What If: CH-47s available for D-Day

[DerAdlerIstGelandet]

Why could Black Hawks operate during the day, and Chinooks not?

Apaches have all their weapons to defend themselves.

I assume because we were a much smaller target. The Chinooks only operated at night when I was there.

 

[DerAdlerIstGelandet]

My original thought was that they would replace C-47s and Gliders in landing troops behind the landing beaches the night before the invasion.

I had thought to replace all C-47s/paratroopers with CH-47s, but there weren't enough CH-47s built to do that.

As to point to point air movements and assault, I would imagine that the CH-47 could place troops much closer to their objective - for example, unloading troops on a road a few miles from a bridge that needs securing.

At night behind the beaches would be viable and work. Afterwards night troop movements.

 

[GrauGeist]

Maybe we should add a wing of Buffs.

Or...since the timeline has been compromised: A-10s.

Eff those Tigers and anything else that walks or crawls.

 

[wuzak]

230 miles radius means the landing ops must be perfect, or the Allies know this time-storm will happen and have carriers stocked with jet fuel to get those heloes up and running again. Or simply do land-and-abandon.

Maybe we should add a wing of Buffs.

Approximately 125 miles between Portsmouth and Caen.

So I think the 230 miles radius should be plenty.

 

[Thumpalumpacus]

Approximately 125 miles between Portsmouth and Caen.

So I think the 230 miles radius should be plenty.

125 miles round-trip is 250 miles -- and that's assuming perfect ops, weather, no resistance -- not happening with that math.

Put the heloes on some flat-tops, then yeah, you might get a first-wave airborne assault. Still gotta figure out how to fuel turbine-powered choppers running on JP-4 when you don't have any of that fuel.

 

[EwenS]

And it assumes you are picking up the airborne troops at Portsmouth. Where? Given all the other forces being moved into the area. These placements of troops, aircraft and their movements were planned months, not weeks, in advance.

The airborne forces departed from airfields further north in Wiltshire, Berkshire etc and as far north as Lincolnshire.

The airfields down on the coast were filled with fighters of 2nd TAF and 9th AF.

Edit:- note how they were routed either side of the assault convoys. No chance of repeating the Sicily debacle. Again adds to distance to be flown.

 

[wuzak]

125 miles round-trip is 250 miles -- and that's assuming perfect ops, weather, no resistance -- not happening with that math.

The combat radius of the CH-47 is listed as 230 miles, not the range.

So a round trip of ~460 miles.

Put the heloes on some flat-tops, then yeah, you might get a first-wave airborne assault. Still gotta figure out how to fuel turbine-powered choppers running on JP-4 when you don't have any of that fuel.

Trying to see what the recommended fuel for the T55 turbines used in the CH-47, but not finding anything.

According to Wiki, JP-4 is a 50:50 mix of kerosine and petrol.

Is fuel going to be that big a problem?

 

[EwenS]

If you run a dozen CVE's into the Channel can't you make multiple flights during the night? Gliders were a one and done affair/C-47s have to go all the way back to an airstrip, but the WWII equivalent of an amphibious assault carrier a little ways off the coast would increase your lift substantially. Then convert the Skytrains into AC-47s - your Chinook crews should be aware of them.

And the CVE captain probably wouldn't be too upset by having all the avgas replaced by kerosene.

CVE flight deck approx 450-470ft long Bogue/Casablanca class. CH-47 is 98ft over the rotors. So max 3 to be ranged safely at a time. And they don't fit in the hangars (too long for lifts, too tall for hangars, even if the rotors could be folded/unfolded quickly).

This was the Thetis Bay in 1963, a Casablanca, converted postwar as an experimental LPH-6. Note the 5 helicopter spots intended for the 20 or so smaller H-34/S58 she was intended to carry. Aft flight deck was cut back to the aft end of the original lift, hence no extra spot right at the stern.

 

[Thumpalumpacus]

The combat radius of the CH-47 is listed as 230 miles, not the range.

So a round trip of ~460 miles.




Trying to see what the recommended fuel for the T55 turbines used in the CH-47, but not finding anything.

According to Wiki, JP-4 is a 50:50 mix of kerosine and petrol.

Is fuel going to be that big a problem?

Well, going by that same Wiki, 230 miles is the combat range -- not radius.

As for fuel being a problem, that depends on where they land, I presume. Or maybe you've got JP-4 sitting around all over, I dunno. Put it where you need it to make the what-if work? *shrug*

 

[GrauGeist]

The early jets (Gloster, Heinkel, etc.) operated with straight Kerosene, so it would have been available.

A fun trivia tidbit that's related: the Chinook's T55 engine is an upscaled T53 gas turbine, which was designed in the 1950's by Anselm Heinz for Lycoming.

Anselm Heinz was the chief designer of the Jumo004 engine.

 

[don4331]

The combat radius of the CH-47 is listed as 230 miles, not the range.

So a round trip of ~460 miles.

Trying to see what the recommended fuel for the T55 turbines used in the CH-47, but not finding anything.

According to Wiki, JP-4 is a 50:50 mix of kerosine and petrol.

Is fuel going to be that big a problem?

Fuel is going to be that big a problem - not because it is difficult to create JP-4, but the volume you require.
CH-47 burns 500 gallons for your 230 mile range flight * 200 choppers = 100,000 gallons of JP-4. Multiply that by 2 or 3 flights/night and you have the fuel problem.
While a CH-47F holds just over 1,000 gallons, full tanks come at the expense of payload (and one does run tanks dry).

Fuel supply can be solved, but it would take time; not something you can drop in the day before the invasion.

 

[Sabrejet]

There must be something on TV surely? Maybe read a book?

 

[wuzak]

Well, going by that same Wiki, 230 miles is the combat range -- not radius.

Sorry, my mistake.

It is, indeed, 230 mile combat range.

 

[EwenS]

Fuel is going to be that big a problem - not because it is difficult to create JP-4, but the volume you require.
CH-47 burns 500 gallons for your 230 mile range flight * 200 choppers = 100,000 gallons of JP-4. Multiply that by 2 or 3 flights/night and you have the fuel problem.
While a CH-47F holds just over 1,000 gallons, full tanks come at the expense of payload (and one does run tanks dry).

Fuel supply can be solved, but it would take time; not something you can drop in the day before the invasion.

US built CVE aviation fuel capacity
Casablanca - 130,000 US gals
Bogue - 186,000 US gals (British manned ships 44,000 Imp gal)

 

[pbehn]

D-Day wasnt like Omaha beach along the complete front. Some beaches faced little opposition and advanced inland quickly, These areas could be used to land stuff that was needed and take out the injured.