Questions tagged [helicopter]

A helicopter is a type of rotorcraft in which lift and thrust are supplied by rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward, and laterally. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft would usually not be able to take off or land.

18 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
6
votes
1answer
196 views

How to say the name of this approach clearance: COPTER RNAV (GPS) 027°

JFK has this approach: https://aeronav.faa.gov/d-tpp/2006/00610COPTERR027.PDF How is this approach said on frequency? Is it the "copter RNAV zero two seven approach" or the "copter RNAV zero two ...
6
votes
1answer
205 views

Do tower-controlled helipads have a standard naming convention?

Just wondering if anyone knows, or if it just depends on the airport. Edit: This question is different than How does the FAA determine which format of location identifier to assign to an airport?. ...
4
votes
0answers
528 views

What is the total lift equation of a helicopter with 3 Flettner rotors?

I'm doing research regarding the possiblity of using Flettner rotors on helicopters. I would like to derive the total lift equation for a helicopter that consist of 3 Flettner rotors. Given that: ...
4
votes
0answers
134 views

How do active blades work on helicopters?

Can someone throw some light on 'active blades' as used in helicopters? I'm mostly interested in the use of piezoelectric material and actuators. How are the actuators able to sense the change of ...
4
votes
0answers
258 views

How far can one be from an helipad when marshalling an helicopter?

I considered 25 meters (as per UN SOP's) but after working years with MI-8's the downwash can flatten a big man. I'm interested in procedures from the FAA etc. ...
2
votes
0answers
110 views

Where can I find more details about how ornithopters work?

I learnt about the special helicopter-ornithopter which was put forward by Delft University. Its principle is different from a common helicopter and it doesn't need a tail rotor. But there is very ...
1
vote
0answers
32 views

Is axial dynamics important for the helicopter equations of motion?

While analyzing helicopter performance, why do we always ignore the axial dynamics from the equations of motion?
1
vote
1answer
66 views

How to do blade element momentum theory analysis for different geometries of airfoil, e.g. NACA airfoils?

I want to analyse NACA airfoils using BEMT. I have only yet done it for basic symmetric airfoils. I would like to know what all assumptions remain same in NACA airfoil analysis and to what degree it ...
1
vote
2answers
104 views

Sub-ideal Autorotation in Rotorcraft

I have another AuRo question for you. When a Helicopter autorotates (ideally) it is in the turbulent wake state and there is virtually no flow through the rotor disk (figure of Leishman attached). Now,...
1
vote
0answers
48 views

How does an accessory drive hydraulic system power a crop duster pump?

Aerial agricultural spraying uses pumps, which are usually powered electrically from the starter/generator. Now I have read, that these pumps can also be powered by an accessory drive hydraulic system....
1
vote
0answers
116 views

Are there any true aerobatic helicopters that aren’t built around the Bo-105?

I know that some aerobatic maneuvers have been performed (legally or otherwise) in many different models of helicopters. However, to my knowledge, I have only heard of Bo-105s being specifically ...
1
vote
0answers
37 views

What are the expected vibration frequencies in a co-axial rotor system with contra-rotating propellers?

I am trying to understand the frequency spectrum of a co-axial rotor system. Form now i have a RC helicopter with two sets of three gear systems arranged in parallel, The number of teeth are 7,23,27) ...
1
vote
0answers
231 views

Are there attempts at fly-by-wire servo flap controlled rotor?

Reading this question and then this document about servo flap controlled rotor I was wondering if there has been any attempt at building one fixed hub helicopter with twistable blades hosting at 75% ...
1
vote
0answers
190 views

Where can I find official information about a recent crash in Mexico?

I have heard about a helicopter crash involving an Agusta A 109 in Mexico, that seems to be causing some turmoil due to the deaths of a newly-elected governor and her husband. Is there any info about ...
1
vote
0answers
268 views

What is the heaviest payload ever carried by a single main rotor helicopter?

What is the most heavy payload ever carried by a single main rotor Helicopter?
0
votes
0answers
57 views

What is the tail rotor rpm for the Sikorsky S58 helicopter?

I need to know the TR rpm for Sikorsky S58. I have tried searching for it and calculating it based on some assumptions I've made. I would like to know the true rpm value and not assume it since this ...
0
votes
0answers
65 views

What is the main and tail rotor speed (RPM) for a Sikorsky S52?

I need the RPMs for the main and tail rotor of a Sikorsky S52 for the research I am doing for my degree. I tried checking flight manuals and other websites, but I don't find concrete numbers, only ...
0
votes
0answers
47 views

Jet Engine Cooling, HTC and cooling calculations

Right now I am working on a project about cooling systems in jet engines. And I don't have a supervisor to ask anything. I would like to know what is the most useful resource (book, analsys programs ...