Northwest Airlines and Delta Air Lines asked their employees this week about the kind of work culture they want for their combined airline, and leaders of two Northwest unions immediately criticized management for asking.

It was an early indicator of how challenging it could be to blend two workforces into one happy family.

"The reason for the survey is to get a broad cross-section of employees to give their perceptions about the merger," Northwest spokeswoman Tammy Lee said Wednesday. She added that the airlines' executives want to know what works well today, what needs to be changed, and "what they would like to see the culture become."

But Northwest's largest union quickly blasted the survey as management's "latest attempt to destroy our organization" by trying to deal directly with its members.

Leaders of the International Association of Machinists and Aerospace Workers (IAM) urged their 12,500 Northwest members not to participate in the survey, which had been posted on the two airlines' internal websites.

"They talk as though you have no union representation," the IAM leadership said on its District 143 web site. The IAM leaders characterized the survey as management's "latest divide-and-conquer scheme."

Kevin Griffin, president of the Northwest flight attendants union, said in a Wednesday interview that the airlines' were "circumventing the unions" by communicating with employees via company websites.

Griffin said that union leaders were not consulted about the phrasing of the questions, and he does not think flight attendants should fill in their employee identification numbers on the surveys. He fears that some employees could face a backlash from management if they are highly critical of the merger or their airline.

Northwest ground workers, who are IAM members, and Northwest flight attendants risk losing union representation under a merger with Delta, because their counterparts do not belong to unions at the larger Delta.

Northwest's Lee said the companies asked employees for their identification numbers so that they can be entered in a drawing for free airline tickets. She also said the carriers do not plan to separate the responses by specific employee groups.

The survey does not ask whether an employee supports or opposes the proposed merger. Nor does it ask whether an employee wants to be represented by a union.

Lee said front-line employees "are critical to running a great airline and our collective future success is dependent on their continued dedication to customer service."

The voluntary survey is being taken of union, nonunion and salaried employees. Lee said about 1,000 Northwest employees responded to it within the first 24 hours it was available online.

"Delta has long engaged employees in key business initiatives, seeking their individual feedback on how to improve our operation and make Delta a great place to work," said Delta spokeswoman Gina Laughlin.

Both companies' spokeswomen said the airlines want their employees to shape their work culture, which directly affects how they meet customer needs.

In a recent video for employees, Delta CEO Richard Anderson described how some aspects of the cultures will mesh. He said that Northwest has "a very strong operating sense" and Delta has been characterized by a "Southern hospitality" toward customers.

Kevin Cashman, a Minneapolis-based expert in company cultures, said, "The survey in itself is not positive or negative. The issue here is the lack of trust in the [Northwest] culture between unions and management."

Cashman said leaders of the merged carrier should address those trust concerns with the Northwest unions as they deal with multiple aspects of merging two work cultures.

Liz Fedor • 612-673-7709