iscoverThis article on the Pratt & Whitney geared turbofan engines originally appeared in the December 2018 magazine edition of Australian Aviation.
The big commercial aircraft engine manufacturers have been negotiating turbulent times as issues with their newest products cause delivery delays, groundings and in-flight shutdowns for some of their customer airlines.
This content is available exclusively to Australian Aviation members.
Login
Become a Member
To continue reading the rest of this article, please login.
To unlock all Australian Aviation magazine content and again unlimited access to our daily news and features, become a member today!
A monthly membership is only $5.99 or save with our annual plans.
A monthly membership is only $5.99 or save with our annual plans.
PRINT
$49.95 for 1 year
Become a Member
See benefits
- Australian Aviation quarterly print & digital magazines
- Access to In Focus reports every month on our website
MOST POPULAR
PRINT + DIGITAL
$99.95 for 1 year
Become a Member
$179.95 for 2 years
Become a Member
See benefits
- Unlimited access to all Australian Aviation digital content
- Access to the Australian Aviation app
- Australian Aviation quarterly print & digital magazines
- Access to In Focus reports every month on our website
- Access to our Behind the Lens photo galleries and other exclusive content
- Daily news updates via our email bulletin
DIGITAL
$5.99 Monthly
Become a Member
$59.95 Annual
Become a Member
See benefits
- Unlimited access to all Australian Aviation digital content
- Access to the Australian Aviation app
- Australian Aviation quarterly print & digital magazines
- Access to In Focus reports every month on our website
- Access to our Behind the Lens photo galleries and other exclusive content
- Daily news updates via our email bulletin
Evan
says:Yeah, it’s masterpeace of modern engeneering. This engine is closer to turboprop engines’ conception due to gear box. Actually, it’s a logical continuing of jet engines’ development.
But what about electric driven fan? Instead of a gear box (it’s complex and expensive unit that requires precise parts) you set a generator and electric motor, rotating the fan. In this case you’ll be able to change speed of fan’s rotation in a small range and thus increase its efficency…
John Reid
says:This is not the first time gearing has made a huge efficiency difference.
Early in the First World War, Britain built a large group of M-class destroyers with direct-drive steam turbines. By 1917, the R class had evolved which were almost identical except that their turbines were geared to allow propeller revs about 300 with turbine revs in the thousands, thus boosting efficiency at both ends of the drive shaft. The cruising range for the same fuel load went up by almost 50%, and the top speed went up from about 34 to about 36 knots (considerable variation in both groups). Anecdotally the reliability went up too. The Rs mostly lasted until the 1930s (one until 1946) whereas the Ms were all discarded by 1920.
Steam turbines universally had gearing by the 1920s – I suspect GTFs will be universal by the 2020s. Re-engining programs anyone?
Stu bee
says:Another great article on the GTF engines… pity though about the decimal then imperial then decimal measurements in regards to describing the fan size.
William
says:The alternative to mechanically gearing down a turbine is to use a generator-motor setup. Given the incredible improvement of electric motors to the point they are 1/5th the weight of piston engines this is beginning to make sense for aircraft. (Most seem to think superconducting motors and transmissions lines will be needed). The turbo-electric drive of large ships allowed not only optimal speed reduction but placement of the boilers, turbines, generators and motors. We may see that in aircraft one day. The EDF electric ducted fan Schübeler make for model aircraft is 200mm in diameter, weighs 3.4kg and provides 25kg thrust for 15kg power.