Welcome to the NavList Message Boards.


A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Add Images & Files
    Re: Alternate theories on Noonan's navigation
    From: h.a.c. van Asten
    Date: 2012 Feb 11, 04:49 -0800

    May 25th , 2011 , Mr. Lapook criticizes the contents of a series of articles on the Earhart-Noonan incident of July 1937 . The main problem concerning the article(s) Mr.Lapook was wrestling with , is that he did not identify the difference between a technical review on a specific navigation issue , and an ad fundum review on the same issue , the latter along the paths of the science and practice of navigation of the era . The first review can be made by any navigator being conversant with reading his tables without any further questions put forward . The second can only be made by thoroughly studying any background that may have brought a navigator to the decision he has actually taken . Mr. Lapook´s main problem concentrated on the sunset - sunrise fixes appearing on stage in the articles . Very good : for air navigation , although mentioned in NIF-1944-Emergency Section , the method is intricate , time consuming , unreliable andsoforth . Sea navigators however , and Noonan was one , try to turn te sunrise-sunset fix to reliability until today´s day , be it for non-commercial use only . Lapook´s scepticism has in the mean time been quenched by his own exploration about an alternative track of the aircraft beteen Lae and Nukumanu Island , depending on a formerly erroneously notation of coordinates (by Balfour , Chater) . A 0519 from aboard radio message placed the flight over an unidentifiable pair 150.7-E/7.3-S . When reading 157-E / 7-03-S according to navigator´s usage to register in degrees and minutes , before the electronic calculator appeared , the coordinates pair is for the village of Ghaghara on Choiseul (Lauru) Island , eastern coast . Herewith the 0519 message acquires reality : mr.Noonan avoided the heavy rain squalls as predicted by the last received weather forecast , by altering the first track Lae-Nukumanu via Gagan on Buka Island to Lae-Ghaghara-Nukumanu via the precomputed sunset fix , also like originally allowing for a last position check before nightfall . From Ghaghara to the sunset-on-board coordinates 159-07-E/04-33.5-S the distance was 226 mls , allowing for 2 hours {at} 113 mph ferry speed which is slow , but one neared the storm depression in the Nukumanu region from the south . At 0718 GMT (watch time of mr.Chater , sunset was 0719:30 GMT) the aircraft was evidently close to the pre-fixed position , whereupon Noonan could safely order the position communicated by the also precomputed coordinates. He clearly decided for the following practial solution : if deviated from your inital track and you have a good , optical , Ghaghara fix available , you fly time-speed-distance DR to your initial next intended fix , you check by sun position lines , and arrive in the sunset region . No observation necessary : a glance at the setting sun and you are back on track within the margins of air navigation since the accuracy is better than by an observation itself . At sunrise next morning a same scenario may have deployed : fly from Nikunau , Beru , or Tabiteuea to your precomputed sunrise fix {at} 150 mls off Howland and if you see the sun actually rise or not : your watch {at} 175453 GMT indicates where you supposedly are . The 2008 EJN article shows that you may be actually 10 miles eastwards in error . A 3rd article , EJN Dec 2011 (davidkbowman.com and go to technical articles) shows that it was (Lae-Nukumanu detour or not)impossible to reach other islands than Howland , or Baker , so that the Earhart crew , in the favorable event , alighted the aircraft on the high seas in the immediate (60 mls)Howland vicinity . H.A.C.van Asten
    NavList message boards and member settings: www.fer3.com/NavList
    Members may optionally receive posts by email.
    To cancel email delivery, send a message to NoMail[at]fer3.com

    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.

    Email Settings

    Posting Code:

    Custom Index

    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site