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    Re: Amelia Earhart's aerial navigation
    From: Jackie Ferrari
    Date: 2009 Nov 21, 08:30 -0000

    Douglas,
    
    Having studied Fred Noonan's navigation as he applied it in PAA for some
    years now, I fully agree with Gary's exposition and conclusion ie that Fred
    Noonan was competent enough to believe that he could find Howland using
    celestial navigation alone. I believe this because of his own comments
    written on the logs of the transpacific  clipper flights together with
    comments from crew members. These leave one in no doubt that he distrusted
    radio direction finding.
       So I ask myself the same question that you ask. 'As a professional with
    the world looking on, would Fred Noonan really have done this with the risks
    before him? '
       I believe he would, if he had the remotest chance that the RDF was going
    to be operative but not if there was NO chance. I believe he would have
    taken the risk for the following reasons,
    
    1. He had himself and instructed others to find Wake on celestial alone
    (although knowing they had radio must have been comforting)
    
    2. His manner of working was professional certainly, but still enough open
    to question for one of those crew members to say in an interview 'He was
    good and he knew it.  He got cocky and threw off all the radio equipment'
    And for Harry Manning to say ' he let things go too long before taking
    observations'. Van Dusen, PAA's PR man positively seemed to hate him saying
    'He was a bum and couldnt navigate his way across my duckpond' (I take this
    with a pinch of salt but its interesting nonetheless).
    
    3. Both he and Amelia were in the risk game. He had risked his life many
    times and so had she.
    
    4. In so much as one's personal habits may inform one's professionalism, he
    was a gambling man.
    
    
    Look what he had to gain if they had pulled it off.  He would have regained
    his credibility which he lost as a result of being fired from PAA. His
    flight would have been up there with those famous flights of Lindbergh's and
    Hollick Kenyon's, written up as examples of exceptional navigation in Weems.
    
    We also have to remember he had done it before, albeit as a member of the
    well oiled PAA team.
    
    I think for these reasons that he would have attempted to locate Howland but
    only if he had the chance that the radio could be of assistance if needed.
    He would have weighed up the odds I believe, but on the day he lost.
    
    Jackie
    
    
    ----- Original Message -----
    From: 
    To: 
    Sent: Friday, November 20, 2009 11:09 PM
    Subject: Re: [NavList 10776] Re: Amelia Earhart's aerial navigation
    
    
    Many thanks to Gary LaPook for the detailed analysis of the Erhart/Noonan
    flight in post 10745.
    Thank you. It has answered some questions I had thought of, and many more
    that I had not. It also raises others, probably not answerable.
    
    Having flown light aircraft, trained with ADF, and having some knowledge of
    electronics (I restore for the fun of it old radio equipment) I can
    appreciate the very interesting points made by Gary about the radio
    direction finding aspects of this.
    
    I find it truly astonishing that they would take off with a useless radio
    direction finder when their lives might have depended on it. Which it did.
    -------
    
    Direction finding by radio was an important navaid in those days at both sea
    and more so for aircraft when they started long distance flying at this time
    in the 1930s;  with the techniques of radio DF firmly established and lifted
    from the marine experience.
    
    I agree,  as Garry pointed out, that flying, in fact just taxying around the
    airfield transmitter,  will give perfectly good DF indication;  and exactly
    overhead is easily indicated and recognised with the needle (in modern
    equipments) indicating a given direction, swinging around lazily anywhere
    for a moment or two, then indicating the opposite direction.  They are very
    sensitive.  The only problem with the type of equipment used by aircraft and
    at sea then is the need for hand rotation of the DF antenna, and there can
    be two DF bearings found at 180 degrees so it is easily possible to fly away
    from the required radio station if you go over it without noticing with the
    hand-rotated antenna method.  Usually though there is provision to have a
    'sense' aerial which tells you the correct bearing, so if he had overflown
    the transmitter he should still know which bearing is correct ... but only
    if the DF equipment is working of course.
    
    Gary is also spot-on with his pointing out that tubes (English English:-
    'valves') equipment of the 1930 was very unreliable indeed, and servicing
    such equipment was a big industry in its own right both in civil radios and
    military.  Further, it would have been part of provision of military
    establishments, so I presume there would have been at least one electronics
    (radio) specialist on Itasca who would have been able to at least try to
    repair the DF radio before they took off.
    
    Gary has made a convincing case that they took off without DF available,
    relying entirely on celestial navigation. If so, this was a highly dangerous
    thing to do given the pioneering flight to be made, and it seems they may
    well have paid the 'ultimate penalty'.  In those days, to take off without a
    working DF radio if you have one, on a flight of that nature, is highly
    suspect at best and unthinkable if your life could depend on it.
    
    That raises several other questions,such as:-
    
    In which case, were they under duress to continue regardless? and if so what
    pressures brought that about?
    Why not wait a few days more, get better time signal checks, and repair the
    radio DF finder before continuing?
    And - what provision would Noonan have made or could have made, for the
    event of not finding the island?
    The film shows them throwing out all of the safety equipment including a
    life raft. Ok they might still not have any realistic survival possibilities
    sitting in one for long but better than just ditching into the 'oggin
    without one at all.
    
    Gary provides an inevitable conclusion and convincing case, that Fred Noonan
    must have been 100% certain he could use celestial navigation for the flight
    without recourse to DF. As a professional, with the world looking on, would
    Fred Noonan really have done this with the risks before him?   Fascinating.
    
    Douglas Denny.
    Chichester. England.
    
    =====================
    
    Original posting:-  #10745
    
    From: glapook---net
    Date: 18 Nov 2009 21:59
    Previous messageNext message
    Greg Rudzinski asked:
    
    Maybe Gary can comment on the following:
    1. Time tick before departure.
    2. Sobriety of Noonan.
    3. Life raft.
    4. Radio antenna.
    5. Head winds.
    6. Celestial opportunities.
    7. Sleep deprivation.
    8. Was it possible to fly right over Howland Island and not see it?
    9. Was Howland charted correctly.
    10.What would have been a better less risky route?
    
    Gary wrote:
    
    Fred may have had a drinking problem but many people with such a problem
    manage to show up sober for work on Monday mornings because their jobs
    depend on it. Noonan had an even greater reason to show up sober, his LIFE
    depended upon it. They landed in Lae on June 29th. The night they arrived in
    Lae he went out drinking with Collopy and Heath and they got toasted.
    Collopy took him back to his hotel about midnight and Noonan was wobbly. On
    the 30th work was done on the plane and they attempted to get a time signal
    so that they could leave on July 1st but were not able to get the radio time
    signal so they had to delay the departure one day. On July 1st Noonan turned
    down an invitation to go out again with Collopy and went to the radio office
    where they finally got the time signal at 10:20 p.m. Earhart and Noonan were
    back in their hotel by 11 p.m. so no bender the night before departure. They
    took off at 10:00 a.m. the next day, July 2nd and the flight lasted over
    twenty hours. Even if Fred had had to be poured into the plane (and the
    movie of the departure shows him steady as he got into the plane) he would
    have had plenty of time to sober up on the way to Howland. Because of all
    this it is very unlikely that any drinking problem Fred may have had
    contributed to the disappearance. This story was pushed to put the blame on
    Fred and totake the focus off of AE's actions.
    
    
    I have posted the following before on another forum and it will answer some
    of the questions.
    
    "Paul, I for one never believed that Noonan made a navigational error.
    He was too experienced, too motivated (his life was on the line) and
    the techniques being used were well proven and of sufficient accuracy
    to have allowed them to find Howland."
    
    There is a lot of evidence that he was careful and competent. I think all
    the stories that came out after the flight besmirching him personally and
    his abilities were for the purpose of exonerating the popular and well known
    American heroine celebrity AE from fault for the disappearance, Fred was
    made the fall guy since he was an unknown nobody.
    
    I posted before that Fred would have been motivated to do a very competent
    job on this leg since it was the sole reason that he was brought along.
    Further proof of that was written by AE in "Last Flight" ( the book written
    by AE as she went around the world and sent back prior to her last flight),
    
     "Fred Noonan has been unable, because of radio difficulties, to set his
    chronometers. Any lack of knowledge of their fastness and slowness would
    defeat the accuracy of celestial navigation. Howland is such a small spot in
    the Pacific that every aid to locating it must be available."
    
    They had to delay the flight for a whole day so that  Fred could get a radio
    time signal (it was broadcast only once a day and there was interference the
    first day) so he could check his chronometers to determine how fast or slow
    they were. This would not have been necessary if they were just planning to
    use radio bearings to find Howland.
    
    This necessity for very accurate time is probably not understood by most
    people on this forum. The earth turns at a rate of 900 knots (900 nautical
    miles per hour, or 1035 mph) at the equator which means that it turns one
    nautical mile every four seconds. Without getting into the details of how
    celestial navigation computations are done, it works out that if your
    chronometer (a very accurate clock) is slow by just four seconds then your
    celestial computations will place you one nautical mile further west than
    where you actually are. If it is fast then you will think you are east of
    where you actually are. It doesn't take too many seconds of unknown
    chronometer error to cause you to miss Howland if using only celnav. Since
    their course was mainly eastbound they only had to be sure that they did not
    pass too far north or south of Howland so as to be beyond the range of
    Itasca's transmitter. Precise longitude would not have been needed if they
    planned to just use the radio direction finder for final guidance to the
    island. Since they were willing to wait a whole day just to get an accurate
    time check it shows that they planned to have celnav at least as a backup to
    radio direction finding and knew that they would need the maximum accuracy
    possible in that eventuality.
    
    If they were just going to use radio bearings then AE didn't need Fred, she
    could do that herself since the radio equipment was in the cockpit. It is
    obvious, then, that the entire world flight was planned around the need to
    use celestial to find Howland.
    
    I had also posted that Fred would have pre-computed the landfall procedure
    so that it could be easily accomplished after a long and tiring flight. I
    believe that he would have done this on the ground before takeoff either
    that morning or the day before or early in the flight before becoming
    fatigued. These computations would have only taken about one hour using
    Dreisonstok and plotting the  altitude curve on graph paper for the sun's
    and moon's altitudes as calculated at Howland. With this pre computed he
    could take many shots with his sextant and compare the measured altitudes
    with those on the graph and know instantly if they were staying on the LOP
    to Howland. No further complex computations would need to be done in flight
    while approaching the island.
    
    Even if they were planning to use a radio bearing to find Howland and
    celestial was planned only as a backup Fred would have known not to count on
    the radio working since it had failed them approaching Dakar. In fact he
    didn't have to think back that far. The day before the last flight they had
    had their radio repaired and had test flown the plane to check out it's
    operation. They were unable to get a null which meant that the radio
    direction finder WAS NOT WORKING. For some inexplicable reason they ignored
    that blatant fact and decided that the reason they could not get a null was
    that they were too close to the station. Certainly Noonan appreciated this
    was at least a potential problem and would have redoubled his effort to make
    sure that he did everything possible to ensure that celestial would get them
    to Howland. If he hadn't been confident of this they would not have left
    with an unproven radio direction finder.
    
    I don't know how many instrument rated pilots we have on this forum. I am an
    airline transport pilot and I have also been an instrument flight instructor
    since 1972 so I have some knowledge of how radio direction finders work
    since they were common navigation equipment  in airplanes used for flight in
    the clouds until the recent development of GPS. (I also have a radio amateur
    operators license, call sign KA9UHH.)
    
    When flying on instruments you are inside the clouds and can't see any
    landmarks, obstructions or airports. In order to navigate without visual
    references you rely on different systems of radio navigation equipment which
    for many years included radio direction finders very similar to the one
    installed in NR16020. This equipment uses long wave radio signals in the
    band of 190 to 535 kilocycles (now kilohertz) just below the A.M. broadcast
    band and including 500 kcs the international calling and distress frequency.
    This was the frequency that Itasca was broadcasting on. AE's radio direction
    finder should have been able to get a null and and so determine the bearing
    to fly to get to Itasca.
    
    Getting a null involves turning the loop antenna until it is lined up with
    the direction of the incoming signal which is shown by the received signal
    getting  weaker and weaker until it disappears, this is the "null." If you
    turn the antenna past the null the signal starts to get louder very rapidly.
    The width of this null is very narrow so that the bearing can be determined
    very accurately.
    
    This type of equipment is good for a very long distance mainly determined by
    the power of the transmitting station. For enroute navigation, airways, like
    "highways in the sky" were created with radio transmitters placed on the
    ground at each end of each leg of the airway. The signals have to be strong
    enough so that you can receive them at the halfway point of each airway leg.
    You track outbound from one station until halfway to the next station then
    start following the signal to the second station. As an example, a route I
    flew many times was  "A17" from Bimini, Bahamas to Puerto Rico. You take off
    from Miami or Ft. Lauderdale and tune in the radio station on Bimini which
    transmits on 396 kcs with a Morse code  identification of "ZBB." You use the
    radio direction finder to head for Bimini which is 55 NM from Ft.
    Lauderdale. After passing over Bimini you turn to a heading of 121? magnetic
    and track outbound until halfway to the next radio station located on the
    island of Grand Turk at the very southeast end of the Bahamas chain. Grand
    Turk transmits on a freq. of  232 kcs with the ident of "GT." After passing
    GT the next station is located on the north shore of Puerto Rico about 60
    miles west of San Juan transmitting on the frequency of 391 kcs, ident
    "DDP." Now here is the important part, the leg from ZBB to GT is 516 NM (593
    miles). This means that you can receive the signal 258 NM at least from each
    station. It is reasonable to believe that had AE's radio direction finder
    been working she would have been able to hear Itasca at a similar distance.
    This is born out by the fact that Itasca heard AE's much less powerful
    transmitter several hundred NM out.
    
    Since the leg from Lae to Howland is 2222 NM and the common estimate of DR
    accuracy is 10% of the distance flown then one could expect to fly the
    distance from Lae to Howland solely by dead reckoning and still be confident
    of coming within in 222 NM of Itasca and so be close enough to pick up the
    radio signal and track inbound to Howland. So if AE was willing to rely only
    on radio she didn't need Fred at all. In fact, they saw Nauru island about
    half way so the dead reckoning leg would have only been about 1,000 NM so
    the DR error should not have exceeded 100 nm. But obviously they wouldn't
    just rely on radio.
    
    It is hard for young people today who have grown up with cell phones, the
    internet, TV, satellite dishes and IPODs to have any gut feeling for the
    unreliability of radio equipment in the 1930s. Modern equipment and systems
    are so reliable people don't even think about it anymore. But in the '30s
    comparing the reliability and trust in complicated pieces of electronic
    equipment with resistors, capacitors, and tubes that burned out without
    warning in your own equipment and in the transmitting equipment that was not
    under your control with the proven reliability of a simple sextant, a book
    of tables and a clock (or two clocks for redundancy) and celestial won hands
    down. That was why AE hauled Fred all the way around the world.
    
    Back to the use of radio direction finders. When flying on instruments you
    eventually have to descend to land at an airport that you can't see while
    you are in the clouds that might be in a valley surrounded by mountains. You
    fly to the approach radio station on a specified course and altitude and
    then after you pass over the transmitter's antenna you know it is safe to
    descend  down to the minimum decent altitude that has been established by
    the FAA for the approach to that airport which takes into account the height
    of surrounding obstacles and the altitude of the airport and the distance
    from the transmitter to the runway. When you pass over the antenna and start
    your final decent you start a stop watch. Your approach chart tells how many
    minutes and seconds it will take you to fly from the station to the runway
    at various ground speeds. After you descend to the minimum descent altitude
    you maintain it until you see the runway of until the time runs out by which
    you know you have passed over the runway without seeing it so you must climb
    and go to your alternate.
    
    The reason I went through this long winded explanation is so everyone will
    understand that the radio direction finder works right over the transmitting
    antenna, you can't get closer than that. AE dismissing the failure of her
    radio direction finder because she thought she was too close to the
    transmitter shows either she didn't understand its operation or she was
    satisfied that celestial alone was sufficient to get them to Howland. I
    think the latter explanation makes the most sense since they could have (and
    probably did) check the radio direction finder operation as they flew
    farther away from Lae and continued on even though it was apparent that it
    wasn't working. Again, this would have made Fred work real hard on his
    celestial since he knew, actually KNEW, that he couldn't depend on the
    radio.
    
    Based on all this I believe Fred knew he had to do an exemplary job of
    celestial navigation and if the radio did per chance work when they got near
    Howland then "no harm, no foul." He had confidence in celestial and knew it
    had sufficient accuracy to locate Howland or he wouldn't have gotten into
    the plane.
    
    gl
    
    
    
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