almost comical that you would completely discount what is plain to see in the video, and go off an email received by a third party, based on nothing more than what somebody wrote. []

Chad

dude, get off your high-horse. no-one is calling you out on what you are saying, but yet someone says something negative towards what differs with your OPINION of the thread and you take offense by it...

Personally, if there was a only gear issue, i would leave the gear down, burn off some fuel/smoke (in other words, get rid of the excess weight) and then land. That way IF their was a gear collapse the airplane would be as light as it could possibly be so the damage is reduced / minimized.

What does "privately emailed" mean ? sounds awefully important to me

Uh.......what?

I am unaware of any reference to a stripped servo etc...

I am not, repeat NOT discounting what is "plain to see in the vid". This aint my first frigging rodeo, dude.

In fact, the vid is the primary reference for my opinion, as previously expressed, that the airplane did not spin or snap. Simply put, the thing was in a spiral (the flightpath one sees in a blown spap or spin where the inside wing doesn't stall) , which is completely different. Both wings have to make lift for it to spiral and fly a corkscrew/barrel flightpath like that. Both wings. Not one. Ergo, no stall, spin, snap etc. ***(see below)

Oh, and lets please not forget that it is you , Chad, would like to "discount" the frames which plainly show one or both flaps in the up position, as interpreted by several observers here.

What is "comical" [:@]is that you attack the email source "based on nothing more than what somebody wrote" even as you yourself are more than willing to forward info based on "nothing more than what somebody said".

Apparently, if someone does not share your opinion of what is and is not presented in the vid or the wreckage post-mortem then they are blind. Or stupid. Or lying. Or all three. Sources that contradict your views are "full of crap" while those which support your opinion are deemed reliable.

That is not comical at all. It's beneath your usually gentlemanly demeanor exhibited in these forums, and it's just sad.

Yes, I took info forwarded to me in the email, which was written to me on behalf of the pilot/owner of the crashed viper, on faith.

I had no reason not to. Neither do you.




**** answer these questions:
1) around which axis does a snap/spin rotate?
2) is the subject viper rotating around that axis?
3) if not, why not?

Fail

Most accel/stall occurr or are demo in horizontal flight as in a dearture stall/spin. They are very infrequently seen by ground observers (or pilots for that matter) in a nearly vertical nose down position. What appears as a spiral in the video is most likely a spin but the entry, because it was nearly vertical, makes it appear different. The explanation of flap/radio was very vague....what is the specific evidence? Again, no way to know for sure, but what is the probability of some kind of interference issue at that most likely point you would expect a stall/spin to happen in this circumstance. PROBABLE CAUSE.

The attitude or direction of the flight path at entry are immaterial, as is the flight path once the spin is established, because the laws of aerodynamics don't care which way the jet is flying. A snap on a down line looks the same as one on an up line or a horizontal one.

If the inside wing had been stalled, regardless of the direction of flight, the jet would have been wrapped up a lot tighter and rotating around it's vertical axis and the center of mass of the airplane would have been traveling in an essentially straight line.

What I see in the vid is a barrel roll on a down line. The flight path in the vid, IMO, is not supportive of the snap/spin theory.

The flight path, when coupled with the apparent evidence of flap anomolies, are why I continue to support/defend a pilot I have never met. There is just too much reasonable doubt to be rubber-stamping this as "pilot error", and doing so completely disgards other scenarios from which we might all learn lessons in an effort to preserve the life spans of out own jets.

I think that the very most a reasonable observer should conclude is that it "might" be pilot error. I view as ill-concieved those opinions which categorise it as "probable", let alone "certainly" or "plainly" pilot error.

Cut. The. Guy. Some. Slack. Already.

Please.

The flight path and the aircraft's inertia ARE material. Anyone who has snapped an aircraft going vertically upward knows. It will not establish a stable downward spin until its inertia is spent, has rolled over and started down. The entry into a spin at stall speed horizontally and level is a whole lot different than going horizontally, vertically upward or downward with lots of inertia. Additionally, the control placements after entry can effect the shape and speed of the rotation. In this case, we have no idea what the pilot was doing with the controls after it rolled right. The ventral fins on the Viper would very likely effect it....they sure do on the Navy's T38C which we found would do an unrecoverable flat spin without them and the strips on the nose cowling (this I have firsthand knowledge of). Also, a stable spin is not usually considered stable until it has rotate vertically downward a minimum of three turns.

I do not think anyone is picking on the pilot or the fellow reporting the incident. I hope you remember it was HIS post and request for evaluation of the video and I think everyone's opinion of the video is as valid as yours. No doubt it could have been a control surface problem, but in the absence of more post-accident specifics to the contrary, we have a dirty heavy airplane with a very high angle of attack and wing loading with a pilot possibility pulling back harder than normal to secure a gear (unless he just decided to do a dirty loop seconds after the nose gear went down). There was no evidence of any control issue prior to the abrupt roll to the right. Unless he reports to us some more specifics about a broken linkage or strip gear, I have to stick with what appears, in my opinion, the probably cause which includes more the the shape of the rotation. If anyone wants to video his Viper doing the exact same maneuver and post it here that might give us some more info too.