import { Component } from '@angular/core';

import { NavParams } from 'ionic-angular';

import { AboutPage } from '../about/about';
import { MapPage } from '../map/map';
import { SchedulePage } from '../schedule/schedule';
import { SpeakerListPage } from '../speaker-list/speaker-list';


@Component({
  templateUrl: 'build/pages/tabs/tabs.html'
})
export class TabsPage {
  // set the root pages for each tab
  tab1Root: any = SchedulePage;
  tab2Root: any = SpeakerListPage;
  tab3Root: any = AboutPage;
  tab4Root: any = AboutPage;
  mySelectedIndex: number;

  constructor(navParams: NavParams) {
    this.mySelectedIndex = navParams.data.tabIndex;
  }
}

import { Component } from '@angular/core';

import { NavParams } from 'ionic-angular';

import { AboutPage } from '../about/about';
import { MapPage } from '../map/map';
import { SchedulePage } from '../schedule/schedule';
import { SpeakerListPage } from '../speaker-list/speaker-list';


@Component({
  templateUrl: 'build/pages/tabs/tabs.html'
})
export class TabsPage {
  // set the root pages for each tab
  tab1Root: any = SchedulePage;
  tab2Root: any = SpeakerListPage;
  tab3Root: any = MapPage;
  tab4Root: any = AboutPage;
  mySelectedIndex: number;

  constructor(navParams: NavParams) {
    this.mySelectedIndex = navParams.data.tabIndex || 3;
  }
}

--- 
+++ 
@@ -15,11 +15,11 @@
   // set the root pages for each tab
   tab1Root: any = SchedulePage;
   tab2Root: any = SpeakerListPage;
-  tab3Root: any = MapPage;
+  tab3Root: any = AboutPage;
   tab4Root: any = AboutPage;
   mySelectedIndex: number;
 
   constructor(navParams: NavParams) {
-    this.mySelectedIndex = navParams.data.tabIndex || 3;
+    this.mySelectedIndex = navParams.data.tabIndex;
   }
 }
Make schedule the default tab
