FLOWN APOLLO 11 LM G & N DICTIONARY SHEET.
Apollo 11 LM G & N Dictionary, P27 update (LM), a single sheet printed recto and verso. July 1969. 8 by 5½ inches. With a Typed Letter Signed by Aldrin.
A Lunar Module flight data "pad" sheet on which Neil Armstrong and Buzz Aldrin could log new or updated flight information.
BUZZ ALDRIN'S letter reads in part: "Accompanying this letter is a sheet labeled P27 Update (LM) from the Apollo 11 LM G and N Dictionary, Part No. SKB32100074-361, S/N 1001. The dictionary was carried to the Moon on the flight of Apollo 11 during July 16 to 24, 1969. Then the entire Guidance and Navigation (G and N) Dictionary, including this sheet, was taken to the surface of the Moon in Lunar Module Eagle during the first lunar landing on July 20, 1969. The dictionary had several pages devoted to the procedures and use of the words and numbers printed on this sheet. It is an example of the P27 data grids used in flight operations. Neil Armstrong and myself could use the P27 sheet to update our LGC (LM Guidance Computer) to new flight event times such as the lunar landing or rendezvous.
PURP was short for purpose of the data to be used such as LDG or the landing time on the lunar surface. V was for the command load Verb to be used, either 70, 71, 72, or 73. The GET was the time Ground Elapsed Time for the data recorded in hours, minutes, and seconds. The 1174 01 area was for the index number of command words in octal format and the grids 2 through 24 were correction word identifiers if needed.
The HR, MIN, SEC were the actual hour, minute, and second in mission elapsed time for the confirmation of a ground track verification. The LAT, LON, and ALT were the latitude, longitude, and altitude for this ground track confirmation. N34 was the noun procedure for the time of the event and N43 was the noun procedure for the latitude, longitude, and altitude.
This actual sheet was an excellent quick view reference for myself and Neil Armstrong during the flight. It could have been used for flight operations if necessary."
The letter also states that the sheet has been in his private collection since 1969 and that a copy of the G & N Dictionary cover is enclosed. The dictionary sheet is INSCRIBED AND SIGNED "Carried in EAGLE to the lunar surface on Apollo XI, Buzz Aldrin."