engine “wobble”. 

https://www.facebook.com/share/v/1FAJTxX9Qq/?mibextid=wwXIfr

Very cool. 

Whatever happen to the Rain/Precipitation shafts? Anybody know?

Rain stopped. You could just wait and see. There is a lot of flight dynamic changes developers are waiting on. I think that is far more important.

Edited July 31, 2025Jul 31 by mjrhealth

Interesting video of the pod movement. Think they might want to tone that down a lot - you shake an engine about like that then the attachment bolts are going to fail, they are a lot more rigid than people think. 707's had a habit of shedding engine pods for that reason oh and banging them down hard with a word not allowed landing. 

51 minutes ago, coastaldriver said:

Interesting video of the pod movement. Think they might want to tone that down a lot - you shake an engine about like that then the attachment bolts are going to fail, they are a lot more rigid than people think. 707's had a habit of shedding engine pods for that reason oh and banging them down hard with a word not allowed landing. 

It can very likely be adjustable through dataref values. 

I think it is a great concept how it marries with wing flex is not clear. RW engines in pods have a built failsafe they will detach from the wing when the attachment bolts are released by torque forces. Most jet engines have two engine to pod attachments and the pod fairing or arm has an additional two in the wing! They can bounce around a lot in flight in turbulence but generally no - one that is doing that at TKOF power is exhibiting signs of engine imbalance. Very clever to capture this in the sim - my only gripe how to see the engines except in external or cabin view in most tubeliners the cockpit is  so far ahead you cannot even see the wing tips. 747 cockpit gave a good view, 707 not so much. Going to put a failure mode into the dataref I wonder!

14 hours ago, coastaldriver said:

Interesting video of the pod movement. Think they might want to tone that down a lot - you shake an engine about like that then the attachment bolts are going to fail, they are a lot more rigid than people think. 707's had a habit of shedding engine pods for that reason oh and banging them down hard with a word not allowed landing. 

I'm pretty sure that most modern engines mounted with notable leverage would shake that way when in an RPM band that introduces vibrations. And in that case, you would want to allow for some flexing producing movement instead of clamping the engine down as rigidly as possible and thus running the risk of fatigue cracks and catastrophic failures. Remember what happened to the Electra.

 

8 hours ago, coastaldriver said:

Going to put a failure mode into the dataref I wonder!

See "sim/operation/failures/rel_engsep0" (to 7), which detaches an engine from the aircraft. If I interpret datarefs.txt correctly, this also influences "sim/aircraft/overflow/acf_eng_mass", removing the affected engine's weight. Drag and thrust is likely also nullified.

Looking forward to testing 12.3 beta the day it's delivered to the masses. 

@coastaldriver The 787-9 segment with the Trent 1000 provides a great example of very notable nacelle movement on takeoff roll. And I have to correct my statement above: The shaking is not induced by RPM, but by vibrations induced from the ground roll and then transmitted into the airframe, including nacelles/engines. Laminar just showed off the animation while at standstill.

Timestamped:

 

Edited August 2, 2025Aug 2 by Bjoern

2 hours ago, Bjoern said:

The 787-9 segment with the Trent 1000 provides a great example of very notable nacelle movement on takeoff roll.

The wing flex is very noticeable on that roll, but the engine wobble is barely noticeable.

this has been an XP thing for quite a while, at least 4 years.

 

 

 

Edited August 2, 2025Aug 2 by mSparks

1 hour ago, brinx said:

The wing flex is very noticeable on that roll, but the engine wobble is barely noticeable.

My eyes say differently and I'm not even wearing my glasses.

Edited August 2, 2025Aug 2 by Bjoern

6 hours ago, brinx said:

but the engine wobble is barely noticeable.

Are you watching past the first 5 seconds?  

That's when it becomes as noticeable as the XP12 video in the top post.

58 minutes ago, GoranM said:

Are you watching past the first 5 seconds?  

That's when it becomes as noticeable as the XP12 video in the top post.

I watched Bjoern video a few times. I see it but I just think the wobble effect is subtle. You can almost miss it if you are not looking for it. On the other hand, the wing flex is more apparent. 787 is well known for the wing flex though.