Skip to main content
54 votes

Which manufacturer produced this fan blade?

GE Aviation Clue 1. Parts designed at the Lynn MA plant have part numbers of the form xxxxTxxPxx, where x is a digit. 4922T12P01 fits that pattern. The gr.in is another clue. That refers to a ...
Daniel K's user avatar
  • 5,518
38 votes
Accepted

Why does each fan blade have a different mass and frequency?

Because manufacturing processes are not perfect, and the minute differences between parts as-designed and as-produced are amplified by the high rotational speeds and large diameters of modern jet ...
AEhere supports Monica's user avatar
28 votes

Which manufacturer produced this fan blade?

That looks very much like a TF-34 fan blade. The TF-34 is used on the A-10 Thunderbolt and S-3B Viking. The root style is known as "pinned" or "clevis". You can see a blade being pinned into the rotor ...
Fiddlesticks's user avatar
  • 3,781
28 votes
Accepted

Why are the fan blades mounted loosely?

The blades are loose in their "Fir Tree" blade mounts so that they can self balance. They are called "fir tree" because they are v shaped. As the rotation speed and centrifugal force increases, ...
Mike Sowsun's user avatar
  • 37.8k
22 votes

Why are the fan blades mounted loosely?

I's like to expand the answers on how this could reduce vibrations, as it was mentioned in a comment. Therefore, I'd like to look at something completely different: When computers were equipped with ...
sweber's user avatar
  • 7,267
18 votes

What are those ball-shaped things on some helicopter blades?

The devices are pendulum (or pendular) absorbers: Vibration suppression of helicopter blades by pendulum absorbers - Imao Nagasaka. The pendulum absorbers are used for suppressing the vibrations in ...
Jpe61's user avatar
  • 29.1k
16 votes

Is possible to stick two '2-blade' propellers to get multi-blade propeller?

Sure, this is not only possible, but even has some advantages over single-plane propellers. The catch is you ideally want the two to spin in opposite directions to cancel out torque and vibration. You'...
TypeIA's user avatar
  • 14.4k
16 votes
Accepted

What are the design principles that result in thin, long-span, narrow chord main rotor blades?

Unlike with fixed-wing aircraft, there are very few structural limitations on the planform of helicopter blades. Pic above was used in this answer and shows the centrifugal force acting on the blades....
Koyovis's user avatar
  • 61.8k
15 votes

Why are the fan blades mounted loosely?

There are a few reasons for assembling the blades loosely in the gas turbine engine. The loose attachment of the fan blades allow for the easy installation/removal of the fan blades. Though the ...
aeroalias's user avatar
  • 100k
14 votes

What engine are these fan blades from?

Turbine Blade The turbine blade (part number 1475M35P01) is from the High Pressure Turbine (HPT) a CFM56-3 according to this ATSB report on performance testing of the engine. The report contains ...
Notts90's user avatar
  • 3,569
12 votes

Why does each fan blade have a different mass and frequency?

There are advantages in the blades not being "perfectly identical". If all the vibration frequencies were exactly the same, when the blades were assembled to make the complete fan the vibrations would ...
alephzero's user avatar
  • 3,030
12 votes

Is possible to stick two '2-blade' propellers to get multi-blade propeller?

It's done sometimes, for ultralight aircraft and paramotors. Like this:
xxavier's user avatar
  • 11.1k
11 votes
Accepted

Are engine casings expected to contain turbofan blade fragments?

We don't yet know how or why the engine casing failed to contain the fan blade on Southwest 1380. But yes: Not only are the engines designed to contain blade failures at fan red-line speeds, but they ...
feetwet's user avatar
  • 2,284
11 votes

What causes ram air turbines with more blades to spin slower than turbines with two blades?

The windmilling prop extracts energy from the mass flow through the propeller disk area. An 8-bladed prop can extract more energy from the mass flow, and does this at lower RPM than the 2-bladed prop. ...
Koyovis's user avatar
  • 61.8k
9 votes

What engine are these fan blades from?

The part number on the turbine blade shows it comes from a CFM56-3 series (Boeing 737 classic). No hits on the compressor blade, but it looks similar to one from the same engine.
user71659's user avatar
  • 6,636
9 votes
Accepted

Do fan blades use bell shaped lift distribution curves?

The bell shaped lift distribution has been used on the Horten flying wings in order to reduce lift at the outer, rearward parts of the wing for stability and better controllability. The fan blade of ...
Peter Kämpf's user avatar
7 votes
Accepted

Helicopter mast bumping in low g condition

The answer is yes it could be used in that flight profile as the pilot of that AS300 was never in a low G condition with the rotor unloaded during those maneuvers. Once he dropped the concrete, ...
Romeo_4808N's user avatar
  • 74.1k
7 votes

There is any kind of advantage and disadvantages in making the blades of a helicopter off-center?

There is a theoretical advantage of an L shaped rotor blade insofar as it behaves like a swept wing, and so it's able to operate at a higher mach number where its velocity is highest, at the tip. The ...
John K's user avatar
  • 132k
6 votes

How are helicopter rotor blades balanced?

Most blades are as close as possible when built at the factory. Yes, it is like a car wheel you use weights to balance. For the Blackhawk helicopter there are inserts on the hub near the blade to add ...
Chad's user avatar
  • 61
6 votes
Accepted

What causes a helicopter to autorotate farther?

In general, regardless of the number of blades, the more blade inertia, relative to blade area, the better for autorotation safety because the inertia buys you more time to establish the autorotative ...
John K's user avatar
  • 132k
6 votes
Accepted

How does a Delta-3 hinge on a helicopter tail rotor work?

It's because the blade's span-wise axis is "swept" relative to its flapping hinge line, so when it flaps, the sweep angle results in the blade's effective AOA changing somewhat (for the advancing ...
John K's user avatar
  • 132k
5 votes
Accepted

What could cause a low-pressure compressor first stage blade of a turbofan engine to bend forward?

Forward bending of the first stage of the low pressure compressor is usually associated with (soft) Foreign Object Damage (FOD). Ice and/or large quantities of snow in the engine intake will ...
DeltaLima's user avatar
  • 83.6k
5 votes

How can I calculate the thrust of a fan given the diameter of the blade?

I checked out your original post, and the Quora post referenced in it. The thing is that what is mentioned there is simple impulse dynamics: there is a magic disk with no drag that accelerates air ...
Koyovis's user avatar
  • 61.8k
5 votes

Which manufacturer produced this fan blade?

This is a delayed reply. Your fan blade is made of Ti 8-1-1. The gage code is GE however there are only two manufacturers for this fan blade since 1965. The original manufacturer was Utica Drop Forge ...
Jim Davis's user avatar
5 votes
Accepted

What is the longevity and replacement schedule for turbine engine blades?

There are two primary modes of turbine blade failure, that can be predicted, and hence are used to determine the lives of turbine blades at which they need to be replaced. One is called "creep". The ...
Penguin's user avatar
  • 4,483

Only top scored, non community-wiki answers of a minimum length are eligible