Know your Apache and Chinook

Know your Apache and Chinook

   After years long delay, Finally India signs the deal with US to buy 22 Apache Attack helicopters and 15 Chinook heavy lift Helicopters along with associated equipment's valued $3 billions, the deal was finalized early 2010 by Boeing and India, and Boeing keeps the same price for more than 13 times before signing the deal, so far the signing details not available for public release however the FMS - foreign Military sales document clearly says  Apache would be the AH 64 Block III variant that's the AH 64 E, the most modern helicopter in service with US forces, however no clear information available for which variant of CH 47 would be delivered, as per earlier suggestions in 2010, The CH 47 F would be acquired, and recent time US moved with much modern MH 47 G versions.

   There is no doubt that AH 64 is the most advanced attack helicopter ever developed, during the race with Russian Mi 28, Apache impressed the Indian officials with network centric capability, low flying capability and easy weapon handling, along with fire and forget anti armor missiles and 30mm chain gun impressed the IAF officials very much. the initial plan is to buy 22 apache helicopters followed by another 11 Helicopters in future, that's only for the air force, also Army too insisting the Ministry to buy a set of 39 Apache helicopters, however both follow on order and Army's requests put on hold as of now.

   Apache is an low observable helicopter, when it flies very low, no radar will see it, during the initial stage of attack in Iraq, Apache leads the role by destroying Iraqi early warning radar's, without being detected, It also performed numerous support missions all over Iraq and Afghan proved it's capabilities, most of the Helicopters won't carry fire control radar's, the AH 64 E carries a mast mounted milli meter wave fire control radar developed by the Northrup gruman, the Long bow radar can guide the Radar guided missile Hell fire to engage targets in fire and forget mode, which allows automatic target acquisition and engaging, the Long bow can track more than hundred targets within a minute, both moving and stationary targets, and ripple fire the Hell fire missiles, Apache can carry 16 Hell fire missiles,

   Apache also support the Ground troops using it's missiles and gun's. the Apache's optical systems allows engage hell fire missiles, if the target was lazed by the ground troops. means if Ground troops pinned down by enemy heavy resistance, they can light the enemy positions using the laser which was connected with Apache's computer system, once the target acquired Apache can use missiles, Rockets or Guns to suppress the Target.

    Apache comes with two heavy engines that can boost the Apache's speed by some 300 kilometers per hour, and can fly as much as 20,000 feet, Apache can conduct mission close to some 500 kilometers, these stats for fully armed AH 64 E, if it was stationed in Kashmir region Apache can cover entire Kashmir Region, and reach any given spot within a hour with full combat power. It's believed IAF could use those Apache's close to Border area's to provide air cover to the ground troops, Apache's can't be refueled in the air, however it can be deployed from any forward operating air bases close to the mission area. Apache can also engage air threats like fighter aircraft's, helicopters and UAV's using the Stinger missiles.

   with the Packages, IAF set to receive tons of missiles, ammunition  and spare parts, the package includes" 50 T700-GE-701D engines, 12 AN/APG-78 Fire Control Radars, 12 AN/APR-48A Radar Frequency Interferometers, 812 AGM-114L-3 Hellfire Longbow missiles, 542 AGM-114R-3 Hellfire II missiles, 245 Stinger Block I-92H missiles, and 23 Modernized Target Acquisition Designation Sight/Pilot Night Vision Sensors, rockets, training and dummy missiles, 30mm ammunition, transponders, simulators, global positioning system/inertial navigation systems, communication equipment, spare and repair parts; tools and test equipment, support equipment, repair and return support, this amount of weapons are enough to knock out and front line offensive forces, can also support the Indian Army's offensive forces to achieve the object.

CH 47

   As per the initial contract, IAF Selected the CH 47 F, which is the most advanced variant available for export, however later years, some of the CH 47 units modernized with most complicated sensor suites and inflight refueling capability to extend the range,  the MH 47 G also designed with low observable characteristics, the American using very low numbers of MH 47 G varients, which are used by the JSOC command only, America never exported the MH 47 G to other countries, however still now no clear information about which variant of Chinook, IAF is going to acquire, mostly IAF gets the CH 47 F with some modifications.

    The IAF Plans to buy some 15 Chinooks as initial batch, four more later. the CH 47 F can carry or slug upto 12 tons of load, with the maximum speed of 300 kilometers per hour, it can fly as much as some 18,000 feet height, the Chinook can conduct missions at some 350 kilometers from base and rteurn back to the base with reserve fuel, It can be deployed from forward operating bases too, however the US Army' MH 47 G only has the refueling capability, no others has such capability. 

   IAF selected the CH 47 for many reasons include it's maneuvering capability to fly low and narrow ways in between hills to remain undetected, IAF mainly selected the Chinooks to transport heavy armaments close to border positions which was inaccessible by the roads, IAF also plans to use the CH 47 to carry materials to construct roads and bridges close to borders, the Heavy lifter Mi 26 can carry 20 tons of payload however it can't perform multi role missions like Chinook,

It reported some media sources quoted anonymous sources, Boeing will complete the delivery of both AH 64 and CH 47 within next 36 months.

Chinook 47 Vs Mi 26 HALO

Chinook 47 Vs Mi 26 HALO 

Why the Chinook is efficient and the Mi-26 is a heavy-lifting guzzler

 

Typical Comparison of CH 47 and Mi 26

Introduction: 

      So this one is something that’s been on all our minds for a while. The Mi-26 “Halo” versus the CH-47 “Chinook”. Boeing has been marketing the Chinook in India for years for the Indian Air Force’s heavy lift helicopter requirement.
     
   This role is currently filled by the Russian Mi-26 in India. The Mi-26 is massive in bulk, mass and power. It is the largest helicopter in series production in the world. Its power capacity at sea-level is completely unmatched. And in Indian colors it has been a sight to behold when it takes the air under its massive main rotors. The Mi-26 has been associated with many firsts in the Laddakh area of the Himalayas, ferrying in large quantities of supplies, bulk construction equipment for the Army and so on in an area where no other helicopters, until recent years, could even fly. Elsewhere around the country, the Mi-26 has evacuated civilians, airlifted heavy equipment and has been a vital cog in the Indian airlift capabilities. On the face of it, the Chinook has little chance of doing well against this powerful competitor.

      But for all that, operating the Mi-26 is not without woes. Lack of spares is a problem. In recent years, the Indian Mi-26 fleet (4 helicopters) has spent more time on the ground than in the air. It is not uncommon to find the Mi-26 sitting with panels open and requiring repair more often than they are seen flying. Operating cost is even higher. The Mi-26 is a massive machine that guzzles fuel at a huge rate. Operating this helicopter from main airbases (with their large fuel farms) is one thing. But out in the mountains, the fuel guzzled by this helicopter’s engines can sap the capacity of any forward-deployed unit to keep their helicopters flying. And if the Mi-26 is tasked with carrying its own fuel, just how much payload can it possibly carry? Boeing offers the Chinook as a cost-effective, albeit smaller, option. If it remains more efficient in the Himalayas and requires less fuel for similar payloads, then it has a chance to replace the Mi-26 in the Indian context.

To answer these questions, we will turn to analysis.

       The first thing that strikes the casual observer is the vast difference in design and numbers for the two contenders. The Mi-26 is a massive beast compared even with the large Chinook. The Chinook weighs in at 10,185 kg when empty. The empty weight of the Mi-26 is 28,200 kg! The Mi-26 is almost 2.8 times as heavy as the Chinook when empty. But the Mi-26 is powered by the massive Loratev engines, providing a total of 17,000 KW of lifting power. By comparison, the Chinook is powered by ~7,000 KW of power in its twin rotor arrangement. The Mi-26 loses about 15% of its available power to the tail-rotor, but the Chinook has no such problem due to its tandem rotor design. So there is some recovery of power there in favor of Chinook, but not by much. We readily expect the Chinook to underperform on pure lifting capabilities. In terms of fuel rates, there is surprisingly little difference as well. The Loratev engines have a fuel consumption rate of 0.465 lb/shp-hr and the Chinook has a fuel consumption rate of ~0.5 lb/shp-hr. But because the Chinook weighs a lot less, it has to use a lot less fuel. We will see later how this works.

        Since we are now comparing transport helicopters, we will shift focus from ROC capabilities to payload and more importantly, fuel consumption rates. The reasoning is simple: a helicopter can lift more than the other helicopter, but if it needs twice as much fuel to do it, it loses some (or all) of that additional payload to the extra fuel it must carry for the same range. The plots below will apply for hover conditions OGE.

         The focus of this analysis is on a preliminary aerodynamic and propulsive standpoint. The analysis is done using simulation tools that integrate payload capacities and typical rate-of-climb requirements with a preliminary rotary aerodynamics model and a simple propulsion module. When coupled with an atmospheric simulator for the Himalayas, the performance of each helicopter type can be predicted and compared. Furthermore, the models allow for the performance analysis in Ground Effect conditions. The Ground Effect conditions are encountered when the helicopters are hovering very close to the ground and serves to work as a performance multiplier with regard to power needed in lifting a certain payload.




        The models do not compensate for transmission limitations for the power, which means that the analysis is idealized wherein power generated is power available. This is, of course, not encountered in practice, but works well for high-altitude conditions where power available is almost always less than the transmission limits. At lower altitudes, the performance of the various designs must be assumed to be ideal, rather than restricted from transmission and structural limitations.

        Data for this analysis is obtained from the manufacturers via open-sources. No proprietary information is shared here. Unless where cited, the analysis results are to be considered proprietary of the author. See remarks for details.

Halo versus Chinook:

      The hover OGE performance is evaluated at altitudes varying from 0 ft (SL) to 25,000 ft. Altitudes in the Himalayan Mountains regularly require flights above 10,000 ft and often up to 22,000 ft. There are two sets of plots provided. One set provides the “true-lifting capacity” plots where we compare the Mi-26 and the CH-47F on purely lifting performance regardless of mission profiles etc. This is done to necessarily drive home the difference between the two helicopter performances from an academic standpoint. The second plot then provides a comparison plot where the Mi-26 payload is reduced down to the maximum lifting capacity of the CH-47F and corresponding fuel rates are plotted versus altitude. The intent for the second plot is to compare the two helicopters on equal footing.

    
      At sea-level, there is virtually no comparison between the CH-47F and the Mi-26 for lift capacity. The Mi-26 can lift twice the maximum possible payload capacity (zero fuel and zero crew) of the CH-47F. But that capacity trails of with altitude. The maximum lifting capacity of the Mi-26 starts to drop off after about 3,000 ft altitude. And the drop-off is faster than that of the Chinook. The Chinook overtakes the Mi-26 lift capacity at ~21,000 feet in ideal terms.

      Let’s look at the practical comparison plot for a mission profile. The requirement here is for the CH-47F and the Mi-26 to lift identical payloads of 12,495 kg (max possible payload for the CH-47F) under zero-fuel and zero-crew conditions in hover OGE. It is instantly clear that because of the large power difference between the two helicopters, the Mi-26 is able to maintain that payload limit far in excess of the CH-47F. The CH-47F starts losing payload capacity at ~3,000 ft altitude. The Mi-26 maintains payload capacity up to ~12,000 ft altitude. Note, however, that the CH-47F overtakes the Mi-26 at around ~21,000 ft as pointed out before. In terms of true lift capabilities, the Mi-26 comes out on top.

         Now let’s look at fuel consumption rates. You will notice that the fuel-rates have a maximum point on the curves. This point corresponds to the location where each helicopter begins to lose off payload capacity. With reduced payload comes reduced fuel usage, even though the engines are operating at maximum power for that altitude. The assumption here is that both helicopters maintain their specific-fuel-rates with altitude. If this is not the case, the performance will be worse than what is predicted here. The CH-47F has a substantially lower (almost 50% lower) fuel consumption at sea-level even when it’s carrying the same payload as the Mi-26. It maintains that difference to about ~3,000 ft altitude where the payload capacity drops. Through all altitudes, the Mi-26 consumes fuel at a massive rate compared to the CH-47F.

A typical day in Leh:

      The effect of increased fuel consumption on payload capacity can be explained with a simple example. For a flight that extends for 1 hour in the mountains where the mean altitude is 10,000 ft (for example in Leh, Laddakh), the Mi-26 will lift a maximum of 12,495 kg but will need a fuel of ~2,800 kg. The CH-47F will lift about 8,000 kg at that altitude but will need only ~1,000 kg fuel for the same flight. Let’s assume that both helicopters need about 500 kg of crew and other common items. This means that the Mi-26’s “true” payload will be only ~9,200 kg. The “true” payload of the Chinook will then be ~6,500 kg.

  

A validation of the model:

      As an aerospace engineer looking for validation data for my models, I am like a squirrel looking for berries: always wanting more, never finding enough. But here is a rare example of information provided by Boeing on the Chinook that I would like to share with the reader. Back in 2012, the Boeing Company released a slideshow for the Indian media to highlight the performance benefits of the Chinook. Within those slides was one slide that I will share with you:

      Notice how Boeing claims that the CH-47F has a capacity to carry about 2,600 lbs (1,227 kg) of payload at 20,000 ft. We assume, as always about 300 kg of crew and other items and at least another 1,000 kg of fuel (considering a short flight, plus reserves etc.). So that gives us about a total of 2,527 kg of overall mass that the CH-47 will lift at 20,000 ft. Assuming that some spare power is reserved for climbing, that is effectively about ~3,000 kg of payload in the hover plots above. The models I use for my helicopter analysis predicted 3,013 kg at 20,000 ft altitude for the CH-47F.

Conclusions:

The Chinook is cost effective. A tandem rotor design has significant other advantages over a single rotor design in the high mountains, especially on ridges. The economical fuel consumption of the Chinook versus the Mi-26 helps it get closer to the latter in terms of payload capacities. But in acquiring the Chinook, the IAF will have to forgo some of the true payload capacities of the Mi-26. There will always be a difference in payload in favor of the Mi-26. But as outlined above, is that difference enough of an advantage to balance out so many performance disadvantages? The conclusion of this author is that the Chinook wins this competition on its merits. The end of the days of the Mi-26 in Indian colors could quite possibly be around the corner.

 

  
Article By Vivek Ahuja BRF