Hacker News Reader

Hacker News

Comment by hamburg | Hacker News Reader

Full thread

hamburg

Amazing that those winglets alone are worth GBP 400,000. It's just a few layers of metal, no?

View on HN

The link below says the fuel cost per hour for a 747-300 is ~$21,000.

http://www.what2fly.com/operating_cost/boeing/747-300.php

The winglets save about 3 - 3.5+% fuel consumption. (from Boeing's website and Wikipedia)

So it only takes roughly 2000 hours of flight time to recover the costs from a used set of winglets ($650k each according to the article).

2000 flight hours is generally less than 2 years worth of flights for a normal 747-300. (Couldn't find a great source, didn't look too hard: http://www.airliners.net/aviation-forums/general_aviation/re... )

According to this they weight between 375 - 518 pounds and are ~6 feet tall, which is significantly more than they look. http://www.b737.org.uk/winglets.htm

Edit: doubled the hours, thanks bhousel

$650k per winglet, not per set. So actually more like 2000 hours, but that's still significant fuel savings..

What I don't understand is, why would you order an aircraft without them in the first place,if the saving is so big?

A guess, there are a lot of older planes out there in the fleets and the winglets were a later improvement.

Generally they would be older airframes where winglets weren't an option at the time of manufacture.

Also, if you are running a lot of short flights, fuel costs may not be your primary concern. For example, the 747-400D is a model meant for short domestic routes like between Japanese islands, and doesn't have winglets.

I was amazed by that figure as well. They are six-foot extensions that decrease fuel consumption by about 4 to 6 percent [1]. I'd imagine that insurance and warranties mean that operators can only use approved Boeing parts.

[1] http://en.wikipedia.org/wiki/Wingtip_device#Passenger_aircra...

Insurance - will they pay us if it breaks?

Warranties - will they replace it if it breaks?

Regulation - will they sue the pants off us and ban us from flying if we use a non-approved part, regardless of whether it breaks or not?

A few layers of metal and airworthiness approval from every jurisdiction the airplane will fly through.

Classic example of pricing based on value to the end-user (in this case, a pretty nice fuel savings) and not on actual cost of materials. Something to keep in mind as a developer when selling your skills, software, etc...

So where is the competition?

Where is the regulatory certification so that it can be allowed on an airplane?

Not so sure...consider how much is cost to engineer (probably at least a few millions + all the testing/certification costs) spread out over less than 10k units.

I wondered the same and found this thread [1] - they are obviously priced based on the added value, i.e. reduced fuel consumption - and not on material and manufacturing costs.

[1] http://www.airliners.net/aviation-forums/general_aviation/re...

http://en.wikipedia.org/wiki/Wingtip_device "The winglets increased the 747-400's range by 3.5 percent over the 747-300, which is otherwise aerodynamically identical but has no winglets."

Reply on news.ycombinator.com