correct as is A Near Hover firing rockets disables engine cause loss of power . ?

[KoN]

Twice now I've turned in to a near hover to engage targets using Rockets .

This has Twice caused loss of engine power and a downward spiral into the ground . = Death . 

The First time was on a take off and  use of Rockets on moving targets and the second time on was again on take off while engaging targets .

Both times loosing power and engine failed. 

Is this a Bug . ??? or real life simulation . 

Edited October 29, 2023 by KoN

[AeriaGloria]

Not a bug, it was in the change log when introduced. Under 100 kmh, the smoke ingestion from rockets created a chance of engine compressor stall. 

It won’t happen for every S-5/S-8 shot, but if you use volleys or larger rockets it certainly will. It’s also implemented on Ka-50/Mi-8. 

Just ascending can reduce it, but really you need to be above 100 kmh to stop it. This is reflected in real life documented that gives speed limits for every rocket launch of 100 kmh to max kmh. 

It even caused a Mi-28N crash in about 2007-2008 when they were firing S-8 at about 50-100m altitude, had compressor stall, and crashed into the ground. 
 

https://aviation-safety.net/wikibase/66316

https://russiandefpolicy.com/tag/budennovsk/

Edited October 29, 2023 by AeriaGloria

[Dragon1-1]

Yup, as a rule, engines don't like breathing rocket smoke. Not a problem for most fixed wing aircraft, but it's a big thing in helos.

[KoN]

Wow that's awesome. Thank you . I did think would it be the backfire maybe cause some kind of stall . I've been too busy to read the change logs . Great answer and well done ED. love the hind . 

I'll keep it above 100 . 

Edited October 30, 2023 by KoN

[admiki]

If you fire just one rocket in hover you can see massive engine RPM spike on affected side. 2 or more will cause engine shutdown

[YoYo]

10 hours ago, KoN said:

Twice now I've turned in to a near hover to engage targets using Rockets .

This has Twice caused loss of engine power and a downward spiral into the ground . = Death . 

The First time was on a take off and  use of Rockets on moving targets and the second time on was again on take off while engaging targets .

Both times loosing power and engine failed. 

Is this a Bug . ??? or real life simulation . 

 

No its a feature  . In the real Hind you can notice kind of „flameout” too. Notice also that Mi-24 is a kind a helicopter for run attack only (during movement you can reach less smoke which gets to the engines, so better to attack from run, not from the hover). As I remember during the testing weapons in the real Hind (during developement process) Russians testers had the big problem with unguided rockets with bigger caliber. Smoke from rocket engine was very dangerous and they finally banned the use of large caliber rockets.

[AeriaGloria]

5 hours ago, YoYo said:

No its a feature  . In the real Hind you can notice kind of „flameout” too. Notice also that Mi-24 is a kind a helicopter for run attack only (during movement you can reach less smoke which gets to the engines, so better to attack from run, not from the hover). As I remember during the testing weapons in the real Hind (during developement process) Russians testers had the big problem with unguided rockets with bigger caliber. Smoke from rocket engine was very dangerous and they finally banned the use of large caliber rockets.

Anything I can read about the banning of large caliber rockets? I know they restricted use of S-24 on Su-25 for smoke ingestion, and that S-25 rocket on Mi-24 didn’t work out, but haven’t heard much else about the banning of large caliber rockets 

[YoYo]

4 hours ago, AeriaGloria said:

Anything I can read about the banning of large caliber rockets? I know they restricted use of S-24 on Su-25 for smoke ingestion, and that S-25 rocket on Mi-24 didn’t work out, but haven’t heard much else about the banning of large caliber rockets 

Yes, what I was writing concerns the weapon testing phase during the development process of the Mi-24. There were very big problems with the S-24, but larger calibers were also tested. After this, these tests were banned, only S-24 option was left, but with big problems anyway, that I know.

[FusRoPotato]

Why was something that came up as a rare possibility turned into a guaranteed happens every time issue?

Maybe the effect possibility is correct, but are its chances correct? By the descriptions I'm seeing, sounds overdone. Not like that kind of thing has never happened before around here.

Edited November 11, 2023 by FusRoPotato

[admiki]

4 hours ago, FusRoPotato said:

Why was something that came up as a rare possibility turned into a guaranteed happens every time issue?

Maybe the effect possibility is correct, but are its chances correct? By the descriptions I'm seeing, sounds overdone. Not like that kind of thing has never happened before around here.

 

How did you figure out it's a rare possibility?

Real life Hind pilot manual states it's prohibited to fire rockets below 100 kph. They had their reasons. What are you reasons for your statement?

[AeriaGloria]

Yeah, Mi-8 manual says the same thing. So does Ka-50 manual. It seems like from the crash that I linked, the Russian got complacent and tried it with Mi-28 and small salvos and got punished for it. I wish the video of it was still around, but they weren’t doing large salvos. Maybe 2-3 small pair launches, then crash 

I would be more surprised what you are trying to do with rockets below 100 kmh? They aren’t very accurate or have good range in a hover, and can’t use the Mi-24s amazing speed 

[FusRoPotato]

19 hours ago, admiki said:

How did you figure out it's a rare possibility?

Real life Hind pilot manual states it's prohibited to fire rockets below 100 kph. They had their reasons. What are you reasons for your statement?

The reason is because of something called a safety factor. Just because it's against a rule or regulation due to safety doesn't mean the dangerous outcome is guaranteed to happen when you do it anyways. Perfect example of this is G limits and crack propagation. 

If you can't prove for a fact that an engine will stall every time a rocket is fired, or have a credible and definitive reference and proof such outcome is expected based on numerous case reports, research, and CFD, but instead base that assumption on rules, regulations, and secondhand stories, you are making an assumption.

On 10/29/2023 at 4:27 PM, AeriaGloria said:

It even caused a Mi-28N crash in about 2007-2008 when they were firing S-8 at about 50-100m altitude, had compressor stall, and crashed into the ground. 

 

There's video of it. Definitely not an S-8. That's not documented and was obviously something much much larger.

[admiki]

Well, if you cant prove it won't happen, I'll stick with manufacturer's limitation, TYVM

[bingbean]

You can find now lots of videos where Mi-24 or Ka-52 fly extremely low , then pitch up slow down extremely and shop all rockets in to sky.

https://youtube.com/shorts/pLb0256NuVk?si=ivNlh0bebvcEA2kN

 

[AeriaGloria]

3 hours ago, bingbean said:

You can find now lots of videos where Mi-24 or Ka-52 fly extremely low , then pitch up slow down extremely and shop all rockets in to sky.

https://youtube.com/shorts/pLb0256NuVk?si=ivNlh0bebvcEA2kN

 

Tables in the manual for rocket lofting have a minimum speed of 200 kmh. So depends on definition of “slow down” 

6 hours ago, FusRoPotato said:

The reason is because of something called a safety factor. Just because it's against a rule or regulation due to safety doesn't mean the dangerous outcome is guaranteed to happen when you do it anyways. Perfect example of this is G limits and crack propagation. 

If you can't prove for a fact that an engine will stall every time a rocket is fired, or have a credible and definitive reference and proof such outcome is expected based on numerous case reports, research, and CFD, but instead base that assumption on rules, regulations, and secondhand stories, you are making an assumption.

There's video of it. Definitely not an S-8. That's not documented and was obviously something much much larger.

Why do you say it was definitely not an S-8? What I remember from the video of the crash it was an S-8, easily identifiable by the pod and the fact that Mi-28 hardly used any other unguided rockets at the time in 2008 when the crash from rocket exhaust ingestion occurred. I do not know why you would say it is undocumented when it was 

It is a flight limitation across all TV3/VK-2500 platforms firing rockets, I do not know what you expect ED to do. 
 

You can already often get away with single firing of single pairs of rockets. I’ve seen the Ka-50 people do it. You just can’t do volleys. You want to be able to fire more rockets without engine surge? 

[FusRoPotato]

On 11/12/2023 at 5:24 AM, AeriaGloria said:

 

Why do you say it was definitely not an S-8?

Why don't you watch the video linked in the incident you shared and look at the smoke trail? Then go look at videos of an S-8 salvo. An S-8 is not going to engulf an entire helicopter in black smoke. 

[admiki]

It's really grainy video, but nevertheless, manual prohibits firing of ANY rocket type below 100 kph. That's good enough for me.

Unless you have proof that rocket salvo will not result in engine shutdown, ED shouldn't change a thing.

On 11/12/2023 at 11:05 AM, bingbean said:

You can find now lots of videos where Mi-24 or Ka-52 fly extremely low , then pitch up slow down extremely and shop all rockets in to sky.

https://youtube.com/shorts/pLb0256NuVk?si=ivNlh0bebvcEA2kN

 

As AG said, even with slowing down, it still had quite a speed at left exit turn. That's not the same.

BTW, did you know that Apache has the same "no rockets from hover" limit?

[admiki]

On 11/12/2023 at 11:05 AM, bingbean said:

You can find now lots of videos where Mi-24 or Ka-52 fly extremely low , then pitch up slow down extremely and shop all rockets in to sky.

https://youtube.com/shorts/pLb0256NuVk?si=ivNlh0bebvcEA2kN

 

I finally did some testing. Doing 150 kph, which is really not that fast for the Hind, pulling up and firing long salvos, I finished with 100 kph on the clock.

Did another test, flying level at 80 kph and firing long salvos, nothing happened.

[AeriaGloria]

5 hours ago, FusRoPotato said:

Why don't you watch the video linked in the incident you shared and look at the smoke trail? Then go look at videos of an S-8 salvo. An S-8 is not going to engulf an entire helicopter in black smoke. 

My country has blocked the website

[Raptor9]

5 hours ago, admiki said:

BTW, did you know that Apache has the same "no rockets from hover" limit?

There is no such limit for the AH-64.

[admiki]

53 minutes ago, AeriaGloria said:

My country has blocked the website

It's YT link

50 minutes ago, Raptor9 said:

There is no such limit for the AH-64.

• Firing MK66 in a hover or low speed at
a height of less than 7 ft AGL, and for
all other flight conditions of 5 ft AGL,
is not authorized.

and

• Due to the possibility of surging the
engines, do not fire rockets from inboard
stations. Fire no more than
pairs with two outboard launchers every
three seconds, or fire with only
one outboard launcher installed without
restrictions (ripples permitted).

 

If I misunderstood something, I apologize.

Edited November 14, 2023 by admiki

[AeriaGloria]

3 minutes ago, admiki said:

It's YT link

• Firing MK66 in a hover or low speed at
a height of less than 7 ft AGL, and for
all other flight conditions of 5 ft AGL,
is not authorized.

and

• Due to the possibility of surging the
engines, do not fire rockets from inboard
stations. Fire no more than
pairs with two outboard launchers every
three seconds, or fire with only
one outboard launcher installed without
restrictions (ripples permitted).

Huh thanks, looks like they were doing small pair firings first which were fine, then one large salvo finished it off. Don’t know how that could be anything but S-8 unless it was carrying two types at once

[admiki]

IDK, but smoke trail does look huge for S-8. Again, it's really grainy video, so.....

[Raptor9]

7 hours ago, admiki said:

BTW, did you know that Apache has the same "no rockets from hover" limit?

1 hour ago, admiki said:

• Firing MK66 in a hover or low speed at
a height of less than 7 ft AGL, and for
all other flight conditions of 5 ft AGL,
is not authorized.

and

• Due to the possibility of surging the
engines, do not fire rockets from inboard
stations. Fire no more than
pairs with two outboard launchers every
three seconds, or fire with only
one outboard launcher installed without
restrictions (ripples permitted).

Nowhere does it say that rockets cannot be fired from a hover. In fact, firing rockets from AH-64's while in a hover is routinely practiced. Firing rockets (or missiles) when hovering or flying at very low altitudes over the surface is a hazard because the munitions themselves may impact the ground near the helicopter; it is not because of the risk of ingesting rocket motor exhaust.

Firing rockets from inboard pylons or in large salvos carries an increased possibility of the AH-64 engines surging, which is why that restriction is written. However, it is certainly feasible to do so (and was also employed on regular occasions in the past, despite folklore claiming otherwise); but given the increased risk, this is a practice that is avoided nowadays. It's a matter of statistical likelihood versus the unnecessary risk of doing so.

(AH-64D's ripple firing from two outboard launchers in large salvos as a demonstration in 2015)

Anyway, this AH-64 talk is of course a little off topic in the Mi-24 section, but I wanted to bring some context to some of the rumors regarding the subject.

[admiki]

I'll admit that I am an idiot and completely missed to connect those 2 rows regarding hover and low alt. Thanks for clarification