There is no conceivable way, without writing a book in and of itself, in which I can list all the active and retired military personnel who question the official explanation of the events of 9-11 (including myself). Instead, I have opted to recount a few statements from those personnel whose areas of expertise are particularly relevant to the events, who have specific issues to be addressed.

Summary:
1. Commander Ralph Kolstad (ret), former Navy Top Gun and Air Combat Instructor
2. Major General Albert Stubblebine (ret), former Commanding General of U.S. Army Intelligence and Security Command
3. Col. George Nelson (ret), former U.S. Air Force aircraft accident investigator and airplane parts authority
4. Lt. Col. Karen U. Kwiatkowski, former Air Force staff member of the Director of the National Security Agency and eyewitness to Pentagon crash
5. Lt. Col. Jeff Latas, former Air Force combat fighter pilot and Aerospace Engineer
6. Commander Ted Muga, retired Naval Aviator
7. Capt. Russ Wittenberg, former Air Force combat fighter pilot and retired commercial pilot, previously flown two of the actual aircraft involved
8. Capt. Daniel Davis, Former U.S. Army Air Defense Officer and NORAD Tac Director, and Founder/Former CEO of Turbine Technology Services Corp

Commander Ralph Kolstad (ret), former Navy Top Gun and Air Combat Instructor. The following is taken verbatim from his interview with OpEd News [1]:

Career. Now retired, Commander Kolstad was a top-rated fighter pilot during his 20-year Navy career. Early in his career, he was accorded the honor of being selected to participate in the Navy’s ‘Top Gun’ air combat school, officially known as the U.S. Navy Fighter Weapons School. The Tom Cruise movie, “Top Gun” reflects the experience of the young Navy pilots at the school. Eleven years later, Commander Kolstad was further honored by being selected to become a ‘Top Gun’ adversary instructor. While in the Navy, he flew F-4 Phantoms, A-4 Skyhawks, and F-14 Tomcats and completed 250 aircraft carrier landings. Commander Kolstad had a second career after his 20 years of Navy active and reserve service and served as a commercial airline pilot for 27 years, flying for American Airlines and other domestic and international careers. He flew Boeing 727, 757 and 767, McDonnell Douglas MD-80, and Fokker F-100 airliners. He has flown a total of over 23,000 hours in his career.

His questions and statements:
• Commander Kolstad is especially critical of the account of American Airlines Flight 77 that allegedly crashed into the Pentagon. He says, “At the Pentagon, the pilot of the Boeing 757 did quite a feat of flying. I have 6,000 hours of flight time in Boeing 757’s and 767’s and I could not have flown it the way the flight path was described.” Commander Kolstad adds, “I was also a Navy fighter pilot and Air Combat Instructor and have experience flying low altitude, high speed aircraft. I could not have done what these beginners did. Something stinks to high heaven!”
• He points to the physical evidence at the Pentagon impact site and asks in exasperation, “Where is the damage to the wall of the Pentagon from the wings? Where are the big pieces that always break away in an accident? Where is all the luggage? Where are the miles and miles of wire, cable, and lines that are part and parcel of any large aircraft? Where are the steel engine parts? Where is the steel landing gear? Where is the tail section that would have broken into large pieces?”
• Regarding the alleged impact site of United Airlines Flight 93 near Shanksville, PA, he asks, “Where is any of the wreckage? Of all the pictures I have seen, there is only a hole! Where is any piece of a crashed airplane? Why was the area cordoned off, and no inspection allowed by the normal accident personnel? Where is any evidence at all?”
• Commander Kolstad also questions many aspects of the attack on the World Trade Center. “How could a steel and concrete building collapse after being hit by a Boeing 767? Didn’t the engineers design it to withstand a direct hit from a Boeing 707, approximately the same size and weight of the 767? The evidence just doesn’t add up."
• "Why did the second building collapse before the first one, which had been burning for 20 minutes longer after a direct hit, especially when the second one hit was just a glancing blow? If the fire was so hot, then why were people looking out the windows and in the destroyed areas? Why have so many members of the New York Fire Department reported seeing or hearing many ‘explosions’ before the buildings collapsed?”

Major General Albert Stubblebine (ret), former Commanding General of U.S. Army Intelligence and Security Command. The following is taken verbatim from PatriotsQuestion911 [2]:

Career. Former Commanding General of U.S. Army Intelligence and Security Command, 1981 - 1984. Also commanded the U.S. Army’s Electronic Research and Development Command and the U.S. Army’s Intelligence School and Center. Former head of Imagery Interpretation for Scientific and Technical Intelligence. 32-year Army career. Member of the Military Intelligence Hall of Fame [3].

His statement: "One of my experiences in the Army was being in charge of the Army’s Imagery Interpretation for Scientific and Technical Intelligence during the Cold War. I measured pieces of Soviet equipment from photographs. It was my job. I look at the hole in the Pentagon and I look at the size of an airplane that was supposed to have hit the Pentagon. And I said, ‘The plane does not fit in that hole’. So what did hit the Pentagon? What hit it? Where is it? What's going on?" [4]

Col. George Nelson (ret), former U.S. Air Force aircraft accident investigator and airplane parts authority. The following is taken verbatim from PatriotsQuestion911:

Career. Former U.S. Air Force aircraft accident investigator and airplane parts authority. Graduate, U.S. Air Force War College. 34-year Air Force career. Licensed commercial pilot. Licensed airframe and powerplant mechanic

His essay:
• "In all my years of direct and indirect participation, I never witnessed nor even heard of an aircraft loss, where the wreckage was accessible, that prevented investigators from finding enough hard evidence to positively identify the make, model, and specific registration number of the aircraft -- and in most cases the precise cause of the accident. ...
• The government alleges that four wide-body airliners crashed on the morning of September 11 2001, resulting in the deaths of more than 3,000 human beings, yet not one piece of hard aircraft evidence has been produced in an attempt to positively identify any of the four aircraft. On the contrary, it seems only that all potential evidence was deliberately kept hidden from public view. …
• With all the evidence readily available at the Pentagon crash site, any unbiased rational investigator could only conclude that a Boeing 757 did not fly into the Pentagon as alleged. Similarly, with all the evidence available at the Pennsylvania crash site, it was most doubtful that a passenger airliner caused the obvious hole in the ground and certainly not the Boeing 757 as alleged."[5]

Lt. Col. Karen U. Kwiatkowski, former Air Force staff member of the Director of the National Security Agency and eyewitness to Pentagon crash. The following is taken verbatim from PatriotsQuestion911:

Career. Former Political-Military Affairs Officer in the Office of the Secretary of Defense. Also served on the staff of the Director of the National Security Agency. 20-year Air Force career. Member adjunct faculty, Political Science Department, James Madison University. Instructor, University of Maryland University College and American Public University System. Author of African Crisis Response Initiative: Past Present and Future (2000) and Expeditionary Air Operations in Africa: Challenges and Solutions (2001).

Her statements:
• "It is as a scientist that I have the most trouble with the official government conspiracy theory, mainly because it does not satisfy the rules of probability or physics. The collapses of the World Trade Center buildings clearly violate the laws of probability and physics. ...
• There was a dearth of visible debris on the relatively unmarked [Pentagon] lawn, where I stood only minutes after the impact. Beyond this strange absence of airliner debris, there was no sign of the kind of damage to the Pentagon structure one would expect from the impact of a large airliner. This visible evidence or lack thereof may also have been apparent to the secretary of defense [Donald Rumsfeld], who in an unfortunate slip of the tongue referred to the aircraft that slammed into the Pentagon as a "missile".[6]
• I saw nothing of significance at the point of impact - no airplane metal or cargo debris was blowing on the lawn in front of the damaged building as smoke billowed from within the Pentagon. ... all of us staring at the Pentagon that morning were indeed looking for such debris, but what we expected to see was not evident.
• The same is true with regard to the kind of damage we expected. ... But I did not see this kind of damage. Rather, the facade had a rather small hole, no larger than 20 feet in diameter. Although this facade later collapsed, it remained standing for 30 or 40 minutes, with the roof line remaining relatively straight.
• The scene, in short, was not what I would have expected from a strike by a large jetliner. It was, however, exactly what one would expect if a missile had struck the Pentagon..."

Lt. Col. Jeff Latas, former Air Force combat fighter pilot and Aerospace Engineer. The following is taken verbatim from PatriotsQuestion911:

Career. Former combat fighter pilot. Aerospace engineer. Currently Captain at a major airline. Combat experience includes Desert Storm and four tours of duty in Northern and Southern Watch. Aircraft flown: McDonnell Douglas F-15E Strike Eagle and General Dynamics F-111 Aardvark fighter/bomber. Former President, U.S. Air Force Accident Investigation Board. Also served as Pentagon Weapons Requirement Officer and as a member of the Pentagon's Quadrennial Defense Review. Awarded Distinguish Flying Cross for Heroism, four Air Medals, four Meritorious Service Medals, and nine Aerial Achievement Medals. 20-year Air Force career.

His statements:
• Regarding the 9/11 Commission's account of the impact of Flight 77 at the Pentagon and discrepancies with the actual Flight Data Recorder information: "After I did my own analysis of it, it's obvious that there's discrepancies between the two stories; between the 9/11 Commission and the flight data recorder information. And I think that's where we really need to focus a lot of our attention to get the help that we need in order to put pressure on government agencies to actually do a real investigation of 9/11. And not just from a security standpoint, but from even an aviation standpoint, like any accident investigation would actually help the aviators out by finding reasons for things happening.
• The things that really got my attention were the amount of descent rate that you had to have at the end of the flight, of Flight 77, that would have made it practically impossible to hit the light poles. [Editor's note: Destruction of the light poles near the Pentagon by Flight 77 was stated in the 9/11 Commission Report.] Essentially it would have been too high at that point to the point of impact where the main body of the airplane was hitting between the first and second floor of the Pentagon. ...
• You know, I'd ride my bike to the Pentagon. So, you know I'm a little bit familiar with that area. [Editor's note: Lt. Col. Latas served as a Weapons Requirement Officer at the Pentagon.] But, you know, that kind of descent rate it would have been impossible essentially for the results that we see physically from what the flight data recorder was recording. Like I say, that's an area that I think deserves explanation. ...
• The ground track [the path of the airplane] is off from the 9/11 Commission."

Commander Ted Muga, retired Naval Aviator. The following is taken verbatim from PatriotsQuestion911:

Career. Retired Naval aviator (Grumman E-1 and E-2). Retired Pan-Am commercial airline pilot (Boeing 707 and 727).

His statements:
• "The maneuver at the Pentagon was just a tight spiral coming down out of 7,000 feet. And a commercial aircraft, while they can in fact structurally somewhat handle that maneuver, they are very, very, very difficult. And it would take considerable training. In other words, commercial aircraft are designed for a particular purpose and that is for comfort and for passengers and it's not for military maneuvers. And while they are structurally capable of doing them, it takes some very, very talented pilots to do that. ...
• When a commercial airplane gets that high, it gets very, very close to getting into what you refer to as a speed high-speed stall. And a high-speed stall can be very, very violent on a commercial-type aircraft and you never want to get into that situation. I just can't imagine an amateur even being able to come close to performing a maneuver of that nature.
• And as far as hijacking the airplanes, once again getting back to the nature of pilots and airplanes, there is no way that a pilot would give up an airplane to hijackers. ...I mean, hell, a guy doesn't give up a TV remote control much less a complicated 757. And so to think that pilots would allow a plane to be taken over by a couple of 5 foot 7, 150 pound guys with a one-inch blade boxcutter is ridiculous.
• And also in all four planes, if you remember, none of the planes ever switched on their transponder to the hijack code. There's a very, very simple code that you put in if you suspect that your plane is being hijacked. It takes literally just a split-second for you to put your hand down on the center console and flip it over. And not one of the four planes ever transponded a hijack code, which is most, most unusual. ...
• Commercial airplanes are very, very complex pieces of machines. And they're designed for two pilots up there, not just two amateur pilots, but two qualified commercial pilots up there. And to think that you're going to get an amateur up into the cockpit and fly, much less navigate, it to a designated target, the probability is so low, that it's bordering on impossible."

Capt. Russ Wittenberg, former Air Force combat fighter pilot and retired commercial pilot, previously flown two of the actual aircraft involved. The following is taken verbatim from PatriotsQuestion911:

Career. Former U.S. Air Force fighter pilot with over 100 combat missions. Retired commercial pilot. Flew for Pan Am and United Airlines for 35 years. Aircraft flown: Boeing 707, 720, 727, 737, 747, 757, 767, and 777. 30,000+ total hours flown. Had previously flown the actual two United Airlines aircraft that were hijacked on 9/11 (Flight 93, which impacted in Pennsylvania, and Flight 175, the second plane to hit the WTC).

His statement:
• "I flew the two actual aircraft which were involved in 9/11; the Fight number 175 and Flight 93, the 757 that allegedly went down in Shanksville and Flight 175 is the aircraft that's alleged to have hit the South Tower. I don't believe it's possible for, like I said, for a terrorist, a so-called terrorist to train on a [Cessna] 172, then jump in a cockpit of a 757-767 class cockpit, and vertical navigate the aircraft, lateral navigate the aircraft, and fly the airplane at speeds exceeding it's design limit speed by well over 100 knots, make high-speed high-banked turns, exceeding -- pulling probably 5, 6, 7 G's. And the aircraft would literally fall out of the sky. I couldn't do it and I'm absolutely positive they couldn't do it."
• "The government story they handed us about 9/11 is total B.S. plain and simple… there was absolutely no possibility that Flight 77 could have "descended 7,000 feet in two minutes, all the while performing a steep 270 degree banked turn before crashing into the Pentagon's first floor wall without touching the lawn."…For a guy to just jump into the cockpit and fly like an ace is impossible - there is not one chance in a thousand," said Wittenberg, recalling that when he made the jump from Boeing 727's to the highly sophisticated computerized characteristics of the 737's through 767's it took him considerable time to feel comfortable flying."
• Regarding Flight 77, which allegedly hit the Pentagon: "The airplane could not have flown at those speeds which they said it did without going into what they call a high speed stall. The airplane won’t go that fast if you start pulling those high G maneuvers at those bank angles. … To expect this alleged airplane to run these maneuvers with a total amateur at the controls is simply ludicrous... It’s roughly a 100 ton airplane. And an airplane that weighs 100 tons all assembled is still going to have 100 tons of disassembled trash and parts after it hits a building. There was no wreckage from a 757 at the Pentagon. … The vehicle that hit the Pentagon was not Flight 77. We think, as you may have heard before, it was a cruise missile."

Capt. Daniel Davis, Former U.S. Army Air Defense Officer and NORAD Tac Director, and Founder/Former CEO of Turbine Technology Services Corp. The following is taken verbatim from PatriotsQuestion911:

Career. Former U.S. Army Air Defense Officer and NORAD Tac Director. Decorated with the Bronze Star and the Soldiers Medal for bravery under fire and the Purple Heart for injuries sustained in Viet Nam. Also served in the Army Air Defense Command as Nike Missile Battery Control Officer for the Chicago-Milwaukee Defense Area. Founder and former CEO of Turbine Technology Services Corp., a turbine (jet engine) services and maintenance company (15 years). Former Senior Manager at General Electric Turbine (jet) Engine Division (15 years). Private pilot.

His statements:
• "As a former General Electric Turbine engineering specialist and manager and then CEO of a turbine engineering company, I can guarantee that none of the high tech, high temperature alloy engines on any of the four planes that crashed on 9/11 would be completely destroyed, burned, shattered or melted in any crash or fire. Wrecked, yes, but not destroyed. Where are all of those engines, particularly at the Pentagon? If jet powered aircraft crashed on 9/11, those engines, plus wings and tail assembly, would be there.
• Additionally, in my experience as an officer in NORAD as a Tactical Director for the Chicago-Milwaukee Air Defense and as a current private pilot, there is no way that an aircraft on instrument flight plans (all commercial flights are IFR) would not be intercepted when they deviate from their flight plan, turn off their transponders, or stop communication with Air Traffic Control. No way! With very bad luck, perhaps one could slip by, but no there's no way all four of them could!
• Finally, going over the hill and highway and crashing into the Pentagon right at the wall/ground interface is nearly impossible for even a small slow single engine airplane and no way for a 757. Maybe the best pilot in the world could accomplish that but not these unskilled "terrorists".

References:
[1] http://www.opednews.com/articles/genera_alan_mil_070905_u_s__navy__top_g...
[2] http://patriotsquestion911.com
[3] http://huachuca-www.army.mil/USAG/PAO/2001scouts/MI%Hall%of%Fame%2001.pdf
[4] http://www.undersiegemovie.com/media/stubblebine.wmv
[5] http://www.physics911.net/georgenelson
[6] http://www.defenselink.mil/transcripts/transcript.aspx?TranscriptID=3845