American G.I. Chris, played by Gannon O’Brien, left, and Vietnamese bargirl Kim, played by Diana Huey, find love during wartime in “Miss Saigon,” now playing at Virginia’s Signature Theatre through Sept. 29.  (Christopher Mueller)

Let’s deal right at the top with the urgent transportation question of the day:

Yes, “Miss Saigon” works without the helicopter.

Some of you will recall that the technical coup in the long-running Broadway show (10 years, 4,092 performances) by the creators of “Les Miserables” (16 years, 6,680 performances) was the military whirlybird that landed onstage at the Broadway Theatre (and on tour later at the Kennedy Center). The musical got endless ribbing for it, but as a method of infusing an epic feel into a borderline sappy pop-opera set around the 1975 U.S. evacuation of Saigon, it was a masterstroke.

For the faithful, well-assembled and ultimately touching “Miss Saigon” it has mounted in its 250-seat main-stage space, Signature Theatre lacked the fiscal and physical overhead to recreate Broadway’s high-flying hydraulics. Required to go rotor-less, director Eric Schaeffer becomes even more heavily dependent on the three leads to provide a powerful lift for the musical, closely modeled on Puccini’s “Madame Butterfly.”

Two of them — Diana Huey as the doomed, heroic Kim, and Thom Sesma, playing the scurrilous Vietnamese fixer, the Engineer — color skillfully within their characters’ outlines. Huey, especially, seizes her moments and potently shares with us the full dimensions of Kim’s tragedy. But as the American Marine who falls in love with Kim and leaves her behind during the airlift, the vocally sound Gannon O’Brien is not yet completely up to their level.

“Miss Saigon” requires a Chris who’s a match for Kim in ardor and strength. O’Brien, who inherited the role at the last minute, after Jason Michael Evans developed vocal problems, is still feeling his way: His portrayal comes across as too bland and boyish. An actor needs to muster sufficient intensity to convince us Chris is a man of war and, yes, that he’s that into Kim. (Chris Sizemore, as Chris’s Army buddy John, and Erin Driscoll, as Chris’s stateside wife, Ellen, provide solid support.)

The 1989 show, a tuneful artifact from the heyday of producer Cameron Mackintosh’s hit mega-musicals (“Cats,” “Les Mis,” “The Phantom of the Opera”), has enough buoyant primary-color melodies by Claude-Michel Schonberg to mask some of its other flaws: namely, the ham-handed, first-rhyme-you-can-think-of lyrics by Richard Maltby Jr. and Alain Boublil (“I have a heart like the sea / A million dreams are in me”). And the reductive treatment of the Vietnam War leads to unfortunate caricature, as in the portrait of Thuy (Christopher Mueller), a laughably belligerent Communist functionary thwarted in his designs on Kim.

For me, what rescues “Miss Saigon” is the love story when told from Kim’s perspective and the resulting elevation of a hapless victim of war to pop heroine. The musical’s early scenes, concerning Kim’s indoctrination by the Engineer into the life of a bar girl in Saigon — rechristened Ho Chi Minh City after the Communist takeover — establishes one of the musical’s motifs, that of the desperate desire of the South Vietnamese to leave when the Americans go. In the haunting “The Movie in My Mind,” another bar girl, Gigi (the excellent Cheryl Daro) leads us into a song (with more serviceable lyrics) about the fantasy of escape: “And in a strong G.I.’s embrace / Flee this life / Flee this place.”

Schonberg composes one stirring, romantic ballad after another for Kim, in combination with other characters: “Sun and Moon,” “Last Night of the World,” “I Still Believe.” Huey’s work here confirms that “Miss Saigon” can be a success if its Kim is one; the actress manages, as deftly as any Kim I’ve ever seen, to embody the character’s steely nature without sacrificing her vulnerability. Sure, Kim is close to perfect, but in a musical, you can live with a saint who sings pretty music this well.

Schaeffer’s mature treatment does not tamper with the original blueprint in any intrusive way. He’s a director who is at his best when he’s less concerned with concept than heart; his intimate production amplifies the story’s emotional core. And in Matt Rowe’s finely modulated sound design, the 15-member orchestra conducted by Gabriel Mangiante pleasurably supports the mystique of Schonberg’s love songs.

In Sesma, Schaeffer has found an actor who easily wears a coat of sleaze. The Engineer has a dream, too: He’s a gnat who imagines he can someday be a tarantula. Except he really can’t. That’s communicated in the delusions whipped up in the Engineer’s songs, especially the Fosse-like 11 o’clock number, “The American Dream.” In an effort to underline the garishness of the Engineer’s faith in Western capitalism, the number was overproduced in the original production. Another expensive vehicle — a Cadillac — materialized onstage, and soon, the Engineer (a role originated by a reptilian Jonathan Pryce) was singing and making love to it.

Here, choreographer Karma Camp takes crafty advantage of Sesma’s slithery song-and-dance skills to fashion an off-kilter production number (sans automobile) that grows more fittingly out of the narrowness of the character’s mind. “Miss Saigon” doesn’t boast extraordinary opportunities for dance, but the relentless advance of the Viet Cong is neatly conveyed in the marching feet that clang on the set’s metal grates in “The Morning of the Dragon.”

Adam Koch’s set, curtained by a parachute, with walls of corrugated steel, functionally hews to Schaeffer’s stark aesthetic here, and lighting designer Chris Lee executes a nifty effect during the embassy evacuation scene, in which the world around Kim fades into brutal black and white.

That’s the scene in which the celebrated chopper is supposed to make its entrance. Rowe lets you feel the thudding force of unseen blades, and Koch provides glimpses of landing lights. But the more essential and exhilarating pulse belongs to Huey.

Miss Saigon

music by Claude-Michel Schonberg, lyrics by Richard Maltby Jr. and Alain Boublil. Directed by Eric Schaeffer. Choreography, Karma Camp; music direction, Gabriel Mangiante; sets, Adam Koch; lighting, Chris Lee; costumes, Frank Labovitz; sound, Matt Rowe; orchestrations, William D. Brohn. With Eunice Bae, Katie Mariko Murray, Tamara Young, Stephen Gregory Smith, Ryan Sellers. About 21 / 2 hours. Through Sept. 29 at Signature Theatre, 4200 Campbell Ave., Arlington. Visit or call 703-573-7328.