diff --git a/include/plane.h b/include/plane.h
index 7b1936a6..2133f362 100644
--- a/include/plane.h
+++ b/include/plane.h
@@ -73,7 +73,7 @@ struct plnstr {
     float pln_theta;		/* position in orbital sine wave */
 };
 
-#define	PLN_LAUNCHED	bit(0)	/* A satellite that's in orbit */
+#define	PLN_LAUNCHED	bit(0)	/* Flying (satellite: in orbit) */
 #define	PLN_SYNCHRONOUS	bit(1)	/* A satellite in geo-synchronous orbit */
 #define	PLN_AIRBURST	bit(2)	/* Airburst the nuke we're armed with */
 
@@ -160,9 +160,7 @@ extern void ac_combat_headers(natid, natid);
 extern void ac_airtoair(struct emp_qelem *, struct emp_qelem *);
 extern int ac_flak_dam(int, int, int);
 extern void ac_encounter(struct emp_qelem *, struct emp_qelem *, coord,
-			 coord, char *, int, int,
-			 struct emp_qelem *, struct emp_qelem *);
-extern int ac_isflying(struct plnstr *, struct emp_qelem *);
+			 coord, char *, int, int);
 extern void sam_intercept(struct emp_qelem *, struct emp_qelem *,
 			  natid, natid, coord, coord, int);
 
diff --git a/include/prototypes.h b/include/prototypes.h
index 5fa5cb37..1a127da7 100644
--- a/include/prototypes.h
+++ b/include/prototypes.h
@@ -402,8 +402,8 @@ extern void stop_service(void);
 extern int confirm(char *);
 extern int askyn(char *);
 /* bridgefall.c */
-extern void bridge_damaged(struct sctstr *, struct emp_qelem *);
-extern void bridgefall(struct sctstr *, struct emp_qelem *);
+extern void bridge_damaged(struct sctstr *);
+extern void bridgefall(struct sctstr *);
 /* bsanct.c */
 extern void bsanct(void);
 /* caploss.c */
@@ -468,7 +468,7 @@ extern int roundrange(double);
 extern int shipsatxy(coord, coord, int, int);
 extern int carriersatxy(coord, coord, natid);
 extern int unitsatxy(coord, coord, int, int);
-extern int planesatxy(coord, coord, int, int, struct emp_qelem *);
+extern int planesatxy(coord, coord, int, int);
 extern int asw_shipsatxy(coord, coord, int, int, struct plnstr *,
 			 struct shiplist **);
 extern int num_shipsatxy(coord, coord, int, int);
@@ -484,7 +484,7 @@ extern int bmaps_intersect(natid, natid);
 extern int share_bmap(natid, natid, struct nstr_sect *, char, char *);
 /* mission.c */
 extern char *mission_name(short);
-extern int collateral_damage(coord, coord, int, struct emp_qelem *);
+extern int collateral_damage(coord, coord, int);
 extern int mission_pln_equip(struct plist *, struct ichrstr *, int, char);
 extern int ground_interdict(coord, coord, natid, char *);
 extern int unit_interdict(coord, coord, natid, char *, int, int);
@@ -559,7 +559,6 @@ extern int pln_arm(struct emp_qelem *, int, char, struct ichrstr *,
 extern int pln_mobcost(int, struct plnstr *, int);
 extern void pln_put(struct emp_qelem *);
 extern void pln_put1(struct plist *);
-extern void pln_removedupes(struct emp_qelem *, struct emp_qelem *);
 extern void take_plane_off_ship(struct plnstr *, struct shpstr *);
 extern void take_plane_off_land(struct plnstr *, struct lndstr *);
 extern void plane_sweep(struct emp_qelem *, coord, coord);
@@ -630,8 +629,8 @@ extern int sct_prewrite(int, void *);
 extern void item_prewrite(short *);
 extern int issector(char *);
 /* sectdamage.c */
-extern int sect_damage(struct sctstr *, int, struct emp_qelem *);
-extern int sectdamage(struct sctstr *, int, struct emp_qelem *);
+extern int sect_damage(struct sctstr *, int);
+extern int sectdamage(struct sctstr *, int);
 /* ship.c */
 extern char *prship(struct shpstr *);
 extern int shp_postread(int, void *);
diff --git a/src/lib/commands/bomb.c b/src/lib/commands/bomb.c
index f475d47d..b645a138 100644
--- a/src/lib/commands/bomb.c
+++ b/src/lib/commands/bomb.c
@@ -147,8 +147,8 @@ bomb(void)
     }
     mission_flags = pln_arm(&esc_list, 2 * ap_to_target, mission,
 			    ip, P_F | P_ESC, mission_flags);
-    ac_encounter(&bomb_list, &esc_list, ax, ay, flightpath, mission_flags,
-		 0, 0, 0);
+    ac_encounter(&bomb_list, &esc_list, ax, ay,
+		 flightpath, mission_flags, 0);
     if (QEMPTY(&bomb_list)) {
 	pr("No planes got through fighter defenses\n");
     } else if (target.sct_type == SCT_SANCT) {
@@ -218,7 +218,7 @@ pin_bomb(struct emp_qelem *list, struct sctstr *target)
     } else {
 	nships = shipsatxy(target->sct_x, target->sct_y, 0, M_SUB);
     }
-    nplanes = planesatxy(target->sct_x, target->sct_y, 0, 0, list);
+    nplanes = planesatxy(target->sct_x, target->sct_y, 0, 0);
     nunits = unitsatxy(target->sct_x, target->sct_y, 0, 0);
   retry:
     p = getstring("Bomb what? (ship, plane, land unit, efficiency, commodities) ",
@@ -369,9 +369,9 @@ eff_bomb(struct emp_qelem *list, struct sctstr *target)
 	   "%s bombing raid did %d%% damage in %s\n",
 	   cname(player->cnum), oldeff - target->sct_effic,
 	   xyas(target->sct_x, target->sct_y, target->sct_own));
-    bridge_damaged(target, list);
+    bridge_damaged(target);
     putsect(&sect);
-    collateral_damage(target->sct_x, target->sct_y, dam, list);
+    collateral_damage(target->sct_x, target->sct_y, dam);
 }
 
 static void
@@ -447,7 +447,7 @@ comm_bomb(struct emp_qelem *list, struct sctstr *target)
 	   cname(player->cnum), b, ip->i_name,
 	   xyas(target->sct_x, target->sct_y, target->sct_own));
     putsect(&sect);
-    collateral_damage(target->sct_x, target->sct_y, dam, list);
+    collateral_damage(target->sct_x, target->sct_y, dam);
 }
 
 static void
@@ -559,7 +559,7 @@ ship_bomb(struct emp_qelem *list, struct sctstr *target)
 	    /* Bombs that miss have to land somewhere! */
 	    dam = pln_damage(&plp->plane, target->sct_x, target->sct_y,
 			     'p', &nukedam, 0);
-	    collateral_damage(target->sct_x, target->sct_y, dam, list);
+	    collateral_damage(target->sct_x, target->sct_y, dam);
 	    dam = 0;
 	}
 	if (dam <= 0)		/* dam == 0 if only nukes were delivered */
@@ -586,7 +586,7 @@ ship_bomb(struct emp_qelem *list, struct sctstr *target)
 	       prship(&ship),
 	       xyas(target->sct_x, target->sct_y, player->cnum));
 	}
-	collateral_damage(target->sct_x, target->sct_y, dam / 2, list);
+	collateral_damage(target->sct_x, target->sct_y, dam / 2);
       next:
 	;
     }
@@ -615,7 +615,7 @@ plane_bomb(struct emp_qelem *list, struct sctstr *target)
 	plp = (struct plist *)qp;
 	if ((plp->pcp->pl_flags & P_C) && (!(plp->pcp->pl_flags & P_T)))
 	    continue;
-	nplanes = planesatxy(target->sct_x, target->sct_y, 0, 0, list);
+	nplanes = planesatxy(target->sct_x, target->sct_y, 0, 0);
 	if (nplanes == 0) {
 	    pr("%s could not find any planes!\n", prplane(&plp->plane));
 	    continue;
@@ -632,7 +632,7 @@ plane_bomb(struct emp_qelem *list, struct sctstr *target)
 		continue;
 	    }
 	    if (*q == '?') {
-		planesatxy(target->sct_x, target->sct_y, 0, 0, list);
+		planesatxy(target->sct_x, target->sct_y, 0, 0);
 		continue;
 	    }
 	    if (*q == 'd')
@@ -643,8 +643,7 @@ plane_bomb(struct emp_qelem *list, struct sctstr *target)
 	    if (getplane(n, &plane) &&
 		plane.pln_x == target->sct_x &&
 		plane.pln_y == target->sct_y &&
-		((plane.pln_flags & PLN_LAUNCHED) == 0) &&
-		(!ac_isflying(&plane, list)))
+		!(plane.pln_flags & PLN_LAUNCHED))
 		planeno = n;
 	    else
 		pr("Plane #%d not spotted\n", n);
@@ -667,7 +666,7 @@ plane_bomb(struct emp_qelem *list, struct sctstr *target)
 	    /* Bombs that miss have to land somewhere! */
 	    dam = pln_damage(&plp->plane, target->sct_x, target->sct_y,
 			     'p', &nukedam, 0);
-	    collateral_damage(target->sct_x, target->sct_y, dam, list);
+	    collateral_damage(target->sct_x, target->sct_y, dam);
 	    dam = 0;
 	}
 	if (dam <= 0)		/* dam == 0 if only nukes were delivered */
@@ -694,7 +693,7 @@ plane_bomb(struct emp_qelem *list, struct sctstr *target)
 	       cname(player->cnum), dam, prplane(&plane),
 	       xyas(target->sct_x, target->sct_y, own));
 	putplane(plane.pln_uid, &plane);
-	collateral_damage(target->sct_x, target->sct_y, dam, list);
+	collateral_damage(target->sct_x, target->sct_y, dam);
       next:
 	;
     }
@@ -781,7 +780,7 @@ land_bomb(struct emp_qelem *list, struct sctstr *target)
 	    /* Bombs that miss have to land somewhere! */
 	    dam = pln_damage(&plp->plane, target->sct_x, target->sct_y,
 			     'p', &nukedam, 0);
-	    collateral_damage(target->sct_x, target->sct_y, dam, list);
+	    collateral_damage(target->sct_x, target->sct_y, dam);
 	    dam = 0;
 	}
 	if (dam <= 0)		/* dam == 0 if only nukes were delivered */
@@ -798,7 +797,7 @@ land_bomb(struct emp_qelem *list, struct sctstr *target)
 		retreat_land(&land, 'b');
 	nreport(player->cnum, N_UNIT_BOMB, own, 1);
 	putland(land.lnd_uid, &land);
-	collateral_damage(target->sct_x, target->sct_y, dam, list);
+	collateral_damage(target->sct_x, target->sct_y, dam);
       next:
 	;
     }
@@ -830,7 +829,7 @@ strat_bomb(struct emp_qelem *list, struct sctstr *target)
 	   cname(player->cnum), PERCENT_DAMAGE(dam),
 	   xyas(target->sct_x, target->sct_y, target->sct_own));
 
-    sectdamage(target, dam, list);
+    sectdamage(target, dam);
 
     pr("did %d damage in %s\n", PERCENT_DAMAGE(dam),
        xyas(target->sct_x, target->sct_y, player->cnum));
diff --git a/src/lib/commands/desi.c b/src/lib/commands/desi.c
index 54be0688..07f33ae0 100644
--- a/src/lib/commands/desi.c
+++ b/src/lib/commands/desi.c
@@ -132,7 +132,7 @@ desi(void)
 	if (opt_EASY_BRIDGES == 0) {	/* may cause a bridge fall */
 	    if (n != SCT_BHEAD)
 		continue;
-	    bridgefall(&sect, 0);
+	    bridgefall(&sect);
 	}
     }
     if (changed)
diff --git a/src/lib/commands/drop.c b/src/lib/commands/drop.c
index 4b32a14e..fbfffcfe 100644
--- a/src/lib/commands/drop.c
+++ b/src/lib/commands/drop.c
@@ -124,8 +124,8 @@ drop(void)
     }
     mission_flags = pln_arm(&esc_list, 2 * ap_to_target, 'd',
 			    ip, P_ESC | P_F, mission_flags);
-    ac_encounter(&bomb_list, &esc_list, ax, ay, flightpath, mission_flags,
-		 0, 0, 0);
+    ac_encounter(&bomb_list, &esc_list, ax, ay,
+		 flightpath, mission_flags, 0);
     if (QEMPTY(&bomb_list)) {
 	pr("No planes got through fighter defenses\n");
     } else {
diff --git a/src/lib/commands/fly.c b/src/lib/commands/fly.c
index 598fef08..ed55fbca 100644
--- a/src/lib/commands/fly.c
+++ b/src/lib/commands/fly.c
@@ -136,8 +136,8 @@ fly(void)
     }
     mission_flags = pln_arm(&esc_list, ap_to_target, 't',
 			    ip, P_ESC | P_F, mission_flags);
-    ac_encounter(&bomb_list, &esc_list, ax, ay, flightpath, mission_flags,
-		 0, 0, 0);
+    ac_encounter(&bomb_list, &esc_list, ax, ay,
+		 flightpath, mission_flags, 0);
     if (QEMPTY(&bomb_list)) {
 	pr("No planes got through fighter defenses\n");
     } else {
diff --git a/src/lib/commands/laun.c b/src/lib/commands/laun.c
index 39131968..996188b8 100644
--- a/src/lib/commands/laun.c
+++ b/src/lib/commands/laun.c
@@ -321,7 +321,7 @@ launch_missile(struct plnstr *pp, int sublaunch)
 		       cname(player->cnum), dam,
 		       xyas(sx, sy, sect.sct_own));
 	    }
-	    sectdamage(&sect, dam, 0);
+	    sectdamage(&sect, dam);
 	    putsect(&sect);
 	}
     } /* end PINPOINTMISSILE conditional */
@@ -414,6 +414,7 @@ launch_sat(struct plnstr *pp, int sublaunch)
     }
     pp->pln_x = sx;
     pp->pln_y = sy;
+    CANT_HAPPEN(pp->pln_flags & PLN_LAUNCHED);
     pp->pln_flags |= PLN_LAUNCHED;
     pp->pln_mobil = pp->pln_mobil > dist ? pp->pln_mobil - dist : 0;
     putplane(pp->pln_uid, pp);
diff --git a/src/lib/commands/mfir.c b/src/lib/commands/mfir.c
index 58e2cb41..4d3fd893 100644
--- a/src/lib/commands/mfir.c
+++ b/src/lib/commands/mfir.c
@@ -467,7 +467,7 @@ multifire(void)
 	    pr("Shells hit sector %s for %d damage.\n",
 	       xyas(x, y, player->cnum), dam);
 	    if (target != targ_bogus)
-		sectdamage(&vsect, dam, 0);
+		sectdamage(&vsect, dam);
 	    break;
 	case targ_ship:
 	    nreport(player->cnum, N_SHP_SHELL, vict, 1);
@@ -600,7 +600,7 @@ do_defdam(struct emp_qelem *list, double odds)
 	    vict = fp->victim;
 	    pr("Return fire hit sector %s for %d damage.\n",
 	       xyas(fp->x, fp->y, player->cnum), dam);
-	    sectdamage(&sect, dam, 0);
+	    sectdamage(&sect, dam);
 	    putsect(&sect);
 	    if (vict)
 		wu(0, vict, "Return fire hit sector %s for %d damage.\n",
diff --git a/src/lib/commands/para.c b/src/lib/commands/para.c
index e11c20e0..9c976b2b 100644
--- a/src/lib/commands/para.c
+++ b/src/lib/commands/para.c
@@ -105,8 +105,8 @@ para(void)
     }
     mission_flags = pln_arm(&esc_list, 2 * ap_to_target, 'a',
 			    &ichr[I_MILIT], P_ESC | P_F, mission_flags);
-    ac_encounter(&bomb_list, &esc_list, ax, ay, flightpath, mission_flags,
-		 0, 0, 0);
+    ac_encounter(&bomb_list, &esc_list, ax, ay,
+		 flightpath, mission_flags, 0);
     if (QEMPTY(&bomb_list)) {
 	pr("No planes got through fighter defenses\n");
     } else {
diff --git a/src/lib/commands/reco.c b/src/lib/commands/reco.c
index ebcf597f..fcd4d135 100644
--- a/src/lib/commands/reco.c
+++ b/src/lib/commands/reco.c
@@ -118,8 +118,8 @@ reco(void)
     if (*player->argp[0] == 's')
 	mission_flags |= PM_S;
 
-    ac_encounter(&bomb_list, &esc_list, ax, ay, flightpath, mission_flags,
-		 0, 0, 0);
+    ac_encounter(&bomb_list, &esc_list, ax, ay,
+		 flightpath, mission_flags, 0);
     if (QEMPTY(&bomb_list)) {
 	pr("No planes got through fighter defenses\n");
     } else {
diff --git a/src/lib/commands/sabo.c b/src/lib/commands/sabo.c
index c12c6ad9..7911dfc8 100644
--- a/src/lib/commands/sabo.c
+++ b/src/lib/commands/sabo.c
@@ -103,7 +103,7 @@ sabo(void)
 	land.lnd_own = 0;
 	putland(land.lnd_uid, &land);
 
-	sectdamage(&sect, dam, 0);
+	sectdamage(&sect, dam);
 	putsect(&sect);
 
 	land.lnd_own = player->cnum;
diff --git a/src/lib/common/ef_verify.c b/src/lib/common/ef_verify.c
index fac43103..fb677145 100644
--- a/src/lib/common/ef_verify.c
+++ b/src/lib/common/ef_verify.c
@@ -40,6 +40,7 @@
 #include "file.h"
 #include "misc.h"
 #include "nsc.h"
+#include "plane.h"
 #include "product.h"
 
 static void verify_fail(int, int, struct castr *, int, char *, ...)
@@ -163,6 +164,26 @@ verify_row(int type, int row)
     return ret_val;
 }
 
+static void
+pln_zap_transient_flags(void)
+{
+    int i;
+    struct plnstr *pp;
+
+    /* laziness: assumes plane file is EFF_MEM */
+    for (i = 0; (pp = getplanep(i)) != NULL; i++) {
+	if (pp->pln_flags & PLN_LAUNCHED
+	    && (plchr[pp->pln_type].pl_flags & (P_M | P_O)) != P_O) {
+	    pp->pln_flags &= ~PLN_LAUNCHED;
+	    verify_fail(EF_PLANE, i, NULL, 0, "stuck in the air (patched)");
+	    /*
+	     * Can't putplane() here, because pln_prewrite() crashes
+	     * without a valid player.
+	     */
+	}
+    }
+}
+
 int
 ef_verify()
 {
@@ -188,5 +209,6 @@ ef_verify()
 	}
     }
 
+    pln_zap_transient_flags();
     return retval;
 }
diff --git a/src/lib/subs/aircombat.c b/src/lib/subs/aircombat.c
index 9c833d9b..3b87878f 100644
--- a/src/lib/subs/aircombat.c
+++ b/src/lib/subs/aircombat.c
@@ -64,16 +64,13 @@ static void ac_doflak(struct emp_qelem *, struct sctstr *);
 static void ac_landflak(struct emp_qelem *, coord, coord);
 static void ac_shipflak(struct emp_qelem *, coord, coord);
 static void ac_fireflak(struct emp_qelem *, natid, int);
-static void getilist(struct emp_qelem *, natid,
-		     struct emp_qelem *, struct emp_qelem *,
-		     struct emp_qelem *, struct emp_qelem *);
+static void getilist(struct emp_qelem *, natid);
 static int do_evade(struct emp_qelem *, struct emp_qelem *);
 
 void
 ac_encounter(struct emp_qelem *bomb_list, struct emp_qelem *esc_list,
 	     coord x, coord y, char *path, int mission_flags,
-	     int no_air_defense, struct emp_qelem *obomb,
-	     struct emp_qelem *oesc)
+	     int no_air_defense)
 {
     int val, non_missiles;
     int rel;
@@ -135,7 +132,6 @@ ac_encounter(struct emp_qelem *bomb_list, struct emp_qelem *esc_list,
 	}
     }
 
-    pln_removedupes(bomb_list, esc_list);
     while ((dir = mypath[myp++]) && !QEMPTY(bomb_list)) {
 	if ((val = diridx(dir)) == DIR_STOP)
 	    break;
@@ -247,8 +243,7 @@ ac_encounter(struct emp_qelem *bomb_list, struct emp_qelem *esc_list,
 	    continue;
 
 	if (unfriendly[sect.sct_own] && !gotilist[sect.sct_own]) {
-	    getilist(&ilist[sect.sct_own], sect.sct_own,
-		     bomb_list, esc_list, obomb, oesc);
+	    getilist(&ilist[sect.sct_own], sect.sct_own);
 	    gotilist[sect.sct_own]++;
 	}
 	if (rel > HOSTILE)
@@ -307,8 +302,7 @@ ac_encounter(struct emp_qelem *bomb_list, struct emp_qelem *esc_list,
 	    if (unfriendly[cn]) {
 		/* They are unfriendly too */
 		if (!gotilist[cn]) {
-		    getilist(&ilist[cn], cn, bomb_list, esc_list, obomb,
-			     oesc);
+		    getilist(&ilist[cn], cn);
 		    gotilist[cn]++;
 		}
 		PR(plane_owner, "Flying over %s ships in %s\n",
@@ -336,8 +330,7 @@ ac_encounter(struct emp_qelem *bomb_list, struct emp_qelem *esc_list,
 	    if (unfriendly[cn]) {
 		/* They are unfriendly too */
 		if (!gotilist[cn]) {
-		    getilist(&ilist[cn], cn, bomb_list, esc_list, obomb,
-			     oesc);
+		    getilist(&ilist[cn], cn);
 		    gotilist[cn]++;
 		}
 		PR(plane_owner, "Flying over %s land units in %s\n",
@@ -416,6 +409,8 @@ sam_intercept(struct emp_qelem *att_list, struct emp_qelem *def_list,
 		free(dqp);
 		continue;
 	    }
+	    CANT_HAPPEN(dplp->plane.pln_flags & PLN_LAUNCHED);
+	    dplp->plane.pln_flags |= PLN_LAUNCHED;
 	    if (first) {
 		first = 0;
 		PR(plane_owner, "%s launches SAMs!\n", cname(def_own));
@@ -481,7 +476,8 @@ ac_intercept(struct emp_qelem *bomb_list, struct emp_qelem *esc_list,
 	dist = mapdist(x, y, pp->pln_x, pp->pln_y) * 2;
 	if (pp->pln_range < dist)
 	    continue;
-	if (mission_pln_equip(plp, 0, P_F, 0) < 0) {
+	if (CANT_HAPPEN(pp->pln_flags & PLN_LAUNCHED)
+	    || mission_pln_equip(plp, 0, P_F, 0) < 0) {
 	    emp_remque(qp);
 	    free(qp);
 	    continue;
@@ -489,6 +485,7 @@ ac_intercept(struct emp_qelem *bomb_list, struct emp_qelem *esc_list,
 	/* got one; delete from def_list, add to int_list */
 	emp_remque(qp);
 	emp_insque(qp, &int_list);
+	pp->pln_flags |= PLN_LAUNCHED;
 	pp->pln_mobil -= pln_mobcost(dist, pp, P_F);
 	putplane(pp->pln_uid, pp);
 	icount++;
@@ -983,36 +980,11 @@ ac_flak_dam(int guns, int def, int pl_flags)
     return dam;
 }
 
-/*
- * See if this plane is flying in this list
- */
-int
-ac_isflying(struct plnstr *plane, struct emp_qelem *list)
-{
-    struct emp_qelem *qp;
-    struct emp_qelem *next;
-    struct plnstr *pp;
-    struct plist *plp;
-
-    if (!list)
-	return 0;
-    for (qp = list->q_forw; qp != list; qp = next) {
-	next = qp->q_forw;
-	plp = (struct plist *)qp;
-	pp = &plp->plane;
-	if (plane->pln_uid == pp->pln_uid)
-	    return 1;
-    }
-    return 0;
-}
-
-
 /*
  * Get a list of planes available for interception duties.
  */
 static void
-getilist(struct emp_qelem *list, natid own, struct emp_qelem *a,
-	 struct emp_qelem *b, struct emp_qelem *c, struct emp_qelem *d)
+getilist(struct emp_qelem *list, natid own)
 {
     struct plchrstr *pcp;
     struct plnstr plane;
@@ -1027,6 +999,8 @@ getilist(struct emp_qelem *list, natid own, struct emp_qelem *a,
 	pcp = &plchr[(int)plane.pln_type];
 	if ((pcp->pl_flags & P_F) == 0)
 	    continue;
+	if (plane.pln_flags & PLN_LAUNCHED)
+	    continue;
 	if (plane.pln_mission != 0)
 	    continue;
 	if (plane.pln_mobil <= 0)
@@ -1035,16 +1009,6 @@ getilist(struct emp_qelem *list, natid own, struct emp_qelem *a,
 	    continue;
 	if (!pln_airbase_ok(&plane, 0, 0))
 	    continue;
-	/* Finally, is it in the list of planes already in
-	   flight? */
-	if (ac_isflying(&plane, a))
-	    continue;
-	if (ac_isflying(&plane, b))
-	    continue;
-	if (ac_isflying(&plane, c))
-	    continue;
-	if (ac_isflying(&plane, d))
-	    continue;
 	/* got one! */
 	ip = malloc(sizeof(*ip));
 	ip->bombs = 0;
diff --git a/src/lib/subs/attsub.c b/src/lib/subs/attsub.c
index 4c9decae..5183b2a5 100644
--- a/src/lib/subs/attsub.c
+++ b/src/lib/subs/attsub.c
@@ -650,7 +650,7 @@ att_approach(struct combat *off, struct combat *def)
     }
     if (off->type == EF_SECTOR) {
 	getsect(off->x, off->y, &sect);
-	sectdamage(&sect, dam, 0);
+	sectdamage(&sect, dam);
 	putsect(&sect);
 	pr("Enemy fleet at %s does %d damage to %s\n",
 	   xyas(def->x, def->y, player->cnum), dam, prcom(0, off));
diff --git a/src/lib/subs/bridgefall.c b/src/lib/subs/bridgefall.c
index edf0e7f7..f407f32f 100644
--- a/src/lib/subs/bridgefall.c
+++ b/src/lib/subs/bridgefall.c
@@ -49,7 +49,7 @@
 #include "sect.h"
 #include "xy.h"
 
-static void knockdown(struct sctstr *, struct emp_qelem *);
+static void knockdown(struct sctstr *);
 
 /*
  * Check bridges at and around SP after damage to SP.
@@ -60,7 +60,7 @@ static void knockdown(struct sctstr *, struct emp_qelem *);
  * left to the caller.
  */
 void
-bridge_damaged(struct sctstr *sp, struct emp_qelem *list)
+bridge_damaged(struct sctstr *sp)
 {
     int des;
 
@@ -69,13 +69,13 @@ bridge_damaged(struct sctstr *sp, struct emp_qelem *list)
 
     des = sp->sct_type;
     if (des == SCT_BSPAN || des == SCT_BTOWER)
-	knockdown(sp, list);
+	knockdown(sp);
     if ((des == SCT_BHEAD || des == SCT_BTOWER) && !opt_EASY_BRIDGES)
-	bridgefall(sp, list);
+	bridgefall(sp);
 }
 
 void
-bridgefall(struct sctstr *sp, struct emp_qelem *list)
+bridgefall(struct sctstr *sp)
 {
     int i;
     int j;
@@ -112,7 +112,7 @@ bridgefall(struct sctstr *sp, struct emp_qelem *list)
 	    }
 	}
 	if (j > 6) {
-	    knockdown(&sect, list);
+	    knockdown(&sect);
 	    putsect(&sect);
 	}
     }
@@ -121,7 +121,7 @@ bridgefall(struct sctstr *sp, struct emp_qelem *list)
 /* Knock down a bridge span.  Note that this does NOT write the
  * sector out to the database, it's up to the caller to do that. */
 static void
-knockdown(struct sctstr *sp, struct emp_qelem *list)
+knockdown(struct sctstr *sp)
 {
     struct lndstr land;
     struct plnstr plane;
@@ -165,9 +165,6 @@ knockdown(struct sctstr *sp, struct emp_qelem *list)
 	    continue;
 	if (plane.pln_ship >= 0)
 	    continue;
-	/* Is this plane flying in this list? */
-	if (ac_isflying(&plane, list))
-	    continue;
 	np = getnatp(plane.pln_own);
 	if (np->nat_flags & NF_BEEP)
 	    mpr(plane.pln_own, "\07");
diff --git a/src/lib/subs/detonate.c b/src/lib/subs/detonate.c
index e027eb4a..f92ac6a1 100644
--- a/src/lib/subs/detonate.c
+++ b/src/lib/subs/detonate.c
@@ -105,7 +105,7 @@ detonate(struct nukstr *np, coord x, coord y, int airburst)
 	}
 	if (opt_FALLOUT)
 	    fallout = sect.sct_fallout;
-	sect_damage(&sect, damage, 0);
+	sect_damage(&sect, damage);
 	if (sect.sct_x == x && sect.sct_y == y)
 	    retval = damage;
 	if (opt_FALLOUT) {
diff --git a/src/lib/subs/list.c b/src/lib/subs/list.c
index 96ce5d2d..3c9574c1 100644
--- a/src/lib/subs/list.c
+++ b/src/lib/subs/list.c
@@ -162,8 +162,7 @@ unitsatxy(coord x, coord y, int wantflags, int nowantflags)
 }
 
 int
-planesatxy(coord x, coord y, int wantflags, int nowantflags,
-	   struct emp_qelem *list)
+planesatxy(coord x, coord y, int wantflags, int nowantflags)
 {
     int first;
     int planes;
@@ -179,9 +178,6 @@ planesatxy(coord x, coord y, int wantflags, int nowantflags,
 	    continue;
 	if (plane.pln_flags & PLN_LAUNCHED)
 	    continue;
-	/* Is this plane one of the ones flying somewhere? */
-	if (ac_isflying(&plane, list))
-	    continue;
 	plp = &plchr[(int)plane.pln_type];
 	if (first) {
 	    pr(" #          owner           eff       type\n");
diff --git a/src/lib/subs/lndsub.c b/src/lib/subs/lndsub.c
index 1029adee..395ffcf2 100644
--- a/src/lib/subs/lndsub.c
+++ b/src/lib/subs/lndsub.c
@@ -799,7 +799,7 @@ lnd_missile_interdiction(struct emp_qelem *list, coord newx, coord newy,
 			    MI_INTERDICT);
     if (dam) {
 	mpr(victim, "missile interdiction mission does %d damage!\n", dam);
-	collateral_damage(newx, newy, dam, 0);
+	collateral_damage(newx, newy, dam);
     }
     qp = msl_list.q_forw;
     while (qp != msl_list.q_forw) {
diff --git a/src/lib/subs/mission.c b/src/lib/subs/mission.c
index c8ee9cfd..580cdea9 100644
--- a/src/lib/subs/mission.c
+++ b/src/lib/subs/mission.c
@@ -108,13 +108,13 @@ ground_interdict(coord x, coord y, natid victim, char *s)
 		cname(cn), newdam);
     }
     if (dam) {
-	collateral_damage(x, y, dam, 0);
+	collateral_damage(x, y, dam);
     }
     return dam;
 }
 
 int
-collateral_damage(coord x, coord y, int dam, struct emp_qelem *list)
+collateral_damage(coord x, coord y, int dam)
 {
     int coll;
     struct sctstr sect;
@@ -129,7 +129,7 @@ collateral_damage(coord x, coord y, int dam, struct emp_qelem *list)
 	    return 0;
 	mpr(sect.sct_own, "%s takes %d%% collateral damage\n",
 	    xyas(x, y, sect.sct_own), coll);
-	sectdamage(&sect, coll, list);
+	sectdamage(&sect, coll);
 	putsect(&sect);
 	return coll;
     }
@@ -201,7 +201,7 @@ unit_interdict(coord x, coord y, natid victim, char *s, int hardtarget,
 	}
     }
     if (dam) {
-	collateral_damage(x, y, dam, 0);
+	collateral_damage(x, y, dam);
     }
     return dam;
 }
@@ -668,7 +668,7 @@ perform_mission(coord x, coord y, natid victim, struct emp_qelem *list,
 	       xyas(air->x, air->y, air->own));
 	}
 
-	ac_encounter(&b, &e, air->x, air->y, pp, mission_flags, 0, 0, 0);
+	ac_encounter(&b, &e, air->x, air->y, pp, mission_flags, 0);
 
 	if (!QEMPTY(&b))
 	    air_dam +=
@@ -930,17 +930,20 @@ mission_pln_arm(struct emp_qelem *list, coord x, coord y, int dist,
     struct emp_qelem *qp;
     struct emp_qelem *next;
     struct plist *plp;
+    struct plnstr *pp;
 
     for (qp = list->q_forw; qp != list; qp = next) {
 	next = qp->q_forw;
 	plp = (struct plist *)qp;
+	pp = &plp->plane;
 
-	if (plp->plane.pln_x != x)
+	if (pp->pln_x != x)
 	    continue;
-	if (plp->plane.pln_y != y)
+	if (pp->pln_y != y)
 	    continue;
 
-	if (mission_pln_equip(plp, ip, flags, mission) < 0) {
+	if (CANT_HAPPEN(pp->pln_flags & PLN_LAUNCHED)
+	    || mission_pln_equip(plp, ip, flags, mission) < 0) {
 	    emp_remque(qp);
 	    free(qp);
 	    continue;
@@ -966,13 +969,9 @@ mission_pln_arm(struct emp_qelem *list, coord x, coord y, int dist,
 	    mission_flags &= ~P_MINE;
 	}
 
-	/*
-	 *      Mob costs for missions are 1/2 normal
-	 *       Not anymore. :)
-	 */
-/*	plp->plane.pln_mobil -= pln_mobcost(dist,&plp->plane,flags)/2;*/
-	plp->plane.pln_mobil -= pln_mobcost(dist, &plp->plane, flags);
-
+	CANT_HAPPEN(pp->pln_flags & PLN_LAUNCHED);
+	pp->pln_flags |= PLN_LAUNCHED;
+	pp->pln_mobil -= pln_mobcost(dist, pp, flags);
     }
     return mission_flags;
 }
@@ -1217,7 +1216,7 @@ air_damage(struct emp_qelem *bombers, coord x, coord y, int mission,
 	    }
 	    /* Now, even though we missed, the bombs
 	       land somewhere. */
-	    collateral_damage(x, y, newdam, bombers);
+	    collateral_damage(x, y, newdam);
 	}
 
 	/* use up missiles */
@@ -1396,7 +1395,7 @@ air_defense(coord x, coord y, natid victim, struct emp_qelem *bomb_list,
 	    /* Now, fly the planes to the sector */
 	    emp_initque(&empty);
 	    ac_encounter(&i, &empty, air->x, air->y,
-			 path, mission_flags, 1, bomb_list, esc_list);
+			 path, mission_flags, 1);
 
 	    /* If none made it, continue */
 	    if (QEMPTY(&i))
diff --git a/src/lib/subs/mslsub.c b/src/lib/subs/mslsub.c
index 3f4bb5e4..4b1a0cdd 100644
--- a/src/lib/subs/mslsub.c
+++ b/src/lib/subs/mslsub.c
@@ -116,7 +116,7 @@ msl_hit(struct plnstr *pp, int hardtarget, int type, int news_item,
 		    pr("Explosion damages %s %d%%",
 		       xyas(pp->pln_x, pp->pln_y, pp->pln_own), dam);
 		    getsect(pp->pln_x, pp->pln_y, &sect);
-		    sectdamage(&sect, dam, 0);
+		    sectdamage(&sect, dam);
 		    putsect(&sect);
 		}
 	    }
@@ -406,7 +406,7 @@ msl_launch_mindam(struct emp_qelem *list, coord x, coord y, int hardtarget,
 	    } else {
 		/* Missiles that miss have to hit somewhere! */
 		newdam = pln_damage(&plp->plane, x, y, 'p', &nukedam, 0);
-		collateral_damage(x, y, newdam, 0);
+		collateral_damage(x, y, newdam);
 	    }
 	    plp->plane.pln_effic = 0;
 	    putplane(plp->plane.pln_uid, &plp->plane);
diff --git a/src/lib/subs/plnsub.c b/src/lib/subs/plnsub.c
index d54643fc..1c5c8ad5 100644
--- a/src/lib/subs/plnsub.c
+++ b/src/lib/subs/plnsub.c
@@ -553,11 +553,14 @@ pln_arm(struct emp_qelem *list, int dist, char mission, struct ichrstr *ip,
     struct emp_qelem *qp;
     struct emp_qelem *next;
     struct plist *plp;
+    struct plnstr *pp;
 
     for (qp = list->q_forw; qp != list; qp = next) {
 	next = qp->q_forw;
 	plp = (struct plist *)qp;
-	if (pln_equip(plp, ip, flags, mission) < 0) {
+	pp = &plp->plane;
+	if ((pp->pln_flags & PLN_LAUNCHED)
+	    || pln_equip(plp, ip, flags, mission) < 0) {
 	    emp_remque(qp);
 	    free(qp);
 	    continue;
@@ -584,8 +587,11 @@ pln_arm(struct emp_qelem *list, int dist, char mission, struct ichrstr *ip,
 	    mission_flags &= ~P_MINE;
 	    /* FIXME no effect */
 	}
-	plp->plane.pln_mobil -= pln_mobcost(dist, &plp->plane, flags);
-	pr("%s equipped\n", prplane(&plp->plane));
+	CANT_HAPPEN(pp->pln_flags & PLN_LAUNCHED);
+	pp->pln_flags |= PLN_LAUNCHED;
+	pp->pln_mobil -= pln_mobcost(dist, pp, flags);
+	putplane(pp->pln_uid, pp);
+	pr("%s equipped\n", prplane(pp));
     }
     return mission_flags;
 }
@@ -742,8 +748,16 @@ pln_put1(struct plist *plp)
     struct sctstr sect;
 
     pp = &plp->plane;
-    if (!pp->pln_own) {
-	/* crashed */
+
+    if (CANT_HAPPEN((pp->pln_flags & PLN_LAUNCHED)
+		    && (plchr[pp->pln_type].pl_flags & P_M)
+		    && pp->pln_effic >= PLANE_MINEFF))
+	pp->pln_effic = 0;   /* bug: missile launched but not used up */
+
+    if (!(pp->pln_flags & PLN_LAUNCHED))
+	;			/* never took off */
+    else if (pp->pln_effic < PLANE_MINEFF) {
+	/* destroyed */
 	if (pp->pln_ship >= 0) {
 	    getship(pp->pln_ship, &ship);
 	    take_plane_off_ship(pp, &ship);
@@ -775,42 +789,12 @@ pln_put1(struct plist *plp)
 	    pp->pln_effic = 0;
 	}
     }
+    pp->pln_flags &= ~PLN_LAUNCHED;
     putplane(pp->pln_uid, pp);
     emp_remque(&plp->queue);
     free(plp);
 }
 
-void
-pln_removedupes(struct emp_qelem *bomb_list, struct emp_qelem *esc_list)
-{
-    struct emp_qelem *bomb;
-    struct emp_qelem *esc;
-    struct plist *bombp;
-    struct plist *escp;
-
-    if (QEMPTY(bomb_list) || QEMPTY(esc_list))
-	return;
-    bomb = bomb_list->q_forw;
-    while (bomb != bomb_list) {
-	if (QEMPTY(esc_list)) {
-	    bomb = bomb_list;
-	    continue;
-	}
-	esc = esc_list->q_forw;
-	bombp = (struct plist *)bomb;
-	while (esc != esc_list) {
-	    escp = (struct plist *)esc;
-	    if (escp->plane.pln_uid == bombp->plane.pln_uid) {
-		emp_remque(esc);
-		free(esc);
-		esc = esc_list;
-	    } else
-		esc = esc->q_forw;
-	}
-	bomb = bomb->q_forw;
-    }
-}
-
 /*
  * Fit a plane of PP's type on ship SP.
  * Adjust SP's plane counters.
diff --git a/src/lib/subs/sect.c b/src/lib/subs/sect.c
index 1b90c03c..541b9b9b 100644
--- a/src/lib/subs/sect.c
+++ b/src/lib/subs/sect.c
@@ -68,7 +68,7 @@ sct_prewrite(int id, void *ptr)
     struct sctstr *sp = ptr;
     struct sctstr sect;
 
-    bridge_damaged(sp, NULL);
+    bridge_damaged(sp);
     checksect(sp);
     getsect(sp->sct_x, sp->sct_y, &sect);
     return 1;
diff --git a/src/lib/subs/sectdamage.c b/src/lib/subs/sectdamage.c
index a14dad48..920f45aa 100644
--- a/src/lib/subs/sectdamage.c
+++ b/src/lib/subs/sectdamage.c
@@ -49,7 +49,7 @@
 #include "xy.h"
 
 int
-sect_damage(struct sctstr *sp, int dam, struct emp_qelem *list)
+sect_damage(struct sctstr *sp, int dam)
 {
     int eff;
 
@@ -69,13 +69,13 @@ sect_damage(struct sctstr *sp, int dam, struct emp_qelem *list)
     if (sp->sct_mobil > 0)
 	sp->sct_mobil = damage(sp->sct_mobil, dam);
     item_damage(dam, sp->sct_item);
-    bridge_damaged(sp, list);
+    bridge_damaged(sp);
     putsect(sp);
     return eff;
 }
 
 int
-sectdamage(struct sctstr *sp, int dam, struct emp_qelem *list)
+sectdamage(struct sctstr *sp, int dam)
 {
     struct nstr_item ni;
     struct lndstr land;
@@ -87,7 +87,7 @@ sectdamage(struct sctstr *sp, int dam, struct emp_qelem *list)
     /* the damage accordingly. Makes forts a pain */
     dam = ldround(dam / sector_strength(sp), 1);
 
-    eff = sect_damage(sp, PERCENT_DAMAGE(dam), list);
+    eff = sect_damage(sp, PERCENT_DAMAGE(dam));
 
     /* Damage all the land units in the sector */
     /* Units don't take full damage */
@@ -114,9 +114,6 @@ sectdamage(struct sctstr *sp, int dam, struct emp_qelem *list)
 	    continue;
 	if (plane.pln_ship >= 0)
 	    continue;
-	/* Is this plane flying in this list? */
-	if (ac_isflying(&plane, list))
-	    continue;
 	planedamage(&plane, dam);
 	putplane(plane.pln_uid, &plane);
     }
diff --git a/src/lib/update/revolt.c b/src/lib/update/revolt.c
index 8684eaa2..e9ef4e46 100644
--- a/src/lib/update/revolt.c
+++ b/src/lib/update/revolt.c
@@ -271,7 +271,7 @@ guerrilla(struct sctstr *sp)
 	wu(0, sp->sct_own,
 	   "Production %s disrupted by terrorists in %s\n",
 	   effadv(n), ownxy(sp));
-	sect_damage(sp, n / 10, 0);
+	sect_damage(sp, n / 10);
 	/*logerror("(#%d) che blew up %s for %d", sp->sct_own, */
 	/*ownxy(sp), n); */
 	recruit++;