Fully loaded Chinook shot down in Iraq

[Scootter]

Originally posted by miko2d


 Also, Chinook with a three dozen troops is hardly "heavy".

 miko

I contend the a CH-47 with 36 troops is not only heavy but overloaded.


and 12k is above the AC's ceiling of 11,100 ft


Sometimes you think you are soooo smart, little bloopers like can make people question other things you say.


We would not want that, would we?



http://www.boeing.com/rotorcraft/military/ch47sd/ch47sdspec.htm

CH-47D/F Chinook Specifications
Powerplant:
  • Two Textron Lycoming T55-L712 engines
 
 
Rotor System:
  • Three blades per hub (two hubs)
  • Fiberglass construction
  • Speed: 225 r/min
  • Manual folding blades
 
Performance at 50,000 lb:

SL cruise:
 143 kn.
 
Rate of climb:
 1,522 ft/min.
 
Range:
 SL and ISA, 230 nmi.
 
 
Crew:

Cockpit-crew seats:
 2
 
Cabin-troop seats/litters:
 33/24
 
 
Weights:

Max gross:
 50,000 lbs.
 
Empty:
 23,401 lbs.
 
 

--------------------------------------------------------------------------------

[MJHerman]

Originally posted by Scootter
I contend the a CH-47 with 36 troops is not only heavy but overloaded.


and 12k is above the AC's ceiling of 11,100 ft



http://www.boeing.com/rotorcraft/military/ch47sd/ch47sdspec.htm

CH-47D/F Chinook Specifications
Powerplant:
  • Two Textron Lycoming T55-L712 engines
 
 
Rotor System:
  • Three blades per hub (two hubs)
  • Fiberglass construction
  • Speed: 225 r/min
  • Manual folding blades
 
Performance at 50,000 lb:

SL cruise:
 143 kn.
 
Rate of climb:
 1,522 ft/min.
 
Range:
 SL and ISA, 230 nmi.
 
 
Crew:

Cockpit-crew seats:
 2
 
Cabin-troop seats/litters:
 33/24
 
 
Weights:

Max gross:
 50,000 lbs.
 
Empty:
 23,401 lbs.
 
 

--------------------------------------------------------------------------------

I don't know about that.  Let's say that the 36 (plus 3 or 4 crew) are really large people.  So you have 40 people at 250 lbs. each is 10,000 lbs. or 5 tonnes.  I think a Chinook can carry more than that, at least as a slingload.

Also remember that any aircraft runs out of volume before it runs out of lifting capacity, so just because only 30 or so people would actually fit in the aircraft doesn't mean that it can only lift 30 or so people.

[MJHerman]

From the same link:

Weights
  • Max Gross, lbs (kg) - 54,000 (24,493)
  • Empty, lbs (kg) - 25,463 (11,549)
  • Useful Load, lbs (kg) - 28,537 (12,943)
  • Fwd & Aft Cargo Hooks, lbs (kg)
      20,000 (9,072) each
      25,000 (11,340) tandem
  • Center Cargo Hook, lbs (kg)
      28,000 (12,700)

The danger of not reading all of the specs.  

[Scootter]

the term is cubed out (as in cubic feet)

a sling load can be overloaded as it can be droped if you loose an engine, troops on the other are more less eager to jump.

The loadmaster has a set of TO's for the AC loading and I think the seating is a requirment (unless an emergency).

The CH-47 could carry it if you can close the door but you must consider the loss of power.

AC load calculations are not figured with what it can carry with full power, or every time an engine quite the AC would crash.

[Scootter]

Originally posted by MJHerman
From the same link:

Weights
  • Max Gross, lbs (kg) - 54,000 (24,493)
  • Empty, lbs (kg) - 25,463 (11,549)
  • Useful Load, lbs (kg) - 28,537 (12,943)
  • Fwd & Aft Cargo Hooks, lbs (kg)
      20,000 (9,072) each
      25,000 (11,340) tandem
  • Center Cargo Hook, lbs (kg)
      28,000 (12,700)

The danger of not reading all of the specs.  

Useful Load INCLUDES FUEL not just payload


2068 X 6.5 ppg = 13442 lbs  for pods
internal  fuel not given

the danger of not understanding what you are reading

[MJHerman]

Originally posted by Scootter
Useful Load INCLUDES FUEL not just payload


2068 X 6.5 ppg = 13442 lbs  for pods


the danger of not understanding what you are reading

internal  fuel not given;)

OK, point taken, but explain this to me (again being a groundpounder not a flyboy):

How then can you then hang 28,000lbs. on the centre cargo hook?  Or, put another way, why even bother rating the center cargo hook at 14 tons if the bird can only lift 6 as a useful load?  Even assuming minimal fuel, you would still never get close to the rated cargo hook capacity (yes I know that they are overstressed).

My point was that I don't think that carrying 40 very large people is overloaded for a Chinook when I have seen them lift artillery pieces, light armoured vehicles, trucks, down aircraft, etc.

Anyway, I think Scootter answered my inquiry

[MJHerman]

I don't know guys.  The sources I'm seeing say that the CH-47 could lift 44 combat troops or 25,000lbs. of cargo, so someone's numbers/calculations are a bit off.

[Scootter]

In reply I think the specs shown should not state USEFUL LOAD as it does. In avaition useful load includes fuel and in this case it cant as you pointed out.

The load you describe would be (IMO) with an empty AC and with a hand close to the cargo release button.

With breathing cargo you would be at the safe limit with 32 or so people. Don’t forget they had a lot of cargo in the form of gear and going home stuff. So lets say average 200 per man and 100 of gear 9600 in cargo min.

Close to 5 tons or a 105-mm field gun right?   Guessing here


Not a lot of room left over inside for more

I think 36 troops (as stated as not a big load early in this post)

Would take it to 10800 not a small load if they had full fuel (don't know)

Now figure this load needs to keep lifting if you loose an engine and the pilot would agree that its a good load.

Max load (28000) most definitely  would not be with full fuel.

[Scootter]

Originally posted by MJHerman
I don't know guys.  The sources I'm seeing say that the CH-47 could lift 44 combat troops or 25,000lbs. of cargo, so someone's numbers/calculations are a bit off.

D model or F   = 33 troops

The SD has larger engines and and can take 37 in back



cargo ratings include sling load and can be much higher as it can be droped if power is lost

Darn thing can probabley lift 40k with low fuel and a fearless crew

[MJHerman]

Originally posted by Scootter
In reply I think the specs shown should not state USEFUL LOAD as it does. In avaition useful load includes fuel and in this case it cant as you pointed out.

The load you describe would be (IMO) with an empty AC and with a hand close to the cargo release button.

With breathing cargo you would be at the safe limit with 32 or so people. Don’t forget they had a lot of cargo in the form of gear and going home stuff. So lets say average 200 per man and 100 of gear 9600 in cargo min.

Close to 5 tons or a 105-mm field gun right?   Guessing here


Not a lot of room left over inside for more

I think 36 troops (as stated as not a big load early in this post)

Would take it to 10800 not a small load if they had full fuel (don't know)

Now figure this load needs to keep lifting if you loose an engine and the pilot would agree that its a good load.

Max load (28000) most definitely  would not be with full fuel.

The problem with manufacturer's specs. is they mean F-all in the real world

At max load I doubt it would have full fuel since, as you correctly pointed at, you would need full power and/or not have enough power to lift the 28K load.  None of us have any idea as to what the fuel load was on this particular CH-47, but I still say that 40 people does not overload a CH-47 in terms of weight lifting capability.  In terms of volume yes, but not in terms of lifting power (assuming something less than max external and internal fuel).

[MJHerman]

"Close to 5 tons or a 105-mm field gun right? Guessing here"

That, and Bisons (i.e., LAV-25s, LAV IIIs).  I think a Bison is around 13 to 15 tons.

[Raubvogel]

Umm....the CH-47's ceiling is certainly NOT 11,100 ft. Hell,  UH-1 can go past 14k (been there done that). There is a special Army aviation unit in Alaska that has flown over Mt. McKinley in oxygen equipped CH-47s. Typically, you will fly at whatever altitude the big eye-in-the-sky tells you. Even helicopters are usually controlled by AWACS in a combat theater. Lower altitude=lower exposure time to a tracking weapon. But of course, you all knew all this already.

[Scootter]

Originally posted by Raubvogel
Umm....the CH-47's ceiling is certainly NOT 11,100 ft. Hell,  UH-1 can go past 14k (been there done that). There is a special Army aviation unit in Alaska that has flown over Mt. McKinley in oxygen equipped CH-47s. Typically, you will fly at whatever altitude the big eye-in-the-sky tells you. Even helicopters are usually controlled by AWACS in a combat theater. Lower altitude=lower exposure time to a tracking weapon. But of course, you all knew all this already.

Gosh..... Don’t tell me, tell Boeing, it's their site that is posting the info.

You could help them win new contracts with your wisdom

you do know what service Ceiling is right?
at gross right?

http://www.boeing.com/rotorcraft/military/ch47sd/ch47sdspec.htm

[Raubvogel]

Well, I was only a US Army helicopter crew chief for 6 years, so you'll have to pardon my ignorance. That ceiling is at just about max gross weight. I seriously doubt that the Hook shot down was anywhere near that. 1 person is figured at 250lbs for weight and balance purposes on Army aircraft.  36 troops=3 in cabin, 33 in rear. 36x250=9000lbs+25,000lb empty weight=34,000lbs. Even assuming a full fuel load and estimating 2,000gal*7.0 (approx)=14,000lbs. 34,000+14,000=48,000lbs, still well below the max gross weight. I seriously doubt that ammo, guns, etc weigh more than the 6,000lbs that would put it over the top.  Just my 2 cents.

The whole point is still moot though. Army aircraft do not regularly fly anywhere near that high unless they have to for weather or some other reason.

[miko2d]

Scootter: Sometimes you think you are soooo smart, little bloopers like can make people question other things you say.

  I trust the guys have explained to you the difference between the seating capacity and weight load capacity....


Raubvogel: Army aircraft do not regularly fly anywhere near that high unless they have to for weather or some other reason.

 Well, now we know one good reason to stay up.

 miko