I believe this to be Armstrong's first Autopen pattern, circa 1962. When used with a fountain pen the resulting signatures are deceptively natural-looking. This signature is often seen on Group 2 signed covers.

I orignally had a pattern 2 which was just a distorted version of pattern 1 above. Although the pattern is now removed I have left the pattern numbering unchanged as this numbering system has been quite widely-referred to elsewhere.

This signature style from around the Gemini era (seen used in 1966) through early Apollo era (current in late 1968) has a distinctive downwards-pointing arrowhead shape in the "A". Note that the last example shows a distinct difference in the first stroke of the "N" but I believe this to be due to the paper moving under the machine.

Seen from late 1969 onwards the new autopen patterns end with a distinctive loop back under the signature.

Quite common on Apollo 11 signed items (and used from 1969 through to at least 1979) this pattern seems to appear in two variants - A and B.

This pattern dates from late 1969 and is commonly seen on Apollo 11 first day covers.
It seems to be a variant of pattern 5A above, but the first two strokes of the "N" displaced to the right so that they cross the third stroke slightly. Note that with both 5A and 5B the top left of the "A" is sometimes just open (as in the first example) or more often just closed (slightly overlapping) as in the second example.

Possibly the last autopen pattern made for Armstrong. The surname is compressed to just a few penstrokes.

This odd-looking pattern is rarely seen and generally seems to appear with very distinctive (but deceptively natural-looking) ink blobs towards the end of each pen stroke. I've seen an example that was sent through the mail in November 1970. Presumably this pattern was used for only a very short period of time before being replaced.

Another unusual pattern, this one seen on an early Apollo 11 crew glossy, on a business suit portrait, and on a cover dated November 1969.

During a limited period following the first moonlanding, when the Astronaut Office was presumably overwhelmed with mailed-in requests for the autographs of Neil Armstrong and the Apollo 11 crew, a number of these requests were apparently returned from NASA without the usual Autopen signatures. Instead, the items were hand signed but not by the astronauts themselves

It's important to note that the term 'secretarial' is used loosely here. It is very unlikely that Armstrong's secretary was responsible for these signatures. Indeed the fact that many Apollo 11 pieces were returned with the fake signatures of all three crew members in the same distinctive style indicates that the signee was not attached to any one astronaut.

Presumably the signatures were created in the loop where the Autopen machine would normally be used. We can only speculate as to why someone faked the signatures rather than use the Autopen machine. Perhaps the sheer volume of request meant that someone found it quicker and easier to add the signatures by hand than to use the machine. Maybe the unprecedented demand on the Autopen machine meant that it broke down at some stage, leaving someone with a vast stack of requests for autographs and no way to comply until the machine was repaired.

Whatever the case, the fact that these fake autographs were sent out from NASA's offices means that those who received them had no reason to doubt their authenticity. It can be difficult to convince these people today that they've been deceived.

The following examples show a few 'secretarial' Armstrong signatures. I would say that the person that created these signatures was using Autopen Pattern 4 as their guideline.