﻿SOARING 
  FLIGHT 
  KLEMPERER 
  233 
  

  

  we 
  experienced 
  the 
  sensation 
  that 
  in 
  trjdng 
  to 
  spiral 
  down 
  one 
  way 
  

   we 
  were 
  unable 
  to 
  bring 
  the 
  machine 
  down 
  to 
  land 
  on 
  the 
  flying- 
  

   field 
  in 
  the 
  hollow, 
  the 
  motor 
  throttled 
  way 
  down, 
  whereas 
  circling 
  

   the 
  other 
  way 
  around 
  between 
  the 
  mountains, 
  we 
  would 
  be 
  knocked 
  

   down 
  so 
  vehemently 
  one 
  had 
  to 
  open 
  full 
  throttle 
  again 
  to 
  prevent 
  

   crashing 
  into 
  the 
  rocks 
  that 
  lined 
  the 
  field. 
  It 
  may 
  be 
  superfluous 
  to 
  

   mention 
  that 
  the 
  inversion 
  zone 
  was 
  rather 
  rough 
  riding 
  and 
  bumpy, 
  

   too. 
  Sometimes 
  the 
  altitude 
  of 
  the 
  zone 
  of 
  wind 
  inversion 
  was 
  indi- 
  

   cated 
  by 
  peculiar 
  formations 
  of 
  many 
  small 
  clouds 
  rapidly 
  forming 
  

   and 
  disappearing. 
  I 
  should 
  not 
  wonder 
  if 
  similar 
  conditions 
  may 
  be 
  

   encountered 
  in 
  parts 
  of 
  the 
  Kocky 
  Mountains, 
  also. 
  

  

  Even 
  without 
  a 
  pronounced 
  border 
  surface 
  between 
  two 
  distinct 
  

   wind 
  layers, 
  there 
  can 
  be 
  energy 
  stored 
  in 
  accessible 
  form 
  where 
  

   the 
  wind 
  is 
  gradually 
  increasing 
  with 
  altitude. 
  This 
  sort 
  of 
  power 
  

   gain 
  is 
  most 
  suitable 
  for 
  a 
  machine 
  capable 
  of 
  a 
  high 
  rate 
  of 
  

   climb. 
  The 
  gain 
  in 
  terms 
  of 
  the 
  original 
  rate 
  of 
  climb 
  is 
  approxi- 
  

   mately 
  equal 
  to 
  the 
  proportion 
  of 
  gravity 
  to 
  which 
  the 
  product 
  of 
  

   the 
  vertical 
  gradient 
  of 
  the 
  wind 
  velocity 
  and 
  the 
  forward 
  speed 
  

   of 
  the 
  airplane 
  amounts. 
  This 
  is 
  the 
  reason 
  wliy, 
  even 
  above 
  a 
  level 
  

   plain, 
  airplanes 
  generally 
  climb 
  better 
  against 
  the 
  wind 
  than 
  before 
  

   the 
  wind, 
  which, 
  after 
  the 
  very 
  take-off, 
  would 
  make 
  no 
  diflierence 
  if 
  

   the 
  wind 
  did 
  not 
  increase 
  with 
  height. 
  A 
  racer 
  would 
  experience 
  

   a 
  difference 
  of 
  about 
  20 
  per 
  cent 
  in 
  the 
  rate 
  of 
  climb 
  between 
  the 
  

   two 
  directions 
  of 
  flight 
  in 
  an 
  atmosphere 
  where 
  the 
  wind 
  speed 
  would 
  

   increase 
  by 
  10 
  feet 
  per 
  second 
  per 
  1,000 
  feet 
  altitude, 
  which 
  is 
  not 
  

   exceptional. 
  

  

  An 
  interesting 
  suggestion 
  has 
  been 
  made 
  by 
  a 
  Bavarian 
  inventor, 
  

   Herr 
  Wolfmiiller. 
  His 
  device 
  is 
  the 
  true 
  aerial 
  counterpart 
  to 
  the 
  

   sailing 
  boat, 
  and 
  really 
  deserves 
  the 
  name 
  of 
  sailing 
  flight. 
  

  

  His 
  argument 
  is 
  this: 
  The 
  sailboat 
  uses 
  a 
  high 
  mast 
  to 
  make 
  the 
  

   sails 
  reach 
  way 
  up 
  into 
  the 
  strong 
  wind. 
  Why 
  not 
  build 
  the 
  air- 
  

   plane 
  so 
  big 
  tliat 
  its 
  upper 
  and 
  lower 
  extremities 
  extend 
  into 
  differ- 
  

   ent 
  layers 
  of 
  wind, 
  the 
  upper 
  wings 
  to 
  act 
  as 
  sails, 
  the 
  lower 
  ones 
  as 
  

   a 
  keel? 
  The 
  idea 
  sounds 
  fantastic. 
  But 
  what 
  he 
  actually 
  did 
  is 
  to 
  

   fly 
  two 
  kites, 
  one 
  raised 
  way 
  up 
  high, 
  the 
  other 
  one 
  kept 
  low. 
  The 
  

   two 
  strings 
  were 
  tied 
  together 
  and 
  let 
  go. 
  On 
  evenings 
  when 
  the 
  

   wind 
  was 
  known 
  to 
  blow 
  from 
  the 
  opposite 
  direction 
  at 
  the 
  higher 
  

   level 
  than 
  down 
  close 
  to 
  the 
  ground, 
  these 
  kite 
  teams 
  would 
  travel 
  

   many 
  miles, 
  and 
  he 
  did 
  not 
  always 
  recover 
  them. 
  Being 
  of 
  rather 
  

   elaborate 
  design, 
  they 
  even 
  could 
  be 
  stabilized 
  at 
  certain 
  relative 
  

   angles 
  and 
  made 
  to 
  travel 
  across 
  the 
  wind 
  at 
  considerable 
  speed, 
  just 
  

   as 
  a 
  sailboat 
  cruises. 
  Interesting 
  though 
  the 
  principle 
  may 
  be. 
  it 
  is 
  

   not 
  very 
  likelj^ 
  to 
  be 
  put 
  to 
  practical 
  use. 
  

  

  The 
  principles 
  underlying 
  the 
  various 
  methods 
  of 
  dynamic 
  soaring 
  

   flight 
  ma}^ 
  seem 
  to 
  many 
  rather 
  remote 
  ideas. 
  Yet 
  dynamical 
  prob- 
  

  

  