Questions tagged [experimental-aircraft]
For questions about experimental aircraft that have not been granted a type certificate by a regulatory agency.
107
questions
5
votes
1
answer
317
views
Does the X-59 comply with the "area rule"?
The Lockheed Martin X-59 was rolled out yesterday :-)
Brett Tingley, Watch NASA's sci-fi-looking X-59 'quiet' supersonic jet roll out of the hangar, August 2023.
I am no expert here (and no English ...
- 53
7
votes
2
answers
590
views
What is the difference between a standard airworthiness and a experimental airworthiness certificate?
What is an experimental certificate? Is it just a certificate that is for aircraft that were built experimentally such as home-built aircraft? What is the purpose of the certificate?
- 889
8
votes
1
answer
921
views
Are there any variable-diameter propellers?
Have there been any known tests or prototypes of variable-diameter propellers?
There's this paywalled paper from 2014 that seems to have made a virtual prototype model, have there been any physical ...
- 4,368
4
votes
1
answer
212
views
Amending Operating Limitations for IFR operations
I own an experimental aircraft and have installed all the equipment necessary to fly under IFR. I found that there's a line on the Operating Limitations document that says "Day/Night VFR ...
- 5,546
0
votes
0
answers
77
views
Sensors used on a blade
How to measure the strain, temperature and rotational dynamics on a running engine fan blade? How can you do the experiment?
6
votes
1
answer
1k
views
Are ex military airplanes experimental?
What makes a plane experimental, and why do all warbirds categorize as experimental aircraft?
- 6,160
33
votes
4
answers
5k
views
Why was the skid landing gear located so far aft on the X-15?
The X-15 famously used a pair of steel skids as the main landing gear rather than conventional wheels, which saved weight, allowed the skids to be mounted externally (where wheels and tires would have ...
- 595
5
votes
2
answers
720
views
Why do experimental aircraft have such long tubes on the nose?
Why do experimental aircrafts (like the X-35, the Space Shuttle Enterprise, the H160 or the X-15 in the pictures) have such long Pitot tubes at the nose when compared to the production aircraft? Are ...
0
votes
1
answer
208
views
(UK) Why did Colin Furze's Hoverbike not require a licence?
Link:
Why did he not need a licence to fly this?
- 13
1
vote
1
answer
228
views
Did the Nazis ever have a pulse jet hovercraft?
I recently read an article about experimental aircraft Nazis had made during WW2. And one aircraft caught my attention.It was a experimental aircraft Named “Die Glocke” It was first described by a ...
- 217
5
votes
0
answers
984
views
Why isn't Yamaha EPeX300Ti more popular in aviation?
The answer to this question might be obvious to experienced aviators. But as an armchair enthusiast, I really couldn't find a satisfactory answer anywhere on the internet.
Below two pages came from ...
- 51
5
votes
2
answers
386
views
Besides forward swept wings, which are the other most unstable wing configurations?
I know that forward swept wings are unstable and all, and that's one of the reasons they aren't vastly used in planes in general.
However, I would like to know more about other types of wing ...
- 562
0
votes
1
answer
263
views
Is an aircraft considered experimental if built when having A&P licence?
I got my Airframe and Powerplant while in the Army 20 years ago, never used it after I got out. If I built an aircraft from scratch would it be considered amature experimental?
- 103
10
votes
1
answer
317
views
Why does the X-3 have two oil pressure gauges per engine?
The X-3, as currently in the National Museum of the US Air Force, has two oil pressure gauges per engine, and one fuel pressure gauge per engine. One of the per-engine oil pressure gauges is labeled ...
- 716
9
votes
1
answer
1k
views
Strange airspeed indicator in the Douglas X-3 Stiletto
The cockpit of the Douglas X-3 Stiletto has a rather weird looking airspeed indicator. (The leftmost instrument in the top row.) Two concentric circular scales, the outer one goes from 0 to 20, the ...
- 716
0
votes
3
answers
401
views
What is the AeroVironment Helios' Kármán line?
If it's true that the NASA/AeroVironment Helios maintained level flight 96,000 ft above sea level at a maximum airspeed of 23.5 kts (43.5 km/h) I assume it must have a very high Kármán altitude, the ...
- 997
35
votes
1
answer
6k
views
What is this 3-engine beast?
What is this 3-engine beast? It has an unusual 6-bladed propeller as well.
- 981
10
votes
1
answer
415
views
What does it mean exactly when an aircraft is "35% unstable"? (aircraft stability factor)
CNN's Grumman X-29: The impossible fighter jet with inverted wings contains several interesting photos, and says:
It was unflyable -- literally -- without a digital flight computer on board, which ...
- 5,758
1
vote
2
answers
496
views
What are the effects of placing the vertical stabilizer at the front of the aircraft? [duplicate]
I am experimenting with different aircraft designs. The one I am trying right now is a canard (horizontal stabilizer at the front) and the main wings are quite far back. I wondered if it would be of ...
- 133
4
votes
1
answer
252
views
Does/did Russia or the Soviet Union ever fly rocket planes?
Did Russia or the Soviet Union ever have their own experimental or military rocket planes (other than the Buran), or did their military merely use jets and other non-rocket aircraft? America flew ...
- 193
5
votes
3
answers
272
views
Can air-to-air refueling be done in compliance with the FAR's?
I am wondering if any FAR's would prohibit the air-to-air refueling of two civilian aircraft in the US. In our use case, the receiving aircraft would be custom-built, and it would receive fuel pumped ...
- 53
5
votes
1
answer
328
views
On video equipment used to help assemble the X-59
On 2020 Dec 14, NASA reported on Lockheed Martin's construction of the X-59.
NASA’s supersonic X-59 assembly team marks wing milestone.
The report's photos include an unexplained apparatus, ...
- 10.5k
2
votes
1
answer
345
views
How are composite aircraft canopies constructed that sit flush with the fuselage?
More specifically, how is the composite frame of the canopy manufactured? Attached picture as an example.
- 1,232
3
votes
2
answers
364
views
Does anyone know more about the 1958 Heinkel-211 project?
Industria Aeronáutica Argentina worked in the 50s in a Jet airliner, Kurt Tank design, the IA-36, 'Cóndor', with simmilarities to 1958 Heinkel-211 project, turbines intake aspirating fuselage boundary ...
- 1,631
1
vote
1
answer
366
views
What about a Plane-Train?
The Shanghai Maglev Train's max speed is 267 mph. Could a plane be made to follow a rail, surface area provided, if not an existing rail to travel along? How much faster could the heavily modified ...
- 1,006
2
votes
1
answer
180
views
Could a wing be designed to exploit both normal flying and ground effect?
Ground Effect planes' wings are stubby and the height over the ground or water is limited to wing span.
Could a wing be designed to exploit both normal flying and ground effect together to give the ...
- 1,006
3
votes
3
answers
745
views
Is it feasible to replace a C152's engine with multiple small turbine engines?
If I wanted to remove the piston engine from a cheap plane like a Cessna 152 and add small turbine engines with an equivalent thrust but weighing less, where would be the best place structurally to ...
- 1,006
1
vote
1
answer
396
views
Any idea what this Ampaire plane is?
(Source)
This is certainly not the Ampaire 337 or Electric EEL, which is a converted Cessna 337. It looks like a boundary layer ingestor. Being from Ampaire, it probably is electric or hybrid.
I've ...
- 3,524
1
vote
0
answers
41
views
How is NASA going to get high fuel economy on the X-57? [duplicate]
This X-plane is meant to fly soon.
It's a modified Tecnam.
The propeller direct wash over the wings, increasing lift. This allows the use of a smaller, high-aspect ratio, low drag wing.
But this isn'...
- 3,524
1
vote
3
answers
504
views
The NASA X-57 uses 12 electric motors for takeoff. Does it need 12 control levers or just one?
If the NASA X-57 uses 12 motors for takeoff, does it need 12 controllers (like throttle levers), or just one?
The traditional way of engine throttle design was 1 throttle per engine, but what if you ...
- 1,029
20
votes
1
answer
5k
views
What is the asymmetric feature on the rear of a Sukhoi Su-47?
I saw this part on the rear of the Sukhoi Su-47 Berkut, and I can see that it is asymmetric. Is it maybe for interference, or is it a take-off aid because the Su-47 is a STOL plane?
What is it and ...
- 839
4
votes
3
answers
3k
views
What are the disadvantages of a Tail providing lift? (tandem-wings included)
Most aircraft feature the tailplane configuration, which requires the main wing to provide higher lift than the weight of the plane itself, what seems counterproductive.
Few aircraft have featured ...
- 55
1
vote
1
answer
408
views
Are there any NACA airfoils that resemble the X-29's wing?
As a part of my project, I am trying to perform structural and aerodynamic analysis of a forward swept wing on an aircraft, specifically the Grumman X-29 (pictured below).
I am assuming that ...
user44406
4
votes
1
answer
421
views
Would "Mad" Mike Hughes' steam-powered rocket have been certified airworthy by the FAA?
Daredevil 'Mad' Mike Hughes died after his homemade rocket crashed on 22 February 2020. The cause appears to be the premature deployment of the parachute used for a safe return. He was hoping to reach ...
- 11k
33
votes
5
answers
10k
views
Why Didn't the USSR Build An X-15?
In the history of aerospace engineering in the United States, the X-15 is lauded as a critical and necessary step on the path to manned spaceflight. Throttle-able chemical rocket propulsion systems, ...
- 1,120
0
votes
0
answers
232
views
Does a 3-blade prop handle up/down drafts better than a 2-blade?
I'm about to order a plane kit (RV-10) and one of the choices I'll be making is a 3-blade vs 2-blade propeller. A 3-blade prop should be: easier to balance, quieter and capable of generating more ...
- 101
1
vote
0
answers
210
views
Can an aircraft be issued a standard airworthiness certificate after being operated under and experimental certificate?
14 CFR, §21.191 (b) states that experimental airworthiness certificates can be used when:
Showing compliance with regulations. Conducting flight tests and other operations to show compliance with ...
- 1,775
3
votes
0
answers
119
views
What were the typical rotation and landing speeds of the X-29?
Looking online through all the available literature, I could not find the typical rotation ($V_r$), landing or even stall speed of the experimental forward swept wing X-29 aircraft.
I'm curious to ...
- 61
4
votes
1
answer
948
views
Are there experimental aircraft regulations in Germany?
The title is the question.
Are there any special regulations regarding experimental aircraft in Germany (or the EU)?
Those "special regulations" would (hopefully) be looser set of regulations in ...
- 247
1
vote
3
answers
539
views
Can a gas turbine be able to switch from torque to thrust?
Can a turbine engine be switched from providing torque (like a helicopter) to the rotor to transfer power to provide exhaust thrust (like a jet plane)?
Related: BV-347 upgrade this way?
- 1
-1
votes
2
answers
2k
views
Could a BV-347 be upgraded by extending the wings?
The CH-47 Model 347, also referenced as BV-347, was a helicopter that utilized a wing for forward flight and to carry external payloads. Could the wings be extended and engines on the rear rotor ...
- 1
10
votes
1
answer
3k
views
What kind of Chinook helicopter/airplane hybrid is this?
I had this question: Could this helicopter's body be a flying wing? and this picture came up.
What kind of helicopter is this?
What is the extra wing for?
- 1
8
votes
1
answer
746
views
How does the X-59 achieve low-noise supersonic flight?
By what mechanism or combination of mechanisms does the X-59 reduce the noise produced by its sonic boom? What are the design choices that led to this outcome? I really want to understand the issue ...
- 262
9
votes
1
answer
5k
views
Why did the AvroCar fail to fly above 3 feet?
I don’t quite understand why the AvroCar didn’t reach more than 3 feet? Was it a ground effect keeping it at that height and it didn’t have the capability to fly higher?
- 93
2
votes
1
answer
592
views
Could this helicopter's body be a flying wing?
This question: Could a helicopter fly like a plane this way? asks if a helicopter can turn sideways using additional wings to tip forward to allow the rotor blades to act as a propeller. The tail-...
- 1
-2
votes
2
answers
153
views
Would a long pole help stablize a jet pack?
Jet packs are classically worn like a book-bag on the back. Would it be more stable if the exhaust ports were separated? Would the jet pack be easier to control if the turbines were at the ends of a ...
- 1
0
votes
5
answers
832
views
Could a helicopter fly like a plane this way?
Could a wing be added to a helicopter to allow the entire craft to tip 90 degrees forward allowing it to fly faster like a plane using a fixed wing and leaning into the wing for lift?
I understand ...
- 1
6
votes
2
answers
459
views
Has a small airplane ever been air launched from a heavy-lift helicopter?
I would like to know if a small airplane, like a Cessna, has ever been air launched from a heavy-lift helicopter, perhaps as a stunt or as an aviation experiment?
I think it would have been a simple ...
user36220
1
vote
1
answer
200
views
What rotors would be best for atmospheric reentry?
What rotor blade set up would be the best for entering Earth atmosphere or to shed speed before landing in place of a parachute?
I understand that the longer blades are more efficient, but are not as ...
- 1
8
votes
1
answer
591
views
How are businesses able to use experimental aircraft?
I saw businesses like this using military jets to sell rides to civilians. Since warbirds are considered experimental aircraft, does the FAA issue special certs to fly them commercially?
According ...
- 103