What is the question for "twice as many ... as" format?

I have a question about how to make a certain type of question.

There is the statement here:

The airplane has twice as many engines as it requires.

I want to make a question the answer to which is:

twice as many engines as it requires

which specifically emphasizes twice as many. Not a yes/no question, but a wh/h question.

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I asked some native speakers of English and they provided me with sentences like:

How many engines does the airplane have?

or

How many more engines does the airplane have?

But I think the answers to those questions, for example for a plane with 8 engines, are "eight engines", and "four more engines", not "twice as many engines as it requires".

I made the following question but I wonder if it's grammatically correct:

How many times as many engines as required does the airplane have?

Does anyone have a better suggestion?

Answer

Okay, the concept of "times" or "factor" is - if I've read all your comments correctly - critical. So how about:

How many times the required number of engines does this airplane have?

Or:

By what factor does this airplane’s number of engines exceed the requirement?

The answer to both questions cannot be:

The airplane has eight engines.

Nor can it be:

It has four more engines than it requires.

The answer (given a required 4 but extant 8) must be:

The airplane has twice as many engines as it requires.