Judging from mail and telephone calls, the chief job-related fear of federal workers is that Congress will alter or destroy their retirement program, by raising the retirement age, cutting benefits or increasing employe payments to the pension fund.

Today's collection of letters leads with one from a fed who thinks the government should play by the same retirement rules it has imposed, by law, on the private sector:

"I assume I will read in your cheery column one morning that overnight my entire life has changed, that I will have been ordered, against my weak will, to work another five more years until retirement.

"I find this proposal to be almost unthinkable, and a most violent intrusion of people's rights.

"An imaginative ruling body could have said to its employes, 'We have a goal. This is what it is, and there are X number of ways to accomplish this . . . . Now vote on which way it is to be.'

"Industry is twice as imaginative as government in approaches to pensions and fringes. Industry is light years ahead of Uncle Sam in permitting employes to elect certain choices of their future fiscal plans.

"The best example of this is the law that says the employe's dollar is always his, and must be invested to return high reasonable rates . . . currently 10 to 24 percent.

"Do you know what Sam's plan is? The dollar will not be yours: It will go into a pot, and there will be absolutely no accounting . . . .

"Let Congress overhaul the civil service retirement system, but don't pull out teeth out in the process. I say the system is in trouble and the politicians are about to make it worse. Give the worker an option or two." -- S.E.C., Washington

On other subjects:

"You have often printed horror stories from retirees who tell of long delays in getting their first retirement checks from the Office of Personnel Management. I thought you would like to hear the other side of the coin.

"I retired Jan. 3. On Feb. 14 I got a special payment from OPM equal to about 80 percent of my projected annuity. On March 1 I got another special payment, then on March 30 a third special payment, bringing me up to date.

"May 1 my first full annuity check arrived. That is very good work on OPM's part!" -- M.S., Silver Spring

"Please remind those elected officials who advocate giving full cost-of-living raises only to a low-income federal retirees that there was no 'means test' applied to determine the amount withheld from our salaries to support this program.

"May we next expect our federally insured banks and savings and loan companies to apply a 'means test' to determine how much interest to pay on our deposits?" -- B.W., still in civil service

"On the subject of making it more difficult to get step pay increases, here's a question: Who decided that they are bad for the country? What ignoramus thinks the majority of federal workers stay in the same grade for 18 years the time it takes a worker to move from the first to the 10th step of each pay grade ?

"In my 46-year federal career I did not know of a single employe who did not qualify for a grade promotion. I know of numerous women who were promoted from Grade 3 secretary-stenos to Grade 12 program specialists in less than 16 years.

"That was a raise of from $10,000 per year to $36,000 per year, and they all deserved it." -- Grace, retired civil servant