NavList:

Howard, I disagree with most of your points. (I read the article.)

First, as to lack of an astrodome or astrocomapass or periscopic sextant. Well, periscopic sextants had not been invented yet so that was not a bad choice, in fact, no choice was possible. Same as to the astrodome, not invented yet. Neither the Sikorsky S-142 nor the later Martin M-130 had one and Noonan had done plenty of successful navigation in the S-142 both in the Carribean and accross the Pacific. You claim that without these that Noonan couldn't determine accurately the deviation of the compass, not so. The plane had a B-2 drift sight which could be mounted on either side of the plane to measure the azimuth of any celestial body and determine the actual true heading of the plane thereby allowing determination of the compass deviation. Speaking of which, you denigrate her compass (a standard aircraft compass mounted above the instrument panel) but you are apparantly not aware that she also had an aperiodic compass mounted on the floor of the cockpit next to her right foot. This is the same type of compass used at all the navigation stations in all of our C-47s, C-46s, B-17s, etc. and relied upon by our navigators as THE standard for accuracy. They were also the standard used in similar RAF planes as well as in Spitfires and other fighter planes, mounted on a pedestal above the floor between the pilot's legs. (I even flew a Gipsy Moth, G-ACDC, ) like the one Sir Francis Chichester flew across the Taman Sea in 1931 that had an aperiodic compass mounted the same way. BTW, it was on this flight that Chichester was given credit for inventing the single line of position landfall procedure that was used countless times by our air navigators to find islands in the Pacific during WW2.  Actually, Admiral Gago Cotinho of the Portugese navy, used this procedure in 1922 to find Saint Peter's & Paul's rocks while crossing the South Atlantic. Using a sun line, like Noonan was doing, was the STANDARD way to find islands during WW2 and later.

The aircraft had mounts for B-2 driftmeter on both sides as well as a mount that allowed drift sights to be taken through a propped open door to allow drift readings.

Your complaints about lack of an astrodome is unwaranted as Noonan took 14 shots on the way to Hawaii and 8 shots on the way to Dakar so no problem there. As long as your stars were not terribly high shooting through a side window works perfectly fine. I have a photo of Manning taking what looks like a 45 degree high observation through the left hand window. And, as long as the inside and outside surfaces of the glass in the window are parallel (which they are!) there is no refraction or distortion. In fact, the astrodome had lots of distortion and a correction table to try to minimize that distortion of the observations. 

You also fault the use of a twin engined plane since you then have twice the chance of an engine failure.This is true and a problem if the plane cannot maintain flight on just one engine. This was true of the Electra L-10 during the phase of flight right after takeoff when the plane was heavy with fuel because the propellors could not be "feathered."  So, L-10s had two "dump valve" handles mounted under the pilot's seat so that he could dump a tank (only one, please) to lighten the plane when the two tanks were full which then allowed the plane to maintain flight on the remaining one engine. Earhart's [lane had many such handles mounted along the starboard side of the cabin to all the many tanks in her plane. Later on in the flight, after a significant amount of fuel had been consumed, this problem goes away. (I have been a multi-engine flight instructor since 1972, 52 years.)

The original plan was to fly westward from California to Hawaii and then non stop to Tokyo. Then, due to concerns about a very heavy takeoff from Hawaii necessitated by the large fuel load needed to reach Tokyo, Earhart obtained support from the U.S. Navy to refuel in flight over Midway Island since there was no airport there, only a seaplane base in spite of the Navy's concern that AE lacked the piloting skills for the in flight refueling. However, this plan was not followed as the plan was changed to include a leg from Hawaii to Howland, about 1800 nautical miles (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 with Manning as far as Darwin, Australia, and then for AE to continue on alone after Darwin with Manning and Noonan to return by ship. It is obvious that e veryone appreciated that the leg to Howland was to be the most challenging navigationally They flew from Oakland to Hawaii on March 18, 1937 Greenwich time and date(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. I have annalyzed each of them. This flight took 15 hours and 48 minutes. The plane had departed Oakland with 947 gallons of fuel and Earhart stated that four hours of fuel remained on landing in Hawaii. 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. (Two days ago I was standing on Ford Island in Hawaii where this crash occured!) The plane was crated up and shipped back to California 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 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 116 NM further north at St. Louis. We have the chart used on this flight showing eight lines of position (LOP)derived from observations of the sun. They then continued on around the world and arrived at Lae New Guinea 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 radio direction finder (RDF)which didn't work on high frequency although it had checked out ok on 500 khz. They ignored this problem and departed at 10:00 a.m. (Zone Description -10) on July 2nd, (0000 Z or GMT, July 2nd), for a planned 18 hour flight to Howland. This leg is 2222 NM long and the course is 078º True approaching the island. The rhumb 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 550 kHz. The Itasca maintained time with a ZD of + 11.5. AE maintained two way radio contact with Lae 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 the 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 needed only for transmitting on 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 destination 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. Experimental high frequency (HF) RDF equipment was set up on Howland but there are no documents showing that Earhart knew of its existence, it appears that it was a last minute addition by Mr. Black when sailing out on the Itasca. If she did know about a plan to have it installed on Howland it is inexplicable that in none of her radiograms to Itasca did she ask to have its installation confirmed before relying on it, yet there is no mention of it in her messages. This is especially true after she got from Itasca the list of their RDF frequencies that did not mention any HF capability. If she knew about the HF RDF you would have expected her to ask for confirmation. Even if she had been told earlier that it would be installed on Howland many things could have gone wrong in the interim demanding such reconfirmation of it availability. As it turned out the equipment was used for a long period prior to her arrival in the vicinity of Howland so the batteries were dead at the time it was most needed at the end of the flight. 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 1745 Z (0615 Itasca time) and for more than an hour afterwards, the azimuth of the sun remained 067º T so the resulting LOP ran 157-337º True. 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 crossing angles with the sun line to provide daylight fixes. AE's last transmission at 2013 Z (0843 Itasca Time) stated they were on the 157º-337º line of position. 

For some inexplicable reason, Earhart notified the Itasca to transmit the homing signal on 7.5 mc which was well above the direction finding limit of her radio. She had specified other homing signal frequencies for the other two vessels that were appropriate, but not the all important one at Howland!

So the loss was due to her not replacing Manning with another skilled radio operator, a need that had been recognized from the start. I suspect it was purse strings that dictated this as on the second attempt the radio guy would have to travel all the way around the world and not just the several days as contemplated for the first attempt.

As to the limited range, as C-47 only has a range of 1650 miles, much less that the Electra.

gl

File:

File:

File: