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IFTNFS · 01-24-2002, 12:57 AM

Just thought I'd add to this thread what I saw in the current issue of Airways (March 2002) in their Mailbag section. The letter/response this was taken from can be found on page 64, and includes pictures which I unfortunately could not find anywhere on the net.
I'm just going to post the response part since I have to type it all in:

The Volpar Aircraft Corporation (Van Nuys, California) proposed a 727 twin-conversion program using CFM International CFM56-5C2 engines. These would have offered easy compliance with Part 36, Stage 3 noise regulations (and possibly lower noise levels than any airliner except the 777), and reduced fuel burn estimated at an annual saving of $750,000 per aircraft. Performance would have been greatly enhanced, with a 48% increase in range and no payload or cruise penalties, and engine maintenance costs significantly reduced. Although Volpar intended to apply for a Supplemental Type Certificate (STC), no timetable was released, and in 1990 the company was acquired by Gaylord Holdings of Switzerland.

CFM International itself announced that it had interest in a twin CFM56-5B/-5C conversion from 'a larger 727 operator', and International Aero Engines (IAE) revealed in 1992 that it was working on a 727 twin using V2530-D5 engines (similar to those used on the McDonnell Douglas MD-90) for in-service entry in mid-1995 or 1996.

Subsequently, Snow Aviation International (Colombus, Ohio) offered a similar retrofit, using two V2530-W5 turbofans. This program also included a two-crew glass cockpit and structural upgrades with a price tag of $20 million, or about half the cost of a 757. Snow calculated that the conversion would save $600,000 a year in fuel bills (a 25-30% burn improvement) and increase range by 750nm (1,400km), giving the 727 nonstop US transcontinental ability.

While estimates put the potential of a 727 twin at around 500 conversions, it may be assumed that Boeing did not encourage such programs as they would have impacted sales of the 757.

There are two pictures of the proposed twin-engined 727. One is an artist's drawing of the one by Snow Aviation with the V2500 engines, the other is a picture of a model of the proposed CFM-powered version wearing the Delta "widget" color scheme. Each has a round tail cone that would have gone in place of the #2 exhaust, and each looks like it would have a new fairing in place of the #2 intake (as opposed to getting a whole new vertical stabilizer).

So maybe Dar's idea isn't so crazy after all...

Rick

01-24-2002, 12:57 AM	#10
IFTNFS Senior Collector Join Date: Jul 2000 Location: Harwich, MA, USA Age: 27 Posts: 427	Just thought I'd add to this thread what I saw in the current issue of Airways (March 2002) in their Mailbag section. The letter/response this was taken from can be found on page 64, and includes pictures which I unfortunately could not find anywhere on the net. I'm just going to post the response part since I have to type it all in: The Volpar Aircraft Corporation (Van Nuys, California) proposed a 727 twin-conversion program using CFM International CFM56-5C2 engines. These would have offered easy compliance with Part 36, Stage 3 noise regulations (and possibly lower noise levels than any airliner except the 777), and reduced fuel burn estimated at an annual saving of $750,000 per aircraft. Performance would have been greatly enhanced, with a 48% increase in range and no payload or cruise penalties, and engine maintenance costs significantly reduced. Although Volpar intended to apply for a Supplemental Type Certificate (STC), no timetable was released, and in 1990 the company was acquired by Gaylord Holdings of Switzerland. CFM International itself announced that it had interest in a twin CFM56-5B/-5C conversion from 'a larger 727 operator', and International Aero Engines (IAE) revealed in 1992 that it was working on a 727 twin using V2530-D5 engines (similar to those used on the McDonnell Douglas MD-90) for in-service entry in mid-1995 or 1996. Subsequently, Snow Aviation International (Colombus, Ohio) offered a similar retrofit, using two V2530-W5 turbofans. This program also included a two-crew glass cockpit and structural upgrades with a price tag of $20 million, or about half the cost of a 757. Snow calculated that the conversion would save $600,000 a year in fuel bills (a 25-30% burn improvement) and increase range by 750nm (1,400km), giving the 727 nonstop US transcontinental ability. While estimates put the potential of a 727 twin at around 500 conversions, it may be assumed that Boeing did not encourage such programs as they would have impacted sales of the 757. There are two pictures of the proposed twin-engined 727. One is an artist's drawing of the one by Snow Aviation with the V2500 engines, the other is a picture of a model of the proposed CFM-powered version wearing the Delta "widget" color scheme. Each has a round tail cone that would have gone in place of the #2 exhaust, and each looks like it would have a new fairing in place of the #2 intake (as opposed to getting a whole new vertical stabilizer). So maybe Dar's idea isn't so crazy after all... Rick