FLUG REVUE May 2005: Chinook upgrade enters production

May 2005

CH-47F: BOEING´S NEW CHINOOK

By Karl Schwarz

Wherever the US Army is deployed, extensive use is invariably made of Chinooks, as troop-carriers, for the transportation of ammunition and large parts like cannons or to support Special Operations Forces. Around 425 CH-47D's, ten MH-47D's and two dozen MH-47E's are in service with the US Army. Apart from a handful of new-build machines, these Chinooks are made from CH-47A, B or C airframes, which have been completely taken apart, refurbished and equipped with new systems.

CH-47 Chinook

The longevity of the Chinook, which entered service in August 1962, is also legendary. And after over 40 years there is still no sign of a suitable successor. For the Boeing factory in Ridley Park, a suburb of Philadelphia, this is great, as it means that CH-47's will continue to roll out of the giant assembly hall, extending the production run of the company's longest running model by a further 10 to 15 years.

The latest plans unveiled by the US Army in Washington in mid-January envisage the production of 55 new CH-47F's, plus the construction of 397 CH-47F's and 61 CH-47G's based on existing CH-47D's. According to Colonel William T. Crosby, Army project manager for transport helicopters, an outlay of around $11.4 billion (€8.6 billion) will have been ploughed into these upgrades by 2018. The programme is thus a lot more extensive than was thought only a few years ago, since for a long time it was assumed that there would be around 300 CH-47F's Improved Cargo Helicopters (ICH). These were intended to plug the gap until the arrival of the Joint Transport Rotorcraft, but that programme has not yet materialised due to lack of funds.

Now the US Army is once again focused on the Chinook. Development of the F model has been under way since May 1998, when Boeing received a first contract worth $76 million (€57 million). The maiden flight of the new version took place on 25 June 2001, with Erik Kocher and Randy Wells at the controls. Together with a second converted CH-47D (new serial numbers 98-00011 and 98-00012), the helicopter completed several hundred hours of testing.

In the meantime it has become apparent that Special Operations Command does not have nearly enough MH-47D's and MH-47E's to cope with the hugely increased requirements imposed by the war against terror. The first production batch, ordered in January 2003, therefore contained only one CH-47F and six MH-47G's, while the follow-on order of December 2003 ran to 16 MH-47G's. Only on 21 December 2004 were a further 17 CH-47F's ordered for $549 million (€412 million). These are the first helicopters to be built from scratch. The next contract, for the conversion of twelve CH-47D's to MH-47G's (worth $223.495 million = €167 million), followed on 14 January 2005.

Between the handover of the first CH-47F's in July 2004 and the construction of the next transport helicopter model for delivery in September 2006, there is thus a gap which Philadelphia is utilising to improve its production methods. The final assembly line has been remodelled with the aid of work teams so as to improve efficiency. The priority has been to reduce the manufacturing costs of new airframes by almost one-half. “Because we provided more resources for studies and development work, Boeing was in a position to reduce the price of a new helicopter from $42 million to around $32 million (€24 million). At the same time we agreed to use new airframes for around 425 of the reconstructed (as CH-47F or MH-47G) CH-47D's instead of airframes that have had a full overhaul, and at a similar or even lower price,” Colonel Crosby explains.

According to Jack Dougherty, Boeing's director for the Chinook programme, a new Chinook airframe can now be had for $5.1 million (€3.82 million). This has become possible due to the redesign of many details using today's computer-aided design technology and to making greater use of larger, milled components. The number of parts in the tail, the loading ramp and the rear rotor pylon has been reduced, for example, from 3,960 to 2,416. Moreover, production of section 43 (centre fuselage) has been outsourced to Crestview in Florida and section 46 (tail) to the Boeing factory in Macon, Georgia. Again, some of the components of the nose, which is still assembled in Philadelphia, are now supplied more quickly and cost-effectively by subcontractors.

Another change for the CH-47F series from batch 3 affects the cockpit. Although this will continue to be fitted with Rockwell Collins visual displays, instead of a configuration similar to the MH-47D, the standard fit will now comprise five 15.2 x 20.3cm, liquid crystal displays (two for flight management, two as system displays and one for a digital map) and two data input units on the central console. This is part of the Rockwell Collins Common Avionics Architecture Systems (CAAS) that is also being installed in other Army helicopters (MH-47G, MH-60M and MH-6M).

Improvements in the avionics extend to a digital flight control computer from BAE Systems and a digital intercom with encryption from Telephonics. A stormscope is also included in the upgrade.

To improve the transport capability of the CH-47F, disassembly of the rear rotor pylon has been significantly simplified. It now takes only two hours instead of five-and-a-half, while the assembly time is down from almost ten hours to three hours 15 minutes. This has entailed introducing quick disconnects for the hydraulic lines, and the gearbox no longer has to be specifically removed.

The engines are T55-GA-714A's equipped with FADEC and integrated particle separator. They each generate 3,653kW (4,968shp) instead of the 2,755kW of the T-55-L-712 in the first CH-47D's. Specific fuel consumption is seven percent better. Honeywell is also promising twice as much reliability. Container-shaped auxiliary tanks in the cabin (up to three x 3,030 litres) can extend the range to over 2,000km, if required.

In the long-term a new rotor head could also be introduced. In a design that is geared towards minimising the maintenance effort, it would be possible to forego the extensive lubrication, as elastomer bearings would be used. However, no orders have yet been received for this option.

After problems with cost overruns, the Chinook programme appears to be back on a solid footing, and Boeing is hoping to be able to land a major order extending over several years in 2007 if further efficiencies are achieved. Thanks to the upgrade programme, the company once again has an attractive model to market internationally in the state-of-the-art CH-47F. “There are a huge number of CH-47's around the world which one could modernise,” says sales manager Robert Torgerson. Apparently interest has already been expressed by NATO states and from Asia (Japan, South Korea).

For potential customers who cannot afford new Chinooks, the U.S. Army has a stock of used CH-47D's. Boeing calculates that six to eight helicopters per year could be made available for resale to export customers. Some of the CH-47F programme costs would be financed with the revenue from the Cargo Helicopter Airframe Procurement Support (CHAPS) programme.

From page 42 of FLUG REVUE 5/2005

Last updated 14 April 2005

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