|Howard Mann's Comments on the
FDR Analysis by Richard Hirsch
Richard, I have received your "The 12 Second Solution" and I thank you for including me in the distribution. I have a few comments and in view of the wide distribution you have given your paper I have taken the liberty of directing my comments to the same persons. You have accomplished a great deal working with the data the NTSB has provided. Unfortunately, I believe the data you are working with is not credible.
The wave form data (the blue sheet) you have included in your paper shows the inter-record gap between the 10 second record and the 11 second record between word 25, bit 9 and word 26 bit 3. The NTSB originally published Section 10, page 42 shows that there were two indications of word 27 (stabilizer trim) in the 10second record and while this is possible you and I both know it is not possible with the inter-record gap as shown on the NTSB blue page. I am not asking you to explain this discrepancy and in my opinion you should not be asking other private investigators to accept it or explain it as I know you have done. Everyone connected with this investigation should be asking the NTSB to explain this impossibility.
On another more serious matter which you mentioned and then seemed to ignore is the indication of time (seconds) being registered twice in the 10 second record. We know that is possible if the two indications are consecutive ie; 2-3, 4-5 or 7-8 but indications of 3 seconds and 8 seconds recorded in the same record. within 7/10 of a second as you have shown on record 20:31:10 , would indicate that there are 5 seconds missing from the tape; and I would expect the NTSB to explain that.
In case you did not know, at the same time these discrepancies are indicated on the Flight Data Recorder Tape there are similar problems associated with the CVR readout. For example at time 20:31:03 there was an unidentified word on that record and at 20:31:05 there was the sound of recording tape damage. Both of these incidents at the time indicated, coupled with possibility of 5 seconds missing from the FDR Tape, need further investigation.
It is my belief that there may be an innocent explanation for the 5 second gap in the FDR record. A momentary interruption of electrical power involving the Essential Power Bus would be one explanation which is possible and which could have automatically corrected itself, thereby restoring power. I am currently writing a paper describing how this is possible and it will be forwarded to you when it is completed.
Sincerely, Howard T.Mann