John D. Thomas Vice President Finance/Treasurer July 28, 2003 CONFIDENTIAL Mr. Robert L. Collins ECC International, Inc. 2001 West Oak Ridge Road Orlando, FL 32809

EXHIBIT (d)(4)

Xxxx X. Xxxxxx
Vice President Finance/Treasurer

July 28, 2003

CONFIDENTIAL

Xx. Xxxxxx X. Xxxxxxx
ECC International, Inc.
0000 Xxxx Xxx Xxxxx Xxxx
Xxxxxxx, XX 00000

RE:

INDICATION OF INTEREST
EXTENSION OF TIME

Dear Xxxxxx:

On June 26, 2003, Xxxxx and ECC entered into an Indication of Interest letter agreement. The second paragraph of that letter referred in Line 5 to a period of exclusivity in our arrangements which would last until August 1, 2003.

As you know, we have been diligently pursuing our due diligence investigation, but it will not be complete by August 1, 2003. We have discussed mutually continuing the period of exclusivity to August 8, 2003, and we have agreed to do so.

Therefore, this will confirm that the Representatives and ECC hereby agree with Cubic that the date of August 8, 2003, shall be substituted in Line 5 of the second paragraph of the letter of June 26, 2003, for the date of August 1, 2003.

Best regards,
/s/  XXXX X. XXXXXX     Xxxx X. Xxxxxx Vice President Finance and Treasurer
Agreed to on behalf of ECC International, Inc., and its directors and executive officers:
/s/  XXXXXX X. XXXXXXX		July 30, 2003
Xxxxxx X. Xxxxxxx Chief Executive Officer ECC International, Inc.

0000 Xxxxxx Xxx., Xxx Xxxxx, XX 00000 • P.O. Box 85587, San Diego, CA 92186-5587
000-000-0000 • Fax 000-000-0000 • Email: xxx.xxxxxx@xxxxx.xxx
xxx.xxxxx.xxx • American Stock Exchange Symbol: CUB

August 6, 2003

CONFIDENTIAL

Xx. Xxxxxx X. Xxxxxxx
ECC International, Inc.
0000 Xxxx Xxx Xxxxx Xxxx
Xxxxxxx, XX 00000

Re:

Indication of Interest
Extension of Time

Dear Xxxxxx:

On June 26, 2003 Xxxxx and ECC entered into an Indication of Interest letter agreement. The second paragraph of that letter referred, in line 5, to a period of exclusivity in our arrangements which would last until August 1, 2003. On July 28, 2003 we extended that time period to August 8, 2003.

As you know, we have been diligently pursuing our due diligence investigation, but it will not be complete by August 8th. We have discussed mutually continuing the period of exclusivity to August 15th, and we have agreed to do so.

Therefore, this will confirm that the Representatives and ECC hereby agree with Cubic that the date of August 15, 2003 shall be substituted in line 5 of the second paragraph of the letter of June 26, 2003 for the date of August 8, 2003.

Best regards,
/s/  XXXX X. XXXXXX     Xxxx Xxxxxx Vice President, Finance
Agreed to on behalf of ECC International, Inc. and its directors and executive officers:
/s/  XXXXXX X. XXXXXXX		August 8, 2003
Xxxxxx X. Xxxxxxx Chief Executive Officer ECC International, Inc.

0000 Xxxxxx Xxx., Xxx Xxxxx, XX 00000 • P.O. Box 85587, San Diego, CA 92186-5587
000-000-0000 • Fax 000-000-0000
xxx.xxxxx.xxx • American Stock Exchange Symbol: CUB

August 6, 2003

CONFIDENTIAL

Xx. Xxxxxx X. Xxxxxxx
ECC International, Inc.
0000 Xxxx Xxx Xxxxx Xxxx
Xxxxxxx, XX 00000

Re:

Indication of Interest
Extension of Time

Dear Xxxxxx:

On June 26, 2003 Xxxxx and ECC entered into an Indication of Interest letter agreement. The second paragraph of that letter referred, in line 5, to a period of exclusivity in our arrangements which would last until August 1, 2003. On July 28, 2003 we extended that time period to August 8, 2003.

As you know, we have been diligently pursuing our due diligence investigation, but it will not be complete by August 8th. We have discussed mutually continuing the period of exclusivity to August 20th, and we have agreed to do so.

Therefore, this will confirm that the Representatives and ECC hereby agree with Cubic that the date of August 15, 2003 shall be substituted in line 5 of the second paragraph of the letter of June 26, 2003 for the date of August 8, 2003.

Best regards,
/s/  XXXX X. XXXXXX     Xxxx Xxxxxx Vice President, Finance
Agreed to on behalf of ECC International, Inc. and its directors and executive officers:
/s/  XXXXXX X. XXXXXXX		August 8, 2003
Xxxxxx X. Xxxxxxx Chief Executive Officer ECC International, Inc.

0000 Xxxxxx Xxx., Xxx Xxxxx, XX 00000 • P.O. Box 85587, San Diego, CA 92186-5587
000-000-0000 • Fax 000-000-0000
xxx.xxxxx.xxx • American Stock Exchange Symbol: CUB