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24 votes
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Did the FAA order the installation of "Cooper vanes?"

The answer to both of your questions is "yes". The FAA ordered, in effect, the installation of "Cooper Vanes" and did do so in 1972. The reason you could not find the answer may have been that the ...
DeltaLima's user avatar
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6 votes
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Why was the 307’s pressurisation system removed when it was modified into the C-75, despite the fuel-burn advantage of higher-altitude flight?

Pressurization is primarily for crew and passenger comfort. The B307 was a very early attempt at cabin pressurization and the marginal pressurization differential of only 2.4 psi did not allow much of ...
Mike Sowsun's user avatar
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5 votes

private jet based of an sr 71

Yes, a private jet could be based on the design of the SR-71, but there would have to be a market for it. Considering how expensive it would be to produce, operate, and maintain, no one would want ...
Mike Sowsun's user avatar
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5 votes
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Does 'Fat Albert' Have any significant modifications?

I will preface this by saying that I could be wrong. I know that the USAF Thunderbirds' F-16 aircraft are not modified other than paint and smoke capabilities. I'm pretty sure that the Blue Angels' F/...
Saxon Xander's user avatar
4 votes
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Does a converted aircraft require recertification? Does it break manufacturer rights?

At this point in the video it says about a the verification of all the modifications done to a plane would be verified by an independent third party. Similarly in this website from Stirling Dynamics, ...
jcbge's user avatar
  • 56
4 votes
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How would a fighter be changed from having static stability to having relaxed stability?

The first and most important step is to move the center of gravity back relative to the neutral point of the configuration. This is done either by shifting masses on the airframe back or by shifting ...
Peter Kämpf's user avatar
4 votes

How to record flights and cockpit radio com using an Android phone?

Android by default has Google Now enables, which include voice search. Voice search listens for the words "Ok Google" when you speak, but phones also detect a long press in a headphone button (on ...
GdD's user avatar
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4 votes

At what point does an aircraft need a new type certificate vs a STC?

To start, I would suggest a read through 14 CFR Part 21. But to summarize: a TC is necessary to manufacture a new aircraft, so TCs are the property of the manufacturer of the aircraft. The TC ...
Gerry's user avatar
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3 votes
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Why were most of the first-generation-Learjet wing mods never approved for the Learjet 23?

The cost of approving an STC for an aircraft can be quite expensive and the return on investment may not have been worth it. ...
wbeard52's user avatar
  • 12.7k
3 votes

How can I calculate the speed gain from using multiple STC modifications together?

Not practically speaking no. With sufficient engineering data you could perform calculations to come up with a model for what the additive effects would be of the various modifications. The ...
Casey Rayman's user avatar
2 votes
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How to record flights and cockpit radio com using an Android phone?

Android by default has Google Now installed. Voice search listens for the words "Ok Google" when you speak, but phones also detect a long press in a headphone button (on headphones with controls). It ...
nndhawan's user avatar
  • 221
2 votes
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Would this modified tire work to prespin an aircraft tire?

The idea is good in concept but it would be pretty difficult to match the rpms to the actuual ground speed, in fact if the wheel was spinning faster it would actually wear the tyre more! Another ...
Anilv's user avatar
  • 4,566
2 votes
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A modern replacement for DH.82's Gipsy Major engine

The Avia (now LOM) M132 4 cylinder inverted inline might fit. Some adaptation work is probably required.
Wirewrap's user avatar
  • 899
2 votes

How can I calculate the speed gain from using multiple STC modifications together?

I'm just making this up as I go along, so your mileage may vary. Also I'm only dealing with the drag-reducing mods. It seems this method ought to give a conservative estimate of the combined speed ...
quiet flyer's user avatar
  • 22.7k
2 votes

Where can I get blueprints of older aircraft?

Blueprints and similarly detailed drawings for aircraft are not something that is generally available outside the manufacturer of the aircraft. For a time, aircraft delivered to the US military were ...
Rob McDonald's user avatar
  • 12.6k
1 vote

Where can I get blueprints of older aircraft?

For your purposes a simple cutaway like the following ones should be enough (source first cutaway and source second cutaway): If you need a bigger version you can ask the editor or the owner of those ...
sophit's user avatar
  • 12.9k
1 vote

Can people perform major modifications to an aircraft without an A/P license, as long as their company is certified per part 145?

You can likely find all the answers in 14 CFR Part 145 - Repair Stations. But to provide a somewhat qualified and summarized answer to your question: Per Subpart D - Personnel: The stations is ...
Gerry's user avatar
  • 19.9k
1 vote

How would a fighter be changed from having static stability to having relaxed stability?

I don't have access to the book, but the improvement mentioned in the quote is ... leading edge slats ... Slats wouldn't change the center of gravity noticeably. Your Wikipedia reference doesn't ...
B. Young's user avatar
  • 195
1 vote

Does a converted aircraft require recertification? Does it break manufacturer rights?

Generally no the aircraft will not need to be re-certified however the aircraft will likely need an updated weight and balance. Aircraft have their official weight and balance numbers measured as they ...
Dave's user avatar
  • 101k
1 vote

Continuing Airworthiness Requirements During Major Modification

Assuming you are in the US or a country with regs like the FAR's, this is no different than using type certified components on an aircraft with an experimental airworthiness certificate. In that case ...
Juan Jimenez's user avatar
1 vote

At what point does an aircraft need a new type certificate vs a STC?

I know this is an old post, but the answers here are really quite off the mark. This is precisely the question that is addressed by 14 CFR 21.113(b), 21.19, 21.93 and FAA Advisory Circular (AC) 21.101 ...
Adrian's user avatar
  • 11
1 vote

At what point does an aircraft need a new type certificate vs a STC?

Since this is an aircraft for personal use, is under 19,000lbs gross weight, and less than 19 seats it will fall under Part 23. If you don't plan on selling "kits" to do these modifications, then an ...
Ron Beyer's user avatar
  • 36.2k
1 vote
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How to modify an amateur kit build with wing hard points

You will most likely need a Supplemental Type Certificate from EASA According to their FAQ, emphasis mine: My aircraft has been modified in the USA by Form 337 action. Can EASA accept this? ...
AEhere supports Monica's user avatar
1 vote

A modern replacement for DH.82's Gipsy Major engine

No there isn't. The closest thing would be a Fairchild Ranger inverted in-line 6, almost as old and 70 lbs heavier and I don't think it's ever been tried. The DHC-1 Chipmunk, DeHavilland Canada's ...
John K's user avatar
  • 132k
1 vote

Can a modified aircraft be imported and certified in the US?

If the aircraft you import to the US was certified by country that the US has a aviation bilateral agreement with (https://www.faa.gov/aircraft/air_cert/international/bilateral_agreements/...
Greg 's user avatar
  • 373

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