Jump to content

Apache Crash in Afghanistan


Recommended Posts

He wasn't showing off. That's a standard Return to Target turn and may have been their regular method of approach into that LZ due to winds, terrain, etc. Looks to me like they got into some settling with power on the descent due to high density altitude and too great a rate of descent. The impact snapped the tailboom and damaged the tail rotor driveshaft. The corresponding massive addition of power to pull out probably finished the job on the tail rotor driveshaft, resulting in the spin you see at the end. Glad both crewmen survived. I've got a couple friends from flight school in that battalion.

Jon

Edited by Cobrahistorian
Link to post
Share on other sites

He wasn't showing off. That's a standard Return to Target turn and may have been their regular method of approach into that LZ due to winds, terrain, etc. Looks to me like they got into some settling with power on the descent due to high density altitude and too great a rate of descent. The impact snapped the tailboom and damaged the tail rotor driveshaft. The corresponding massive addition of power to pull out probably finished the job on the tail rotor driveshaft, resulting in the spin you see at the end. Glad both crewmen survived. I've got a couple friends from flight school in that battalion.

Jon

Thanks for the informative post :thumbsup:

Link to post
Share on other sites

Whooohooo! I didnt get in, like Jon did, but being aroudn Ft Rucker and having a personal relationship with the mechs out there, I am glad to hear they got out ok! i love to see those birds when I go home! It is what the wiregrass is all about, Army Aviation!

Also, shout out to our residents on this site! Great resource Mr Bernstein! Good to have you guys aboard!! Now back to those -47's, or whatever you have in the works. We need some good books!!

-Jim

Link to post
Share on other sites

He wasn't showing off. That's a standard Return to Target turn and may have been their regular method of approach into that LZ due to winds, terrain, etc. Looks to me like they got into some settling with power on the descent due to high density altitude and too great a rate of descent. The impact snapped the tailboom and damaged the tail rotor driveshaft. The corresponding massive addition of power to pull out probably finished the job on the tail rotor driveshaft, resulting in the spin you see at the end. Glad both crewmen survived. I've got a couple friends from flight school in that battalion.

Jon

I thought the air gets less dense with altitude - at least at terrestrial altitudes? Glad no-one was hurt.

Too great a rate of descent and mountainous terrain do not a good Martini make.

Darius

Link to post
Share on other sites

I thought the air gets less dense with altitude - at least at terrestrial altitudes? Glad no-one was hurt.

Too great a rate of descent and mountainous terrain do not a good Martini make.

Darius

High density altitude does NOT mean the air is dense. It means the air is LESS dense because you are higher (weather, temperature and humidity can also have factors as well). I've heard the term used and admittedly it sounds confusing, but if you leave out the word density and it makes sense. So, at higher altitudes, there is less air molecules to move and things become more sluggish. I can only imagine what that would do to a helicopter.

Edited by Jay Chladek
Link to post
Share on other sites

High density altitude does NOT mean the air is dense. It means the air is LESS dense because you are higher (weather, temperature and humidity can also have factors as well). I've heard the term used and admittedly it sounds confusing, but if you leave out the word density and it makes sense. So, at higher altitudes, there is less air molecules to move and things become more sluggish. I can only imagine what that would do to a helicopter.

So what should be written is "high altitude density". Use of English old boy, use of English. Always better to use clear unambiguous writing - especially in an accident report.

:cheers:

Darius

Link to post
Share on other sites

Aircraft pressure instruments (altimeter, ASI, VSI) are modelled on the International Standard Atmosphere(ISA). Density Altitude basically takes into account the conditions of the day namely pressure and temperature and resolves it through ISA to give the pilot an indication of the altitude at which his aircraft will perform.

Say for an example you could be physically sat on the deck at sea level but because of the actual air temp(e.g. >15 degrees C) and pressure(e.g. <1013Hpa) you would be at a higher 'density' altitude, and this is where the engines & rotors would perform as if they were at.

correct me if i am wrong but 'settling with power' is that the american for 'vortex ring'?

Glad the crew are ok!

Ta

B

Edited by bazman74
Link to post
Share on other sites

So what should be written is "high altitude density". Use of English old boy, use of English. Always better to use clear unambiguous writing - especially in an accident report.

:cheers:

Darius

Hello Darius,

Just a quick note to clear the air. "Density Altitude" is an aviation term, and used in aircraft performance calculations. In a nutshell, aircraft get better performance at lower altitudes, and lesser performance at higher altitudes where the density is lower. When the temperature is high and the pressure is lower than standard, performance equals that of a higher altitude.

For example, my local airport is about 750ft MSL. In the summer when the temperature is high (28C or above, typically), the performance will equal that of the performance at say around 4000ft MSL. Meaning poor climb rates, longer takeoff roll, etc. So the weather report for the airport will include Density Altitude information.

You are correct in thinking that it should be worded "High Altitude Density", becuase it can be confusing for many pilots when they're first learning (at least it was for me!). I would even prefer "performance altitude" or something similar.

Aaron

Aircraft instruments are modelled on the International Standard Atmosphere(ISA). Density Altitude basically takes into account the conditions of the day namely pressure and temperature and resolves it through the ISA (Instruments) to give the pilot an indication of the altitude at which his aircraft will perform.

Say for an example you could be physically sat on the deck at sea level but because of the actual air temp(e.g. >15 degrees C) and pressure(e.g. <1013Hpa) you would be at a higher 'density' altitude, and this is where the engines & rotors would perform as if they were at.

correct me if i am wrong but 'settling with power' is that the american for 'vortex ring'?

Glad the crew are ok!

Ta

B

I wouldn't say the instruments are modelled or based on ISA, but most performance calculations and charts are based on ISA, and ISA Deviation.

Aaron

Edited by jester292
Link to post
Share on other sites

I'm sorry, but there is no way that wasn't hot-dogging or showing off. That might be a normal return to target maneuver...but a normal approach due to winds and terrain?? Please.

That's just a perfect example to show why in my two last companies ALL the hot-starts, and ALL the over torques were done by ex-army pilots.

Not a single one of them impressed me with their flying skills, what was impressive was their knowledge of the aircraft they USED to fly. Ask them to tensile strength of the rivets holding an Apache or 58 Delta tail boom together and they will tell you from heart. Ask them to fly a normal approach to a small elevated heli deck in fully laden 407 or L4...well..

That being said...there are obviously some BRILLIANT pilots out there poling military hardware around...not denying that in the slightest.

I was trained by one of them, and do my recurrency training with a couple of them, so I know they are out there...but in general military trained pilots are very unimpressive in a civilian setting.

And that "normal" approach was definitely not very impressive. Going into the training archive right next to the "normal" flight between trees.

One of the criteria for settling with power is little or no forward airspeed. From end of the turn until they hit the ground they picked up a lot of speed, hence it wasn't settling with power. You don't need many knots to get out of SWP. Looks to me like they either miscalculated the density altitude, or did the turn out of wind and lost too much altitude as a result.

Glad they survived, and I hoped they learned something! And they owe that guy they almost killed a few beers and a new set of Haynes.

Ken

Edited by Helidriver
Link to post
Share on other sites

I'm sorry, but there is no way that wasn't hot-dogging or showing off.

Read a report online that the Army is taking a hard look at this being a case of hot-dogging. Without being a pilot or knowing anything about the specifics of the incident, it sure looked to be an extremely aggressive maneuver. I've flown in / observed hundreds of Army helos land and have never seen anything close to a landing maneuver like that.

Looked more like they wanted to put on airshow for the grunts (and it sounds like they succeeded from the comments in the background of that tape). It seems awful coincidental that they just happened to have a camera rolling when these guys came in. Almost like they knew in advance that this was going to be something a bit out of the ordinary (which it certainly was).

If this turns out to be the case, the crew should get booted out of the service. They could have killed a lot of guys that day.

Link to post
Share on other sites

Link?

Doesnt need a link, as an investigation was started over a month ago. At the very least with that incident an officer is appointed to do a 15-6 from outside the pilot's company, and a FLIPL and AGAR are conducted by an officer. As far as the link provided by Helidriver or anyone else at this time I'd take it with a grain of salt. When the investigation is done it'll hit the print.

Link to post
Share on other sites

Aircraft pressure instruments (altimeter, ASI, VSI) are modelled on the International Standard Atmosphere(ISA). Density Altitude basically takes into account the conditions of the day namely pressure and temperature and resolves it through ISA to give the pilot an indication of the altitude at which his aircraft will perform.

I've yet to actually fly in an aircraft that displayed Density Altitude on any sort of gauge, only Pressure Altitude. There was a chart to convert to Density altitude for aircraft performance calculations in the manual, but that was it.

Admittedly, all of the aircraft I've flown are a bit older, so maybe there is a more modern solution that actually shows Density Altitude.

Cheers,

Hoops

Link to post
Share on other sites

He wasn't showing off. That's a standard Return to Target turn and may have been their regular method of approach into that LZ due to winds, terrain, etc. Looks to me like they got into some settling with power on the descent due to high density altitude and too great a rate of descent. The impact snapped the tailboom and damaged the tail rotor driveshaft. The corresponding massive addition of power to pull out probably finished the job on the tail rotor driveshaft, resulting in the spin you see at the end. Glad both crewmen survived. I've got a couple friends from flight school in that battalion.

Jon

been in five helecopters that went down one way or another, and there is no good way in my book. The real problem with them is that they rarely give you any serious warning that things are not right till the chain of events starts to take place. They also are very sensitive to air density and temperatures with load outs factored in. His run looked ever so slightly low, but wouldn't call him out on it as being that close to the target makes for better gunnery. Looks to me like he simply lost the air density which in the end makes him loose lifting power. Pretty violent crash even for a chopper, and was surprised there was no fire! Probably a good thing the chopper was CBL'd as it'd have smelled really bad forever. In a guy that's on the line this guy is what you always wanted. He took the strike right down to where he could smell the bad guy's bad breath. He probably has a very high KIA ratio.

gary

Link to post
Share on other sites

That's what happens when your main rotor is turning and your tail rotor isn't.

I was in one that had the last five feet of the tail boom shot off. By the time it was near the ground I was checking my load out thinking this wasn't gonna be fun in three or four minutes

gary

Link to post
Share on other sites

I'm sorry, but there is no way that wasn't hot-dogging or showing off. That might be a normal return to target maneuver...but a normal approach due to winds and terrain?? Please.

That's just a perfect example to show why in my two last companies ALL the hot-starts, and ALL the over torques were done by ex-army pilots.

Not a single one of them impressed me with their flying skills, what was impressive was their knowledge of the aircraft they USED to fly. Ask them to tensile strength of the rivets holding an Apache or 58 Delta tail boom together and they will tell you from heart. Ask them to fly a normal approach to a small elevated heli deck in fully laden 407 or L4...well..

That being said...there are obviously some BRILLIANT pilots out there poling military hardware around...not denying that in the slightest.

I was trained by one of them, and do my recurrency training with a couple of them, so I know they are out there...but in general military trained pilots are very unimpressive in a civilian setting.

And that "normal" approach was definitely not very impressive. Going into the training archive right next to the "normal" flight between trees.

One of the criteria for settling with power is little or no forward airspeed. From end of the turn until they hit the ground they picked up a lot of speed, hence it wasn't settling with power. You don't need many knots to get out of SWP. Looks to me like they either miscalculated the density altitude, or did the turn out of wind and lost too much altitude as a result.

Glad they survived, and I hoped they learned something! And they owe that guy they almost killed a few beers and a new set of Haynes.

Ken

gotta dissagree with you about the kid piloting that chopper. His attack may look scarey, but it's just what the line guy is looking for. He could fly strikes for me anytime

gary

Link to post
Share on other sites

In a guy that's on the line this guy is what you always wanted. He took the strike right down to where he could smell the bad guy's bad breath. He probably has a very high KIA ratio.

gary

Are current Apache tactics such that you are supposed to be chasing the bad guys 3' off the deck? You don't need the cannon then, you can just hit them with your tail wheel at 100 knots. Saves the taxpayer a bunch on ammo costs.

He might be a great pilot to be supporting me in combat but I am not so sure I'd want to fly with this guy.

Link to post
Share on other sites
Guest
This topic is now closed to further replies.
×
×
  • Create New...