Steady Improvement by Fred Piscop

Across 1 Show some backbone, slangily 6 Super-secure airline 10 Did some groundbreaking 14 Without an escort 15 Niels Bohr, for one 16 160 square rods 17 Rarity for a new parent 20 Not so dilute 21 Work in tandem 22 Aurora's Greek counterpart 23 Day-__ colors 25 Highest degree 26 Joan of Arc, e.g. 30 Visible 31 Algerian port 32 Bit of slapstick 33 NFL nail-biters 36 Inventor's goal, proverbially 40 KLM competitor 41 Like a tack 42 __ Lee cakes 43 Cede the pigskin 44 Put to use 46 Run-D.M.C.'s music 49 "__ Loser" (Beatles song) 50 Day before a big event 51 Clear, as a disk 53 Painter's wear, perhaps 58 Item on a New York Times list 61 "For__ us a child . . ." 62 Subway rider's wish 63 Beethoven wrote for her 64 Oxtail __ 65 Rick's __ Américain 66 Like a dim bulb Down 1 Mad and Elle, briefly 2 Jillions 3 Koh-i- __ diamond

4 Disassemble 5 Retailer J.C. __ Company, Inc. 6 Does some lawn work 7 Cowardly Lion portrayer 8 Hard-working insect 9 Moonves of CBS 10 Saintly topper 11 Cruise milieu 12 Not slouching 13 Pool measurement 18 Stereotypical lab assistant 19 Candle bracket 23 Start a new day 24 Floral garlands 26 Unruly groups 27 Square footage 28 Hamelin's problem 29 Blaster's need 30 Show derision 32 Radarange maker 33 Like much lore 34 Poi source 35 Fix, as a pet 37 Catches sight of 38 Baba au __ 39 Cough medicine amt. 44 All caught up 45 Joined forces 46 Picture puzzle 47 "__ We All?" (1923 play) 48 Fake jewels 50 Online party notice 52 Stash overhead 53 Norway's patron saint 54 Fully qualified 55 Butcher's cut 56 Result of a sack, in football 57 __-Ball (arcade game) 59 Upper-left PC key 60 Place to graze

Solution