Are platform images required to run Appium tests?

Hi All

I have configured android SDK, Appium and all related stuffs to get started with appium on some other machine.

However currently that system does not have all platform images except android nougat, and I am trying to run test on android device having Marshmellow/Lollipop version. So I am running a sample test to launch chrome browser and getting below mentioned error:

org.openqa.selenium.SessionNotCreatedException: Unable to create new remote session. desired capabilities = Capabilities [{browserName=Chrome, platformName=Android, deviceName=deviceUDID}], required capabilities = Capabilities [{}]
Build info: version: '3.3.1', revision: '5234b32', time: '2017-03-10 09:04:52 -0800'
System info: host: 'hostname', ip: '', 'Mac OS X', os.arch: 'x86_64', os.version: '10.11.6', java.version: '1.8.0_92'
Driver info: driver.version: AndroidDriver
	at org.openqa.selenium.remote.ProtocolHandshake.createSession(
	at org.openqa.selenium.remote.HttpCommandExecutor.execute(
	at io.appium.java_client.remote.AppiumCommandExecutor.execute(
	at org.openqa.selenium.remote.RemoteWebDriver.execute( 

So just curious to know that are platform images are strictly required(to be downloaded locally under android sdk platforms folder) to run appium tests.

However same script is working fine on other machine which is having images installed.

Please provide any thoughts/comments on this.

Thank you
Ravi Kumar