VTOL question
Very dependant upon density altitude. I can’t remember the basic weight of a SHAR with tanks and winders but I guess it would be c14,000lbs. If that is correct, a standard day (+15/1013) would give you c3,300 of fuel for a wet VTO, according to my ancient whizz-wheel. This equates to 25-30 mins cruise at medium level, with a small recovery margin. On a harry-redders day, that would be more like 2,300.
Mog
Mog
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Thank you for the reply Mog. I know your SHAR course before you headed south was abbreviated, but would a typical squadron Harrier or Sea Harrier pilot practice many VTO's in training or field exercises? It seemed more common for demonstrations (especially early in the program with the parking lot and coal yard type events) and airshow type events, with STOVL much more common for operations. Non-event at the proper weight/desnsity?
Mog
Spent some time on the AV-8B Mission Computer software team (as far as I know, a lot of my code is still running on the remaining USMC AV-8Bs). One of the functions in the MC allows the pilot to compute the shortest rolling takeoff distance for gross weight and conditions. The nozzle stop is set to the computed value and takeoff roll started with the nozzles full aft, then at the computed airspeed the nozzles are rotated to the stop and the aircraft lifts off.
It was possible to get a cleaner VTO by using 75 degrees of nozzle instead of the normal 82 (aircraft sat 8 degrees nose-up). This ensure that recirculating exhaust was vectored behind the intakes. Once clear of ground effect, 82 was reselected, if a hover was required. If not, accel away to wing borne flight was carried out as normal.
It was discovered that VTO performance was also better with gun pods fitted, as the exhaust bounced back off the ground and impinged on the fuselage between the pods. Hence the fitting of strakes if guns were not fitted.
Mog
It was discovered that VTO performance was also better with gun pods fitted, as the exhaust bounced back off the ground and impinged on the fuselage between the pods. Hence the fitting of strakes if guns were not fitted.
Mog
Funniest thing I saw on a grass strip was several dozen Mach 1 voles being ejected vertically as a Jumping Bean selected nozzles down on a short take-off in Sennelager. Cause was over-pressurisation of their burrows!
How I did larf!
Mog
How I did larf!
Mog
Perhaps some slight thread drift here but sort of related...
The issue of power required to lift vertically without aerodynamic assistance is also causing huge headaches in the very latest aviation adventure - EVTOL's. There are some very bold claims being made by some manufacturers about the capabilities of their aircraft in terms of range/speed/endurance, but these are actually just aspirations and rarely based in fact and current physics. One of the myriad issues is the requirement to be able to lift and land vertically, as this requires huge amounts of power and it is currently depleting the batteries at such a rate that relatively little is available for the bit between take-off and landing. Some 'industry leaders' are saying their devices will have an endurance of 90 minutes, yet they cannot currently stay airborne for more than 15, due to the limitations of energy density provision by the latest batteries, and the take-off alone is killing them in terms of battery power available for the flight itself.
Great explanation here: https://www.sciencedirect.com/scienc...42435121002051
Perhaps, in a similar vein to the originators comments, they need a detachable plug which jettisions when the EVTOL is at height and starting the transition to forward flight?...and no, I am not really being serious, but something does need to be done in order for this new technology to meet the claims being made about it.
The issue of power required to lift vertically without aerodynamic assistance is also causing huge headaches in the very latest aviation adventure - EVTOL's. There are some very bold claims being made by some manufacturers about the capabilities of their aircraft in terms of range/speed/endurance, but these are actually just aspirations and rarely based in fact and current physics. One of the myriad issues is the requirement to be able to lift and land vertically, as this requires huge amounts of power and it is currently depleting the batteries at such a rate that relatively little is available for the bit between take-off and landing. Some 'industry leaders' are saying their devices will have an endurance of 90 minutes, yet they cannot currently stay airborne for more than 15, due to the limitations of energy density provision by the latest batteries, and the take-off alone is killing them in terms of battery power available for the flight itself.
Great explanation here: https://www.sciencedirect.com/scienc...42435121002051
Perhaps, in a similar vein to the originators comments, they need a detachable plug which jettisions when the EVTOL is at height and starting the transition to forward flight?...and no, I am not really being serious, but something does need to be done in order for this new technology to meet the claims being made about it.
EVTOL's and battery drain on lift-off - one could amend glider-launch methodology by attaching the aircraft to a large helium filled balloon. Said balloon is attached to a winch, winch ratchet is released, up goes balloon and EVTOL. At a a suitable height, pilot pulls on the release handle and zooms away. Balloon is then winched back down ready for the next customer. Problems solved!
Hmm, maybe I should patent that...
Hmm, maybe I should patent that...
I particular enjoy all of the glossy EVTOL renderings that show attractive and fit professionals whisking off to their next meeting, or lunch at the country club...will be exciting when a few more robust Pax order their air taxi and our poor machine whirrs, whines and beeps....unable to lift off....
Impressive RATO by the Starfighter was fitting sequel to the Me163 rocket interceptor of 1944 which can be seen on Youtube. Postwar the great Winkle Brown was cleared to fly it as a glider but also made an (unauthorised) flight using power. He recalled that the Komet was more a threat to the Luftwaffe than it was to the Allies.
Impressive RATO by the Starfighter was fitting sequel to the Me163 rocket interceptor of 1944 which can be seen on Youtube. Postwar the great Winkle Brown was cleared to fly it as a glider but also made an (unauthorised) flight using power. He recalled that the Komet was more a threat to the Luftwaffe than it was to the Allies.
Impressive RATO by the Starfighter was fitting sequel to the Me163 rocket interceptor of 1944 which can be seen on Youtube. Postwar the great Winkle Brown was cleared to fly it as a glider but also made an (unauthorised) flight using power. He recalled that the Komet was more a threat to the Luftwaffe than it was to the Allies.
!!!!!!!!
And to the point of 'fit professionals whisking off to meetings' - it is absolutely valid. It appears likely that everyone will be required to provide their weight and dimensions before booking a flight - and no, I am not joking (is it even legal to ask that information in most Western countries?). EVTOLS will be extremely weight sensitive, so a couple of my 400lb North American colleagues (and we have a lot of them) might render the machine unable to fly. Imagine being the pilot telling a drunk 400lb Texas cowboy that he is too fat to get in...no thanks.
The idea of electric air vehicles whisking people across cities, cleanly and quickly, is a great one, but as with all things, the Devil is in the details. And there are a lot of details.
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The most impressive set up was a line strung between two booms down the side of a ship for Normandy, a Piper Cub would fly alongside and catch it with a roof mounted hook, he could then fly back off it! Meet the Brodie system.
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Thanks everyone for the interesting replies
And the video took me back in time. I was there when they landed on the M55!
And the video took me back in time. I was there when they landed on the M55!
VLs would also be affected by weight - in fact I recall that was one reason for the demise of the SHAR, in that recoveries with full weapons proved troublesome in hot conditions, and the proposed Pegasus upgrade was too expensive
Yes, VLs were affected to a lesser degree as free hover JPTs were lower that VTO JPTs. This where CRVL is a bonus. I believe the engine upgrade would have required major airframe work as the engine was physically larger. It was never particularly comfortable committing to a wet VL because if the water stopped flowing you would quickly cook the donk.
Mog
Mog