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For general questions related to aircraft engines; use [tag:jet-engine] or [tag:piston-engine] if possible.

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3answers
3k views

How can flying high minimize drag and increase fuel efficiency? [duplicate]

As a plane goes higher, the engines have to work harder to compensate for the air density, therefore it will require more fuel in order to provide the same power at lower altitudes. But I always hear ...
0
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2answers
63 views

Why does a turbine engine compressor ratio affect stagnation pressure?

This might just be a misunderstanding on my part, but in an ideal Brayton cycle, the flow through the compressor and turbine is isentropic, meaning $\Delta s = 0$. However, usually you are given the ...
0
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2answers
202 views

Can a Rutan Quickie be made into a legal Part 103 Ultralight?

I was was thinking about buying a 80s rutan quickie q-1, it has a 18 hp motor. I want to get a ultralight but I like this one because it is fast. Can I get a motor that would be within the ...
0
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1answer
67 views

Does the FBW system of a passenger aircraft use differential thrust for yawing? [duplicate]

Are there situations where the fly-by-wire system of a commercial passenger aircraft will use differential thrust to yaw? Or is that even possible at all (i.e. do the necessary interfaces exist)? I ...
1
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1answer
154 views

How much thrust could a 400 mm EDF produce?

there's a 195mm EDF from Schübeler that produces 25 kg of thrust at a peak power consumption of 15 kW: https://www.schuebeler-jets.de/de/produkte/hst Now, my question is: How much thrust could you ...
1
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1answer
186 views

Gas Turbine Engine Starting Sequence [closed]

How to explain the figure above?
46
votes
2answers
11k views

Could a Dyson fan scale up to be used as a bladeless aircraft engine?

Dyson has been making bladeless fans for a few years now that accelerate a consistent stream of air without exposed blades. If this concept were applied to aircraft engines, it could potentially ...
4
votes
1answer
450 views

What are the consequences of attaching an unused extra engine under Boeing 747 wing?

It turns out Boeing 747 can carry an extra engine under its left wing in case there's need to transport an engine somewhere far away. The engine is attached between the body and the left inner engine ...
0
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1answer
202 views

Does an airplane need a key to start? [duplicate]

Does an airplane require a key to unlock the doors and start the aircraft engines? Is it somewhat like how a car does?
0
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3answers
188 views

Does bypass air produce thrust?

How does bypass air exiting the bypass nozzle produce thrust in a turbofan engine? I thought that thrust was produced by air reacting with the fans. So if thrust happens when there is an action-...
17
votes
11answers
8k views

Why are all engines identical in typical commercial airplanes?

I come from the IT world where redundancy is in place to cover several cases, among other: a statistical failure of a device (so we use more of them expecting that the event is independent) a rogue ...
0
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4answers
272 views

Why do we not see propellers on swept wings or jet engines on straight wings? [closed]

Why are these configurations not observed often? The only time I see propellers are on straight wings or on the nose, while jet engines are always on swept wings or the tail. Why?
1
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1answer
230 views

What is the relationship between EGT, Fuel Flow, N1, N2 and Air Temperature?

I initially wanted some sample data for EGT, Fuel Flow, N1 and N2 to build a prognosis system that predicts engine failure (ECTM). I searched for some sample data online but got to know that there's ...
3
votes
1answer
83 views

Where can I find sample data required for Engine Condition Monitoring? [closed]

I'm trying to find some sample data required for Engine Condition Trend Monitoring to analyse and predict when an engine might fail. I went through a lot of research papers and (kind of) understood ...
0
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0answers
42 views

Are throttleable rocket engines the less efficient the lower the power setting?

Are throttleable rocket engines less efficient the lower the power setting? Logically that would lead to lower pressures in combustion chamber and so lower thermodynamic efficiency. Or is it remedied ...
2
votes
2answers
349 views

Why does the diffuser section generate thrust in a jet engine?

I am studying the thrust distribution of jet engines. But I'm now a bit confused. In Rolls-Royce's "The Jet Engine" book, http://aeromodelbasic.blogspot.com/2012/05/thrust-distribution-distribution-...
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1answer
287 views

How much air does a GE90 ingest at sea level and at cruise level per meter?

I just wanted to know how much air PER METER a GE90 turbofan engine sucks in considering the same thrust output at different altitudes to better understand how the engine can travel further while ...
3
votes
3answers
216 views

How does the nozzle diameter affect the thrust of a ducted propeller?

I currently do some experiments with ducted propellers in which I try to figure out which effect a nozzle has on the thrust produced. My theory goes like this: If I reduce the exit diameter of the ...
9
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2answers
4k views

What airplane is this? and why the strange inlets?

Why does it have such strange intakes?
1
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2answers
100 views

What are technical and aerodynamical limitations to blown wings main propulsion?

Why wouldn't some blown flap or blown wing device (suppressing propeller or fan or jet exhaust from aircraft design) produce sufficient thrust needed for takeoff and cruise flight, opposed to "only" ...
0
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2answers
270 views

Are two little engines or one big engine more efficient for an ultralight?

For an ultralight, should two engines weighing 10kg each and making 7hp each OR one engine weighing 20kg and making 14hp be used?
1
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1answer
292 views

What happens during Engine Performance Restoration

What is the typical process during an Engine Performance Restoration? I am trying to find a resource that gives an overview of what happens but I have not been successful. Any help would be much ...
0
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0answers
45 views

Three-engine jetliners [duplicate]

Why three-engine jetliners were popular in the 1970s? Why they are no longer in production? In case of engine failure, did the 3rd engine not reduce the thrust asymmetry? to keep the aircraft in ...
3
votes
3answers
276 views

Is it possible to build a flight-capable aircraft powered by compressed gas?

I pray this isn't a physics SE question. A star engine can be considered "gas operated". So what if we power a star engine with unleashed, formerly compressed gas instead of... actual gas/aero-...
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1answer
86 views

How does a turbojet power its own compressors? [duplicate]

The title says it all, does the compressor use electricity? if so, how does it generate this electricity? The main power source can't be from the compressor itself as it would lose more power than it ...
0
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0answers
33 views

What's the point of the impact air tubes in the RSA FI system?

As part of the RSA/Bendix fuel injection system, the air metering force controls the fuel poppet, a valve that closes or opens to vary fuel flow. The air metering force is comprised of a diaphragm ...
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0answers
63 views

Is there a standard install direction of the abradable shroud honeycomb on a CF6-80c2 engine?

Is there a standard install direction of the honeycomb cells on the Fan Forward case on the CF6-80C2 abradable shroud section? I have seen engines that the honeycomb cells run point to point front ...
13
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1answer
3k views

Which jet engines have the highest thermal efficiency?

Some automakers (Mercedes-Benz, Toyota) have recently been making news about the improved thermal efficiency of their engines, stating that they reached the 50% mark. I was wondering if it was the ...
1
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1answer
126 views

How are the NEO LEAP-1A engines attached on the A320?

How many bolts hold the NEO LEAP-1A engine to the pylon at the forward mount and at the aft mount?
2
votes
2answers
177 views

What were the make and model of the engine that failed in flight Southwest 1380?

Regarding the tragedy of Southwest 1380 flight on 2018-04-17 involving an engine failure, what company manufactured that engine, and what engine model/type was it?
-1
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1answer
99 views

In BGA or ATR's what are the major causes of ODOR in Cabin or Smoke in Cabin? [closed]

In BGA or ATR's what are the major causes of ODOR in Cabin or Smoke in Cabin? There are some of the maintenance activities that are related to removal of Engines or APU. Removal reason: Smoke in cabin ...
0
votes
1answer
130 views

What forces act on cascade-type thrust reverser blocker doors?

What is the stress or force that loads the cascade-type thrust reverser blocker doors? As we know, blocker doors are closed and block the airflow going through the C duct. The engine is a V2500 with ...
1
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2answers
65 views

What are the main sensor value that cause High pressure compressor fault in turbofan engine?

I have read the paper "Damage Propagation Modeling for Aircraft Engine Run-to-Failure Simulation" (Reference). I am doing analysis to find which sensors to monitor for the faults injected in the ...
2
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2answers
202 views

Which engine manual must a pilot legally use?

Many aircraft have engine/prop performance information provided by the manufacture such as Bonanza, Cessna, Mooney, etc AND the engine manufacture. The performance or recommended settings may vary ...
2
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1answer
564 views

Are there any differences between turbofan and turbojet engines besides bypass air?

I think I understand both engine types, but I am just wondering am I right in saying that the only difference between the two types of engines is the bypass air (i.e. a turbofan is just a turbojet ...
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0answers
129 views

How are turbine blades overhauled?

How are turbine blades overhauled? What techniques are commonly used and how does it affect the integrity of the blade?
7
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2answers
2k views

How are engines numbered?

On a commercial aircraft, the number of engine is usually 2, 4 or 6. When the technician or LAE was given task to inspect an aircraft engine no 2 on a 4 engine aircraft. Which engine would they go to? ...
4
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2answers
288 views

Is feather edge bad?

Currently learning about aircraft piston engine. Feather edge can be found at the engine valves as according to the picture. Can someone explain briefly about what is feather edge? Why it is bad? ...
1
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1answer
161 views

What is the fuel mass flow rate at stationary full power for the CFM56 5C2/3C1 engines?

Does anyone know what is the value of fuel mass flow rate when stationary at full power for CFM56-5C2 or CFM65-3C1 turbofan engines? I am doing a work on engine performance and it seems that only ...
2
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3answers
508 views

What does RPM mean in a propellor aircraft, compared to a jet aircraft? [closed]

What is the practical significance of speed RPM in a propeller aircraft for a pilot? I am not able to correlate it with RPM in jet engines?
1
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1answer
230 views

125 cc engine, 64" propeller 3 blade, 180 kg gross weight, will it climb?

I'm a government teacher in school, currently I made an RC aircraft and flew it, now I'm working on a single engine light weight aircraft, I want to use a Honda CG 125 (single piston) engine, with 64" ...
5
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3answers
3k views

Why don't most military transports use modern commercial engines?

Why don't most military transports use modern commercial engines? More specifically planes like C-17, the Antonov's use older less powerful engines while modern efficient and powerful engines are ...
1
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1answer
195 views

Can an aircraft engine be started midair? [duplicate]

Can one start the aircraft's(commercial/fighters) engine midair at high altitudes especially turbojet or turbofan engines?
3
votes
2answers
1k views

How does the reverse thrust work while landing? [duplicate]

During the landing reverse thrust of an aircraft engine is seen that the compressor fan rotates in opposite direction to counter the aircraft's forward motion if I'm right So, my question here is "...
2
votes
1answer
111 views

What is the maximum decibel noise level of a stage 4 rated engine?

I was just wondering if anyone is able to help me. I need to find out, what is the maximum decibel noise level of a stage 4 rated engine (as defined by the Federal Aviation Administration)? Some more ...
20
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1answer
5k views

How could this weird shaped aircraft Airbus Beluga fly only with two engines and use short runways?

More than that! She could land and take off fully loaded on 2000 meters of runway at Hawarden Airport as seen here in this video. At my local airport the runway is 2500 meters long and an Airbus A300 ...
3
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0answers
196 views

Why would the engine quit when turning on the R magneto after an overhaul?

I just finished overhauling a Lycoming O-360; it's currently on a stand, i.e. it's not in the aircraft. I replaced the capacitors and point gaps on both the L and R mags. I adjusted the E-gap and ...
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0answers
38 views

Is it possible to swap RR trent 900 engines to GP 7200 for existing A380 air frame? [duplicate]

If an A380 was originally equiped with RR trent 900 engines, but decided to switch to GP 7200 for any reason, would this be possible? Has this kind of engine swap (different manufacturer engine swap) ...
0
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1answer
129 views

Flying on one engine [duplicate]

Can a commercial jet with two engines, fly on one. If so, what are the limitations. Maby some are better than others in this situation
4
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2answers
269 views

How can a modified ramjet produce static thrust without a turbine?

A big selling point of the ramjet is its absence of moving parts (hence why it can be translated as "statojet" from other languages). However, an even bigger drawback is that a ramjet cannot produce ...