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Re: Amelia Earhart navigation- basic information & PICTURES
From: Jackie Ferrari
Date: 2009 Dec 1, 07:19 -0000
From: Jackie Ferrari
Date: 2009 Dec 1, 07:19 -0000
Greg, It would be nice to think that Fred had some say in the matter and could purposely choose the date but the whole second flight was pretty rushed. One gets the impression that what planning there was, was driven more by Putnam's desire to have them home for a grandstand finish on July 4th. Jackie. ----- Original Message ----- From: "Greg Rudzinski"
To: "NavList" Sent: Tuesday, December 01, 2009 1:05 AM Subject: [NavList 10866] Re: Amelia Earhart navigation- basic information & PICTURES Ron, At 1745Z sunrise at Howland Island on July 2, 1937 the celestial bodies available in addition to the Sun would have been Venus Hc 44� 42' Az 068� for a LOP of 158�/338� and the Moon Hc 72� 01' Az 043� for a LOP of 133�/313�. Venus would have been visible through the entire day with a clear sky. I believe FN purposely selected July 1 & 2 to maximize celestial opportunities for his morning arrival at Howland Island. The aircraft could have easily adjusted course to provide the best view for an observation. FN would have surely thought of these things ahead of time. There was no need for a very low altitude Sun observation. Greg On Nov 30, 3:38 pm, Ronald P Barrett wrote: > TO ALL, I thought the two pictures might help us in our discussion as to > how or where Noonan might be able to take a sun rise observation off the > nose of the L-10E. Remembering the sun was down and off to the left of the > nose and not up as most non-navs might think right off. Ron Barrett, > President Air Force Navigators Observers Association (AFNOA) > > --- On Sat, 11/28/09, Gary LaPook wrote: > > From: Gary LaPook > Subject: [NavList 10833] Amelia Earhart navigation- basic information. > To: NavList@fer3.com > Date: Saturday, November 28, 2009, 2:28 AM > > Amelia Earhart (AE) attempted to fly around the world in 1937 at about > the equator. Some prior around the world flights had been made at higher > latitudes so encompassed a shorter route. The original plan was to fly > westward and refuel in the air over Midway Island since there was no > airport there, only a seaplane base. The Navy put the kibosh on that > plan because of AE's lack of the piloting skills for the in flight > refueling. The next plan was to fly westward including a leg from Hawaii > to Howland, about 1800 NM, where a runway was bulldozed for her use. > (There is speculation that this also furthered the claim of U.S. > sovereignty's over Howland and the other Line Islands. It may have also > furthered Pan Am's plans for routes across the Pacific.) The plan was > for AE to be accompanied by Harry Manning as navigator and radio > operator and also by Fred Noonan as navigator as far as Howland and for > AE to continue on alone after that with Manning and Noonan to return > from Howland by ship. It is obvious that everyone appreciated that the > leg to Howland was to be the most challenging navigationally > > They flew from Oakland to Hawaii on March 18, 1937 (Z) as planned with > Paul Mantz also aboard, he was a technical adviser to AE. Noonan and /or > Manning took 14 celestial shots during this flight as well as a number > of radio bearings. We have the charts used on this leg. On the > subsequent takeoff with Manning and Noonan onboard AE lost control of > the plane resulting in a ground loop and significant damage to the > plane. The plane was crated up and shipped back to California on the > Lauraline for repairs at the Lockheed plant in Burbank California. It > was decided to reverse the route to travel eastbound after repairs with > the toughest navigation leg to be Lae New > Guinea to Howland. This necessitated carrying a navigator for the the > entire flight. Manning claimed that he had to get back to his full time > job as captain on a ship but he was supposed to have said that he had > lost confidence in AE's abilities so he did not participate in this > second attempt leaving Noonan as the sole navigator. Noonan did not have > Manning's radio skills which proved to be a serious problem later in the > flight. They flew from Oakland down to Natal Brazil. On June 7, 1937 > they flew from Natal towards Dakar Senegal but missed that destination > and landed about 150 NM further north at St. Louis. We have the chart > used on this flight showing five sun lines. > They then continued on around the world and arrived at Lae N.G. on June > 29, 1937. On the 30th the spark plugs were changed and other maintenance > accomplished. They had planned to depart the next day, July 1st, but > were unable to get a radio time signal so put off the departure until > the 2nd. They took advantage of the delay to do a test flight on the 1st > to check out the operation of the RDF which didn't work. They ignored > this problem and departed at 10:00 a.m. (ZD -10) on July 2nd, 0000 Z > July 2nd, for a planned 18 hour flight to Howland. This leg is 2222 NM > long and the course is 078� True approaching the island. The rumb line > and the great circle differ by less than one degree and one-tenth of a > nautical mile since the flight was along the equator. The Coast Guard > Cutter Itasca was off shore of Howland ready to transmit a homing signal > for AE to follow to Howland and had the capability of direction finding > on transmissions made by AE if she transmitted on the correct frequency > within the frequency range of the Itasca's equipment. Itasca had cabled > to Lae on June 28th listing the frequency ranges of its radios. Its RDF > covered only from 270 to 500 kHz. The Itasca maintained time with a ZD > of + 11.5. AE maintained two way radio contact with Lae for five hours > on her daytime frequency of 6210 kHz but contact was lost when she > switched to her night time frequency of 3105 kHz to attempt to call > Itasca. > > AE's radio could transmit on 500, 3105 and 6210 kHz only but she could > tune her receiver to any frequency. Communications on he international > calling frequency of 500 kHz was in Morse code and neither AE nor Noonan > were proficient in Morse though manning was. Since they did not plan to > utilize Morse code without Manning ,the 250 foot long trailing wire > antenna used only for 500 kHz was removed in Florida to save weight. It > is possible that her radio might still have been able to put out a > significantly weakened signal of 500 kHz using the remaining antenna. > > Noonan and AE most likely planned to use radio navigation for terminal > guidance as they approached Howland since radio navigation gets more > accurate as you approach the antenna while celestial's accuracy remains > fixed. AE could have done any necessary radio work by herself so did not > need to carry Noonan all the way around the world if they had not > planned to use celestial, at least as a backup method for finding Howland. > > When they were unable to get the radio signals they needed it is almost > certain that Noonan would have turned off to the left to intercept a sun > line LOP to the northwest of the island. From sunrise at about 1645 Z > (0615 Itasca time) and for more than and hour afterwards the azimuth of > the sun remained 067� T so the resulting LOP ran 157-337� T. Noonan > would have intercepted this LOP and followed it to Howland using the > "single LOP landfall procedure" popularized by Chichester as "deliberate > error" and also known as deliberate offset. This method had sufficient > accuracy to allow them to find Howland and was taught to all flight > navigators and was used thousands of times successfully during WW 2 and > after to find small island destinations. In addition, the moon was also > visible and provided good cuts with the sun line to provide daylight > fixes. > > AE's last transmission at 2013 Z (0843 Itasca Time) stated they were on > the 157�-337 �LOP > > More later. > > gl > > -- > NavList message boards:www.fer3.com/arc > Or post by email to: NavList@fer3.com > To unsubscribe, email NavListemail@example.com > > AE > 67KViewDownload > > AE > 88KViewDownload -- NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To unsubscribe, email NavListfirstname.lastname@example.org -- NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To unsubscribe, email NavListemail@example.com