Theme: Naval Assent - Three entries use a modified "Aye, aye" to start their phrase.
17A. Service available at hotspots : WI-FI ACCESS
39A. Place to see droids or tribbles : SCI-FI CONVENTION
64A. Home theater component : HI-FI SYSTEM
Argyle here with latest offering from the Crusiverbic Duo. Constructor's comments at the bottom.
Across:
5. Phi Beta __ : KAPPA
10. Unit in a plan : STEP
14. Cookie since 1912 : OREO
15. Just picked from the tree : FRESH
16. Schoolbook : TEXT
19. "Phooey!" : "RATS!"
20. Goes bad, as milk : SOURS
21. Sax register : ALTO
22. Pub order : ALE
23. PC key on either side of the space bar : ALT
24. Josh : KID
26. "Laughing" critter : HYENA
28. Does and bucks : DEER
30. Performer's song assortment : MEDLEY
34. Some ER cases : ODs
35. Historical period : ERA
37. Aches and pains : AILMENTS
43. Jet-setter's document : PASSPORT
44. Gen. Lee's side : CSA
45. Oils and such : ART
46. Optimistic : UPBEAT
48. Hitchhiker's ride : LIFT
52. "The Sound of Music" family name : TRAPP
54. Chi follower : PSI. (Greek)
56. Morse T : DAH. (code)
57. "__ pig's eye!" : IN A
58. Trade : SWAP
61. "Time in a Bottle" singer Jim : CROCE. Clip.(2:25)
63. 44-Across soldiers : REBS
66. Very dry, as Champagne : BRUT
67. Daytime talk star : OPRAH
68. Yea or nay : VOTE
69. __ of Man : ISLE. Crossword staple.
70. China's unofficial national flower : PEONY
71. Blog entry : POST
Down:
1. "What a pity!" : "HOW SAD!"
2. Baltimore baseballer : ORIOLE
3. Disprove : REFUTE
4. Pinot __: red wine : NOIR
5. Col. Sanders's company : KFC
6. Gaming area : ARCADE
7. Spa treatment : PEEL
8. Sibilant "Over here!" : "PSST!"
9. Facetious "I get it now" : "AH, SO"
10. Alley cat, e.g. : STRAY
11. "Tower Heist" actress : TEA LEONI. Poster for the movie.
12. Reach as far as, as property vis-à-vis its boundary : EXTEND TO
13. NBA stats : PTs. Points, further broken down into 3-pointers, field goals and foul shots.
18. "If you don't know, __" : ASK
25. Original "Dragnet" words after "My name is Friday" : "I'M A COP"
26. Mass songs : HYMNS
27. Part of PGA: Abbr. : ASSN.
29. Whistle blowers : REFs
31. "Inferno" author : DANTE
32. Actress Tyler : LIV. Picture with short hair.
33. Puts in office : ELECTS
36. Tear to pieces : RIP UP
38. List-ending abbr. : ET AL.
39. Lovers' quarrel : SPAT
40. Transportation companies : CARRIERS
41. Turkey's largest city : ISTANBUL
42. Globe : ORB
47. Rome's __ Way : APPIAN. Map.
49. "Ditto" : "I DO, TOO"
50. Diamond surfaces : FACETS
51. Lincoln Center opera setting, familiarly : THE MET
53. Partner of cut, in editing : PASTE
55. Emotionally distant : ICY
58. Barber's workplace : SHOP
59. Sponge (off) : WIPE
60. Fluffed-up hairdo : AFRO
62. Answer an invite : RSVP
63. Batter's stat : RBI
65. Like a wallflower : SHY
Argyle
Constructor note:
Don came up with this theme. We searched for all the *I FI * phrases with rhyming Long I pattern and settled for the current set. With only 3 theme entries, we tried our best filling in as many long & Monday-friendly answers as we can.