Boeing's "chevron" engine outlets

[Robot_Arm]

@LSLGuy

Lowe fuel costs do two opposing things:

As you say, they reduce the operating cost advantage of new low-burn planes over older higher-burn planes. Which, as you say, tends to support keeping the oldies in service.

The other thing they do is flatter the whole economy which leads to increasingly happy consumers, more ability and desire to buy leisure travel, more business travel, increased profitability for airlines, and all the rest of the good stuff.

Which leads to airlines both growing which means getting additional new jets, and airlines competing on “luxury” and “service”, such as it is within the industry. Which is to say shiny new jets with shiny new interiors, new and faster wifi, etc. Which jets, oh by the way, happen to be more fuel efficient. But fuel efficiency isn’t why they’re being bought. They’re being bought because it’s springtime in the industry to borrow Reagan’s memorable tagline.
During the good times IMO/IME the second effect outweighs the first. Hence my contention in my earlier post.

If fuel prices spike but the economy holds mostly steady you’ll definitely see what you predict: massive parking of the few remaining oldest high-burn jets. OTOH, if recession hits and fuel prices stay low you’ll also see the really old jets retired first in response. If industry disaster hits, e.g. another 9/11 or 2007 stock market crash, after the first wave of retirements you’ll also see a lot of newer, next-oldest jets get parked at least for the duration of the downturn.

Or at least that’s how I read the tea leaves.

So when fuel costs are low, the economy is booming and lots or people are travelling for business and pleasure, and the airlines buy new planes.

When fuel costs are high, the airlines need to squeeze every bit of efficiency they can, so they buy new planes.

Sounds like I should hold my Boeing stock.

[LSLGuy]

As long as interest rates are low, yes. OTOH, my lifetime ROI on stocks I’ve picked is well less than 1. So don’t ask me for stock tips unless you like handing money to the croupier.

[AK84]

So, whats louder? A turbo-prop (like the Bear has) or a low-bypass turbofan? I have heard that pilots intercepting Tu-95 found it incredibly loud, wonder what they crew faced? Or the ground guys.

[ElvisL1ves]

Typically turboprops are louder for a given size of aircraft, partly because propeller noise is not contained by a housing, and partly because the sound is at more-noticeable frequencies. The Tu-95 has counterrotating props, with the aft props partly chopping the wake of the forward ones, so they make as much noise as thrust (the Cessna Skymaster is pretty damn loud too, even though the aft prop is a full fuselage away from the forward one). Plus, there are multiple blade-passing frequencies on it to produce multiple pure tones, which are more noticeable than broad-frequency noise. Planes with single-stage pusher props are all pretty loud, because they’re operating in wing wake and in two different pressure fields every revolution.