Appellants contest their jury conviction under 21 U.S.C. §§ 841(a)(1) & 846 for conspiracy to distribute marijuana. Reeve, Harris, and Law argue that the search of their vans which uncovered 720 pounds of marijuana was improper. Thompson claims that his airplane was searched without his consent and without probable cause. Reeve, Harris, and Thompson also contend that the trial court committed reversible error in postponing the hearing on their motions to suppress until after the jury had begun deliberations. We affirm.

This case arises out of an all-night surveillance effort by federal and state authorities, covering the movement of two vans and an airplane in the contiguous desert areas of Arizona and Nevada. The following morning, the authorities stopped the two vans for the purpose of questioning the occupants. The district court ruled that there was "founded suspicion" to justify this investigatory stop, and appellants do not seriously challenge that determination here. They do argue, however, that the stop ripened into a full-fledged arrest when an officer drew his weapon; that, though the officers may have had sufficient "founded suspicion" to justify the stop, they had no probable cause to arrest; and that, since the arrest was invalid, the fruit of the subsequent search of the vans was inadmissible under Wong Sun v. United States, 371 U.S. 471, 83 S.Ct. 407, 9 L.Ed.2d 441 (1963). This argument is without merit.

A police officer attempting to make an investigatory detention may properly display some force when it becomes apparent that an individual will not otherwise comply with his request to stop, and the use of such force does not transform a proper stop into an arrest. United States v. Richards, 500 F.2d 1025, 1028-29 (9th Cir. 1974), cert. denied, 420 U.S. 924, 95 S.Ct. 1118, 43 L.Ed.2d 393 (1975). See United States v. Coades, 549 F.2d 1303, 1305 (9th Cir. 1977); United States v. Russell, 546 F.2d 839, 841 (9th Cir. 1976) (Wright, J., concurring). In the instant case, a weapon was not drawn until, after the officers had identified themselves and ordered the vans to stop, one van began to move and then suddenly lurched forward. United States v. Ramos-Zaragosa, 516 F.2d 141, 144 (9th Cir. 1975), United States v. Larkin, 510 F.2d 13, 14 n.1 (9th Cir. 1974), and United States v. Strickler, 490 F.2d 378, 380 (9th Cir. 1974), relied upon by appellants, did not involve investigatory stops that were properly initiated through unarmed requests to stop and answer questions and, therefore, are clearly distinguishable. See generally United States v. Nevitt, 409 F.Supp. 1075, 1078-79 n.10 (W.D.Mich.1976); United States v. Diggs, 173 U.S.App.D.C. 95, 522 F.2d 1310, 1326-27 n.5 (1975) (Justice, D. J., dissenting).

After a brief period during which appellants were questioned, the officers detected a strong odor of marijuana coming from one of the vans. We have repeatedly held that, "(i)f after a valid investigatory stop probable cause arises, the search may then be made," United States v. Bugarin-Casas,484 F.2d 853, 854 (9th Cir. 1973), cert. denied, 414 U.S. 1136, 94 S.Ct. 881, 38 L.Ed.2d 762 (1974). See, e.g., United States v. Russell, 546 F.2d 839, 840 (9th Cir. 1976); United States v. Bates, 533 F.2d 466, 468-69 (9th Cir. 1976); United States v. Portillo-Reyes, 529 F.2d 844, 850 (9th Cir. 1975), cert. denied, 429 U.S. 899, 97 S.Ct. 267, 50 L.Ed.2d 185 (1976); United States v. Rocha-Lopez, 527 F.2d 476, 478-79 (9th Cir. 1975), cert. denied, 425 U.S. 977, 96 S.Ct. 2181, 48 L.Ed.2d 802 (1976); United States v. Moreno-Buelna, 524 F.2d 1129, 1132 (9th Cir.) (Chambers J., concurring), cert. denied, 423 U.S. 1035, 96 S.Ct. 570, 46 L.Ed.2d 410 (1975); United States v. Rodriquez-Alvardo, 510 F.2d 1063, 1064 (9th Cir. 1975). And the detection of marijuana odor emanating from a vehicle has been held sufficient in such situations to give rise to probable cause to search. See Russell,supra at 840; United States v. Laird, 511 F.2d 1039, 1040 (9th Cir. 1975); United States v. Ojeda-Rodriquez, 502 F.2d 560, 561 (9th Cir. 1974), cert. denied, 420 U.S. 910, 95 S.Ct. 830, 42 L.Ed.2d 839 (1975); Fernandez v. United States, 321 F.2d 283, 286-87 (9th Cir. 1963).^[1] Appellants were placed under arrest only after the marijuana was discovered.

Next, Thompson, the pilot of the plane, challenges the trial court's findings both that he had consented to the search of the plane and that, in any event, there was probable cause to search it after the officers on the scene were informed that the vans had been seized in another location and were found to contain the marijuana. Having reviewed the record, we cannot say that these findings were clearly erroneous. See United States v. Hart, 546 F.2d 798, 801-02 (9th Cir. 1976) (en banc), cert. denied sub nom. Robles v. United States, 429 U.S. 1120, 97 S.Ct. 1155, 51 L.Ed.2d 571 (1977); United States v. Fong, 529 F.2d 55, 58 (9th Cir. 1975); United States v. Agosto,502 F.2d 612, 614 (9th Cir. 1974); United States v. Page, 302 F.2d 81, 85 (9th Cir. 1962) (en banc); United States v. Patterson, 492 F.2d 995, 996 (9th Cir.), cert. denied, 419 U.S. 846, 95 S.Ct. 82, 42 L.Ed.2d 75 (1974); Costello v. United States, 324 F.2d 260, 261 (9th Cir. 1963), cert. denied, 376 U.S. 930, 84 S.Ct. 699, 11 L.Ed.2d 650 (1964).

Thompson also claims that his consent was not voluntarily given because he was in a "custodial type environment." It is settled that a person in custody may voluntarily consent to a search. United States v. Watson, 423 U.S. 411, 424-25, 96 S.Ct. 820, 46 L.Ed.2d 598 (1976); United States v. Lemon, 550 F.2d 467, 471 (9th Cir. 1977); United States v. Tolias, 548 F.2d 277, 278 (9th Cir. 1977). We find no evidence of duress or coercion in the "totality of all the circumstances" in the record before us. Schneckloth v. Bustamonte, 412 U.S. 218, 227, 93 S.Ct. 2041, 36 L.Ed.2d 854 (1973).

Finally, the argument presented by Reeve, Harris, and Thompson that the trial court committed reversible error in postponing the separate hearing on their motions to suppress is also without merit. They made no objection below to the trial court's adopting this procedure, and, while it is preferable that such motions be decided before trial, see United States v. Mauro, 507 F.2d 802, 806 (2d Cir. 1974), cert. denied, 420 U.S. 991, 95 S.Ct. 1426, 43 L.Ed.2d 672 (1975); United States v. Whitted, 454 F.2d 642, 644 (8th Cir. 1972); Solomon v. United States, 133 U.S.App.D.C. 103, 408 F.2d 1306, 1309 (1969); United States v. Dooling, 406 F.2d 192, 196 (2d Cir.), cert. denied sub nom. Persico v. United States, 395 U.S. 911, 89 S.Ct. 1744, 23 L.Ed.2d 224 (1969); that procedure is not mandatory. A trial court may, in its discretion, defer a hearing on a motion to suppress made before trial for determination at trial or after the verdict as long as no "party's right to appeal is adversely affected." Fed.R.Crim.P. 12(e). See United States v. Kirk,528 F.2d 1057, 1064 (5th Cir. 1976). But see United States v. Smith, 527 F.2d 692, 693 (10th Cir. 1975). Obviously, appellants' rights to appeal were not "adversely affected" by the trial court's decision to postpone the hearing, and we can discern no other prejudice to them that could possibly render the trial court's decision "plain error" under Rule 52(b), see United States v. Segna, 555 F.2d 226, 231 (9th Cir. 1977); Herzog v. United States, 235 F.2d 664, 666-67 (9th Cir.) (en banc), cert. denied, 352 U.S. 844, 77 S.Ct. 54, 1 L.Ed.2d 59 (1956).^[2]

AFFIRMED.